chore(v2): vendor dependencies for offline/China builds

go mod vendor pins onnxruntime_go v1.12.1, Gio and the rest into v2/vendor
so go run/build work without hitting proxy.golang.org (blocked/slow in
China). Verified: CGO_ENABLED=1 go build -mod=vendor ./internal/spike and
GOOS=windows go build -mod=vendor ./internal/ui both pass.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
This commit is contained in:
ila
2026-07-23 16:35:01 +08:00
co-authored by Claude Opus 4.8
parent 97c1c4a974
commit f58728cddd
972 changed files with 597802 additions and 0 deletions
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Copyright 2009 The Go Authors.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following disclaimer
in the documentation and/or other materials provided with the
distribution.
* Neither the name of Google LLC nor the names of its
contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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Additional IP Rights Grant (Patents)
"This implementation" means the copyrightable works distributed by
Google as part of the Go project.
Google hereby grants to You a perpetual, worldwide, non-exclusive,
no-charge, royalty-free, irrevocable (except as stated in this section)
patent license to make, have made, use, offer to sell, sell, import,
transfer and otherwise run, modify and propagate the contents of this
implementation of Go, where such license applies only to those patent
claims, both currently owned or controlled by Google and acquired in
the future, licensable by Google that are necessarily infringed by this
implementation of Go. This grant does not include claims that would be
infringed only as a consequence of further modification of this
implementation. If you or your agent or exclusive licensee institute or
order or agree to the institution of patent litigation against any
entity (including a cross-claim or counterclaim in a lawsuit) alleging
that this implementation of Go or any code incorporated within this
implementation of Go constitutes direct or contributory patent
infringement, or inducement of patent infringement, then any patent
rights granted to you under this License for this implementation of Go
shall terminate as of the date such litigation is filed.
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// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:generate go run gen.go
// Package ccitt implements a CCITT (fax) image decoder.
package ccitt
import (
"encoding/binary"
"errors"
"image"
"io"
"math/bits"
)
var (
errIncompleteCode = errors.New("ccitt: incomplete code")
errInvalidBounds = errors.New("ccitt: invalid bounds")
errInvalidCode = errors.New("ccitt: invalid code")
errInvalidMode = errors.New("ccitt: invalid mode")
errInvalidOffset = errors.New("ccitt: invalid offset")
errMissingEOL = errors.New("ccitt: missing End-of-Line")
errRunLengthOverflowsWidth = errors.New("ccitt: run length overflows width")
errRunLengthTooLong = errors.New("ccitt: run length too long")
errUnsupportedMode = errors.New("ccitt: unsupported mode")
errUnsupportedSubFormat = errors.New("ccitt: unsupported sub-format")
errUnsupportedWidth = errors.New("ccitt: unsupported width")
)
// Order specifies the bit ordering in a CCITT data stream.
type Order uint32
const (
// LSB means Least Significant Bits first.
LSB Order = iota
// MSB means Most Significant Bits first.
MSB
)
// SubFormat represents that the CCITT format consists of a number of
// sub-formats. Decoding or encoding a CCITT data stream requires knowing the
// sub-format context. It is not represented in the data stream per se.
type SubFormat uint32
const (
Group3 SubFormat = iota
Group4
)
// AutoDetectHeight is passed as the height argument to NewReader to indicate
// that the image height (the number of rows) is not known in advance.
const AutoDetectHeight = -1
// Options are optional parameters.
type Options struct {
// Align means that some variable-bit-width codes are byte-aligned.
Align bool
// Invert means that black is the 1 bit or 0xFF byte, and white is 0.
Invert bool
}
// maxWidth is the maximum (inclusive) supported width. This is a limitation of
// this implementation, to guard against integer overflow, and not anything
// inherent to the CCITT format.
const maxWidth = 1 << 20
func invertBytes(b []byte) {
for i, c := range b {
b[i] = ^c
}
}
func reverseBitsWithinBytes(b []byte) {
for i, c := range b {
b[i] = bits.Reverse8(c)
}
}
// highBits writes to dst (1 bit per pixel, most significant bit first) the
// high (0x80) bits from src (1 byte per pixel). It returns the number of bytes
// written and read such that dst[:d] is the packed form of src[:s].
//
// For example, if src starts with the 8 bytes [0x7D, 0x7E, 0x7F, 0x80, 0x81,
// 0x82, 0x00, 0xFF] then 0x1D will be written to dst[0].
//
// If src has (8 * len(dst)) or more bytes then only len(dst) bytes are
// written, (8 * len(dst)) bytes are read, and invert is ignored.
//
// Otherwise, if len(src) is not a multiple of 8 then the final byte written to
// dst is padded with 1 bits (if invert is true) or 0 bits. If inverted, the 1s
// are typically temporary, e.g. they will be flipped back to 0s by an
// invertBytes call in the highBits caller, reader.Read.
func highBits(dst []byte, src []byte, invert bool) (d int, s int) {
// Pack as many complete groups of 8 src bytes as we can.
n := len(src) / 8
if n > len(dst) {
n = len(dst)
}
dstN := dst[:n]
for i := range dstN {
src8 := src[i*8 : i*8+8]
dstN[i] = ((src8[0] & 0x80) >> 0) |
((src8[1] & 0x80) >> 1) |
((src8[2] & 0x80) >> 2) |
((src8[3] & 0x80) >> 3) |
((src8[4] & 0x80) >> 4) |
((src8[5] & 0x80) >> 5) |
((src8[6] & 0x80) >> 6) |
((src8[7] & 0x80) >> 7)
}
d, s = n, 8*n
dst, src = dst[d:], src[s:]
// Pack up to 7 remaining src bytes, if there's room in dst.
if (len(dst) > 0) && (len(src) > 0) {
dstByte := byte(0)
if invert {
dstByte = 0xFF >> uint(len(src))
}
for n, srcByte := range src {
dstByte |= (srcByte & 0x80) >> uint(n)
}
dst[0] = dstByte
d, s = d+1, s+len(src)
}
return d, s
}
type bitReader struct {
r io.Reader
// readErr is the error returned from the most recent r.Read call. As the
// io.Reader documentation says, when r.Read returns (n, err), "always
// process the n > 0 bytes returned before considering the error err".
readErr error
// order is whether to process r's bytes LSB first or MSB first.
order Order
// The high nBits bits of the bits field hold upcoming bits in MSB order.
bits uint64
nBits uint32
// bytes[br:bw] holds bytes read from r but not yet loaded into bits.
br uint32
bw uint32
bytes [1024]uint8
}
func (b *bitReader) alignToByteBoundary() {
n := b.nBits & 7
b.bits <<= n
b.nBits -= n
}
// nextBitMaxNBits is the maximum possible value of bitReader.nBits after a
// bitReader.nextBit call, provided that bitReader.nBits was not more than this
// value before that call.
//
// Note that the decode function can unread bits, which can temporarily set the
// bitReader.nBits value above nextBitMaxNBits.
const nextBitMaxNBits = 31
func (b *bitReader) nextBit() (uint64, error) {
for {
if b.nBits > 0 {
bit := b.bits >> 63
b.bits <<= 1
b.nBits--
return bit, nil
}
if available := b.bw - b.br; available >= 4 {
// Read 32 bits, even though b.bits is a uint64, since the decode
// function may need to unread up to maxCodeLength bits, putting
// them back in the remaining (64 - 32) bits. TestMaxCodeLength
// checks that the generated maxCodeLength constant fits.
//
// If changing the Uint32 call, also change nextBitMaxNBits.
b.bits = uint64(binary.BigEndian.Uint32(b.bytes[b.br:])) << 32
b.br += 4
b.nBits = 32
continue
} else if available > 0 {
b.bits = uint64(b.bytes[b.br]) << (7 * 8)
b.br++
b.nBits = 8
continue
}
if b.readErr != nil {
return 0, b.readErr
}
n, err := b.r.Read(b.bytes[:])
b.br = 0
b.bw = uint32(n)
b.readErr = err
if b.order != MSB {
reverseBitsWithinBytes(b.bytes[:b.bw])
}
}
}
func decode(b *bitReader, decodeTable [][2]int16) (uint32, error) {
nBitsRead, bitsRead, state := uint32(0), uint64(0), int32(1)
for {
bit, err := b.nextBit()
if err != nil {
if err == io.EOF {
err = errIncompleteCode
}
return 0, err
}
bitsRead |= bit << (63 - nBitsRead)
nBitsRead++
// The "&1" is redundant, but can eliminate a bounds check.
state = int32(decodeTable[state][bit&1])
if state < 0 {
return uint32(^state), nil
} else if state == 0 {
// Unread the bits we've read, then return errInvalidCode.
b.bits = (b.bits >> nBitsRead) | bitsRead
b.nBits += nBitsRead
return 0, errInvalidCode
}
}
}
// decodeEOL decodes the 12-bit EOL code 0000_0000_0001.
func decodeEOL(b *bitReader) error {
nBitsRead, bitsRead := uint32(0), uint64(0)
for {
bit, err := b.nextBit()
if err != nil {
if err == io.EOF {
err = errMissingEOL
}
return err
}
bitsRead |= bit << (63 - nBitsRead)
nBitsRead++
if nBitsRead < 12 {
if bit&1 == 0 {
continue
}
} else if bit&1 != 0 {
return nil
}
// Unread the bits we've read, then return errMissingEOL.
b.bits = (b.bits >> nBitsRead) | bitsRead
b.nBits += nBitsRead
return errMissingEOL
}
}
type reader struct {
br bitReader
subFormat SubFormat
// width is the image width in pixels.
width int
// rowsRemaining starts at the image height in pixels, when the reader is
// driven through the io.Reader interface, and decrements to zero as rows
// are decoded. Alternatively, it may be negative if the image height is
// not known in advance at the time of the NewReader call.
//
// When driven through DecodeIntoGray, this field is unused.
rowsRemaining int
// curr and prev hold the current and previous rows. Each element is either
// 0x00 (black) or 0xFF (white).
//
// prev may be nil, when processing the first row.
curr []byte
prev []byte
// ri is the read index. curr[:ri] are those bytes of curr that have been
// passed along via the Read method.
//
// When the reader is driven through DecodeIntoGray, instead of through the
// io.Reader interface, this field is unused.
ri int
// wi is the write index. curr[:wi] are those bytes of curr that have
// already been decoded via the decodeRow method.
//
// What this implementation calls wi is roughly equivalent to what the spec
// calls the a0 index.
wi int
// These fields are copied from the *Options (which may be nil).
align bool
invert bool
// atStartOfRow is whether we have just started the row. Some parts of the
// spec say to treat this situation as if "wi = -1".
atStartOfRow bool
// penColorIsWhite is whether the next run is black or white.
penColorIsWhite bool
// seenStartOfImage is whether we've called the startDecode method.
seenStartOfImage bool
// truncated is whether the input is missing the final 6 consecutive EOL's
// (for Group3) or 2 consecutive EOL's (for Group4). Omitting that trailer
// (but otherwise padding to a byte boundary, with either all 0 bits or all
// 1 bits) is invalid according to the spec, but happens in practice when
// exporting from Adobe Acrobat to TIFF + CCITT. This package silently
// ignores the format error for CCITT input that has been truncated in that
// fashion, returning the full decoded image.
//
// Detecting trailer truncation (just after the final row of pixels)
// requires knowing which row is the final row, and therefore does not
// trigger if the image height is not known in advance.
truncated bool
// readErr is a sticky error for the Read method.
readErr error
}
func (z *reader) Read(p []byte) (int, error) {
if z.readErr != nil {
return 0, z.readErr
}
originalP := p
for len(p) > 0 {
// Allocate buffers (and decode any start-of-image codes), if
// processing the first or second row.
if z.curr == nil {
if !z.seenStartOfImage {
if z.readErr = z.startDecode(); z.readErr != nil {
break
}
z.atStartOfRow = true
}
z.curr = make([]byte, z.width)
}
// Decode the next row, if necessary.
if z.atStartOfRow {
if z.rowsRemaining < 0 {
// We do not know the image height in advance. See if the next
// code is an EOL. If it is, it is consumed. If it isn't, the
// bitReader shouldn't advance along the bit stream, and we
// simply decode another row of pixel data.
//
// For the Group4 subFormat, we may need to align to a byte
// boundary. For the Group3 subFormat, the previous z.decodeRow
// call (or z.startDecode call) has already consumed one of the
// 6 consecutive EOL's. The next EOL is actually the second of
// 6, in the middle, and we shouldn't align at that point.
if z.align && (z.subFormat == Group4) {
z.br.alignToByteBoundary()
}
if err := z.decodeEOL(); err == errMissingEOL {
// No-op. It's another row of pixel data.
} else if err != nil {
z.readErr = err
break
} else {
if z.readErr = z.finishDecode(true); z.readErr != nil {
break
}
z.readErr = io.EOF
break
}
} else if z.rowsRemaining == 0 {
// We do know the image height in advance, and we have already
// decoded exactly that many rows.
if z.readErr = z.finishDecode(false); z.readErr != nil {
break
}
z.readErr = io.EOF
break
} else {
z.rowsRemaining--
}
if z.readErr = z.decodeRow(z.rowsRemaining == 0); z.readErr != nil {
break
}
}
// Pack from z.curr (1 byte per pixel) to p (1 bit per pixel).
packD, packS := highBits(p, z.curr[z.ri:], z.invert)
p = p[packD:]
z.ri += packS
// Prepare to decode the next row, if necessary.
if z.ri == len(z.curr) {
z.ri, z.curr, z.prev = 0, z.prev, z.curr
z.atStartOfRow = true
}
}
n := len(originalP) - len(p)
if z.invert {
invertBytes(originalP[:n])
}
return n, z.readErr
}
func (z *reader) penColor() byte {
if z.penColorIsWhite {
return 0xFF
}
return 0x00
}
func (z *reader) startDecode() error {
switch z.subFormat {
case Group3:
if err := z.decodeEOL(); err != nil {
return err
}
case Group4:
// No-op.
default:
return errUnsupportedSubFormat
}
z.seenStartOfImage = true
return nil
}
func (z *reader) finishDecode(alreadySeenEOL bool) error {
numberOfEOLs := 0
switch z.subFormat {
case Group3:
if z.truncated {
return nil
}
// The stream ends with a RTC (Return To Control) of 6 consecutive
// EOL's, but we should have already just seen an EOL, either in
// z.startDecode (for a zero-height image) or in z.decodeRow.
numberOfEOLs = 5
case Group4:
autoDetectHeight := z.rowsRemaining < 0
if autoDetectHeight {
// Aligning to a byte boundary was already handled by reader.Read.
} else if z.align {
z.br.alignToByteBoundary()
}
// The stream ends with two EOL's. If the first one is missing, and we
// had an explicit image height, we just assume that the trailing two
// EOL's were truncated and return a nil error.
if err := z.decodeEOL(); err != nil {
if (err == errMissingEOL) && !autoDetectHeight {
z.truncated = true
return nil
}
return err
}
numberOfEOLs = 1
default:
return errUnsupportedSubFormat
}
if alreadySeenEOL {
numberOfEOLs--
}
for ; numberOfEOLs > 0; numberOfEOLs-- {
if err := z.decodeEOL(); err != nil {
return err
}
}
return nil
}
func (z *reader) decodeEOL() error {
return decodeEOL(&z.br)
}
func (z *reader) decodeRow(finalRow bool) error {
z.wi = 0
z.atStartOfRow = true
z.penColorIsWhite = true
if z.align {
z.br.alignToByteBoundary()
}
switch z.subFormat {
case Group3:
for ; z.wi < len(z.curr); z.atStartOfRow = false {
if err := z.decodeRun(); err != nil {
return err
}
}
err := z.decodeEOL()
if finalRow && (err == errMissingEOL) {
z.truncated = true
return nil
}
return err
case Group4:
for ; z.wi < len(z.curr); z.atStartOfRow = false {
mode, err := decode(&z.br, modeDecodeTable[:])
if err != nil {
return err
}
rm := readerMode{}
if mode < uint32(len(readerModes)) {
rm = readerModes[mode]
}
if rm.function == nil {
return errInvalidMode
}
if err := rm.function(z, rm.arg); err != nil {
return err
}
}
return nil
}
return errUnsupportedSubFormat
}
func (z *reader) decodeRun() error {
table := blackDecodeTable[:]
if z.penColorIsWhite {
table = whiteDecodeTable[:]
}
total := 0
for {
n, err := decode(&z.br, table)
if err != nil {
return err
}
if n > maxWidth {
panic("unreachable")
}
total += int(n)
if total > maxWidth {
return errRunLengthTooLong
}
// Anything 0x3F or below is a terminal code.
if n <= 0x3F {
break
}
}
if total > (len(z.curr) - z.wi) {
return errRunLengthOverflowsWidth
}
dst := z.curr[z.wi : z.wi+total]
penColor := z.penColor()
for i := range dst {
dst[i] = penColor
}
z.wi += total
z.penColorIsWhite = !z.penColorIsWhite
return nil
}
// The various modes' semantics are based on determining a row of pixels'
// "changing elements": those pixels whose color differs from the one on its
// immediate left.
//
// The row above the first row is implicitly all white. Similarly, the column
// to the left of the first column is implicitly all white.
//
// For example, here's Figure 1 in "ITU-T Recommendation T.6", where the
// current and previous rows contain black (B) and white (w) pixels. The a?
// indexes point into curr, the b? indexes point into prev.
//
// b1 b2
// v v
// prev: BBBBBwwwwwBBBwwwww
// curr: BBBwwwwwBBBBBBwwww
// ^ ^ ^
// a0 a1 a2
//
// a0 is the "reference element" or current decoder position, roughly
// equivalent to what this implementation calls reader.wi.
//
// a1 is the next changing element to the right of a0, on the "coding line"
// (the current row).
//
// a2 is the next changing element to the right of a1, again on curr.
//
// b1 is the first changing element on the "reference line" (the previous row)
// to the right of a0 and of opposite color to a0.
//
// b2 is the next changing element to the right of b1, again on prev.
//
// The various modes calculate a1 (and a2, for modeH):
// - modePass calculates that a1 is at or to the right of b2.
// - modeH calculates a1 and a2 without considering b1 or b2.
// - modeV* calculates a1 to be b1 plus an adjustment (between -3 and +3).
const (
findB1 = false
findB2 = true
)
// findB finds either the b1 or b2 value.
func (z *reader) findB(whichB bool) int {
// The initial row is a special case. The previous row is implicitly all
// white, so that there are no changing pixel elements. We return b1 or b2
// to be at the end of the row.
if len(z.prev) != len(z.curr) {
return len(z.curr)
}
i := z.wi
if z.atStartOfRow {
// a0 is implicitly at -1, on a white pixel. b1 is the first black
// pixel in the previous row. b2 is the first white pixel after that.
for ; (i < len(z.prev)) && (z.prev[i] == 0xFF); i++ {
}
if whichB == findB2 {
for ; (i < len(z.prev)) && (z.prev[i] == 0x00); i++ {
}
}
return i
}
// As per figure 1 above, assume that the current pen color is white.
// First, walk past every contiguous black pixel in prev, starting at a0.
oppositeColor := ^z.penColor()
for ; (i < len(z.prev)) && (z.prev[i] == oppositeColor); i++ {
}
// Then walk past every contiguous white pixel.
penColor := ^oppositeColor
for ; (i < len(z.prev)) && (z.prev[i] == penColor); i++ {
}
// We're now at a black pixel (or at the end of the row). That's b1.
if whichB == findB2 {
// If we're looking for b2, walk past every contiguous black pixel
// again.
oppositeColor := ^penColor
for ; (i < len(z.prev)) && (z.prev[i] == oppositeColor); i++ {
}
}
return i
}
type readerMode struct {
function func(z *reader, arg int) error
arg int
}
var readerModes = [...]readerMode{
modePass: {function: readerModePass},
modeH: {function: readerModeH},
modeV0: {function: readerModeV, arg: +0},
modeVR1: {function: readerModeV, arg: +1},
modeVR2: {function: readerModeV, arg: +2},
modeVR3: {function: readerModeV, arg: +3},
modeVL1: {function: readerModeV, arg: -1},
modeVL2: {function: readerModeV, arg: -2},
modeVL3: {function: readerModeV, arg: -3},
modeExt: {function: readerModeExt},
}
func readerModePass(z *reader, arg int) error {
b2 := z.findB(findB2)
if (b2 < z.wi) || (len(z.curr) < b2) {
return errInvalidOffset
}
dst := z.curr[z.wi:b2]
penColor := z.penColor()
for i := range dst {
dst[i] = penColor
}
z.wi = b2
return nil
}
func readerModeH(z *reader, arg int) error {
// The first iteration finds a1. The second finds a2.
for i := 0; i < 2; i++ {
if err := z.decodeRun(); err != nil {
return err
}
}
return nil
}
func readerModeV(z *reader, arg int) error {
a1 := z.findB(findB1) + arg
if (a1 < z.wi) || (len(z.curr) < a1) {
return errInvalidOffset
}
dst := z.curr[z.wi:a1]
penColor := z.penColor()
for i := range dst {
dst[i] = penColor
}
z.wi = a1
z.penColorIsWhite = !z.penColorIsWhite
return nil
}
func readerModeExt(z *reader, arg int) error {
return errUnsupportedMode
}
// DecodeIntoGray decodes the CCITT-formatted data in r into dst.
//
// It returns an error if dst's width and height don't match the implied width
// and height of CCITT-formatted data.
func DecodeIntoGray(dst *image.Gray, r io.Reader, order Order, sf SubFormat, opts *Options) error {
bounds := dst.Bounds()
if (bounds.Dx() < 0) || (bounds.Dy() < 0) {
return errInvalidBounds
}
if bounds.Dx() > maxWidth {
return errUnsupportedWidth
}
z := reader{
br: bitReader{r: r, order: order},
subFormat: sf,
align: (opts != nil) && opts.Align,
invert: (opts != nil) && opts.Invert,
width: bounds.Dx(),
}
if err := z.startDecode(); err != nil {
return err
}
width := bounds.Dx()
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
p := (y - bounds.Min.Y) * dst.Stride
z.curr = dst.Pix[p : p+width]
if err := z.decodeRow(y+1 == bounds.Max.Y); err != nil {
return err
}
z.curr, z.prev = nil, z.curr
}
if err := z.finishDecode(false); err != nil {
return err
}
if z.invert {
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
p := (y - bounds.Min.Y) * dst.Stride
invertBytes(dst.Pix[p : p+width])
}
}
return nil
}
// NewReader returns an io.Reader that decodes the CCITT-formatted data in r.
// The resultant byte stream is one bit per pixel (MSB first), with 1 meaning
// white and 0 meaning black. Each row in the result is byte-aligned.
//
// A negative height, such as passing AutoDetectHeight, means that the image
// height is not known in advance. A negative width is invalid.
func NewReader(r io.Reader, order Order, sf SubFormat, width int, height int, opts *Options) io.Reader {
readErr := error(nil)
if width < 0 {
readErr = errInvalidBounds
} else if width > maxWidth {
readErr = errUnsupportedWidth
}
return &reader{
br: bitReader{r: r, order: order},
subFormat: sf,
align: (opts != nil) && opts.Align,
invert: (opts != nil) && opts.Invert,
width: width,
rowsRemaining: height,
readErr: readErr,
}
}
+972
View File
@@ -0,0 +1,972 @@
// generated by "go run gen.go". DO NOT EDIT.
package ccitt
// Each decodeTable is represented by an array of [2]int16's: a binary tree.
// Each array element (other than element 0, which means invalid) is a branch
// node in that tree. The root node is always element 1 (the second element).
//
// To walk the tree, look at the next bit in the bit stream, using it to select
// the first or second element of the [2]int16. If that int16 is 0, we have an
// invalid code. If it is positive, go to that branch node. If it is negative,
// then we have a leaf node, whose value is the bitwise complement (the ^
// operator) of that int16.
//
// Comments above each decodeTable also show the same structure visually. The
// "b123" lines show the 123'rd branch node. The "=XXXXX" lines show an invalid
// code. The "=v1234" lines show a leaf node with value 1234. When reading the
// bit stream, a 0 or 1 bit means to go up or down, as you move left to right.
//
// For example, in modeDecodeTable, branch node b005 is three steps up from the
// root node, meaning that we have already seen "000". If the next bit is "0"
// then we move to branch node b006. Otherwise, the next bit is "1", and we
// move to the leaf node v0000 (also known as the modePass constant). Indeed,
// the bits that encode modePass are "0001".
//
// Tables 1, 2 and 3 come from the "ITU-T Recommendation T.6: FACSIMILE CODING
// SCHEMES AND CODING CONTROL FUNCTIONS FOR GROUP 4 FACSIMILE APPARATUS"
// specification:
//
// https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-T.6-198811-I!!PDF-E&type=items
// modeDecodeTable represents Table 1 and the End-of-Line code.
//
// +=XXXXX
// b009 +-+
// | +=v0009
// b007 +-+
// | | +=v0008
// b010 | +-+
// | +=v0005
// b006 +-+
// | | +=v0007
// b008 | +-+
// | +=v0004
// b005 +-+
// | +=v0000
// b003 +-+
// | +=v0001
// b002 +-+
// | | +=v0006
// b004 | +-+
// | +=v0003
// b001 +-+
// +=v0002
var modeDecodeTable = [...][2]int16{
0: {0, 0},
1: {2, ^2},
2: {3, 4},
3: {5, ^1},
4: {^6, ^3},
5: {6, ^0},
6: {7, 8},
7: {9, 10},
8: {^7, ^4},
9: {0, ^9},
10: {^8, ^5},
}
// whiteDecodeTable represents Tables 2 and 3 for a white run.
//
// +=XXXXX
// b059 +-+
// | | +=v1792
// b096 | | +-+
// | | | | +=v1984
// b100 | | | +-+
// | | | +=v2048
// b094 | | +-+
// | | | | +=v2112
// b101 | | | | +-+
// | | | | | +=v2176
// b097 | | | +-+
// | | | | +=v2240
// b102 | | | +-+
// | | | +=v2304
// b085 | +-+
// | | +=v1856
// b098 | | +-+
// | | | +=v1920
// b095 | +-+
// | | +=v2368
// b103 | | +-+
// | | | +=v2432
// b099 | +-+
// | | +=v2496
// b104 | +-+
// | +=v2560
// b040 +-+
// | | +=v0029
// b060 | +-+
// | +=v0030
// b026 +-+
// | | +=v0045
// b061 | | +-+
// | | | +=v0046
// b041 | +-+
// | +=v0022
// b016 +-+
// | | +=v0023
// b042 | | +-+
// | | | | +=v0047
// b062 | | | +-+
// | | | +=v0048
// b027 | +-+
// | +=v0013
// b008 +-+
// | | +=v0020
// b043 | | +-+
// | | | | +=v0033
// b063 | | | +-+
// | | | +=v0034
// b028 | | +-+
// | | | | +=v0035
// b064 | | | | +-+
// | | | | | +=v0036
// b044 | | | +-+
// | | | | +=v0037
// b065 | | | +-+
// | | | +=v0038
// b017 | +-+
// | | +=v0019
// b045 | | +-+
// | | | | +=v0031
// b066 | | | +-+
// | | | +=v0032
// b029 | +-+
// | +=v0001
// b004 +-+
// | | +=v0012
// b030 | | +-+
// | | | | +=v0053
// b067 | | | | +-+
// | | | | | +=v0054
// b046 | | | +-+
// | | | +=v0026
// b018 | | +-+
// | | | | +=v0039
// b068 | | | | +-+
// | | | | | +=v0040
// b047 | | | | +-+
// | | | | | | +=v0041
// b069 | | | | | +-+
// | | | | | +=v0042
// b031 | | | +-+
// | | | | +=v0043
// b070 | | | | +-+
// | | | | | +=v0044
// b048 | | | +-+
// | | | +=v0021
// b009 | +-+
// | | +=v0028
// b049 | | +-+
// | | | | +=v0061
// b071 | | | +-+
// | | | +=v0062
// b032 | | +-+
// | | | | +=v0063
// b072 | | | | +-+
// | | | | | +=v0000
// b050 | | | +-+
// | | | | +=v0320
// b073 | | | +-+
// | | | +=v0384
// b019 | +-+
// | +=v0010
// b002 +-+
// | | +=v0011
// b020 | | +-+
// | | | | +=v0027
// b051 | | | | +-+
// | | | | | | +=v0059
// b074 | | | | | +-+
// | | | | | +=v0060
// b033 | | | +-+
// | | | | +=v1472
// b086 | | | | +-+
// | | | | | +=v1536
// b075 | | | | +-+
// | | | | | | +=v1600
// b087 | | | | | +-+
// | | | | | +=v1728
// b052 | | | +-+
// | | | +=v0018
// b010 | | +-+
// | | | | +=v0024
// b053 | | | | +-+
// | | | | | | +=v0049
// b076 | | | | | +-+
// | | | | | +=v0050
// b034 | | | | +-+
// | | | | | | +=v0051
// b077 | | | | | | +-+
// | | | | | | | +=v0052
// b054 | | | | | +-+
// | | | | | +=v0025
// b021 | | | +-+
// | | | | +=v0055
// b078 | | | | +-+
// | | | | | +=v0056
// b055 | | | | +-+
// | | | | | | +=v0057
// b079 | | | | | +-+
// | | | | | +=v0058
// b035 | | | +-+
// | | | +=v0192
// b005 | +-+
// | | +=v1664
// b036 | | +-+
// | | | | +=v0448
// b080 | | | | +-+
// | | | | | +=v0512
// b056 | | | +-+
// | | | | +=v0704
// b088 | | | | +-+
// | | | | | +=v0768
// b081 | | | +-+
// | | | +=v0640
// b022 | | +-+
// | | | | +=v0576
// b082 | | | | +-+
// | | | | | | +=v0832
// b089 | | | | | +-+
// | | | | | +=v0896
// b057 | | | | +-+
// | | | | | | +=v0960
// b090 | | | | | | +-+
// | | | | | | | +=v1024
// b083 | | | | | +-+
// | | | | | | +=v1088
// b091 | | | | | +-+
// | | | | | +=v1152
// b037 | | | +-+
// | | | | +=v1216
// b092 | | | | +-+
// | | | | | +=v1280
// b084 | | | | +-+
// | | | | | | +=v1344
// b093 | | | | | +-+
// | | | | | +=v1408
// b058 | | | +-+
// | | | +=v0256
// b011 | +-+
// | +=v0002
// b001 +-+
// | +=v0003
// b012 | +-+
// | | | +=v0128
// b023 | | +-+
// | | +=v0008
// b006 | +-+
// | | | +=v0009
// b024 | | | +-+
// | | | | | +=v0016
// b038 | | | | +-+
// | | | | +=v0017
// b013 | | +-+
// | | +=v0004
// b003 +-+
// | +=v0005
// b014 | +-+
// | | | +=v0014
// b039 | | | +-+
// | | | | +=v0015
// b025 | | +-+
// | | +=v0064
// b007 +-+
// | +=v0006
// b015 +-+
// +=v0007
var whiteDecodeTable = [...][2]int16{
0: {0, 0},
1: {2, 3},
2: {4, 5},
3: {6, 7},
4: {8, 9},
5: {10, 11},
6: {12, 13},
7: {14, 15},
8: {16, 17},
9: {18, 19},
10: {20, 21},
11: {22, ^2},
12: {^3, 23},
13: {24, ^4},
14: {^5, 25},
15: {^6, ^7},
16: {26, 27},
17: {28, 29},
18: {30, 31},
19: {32, ^10},
20: {^11, 33},
21: {34, 35},
22: {36, 37},
23: {^128, ^8},
24: {^9, 38},
25: {39, ^64},
26: {40, 41},
27: {42, ^13},
28: {43, 44},
29: {45, ^1},
30: {^12, 46},
31: {47, 48},
32: {49, 50},
33: {51, 52},
34: {53, 54},
35: {55, ^192},
36: {^1664, 56},
37: {57, 58},
38: {^16, ^17},
39: {^14, ^15},
40: {59, 60},
41: {61, ^22},
42: {^23, 62},
43: {^20, 63},
44: {64, 65},
45: {^19, 66},
46: {67, ^26},
47: {68, 69},
48: {70, ^21},
49: {^28, 71},
50: {72, 73},
51: {^27, 74},
52: {75, ^18},
53: {^24, 76},
54: {77, ^25},
55: {78, 79},
56: {80, 81},
57: {82, 83},
58: {84, ^256},
59: {0, 85},
60: {^29, ^30},
61: {^45, ^46},
62: {^47, ^48},
63: {^33, ^34},
64: {^35, ^36},
65: {^37, ^38},
66: {^31, ^32},
67: {^53, ^54},
68: {^39, ^40},
69: {^41, ^42},
70: {^43, ^44},
71: {^61, ^62},
72: {^63, ^0},
73: {^320, ^384},
74: {^59, ^60},
75: {86, 87},
76: {^49, ^50},
77: {^51, ^52},
78: {^55, ^56},
79: {^57, ^58},
80: {^448, ^512},
81: {88, ^640},
82: {^576, 89},
83: {90, 91},
84: {92, 93},
85: {94, 95},
86: {^1472, ^1536},
87: {^1600, ^1728},
88: {^704, ^768},
89: {^832, ^896},
90: {^960, ^1024},
91: {^1088, ^1152},
92: {^1216, ^1280},
93: {^1344, ^1408},
94: {96, 97},
95: {98, 99},
96: {^1792, 100},
97: {101, 102},
98: {^1856, ^1920},
99: {103, 104},
100: {^1984, ^2048},
101: {^2112, ^2176},
102: {^2240, ^2304},
103: {^2368, ^2432},
104: {^2496, ^2560},
}
// blackDecodeTable represents Tables 2 and 3 for a black run.
//
// +=XXXXX
// b017 +-+
// | | +=v1792
// b042 | | +-+
// | | | | +=v1984
// b063 | | | +-+
// | | | +=v2048
// b029 | | +-+
// | | | | +=v2112
// b064 | | | | +-+
// | | | | | +=v2176
// b043 | | | +-+
// | | | | +=v2240
// b065 | | | +-+
// | | | +=v2304
// b022 | +-+
// | | +=v1856
// b044 | | +-+
// | | | +=v1920
// b030 | +-+
// | | +=v2368
// b066 | | +-+
// | | | +=v2432
// b045 | +-+
// | | +=v2496
// b067 | +-+
// | +=v2560
// b013 +-+
// | | +=v0018
// b031 | | +-+
// | | | | +=v0052
// b068 | | | | +-+
// | | | | | | +=v0640
// b095 | | | | | +-+
// | | | | | +=v0704
// b046 | | | +-+
// | | | | +=v0768
// b096 | | | | +-+
// | | | | | +=v0832
// b069 | | | +-+
// | | | +=v0055
// b023 | | +-+
// | | | | +=v0056
// b070 | | | | +-+
// | | | | | | +=v1280
// b097 | | | | | +-+
// | | | | | +=v1344
// b047 | | | | +-+
// | | | | | | +=v1408
// b098 | | | | | | +-+
// | | | | | | | +=v1472
// b071 | | | | | +-+
// | | | | | +=v0059
// b032 | | | +-+
// | | | | +=v0060
// b072 | | | | +-+
// | | | | | | +=v1536
// b099 | | | | | +-+
// | | | | | +=v1600
// b048 | | | +-+
// | | | +=v0024
// b018 | +-+
// | | +=v0025
// b049 | | +-+
// | | | | +=v1664
// b100 | | | | +-+
// | | | | | +=v1728
// b073 | | | +-+
// | | | +=v0320
// b033 | | +-+
// | | | | +=v0384
// b074 | | | | +-+
// | | | | | +=v0448
// b050 | | | +-+
// | | | | +=v0512
// b101 | | | | +-+
// | | | | | +=v0576
// b075 | | | +-+
// | | | +=v0053
// b024 | +-+
// | | +=v0054
// b076 | | +-+
// | | | | +=v0896
// b102 | | | +-+
// | | | +=v0960
// b051 | | +-+
// | | | | +=v1024
// b103 | | | | +-+
// | | | | | +=v1088
// b077 | | | +-+
// | | | | +=v1152
// b104 | | | +-+
// | | | +=v1216
// b034 | +-+
// | +=v0064
// b010 +-+
// | | +=v0013
// b019 | | +-+
// | | | | +=v0023
// b052 | | | | +-+
// | | | | | | +=v0050
// b078 | | | | | +-+
// | | | | | +=v0051
// b035 | | | | +-+
// | | | | | | +=v0044
// b079 | | | | | | +-+
// | | | | | | | +=v0045
// b053 | | | | | +-+
// | | | | | | +=v0046
// b080 | | | | | +-+
// | | | | | +=v0047
// b025 | | | +-+
// | | | | +=v0057
// b081 | | | | +-+
// | | | | | +=v0058
// b054 | | | | +-+
// | | | | | | +=v0061
// b082 | | | | | +-+
// | | | | | +=v0256
// b036 | | | +-+
// | | | +=v0016
// b014 | +-+
// | | +=v0017
// b037 | | +-+
// | | | | +=v0048
// b083 | | | | +-+
// | | | | | +=v0049
// b055 | | | +-+
// | | | | +=v0062
// b084 | | | +-+
// | | | +=v0063
// b026 | | +-+
// | | | | +=v0030
// b085 | | | | +-+
// | | | | | +=v0031
// b056 | | | | +-+
// | | | | | | +=v0032
// b086 | | | | | +-+
// | | | | | +=v0033
// b038 | | | +-+
// | | | | +=v0040
// b087 | | | | +-+
// | | | | | +=v0041
// b057 | | | +-+
// | | | +=v0022
// b020 | +-+
// | +=v0014
// b008 +-+
// | | +=v0010
// b015 | | +-+
// | | | +=v0011
// b011 | +-+
// | | +=v0015
// b027 | | +-+
// | | | | +=v0128
// b088 | | | | +-+
// | | | | | +=v0192
// b058 | | | | +-+
// | | | | | | +=v0026
// b089 | | | | | +-+
// | | | | | +=v0027
// b039 | | | +-+
// | | | | +=v0028
// b090 | | | | +-+
// | | | | | +=v0029
// b059 | | | +-+
// | | | +=v0019
// b021 | | +-+
// | | | | +=v0020
// b060 | | | | +-+
// | | | | | | +=v0034
// b091 | | | | | +-+
// | | | | | +=v0035
// b040 | | | | +-+
// | | | | | | +=v0036
// b092 | | | | | | +-+
// | | | | | | | +=v0037
// b061 | | | | | +-+
// | | | | | | +=v0038
// b093 | | | | | +-+
// | | | | | +=v0039
// b028 | | | +-+
// | | | | +=v0021
// b062 | | | | +-+
// | | | | | | +=v0042
// b094 | | | | | +-+
// | | | | | +=v0043
// b041 | | | +-+
// | | | +=v0000
// b016 | +-+
// | +=v0012
// b006 +-+
// | | +=v0009
// b012 | | +-+
// | | | +=v0008
// b009 | +-+
// | +=v0007
// b004 +-+
// | | +=v0006
// b007 | +-+
// | +=v0005
// b002 +-+
// | | +=v0001
// b005 | +-+
// | +=v0004
// b001 +-+
// | +=v0003
// b003 +-+
// +=v0002
var blackDecodeTable = [...][2]int16{
0: {0, 0},
1: {2, 3},
2: {4, 5},
3: {^3, ^2},
4: {6, 7},
5: {^1, ^4},
6: {8, 9},
7: {^6, ^5},
8: {10, 11},
9: {12, ^7},
10: {13, 14},
11: {15, 16},
12: {^9, ^8},
13: {17, 18},
14: {19, 20},
15: {^10, ^11},
16: {21, ^12},
17: {0, 22},
18: {23, 24},
19: {^13, 25},
20: {26, ^14},
21: {27, 28},
22: {29, 30},
23: {31, 32},
24: {33, 34},
25: {35, 36},
26: {37, 38},
27: {^15, 39},
28: {40, 41},
29: {42, 43},
30: {44, 45},
31: {^18, 46},
32: {47, 48},
33: {49, 50},
34: {51, ^64},
35: {52, 53},
36: {54, ^16},
37: {^17, 55},
38: {56, 57},
39: {58, 59},
40: {60, 61},
41: {62, ^0},
42: {^1792, 63},
43: {64, 65},
44: {^1856, ^1920},
45: {66, 67},
46: {68, 69},
47: {70, 71},
48: {72, ^24},
49: {^25, 73},
50: {74, 75},
51: {76, 77},
52: {^23, 78},
53: {79, 80},
54: {81, 82},
55: {83, 84},
56: {85, 86},
57: {87, ^22},
58: {88, 89},
59: {90, ^19},
60: {^20, 91},
61: {92, 93},
62: {^21, 94},
63: {^1984, ^2048},
64: {^2112, ^2176},
65: {^2240, ^2304},
66: {^2368, ^2432},
67: {^2496, ^2560},
68: {^52, 95},
69: {96, ^55},
70: {^56, 97},
71: {98, ^59},
72: {^60, 99},
73: {100, ^320},
74: {^384, ^448},
75: {101, ^53},
76: {^54, 102},
77: {103, 104},
78: {^50, ^51},
79: {^44, ^45},
80: {^46, ^47},
81: {^57, ^58},
82: {^61, ^256},
83: {^48, ^49},
84: {^62, ^63},
85: {^30, ^31},
86: {^32, ^33},
87: {^40, ^41},
88: {^128, ^192},
89: {^26, ^27},
90: {^28, ^29},
91: {^34, ^35},
92: {^36, ^37},
93: {^38, ^39},
94: {^42, ^43},
95: {^640, ^704},
96: {^768, ^832},
97: {^1280, ^1344},
98: {^1408, ^1472},
99: {^1536, ^1600},
100: {^1664, ^1728},
101: {^512, ^576},
102: {^896, ^960},
103: {^1024, ^1088},
104: {^1152, ^1216},
}
const maxCodeLength = 13
// Each encodeTable is represented by an array of bitStrings.
// bitString is a pair of uint32 values representing a bit code.
// The nBits low bits of bits make up the actual bit code.
// Eg. bitString{0x0004, 8} represents the bitcode "00000100".
type bitString struct {
bits uint32
nBits uint32
}
// modeEncodeTable represents Table 1 and the End-of-Line code.
var modeEncodeTable = [...]bitString{
0: {0x0001, 4}, // "0001"
1: {0x0001, 3}, // "001"
2: {0x0001, 1}, // "1"
3: {0x0003, 3}, // "011"
4: {0x0003, 6}, // "000011"
5: {0x0003, 7}, // "0000011"
6: {0x0002, 3}, // "010"
7: {0x0002, 6}, // "000010"
8: {0x0002, 7}, // "0000010"
9: {0x0001, 7}, // "0000001"
}
// whiteEncodeTable2 represents Table 2 for a white run.
var whiteEncodeTable2 = [...]bitString{
0: {0x0035, 8}, // "00110101"
1: {0x0007, 6}, // "000111"
2: {0x0007, 4}, // "0111"
3: {0x0008, 4}, // "1000"
4: {0x000b, 4}, // "1011"
5: {0x000c, 4}, // "1100"
6: {0x000e, 4}, // "1110"
7: {0x000f, 4}, // "1111"
8: {0x0013, 5}, // "10011"
9: {0x0014, 5}, // "10100"
10: {0x0007, 5}, // "00111"
11: {0x0008, 5}, // "01000"
12: {0x0008, 6}, // "001000"
13: {0x0003, 6}, // "000011"
14: {0x0034, 6}, // "110100"
15: {0x0035, 6}, // "110101"
16: {0x002a, 6}, // "101010"
17: {0x002b, 6}, // "101011"
18: {0x0027, 7}, // "0100111"
19: {0x000c, 7}, // "0001100"
20: {0x0008, 7}, // "0001000"
21: {0x0017, 7}, // "0010111"
22: {0x0003, 7}, // "0000011"
23: {0x0004, 7}, // "0000100"
24: {0x0028, 7}, // "0101000"
25: {0x002b, 7}, // "0101011"
26: {0x0013, 7}, // "0010011"
27: {0x0024, 7}, // "0100100"
28: {0x0018, 7}, // "0011000"
29: {0x0002, 8}, // "00000010"
30: {0x0003, 8}, // "00000011"
31: {0x001a, 8}, // "00011010"
32: {0x001b, 8}, // "00011011"
33: {0x0012, 8}, // "00010010"
34: {0x0013, 8}, // "00010011"
35: {0x0014, 8}, // "00010100"
36: {0x0015, 8}, // "00010101"
37: {0x0016, 8}, // "00010110"
38: {0x0017, 8}, // "00010111"
39: {0x0028, 8}, // "00101000"
40: {0x0029, 8}, // "00101001"
41: {0x002a, 8}, // "00101010"
42: {0x002b, 8}, // "00101011"
43: {0x002c, 8}, // "00101100"
44: {0x002d, 8}, // "00101101"
45: {0x0004, 8}, // "00000100"
46: {0x0005, 8}, // "00000101"
47: {0x000a, 8}, // "00001010"
48: {0x000b, 8}, // "00001011"
49: {0x0052, 8}, // "01010010"
50: {0x0053, 8}, // "01010011"
51: {0x0054, 8}, // "01010100"
52: {0x0055, 8}, // "01010101"
53: {0x0024, 8}, // "00100100"
54: {0x0025, 8}, // "00100101"
55: {0x0058, 8}, // "01011000"
56: {0x0059, 8}, // "01011001"
57: {0x005a, 8}, // "01011010"
58: {0x005b, 8}, // "01011011"
59: {0x004a, 8}, // "01001010"
60: {0x004b, 8}, // "01001011"
61: {0x0032, 8}, // "00110010"
62: {0x0033, 8}, // "00110011"
63: {0x0034, 8}, // "00110100"
}
// whiteEncodeTable3 represents Table 3 for a white run.
var whiteEncodeTable3 = [...]bitString{
0: {0x001b, 5}, // "11011"
1: {0x0012, 5}, // "10010"
2: {0x0017, 6}, // "010111"
3: {0x0037, 7}, // "0110111"
4: {0x0036, 8}, // "00110110"
5: {0x0037, 8}, // "00110111"
6: {0x0064, 8}, // "01100100"
7: {0x0065, 8}, // "01100101"
8: {0x0068, 8}, // "01101000"
9: {0x0067, 8}, // "01100111"
10: {0x00cc, 9}, // "011001100"
11: {0x00cd, 9}, // "011001101"
12: {0x00d2, 9}, // "011010010"
13: {0x00d3, 9}, // "011010011"
14: {0x00d4, 9}, // "011010100"
15: {0x00d5, 9}, // "011010101"
16: {0x00d6, 9}, // "011010110"
17: {0x00d7, 9}, // "011010111"
18: {0x00d8, 9}, // "011011000"
19: {0x00d9, 9}, // "011011001"
20: {0x00da, 9}, // "011011010"
21: {0x00db, 9}, // "011011011"
22: {0x0098, 9}, // "010011000"
23: {0x0099, 9}, // "010011001"
24: {0x009a, 9}, // "010011010"
25: {0x0018, 6}, // "011000"
26: {0x009b, 9}, // "010011011"
27: {0x0008, 11}, // "00000001000"
28: {0x000c, 11}, // "00000001100"
29: {0x000d, 11}, // "00000001101"
30: {0x0012, 12}, // "000000010010"
31: {0x0013, 12}, // "000000010011"
32: {0x0014, 12}, // "000000010100"
33: {0x0015, 12}, // "000000010101"
34: {0x0016, 12}, // "000000010110"
35: {0x0017, 12}, // "000000010111"
36: {0x001c, 12}, // "000000011100"
37: {0x001d, 12}, // "000000011101"
38: {0x001e, 12}, // "000000011110"
39: {0x001f, 12}, // "000000011111"
}
// blackEncodeTable2 represents Table 2 for a black run.
var blackEncodeTable2 = [...]bitString{
0: {0x0037, 10}, // "0000110111"
1: {0x0002, 3}, // "010"
2: {0x0003, 2}, // "11"
3: {0x0002, 2}, // "10"
4: {0x0003, 3}, // "011"
5: {0x0003, 4}, // "0011"
6: {0x0002, 4}, // "0010"
7: {0x0003, 5}, // "00011"
8: {0x0005, 6}, // "000101"
9: {0x0004, 6}, // "000100"
10: {0x0004, 7}, // "0000100"
11: {0x0005, 7}, // "0000101"
12: {0x0007, 7}, // "0000111"
13: {0x0004, 8}, // "00000100"
14: {0x0007, 8}, // "00000111"
15: {0x0018, 9}, // "000011000"
16: {0x0017, 10}, // "0000010111"
17: {0x0018, 10}, // "0000011000"
18: {0x0008, 10}, // "0000001000"
19: {0x0067, 11}, // "00001100111"
20: {0x0068, 11}, // "00001101000"
21: {0x006c, 11}, // "00001101100"
22: {0x0037, 11}, // "00000110111"
23: {0x0028, 11}, // "00000101000"
24: {0x0017, 11}, // "00000010111"
25: {0x0018, 11}, // "00000011000"
26: {0x00ca, 12}, // "000011001010"
27: {0x00cb, 12}, // "000011001011"
28: {0x00cc, 12}, // "000011001100"
29: {0x00cd, 12}, // "000011001101"
30: {0x0068, 12}, // "000001101000"
31: {0x0069, 12}, // "000001101001"
32: {0x006a, 12}, // "000001101010"
33: {0x006b, 12}, // "000001101011"
34: {0x00d2, 12}, // "000011010010"
35: {0x00d3, 12}, // "000011010011"
36: {0x00d4, 12}, // "000011010100"
37: {0x00d5, 12}, // "000011010101"
38: {0x00d6, 12}, // "000011010110"
39: {0x00d7, 12}, // "000011010111"
40: {0x006c, 12}, // "000001101100"
41: {0x006d, 12}, // "000001101101"
42: {0x00da, 12}, // "000011011010"
43: {0x00db, 12}, // "000011011011"
44: {0x0054, 12}, // "000001010100"
45: {0x0055, 12}, // "000001010101"
46: {0x0056, 12}, // "000001010110"
47: {0x0057, 12}, // "000001010111"
48: {0x0064, 12}, // "000001100100"
49: {0x0065, 12}, // "000001100101"
50: {0x0052, 12}, // "000001010010"
51: {0x0053, 12}, // "000001010011"
52: {0x0024, 12}, // "000000100100"
53: {0x0037, 12}, // "000000110111"
54: {0x0038, 12}, // "000000111000"
55: {0x0027, 12}, // "000000100111"
56: {0x0028, 12}, // "000000101000"
57: {0x0058, 12}, // "000001011000"
58: {0x0059, 12}, // "000001011001"
59: {0x002b, 12}, // "000000101011"
60: {0x002c, 12}, // "000000101100"
61: {0x005a, 12}, // "000001011010"
62: {0x0066, 12}, // "000001100110"
63: {0x0067, 12}, // "000001100111"
}
// blackEncodeTable3 represents Table 3 for a black run.
var blackEncodeTable3 = [...]bitString{
0: {0x000f, 10}, // "0000001111"
1: {0x00c8, 12}, // "000011001000"
2: {0x00c9, 12}, // "000011001001"
3: {0x005b, 12}, // "000001011011"
4: {0x0033, 12}, // "000000110011"
5: {0x0034, 12}, // "000000110100"
6: {0x0035, 12}, // "000000110101"
7: {0x006c, 13}, // "0000001101100"
8: {0x006d, 13}, // "0000001101101"
9: {0x004a, 13}, // "0000001001010"
10: {0x004b, 13}, // "0000001001011"
11: {0x004c, 13}, // "0000001001100"
12: {0x004d, 13}, // "0000001001101"
13: {0x0072, 13}, // "0000001110010"
14: {0x0073, 13}, // "0000001110011"
15: {0x0074, 13}, // "0000001110100"
16: {0x0075, 13}, // "0000001110101"
17: {0x0076, 13}, // "0000001110110"
18: {0x0077, 13}, // "0000001110111"
19: {0x0052, 13}, // "0000001010010"
20: {0x0053, 13}, // "0000001010011"
21: {0x0054, 13}, // "0000001010100"
22: {0x0055, 13}, // "0000001010101"
23: {0x005a, 13}, // "0000001011010"
24: {0x005b, 13}, // "0000001011011"
25: {0x0064, 13}, // "0000001100100"
26: {0x0065, 13}, // "0000001100101"
27: {0x0008, 11}, // "00000001000"
28: {0x000c, 11}, // "00000001100"
29: {0x000d, 11}, // "00000001101"
30: {0x0012, 12}, // "000000010010"
31: {0x0013, 12}, // "000000010011"
32: {0x0014, 12}, // "000000010100"
33: {0x0015, 12}, // "000000010101"
34: {0x0016, 12}, // "000000010110"
35: {0x0017, 12}, // "000000010111"
36: {0x001c, 12}, // "000000011100"
37: {0x001d, 12}, // "000000011101"
38: {0x001e, 12}, // "000000011110"
39: {0x001f, 12}, // "000000011111"
}
// COPY PASTE table.go BEGIN
const (
modePass = iota // Pass
modeH // Horizontal
modeV0 // Vertical-0
modeVR1 // Vertical-Right-1
modeVR2 // Vertical-Right-2
modeVR3 // Vertical-Right-3
modeVL1 // Vertical-Left-1
modeVL2 // Vertical-Left-2
modeVL3 // Vertical-Left-3
modeExt // Extension
)
// COPY PASTE table.go END
+102
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// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package ccitt
import (
"encoding/binary"
"io"
)
type bitWriter struct {
w io.Writer
// order is whether to process w's bytes LSB first or MSB first.
order Order
// The high nBits bits of the bits field hold encoded bits to be written to w.
bits uint64
nBits uint32
// bytes[:bw] holds encoded bytes not yet written to w.
// Overflow protection is ensured by using a multiple of 8 as bytes length.
bw uint32
bytes [1024]uint8
}
// flushBits copies 64 bits from b.bits to b.bytes. If b.bytes is then full, it
// is written to b.w.
func (b *bitWriter) flushBits() error {
binary.BigEndian.PutUint64(b.bytes[b.bw:], b.bits)
b.bits = 0
b.nBits = 0
b.bw += 8
if b.bw < uint32(len(b.bytes)) {
return nil
}
b.bw = 0
if b.order != MSB {
reverseBitsWithinBytes(b.bytes[:])
}
_, err := b.w.Write(b.bytes[:])
return err
}
// close finalizes a bitcode stream by writing any
// pending bits to bitWriter's underlying io.Writer.
func (b *bitWriter) close() error {
// Write any encoded bits to bytes.
if b.nBits > 0 {
binary.BigEndian.PutUint64(b.bytes[b.bw:], b.bits)
b.bw += (b.nBits + 7) >> 3
}
if b.order != MSB {
reverseBitsWithinBytes(b.bytes[:b.bw])
}
// Write b.bw bytes to b.w.
_, err := b.w.Write(b.bytes[:b.bw])
return err
}
// alignToByteBoundary rounds b.nBits up to a multiple of 8.
// If all 64 bits are used, flush them to bitWriter's bytes.
func (b *bitWriter) alignToByteBoundary() error {
if b.nBits = (b.nBits + 7) &^ 7; b.nBits == 64 {
return b.flushBits()
}
return nil
}
// writeCode writes a variable length bitcode to b's underlying io.Writer.
func (b *bitWriter) writeCode(bs bitString) error {
bits := bs.bits
nBits := bs.nBits
if 64-b.nBits >= nBits {
// b.bits has sufficient room for storing nBits bits.
b.bits |= uint64(bits) << (64 - nBits - b.nBits)
b.nBits += nBits
if b.nBits == 64 {
return b.flushBits()
}
return nil
}
// Number of leading bits that fill b.bits.
i := 64 - b.nBits
// Fill b.bits then flush and write remaining bits.
b.bits |= uint64(bits) >> (nBits - i)
b.nBits = 64
if err := b.flushBits(); err != nil {
return err
}
nBits -= i
b.bits = uint64(bits) << (64 - nBits)
b.nBits = nBits
return nil
}
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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:generate go run gen.go
// Package basicfont provides fixed-size font faces.
package basicfont // import "golang.org/x/image/font/basicfont"
import (
"image"
"golang.org/x/image/font"
"golang.org/x/image/math/fixed"
)
// Range maps a contiguous range of runes to vertically adjacent sub-images of
// a Face's Mask image. The rune range is inclusive on the low end and
// exclusive on the high end.
//
// If Low <= r && r < High, then the rune r is mapped to the sub-image of
// Face.Mask whose bounds are image.Rect(0, y*h, Face.Width, (y+1)*h),
// where y = (int(r-Low) + Offset) and h = (Face.Ascent + Face.Descent).
type Range struct {
Low, High rune
Offset int
}
// Face7x13 is a Face derived from the public domain X11 misc-fixed font files.
//
// At the moment, it holds the printable characters in ASCII starting with
// space, and the Unicode replacement character U+FFFD.
//
// Its data is entirely self-contained and does not require loading from
// separate files.
var Face7x13 = &Face{
Advance: 7,
Width: 6,
Height: 13,
Ascent: 11,
Descent: 2,
Mask: mask7x13,
Ranges: []Range{
{'\u0020', '\u007f', 0},
{'\ufffd', '\ufffe', 95},
},
}
// Face is a basic font face whose glyphs all have the same metrics.
//
// It is safe to use concurrently.
type Face struct {
// Advance is the glyph advance, in pixels.
Advance int
// Width is the glyph width, in pixels.
Width int
// Height is the inter-line height, in pixels.
Height int
// Ascent is the glyph ascent, in pixels.
Ascent int
// Descent is the glyph descent, in pixels.
Descent int
// Left is the left side bearing, in pixels. A positive value means that
// all of a glyph is to the right of the dot.
Left int
// Mask contains all of the glyph masks. Its width is typically the Face's
// Width, and its height a multiple of the Face's Height.
Mask image.Image
// Ranges map runes to sub-images of Mask. The rune ranges must not
// overlap, and must be in increasing rune order.
Ranges []Range
}
func (f *Face) Close() error { return nil }
func (f *Face) Kern(r0, r1 rune) fixed.Int26_6 { return 0 }
func (f *Face) Metrics() font.Metrics {
return font.Metrics{
Height: fixed.I(f.Height),
Ascent: fixed.I(f.Ascent),
Descent: fixed.I(f.Descent),
XHeight: fixed.I(f.Ascent),
CapHeight: fixed.I(f.Ascent),
CaretSlope: image.Point{X: 0, Y: 1},
}
}
func (f *Face) Glyph(dot fixed.Point26_6, r rune) (
dr image.Rectangle, mask image.Image, maskp image.Point, advance fixed.Int26_6, ok bool) {
if found, rng := f.find(r); rng != nil {
maskp.Y = (int(found-rng.Low) + rng.Offset) * (f.Ascent + f.Descent)
x := int(dot.X+32)>>6 + f.Left
y := int(dot.Y+32) >> 6
dr = image.Rectangle{
Min: image.Point{
X: x,
Y: y - f.Ascent,
},
Max: image.Point{
X: x + f.Width,
Y: y + f.Descent,
},
}
return dr, f.Mask, maskp, fixed.I(f.Advance), r == found
}
return image.Rectangle{}, nil, image.Point{}, 0, false
}
func (f *Face) GlyphBounds(r rune) (bounds fixed.Rectangle26_6, advance fixed.Int26_6, ok bool) {
if found, rng := f.find(r); rng != nil {
return fixed.R(0, -f.Ascent, f.Width, +f.Descent), fixed.I(f.Advance), r == found
}
return fixed.Rectangle26_6{}, 0, false
}
func (f *Face) GlyphAdvance(r rune) (advance fixed.Int26_6, ok bool) {
if found, rng := f.find(r); rng != nil {
return fixed.I(f.Advance), r == found
}
return 0, false
}
func (f *Face) find(r rune) (rune, *Range) {
for {
for i, rng := range f.Ranges {
if (rng.Low <= r) && (r < rng.High) {
return r, &f.Ranges[i]
}
}
if r == '\ufffd' {
return 0, nil
}
r = '\ufffd'
}
}
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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package font defines an interface for font faces, for drawing text on an
// image.
//
// Other packages provide font face implementations. For example, a truetype
// package would provide one based on .ttf font files.
package font // import "golang.org/x/image/font"
import (
"image"
"image/draw"
"io"
"unicode/utf8"
"golang.org/x/image/math/fixed"
)
// TODO: who is responsible for caches (glyph images, glyph indices, kerns)?
// The Drawer or the Face?
// Face is a font face. Its glyphs are often derived from a font file, such as
// "Comic_Sans_MS.ttf", but a face has a specific size, style, weight and
// hinting. For example, the 12pt and 18pt versions of Comic Sans are two
// different faces, even if derived from the same font file.
//
// A Face is not safe for concurrent use by multiple goroutines, as its methods
// may re-use implementation-specific caches and mask image buffers.
//
// To create a Face, look to other packages that implement specific font file
// formats.
type Face interface {
io.Closer
// Glyph returns the draw.DrawMask parameters (dr, mask, maskp) to draw r's
// glyph at the sub-pixel destination location dot, and that glyph's
// advance width.
//
// It returns !ok if the face does not contain a glyph for r. This includes
// returning !ok for a fallback glyph (such as substituting a U+FFFD glyph
// or OpenType's .notdef glyph), in which case the other return values may
// still be non-zero.
//
// The contents of the mask image returned by one Glyph call may change
// after the next Glyph call. Callers that want to cache the mask must make
// a copy.
Glyph(dot fixed.Point26_6, r rune) (
dr image.Rectangle, mask image.Image, maskp image.Point, advance fixed.Int26_6, ok bool)
// GlyphBounds returns the bounding box of r's glyph, drawn at a dot equal
// to the origin, and that glyph's advance width.
//
// It returns !ok if the face does not contain a glyph for r. This includes
// returning !ok for a fallback glyph (such as substituting a U+FFFD glyph
// or OpenType's .notdef glyph), in which case the other return values may
// still be non-zero.
//
// The glyph's ascent and descent are equal to -bounds.Min.Y and
// +bounds.Max.Y. The glyph's left-side and right-side bearings are equal
// to bounds.Min.X and advance-bounds.Max.X. A visual depiction of what
// these metrics are is at
// https://developer.apple.com/library/archive/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyphterms_2x.png
GlyphBounds(r rune) (bounds fixed.Rectangle26_6, advance fixed.Int26_6, ok bool)
// GlyphAdvance returns the advance width of r's glyph.
//
// It returns !ok if the face does not contain a glyph for r. This includes
// returning !ok for a fallback glyph (such as substituting a U+FFFD glyph
// or OpenType's .notdef glyph), in which case the other return values may
// still be non-zero.
GlyphAdvance(r rune) (advance fixed.Int26_6, ok bool)
// Kern returns the horizontal adjustment for the kerning pair (r0, r1). A
// positive kern means to move the glyphs further apart.
Kern(r0, r1 rune) fixed.Int26_6
// Metrics returns the metrics for this Face.
Metrics() Metrics
// TODO: ColoredGlyph for various emoji?
// TODO: Ligatures? Shaping?
}
// Metrics holds the metrics for a Face. A visual depiction is at
// https://developer.apple.com/library/mac/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyph_metrics_2x.png
type Metrics struct {
// Height is the recommended amount of vertical space between two lines of
// text.
Height fixed.Int26_6
// Ascent is the distance from the top of a line to its baseline.
Ascent fixed.Int26_6
// Descent is the distance from the bottom of a line to its baseline. The
// value is typically positive, even though a descender goes below the
// baseline.
Descent fixed.Int26_6
// XHeight is the distance from the top of non-ascending lowercase letters
// to the baseline.
XHeight fixed.Int26_6
// CapHeight is the distance from the top of uppercase letters to the
// baseline.
CapHeight fixed.Int26_6
// CaretSlope is the slope of a caret as a vector with the Y axis pointing up.
// The slope {0, 1} is the vertical caret.
CaretSlope image.Point
}
// Drawer draws text on a destination image.
//
// A Drawer is not safe for concurrent use by multiple goroutines, since its
// Face is not.
type Drawer struct {
// Dst is the destination image.
Dst draw.Image
// Src is the source image.
Src image.Image
// Face provides the glyph mask images.
Face Face
// Dot is the baseline location to draw the next glyph. The majority of the
// affected pixels will be above and to the right of the dot, but some may
// be below or to the left. For example, drawing a 'j' in an italic face
// may affect pixels below and to the left of the dot.
Dot fixed.Point26_6
// TODO: Clip image.Image?
// TODO: SrcP image.Point for Src images other than *image.Uniform? How
// does it get updated during DrawString?
}
// TODO: should DrawString return the last rune drawn, so the next DrawString
// call can kern beforehand? Or should that be the responsibility of the caller
// if they really want to do that, since they have to explicitly shift d.Dot
// anyway? What if ligatures span more than two runes? What if grapheme
// clusters span multiple runes?
//
// TODO: do we assume that the input is in any particular Unicode Normalization
// Form?
//
// TODO: have DrawRunes(s []rune)? DrawRuneReader(io.RuneReader)?? If we take
// io.RuneReader, we can't assume that we can rewind the stream.
//
// TODO: how does this work with line breaking: drawing text up until a
// vertical line? Should DrawString return the number of runes drawn?
// DrawBytes draws s at the dot and advances the dot's location.
//
// It is equivalent to DrawString(string(s)) but may be more efficient.
func (d *Drawer) DrawBytes(s []byte) {
prevC := rune(-1)
for len(s) > 0 {
c, size := utf8.DecodeRune(s)
s = s[size:]
if prevC >= 0 {
d.Dot.X += d.Face.Kern(prevC, c)
}
dr, mask, maskp, advance, _ := d.Face.Glyph(d.Dot, c)
if !dr.Empty() {
draw.DrawMask(d.Dst, dr, d.Src, image.Point{}, mask, maskp, draw.Over)
}
d.Dot.X += advance
prevC = c
}
}
// DrawString draws s at the dot and advances the dot's location.
func (d *Drawer) DrawString(s string) {
prevC := rune(-1)
for _, c := range s {
if prevC >= 0 {
d.Dot.X += d.Face.Kern(prevC, c)
}
dr, mask, maskp, advance, _ := d.Face.Glyph(d.Dot, c)
if !dr.Empty() {
draw.DrawMask(d.Dst, dr, d.Src, image.Point{}, mask, maskp, draw.Over)
}
d.Dot.X += advance
prevC = c
}
}
// BoundBytes returns the bounding box of s, drawn at the drawer dot, as well as
// the advance.
//
// It is equivalent to BoundBytes(string(s)) but may be more efficient.
func (d *Drawer) BoundBytes(s []byte) (bounds fixed.Rectangle26_6, advance fixed.Int26_6) {
bounds, advance = BoundBytes(d.Face, s)
bounds.Min = bounds.Min.Add(d.Dot)
bounds.Max = bounds.Max.Add(d.Dot)
return
}
// BoundString returns the bounding box of s, drawn at the drawer dot, as well
// as the advance.
func (d *Drawer) BoundString(s string) (bounds fixed.Rectangle26_6, advance fixed.Int26_6) {
bounds, advance = BoundString(d.Face, s)
bounds.Min = bounds.Min.Add(d.Dot)
bounds.Max = bounds.Max.Add(d.Dot)
return
}
// MeasureBytes returns how far dot would advance by drawing s.
//
// It is equivalent to MeasureString(string(s)) but may be more efficient.
func (d *Drawer) MeasureBytes(s []byte) (advance fixed.Int26_6) {
return MeasureBytes(d.Face, s)
}
// MeasureString returns how far dot would advance by drawing s.
func (d *Drawer) MeasureString(s string) (advance fixed.Int26_6) {
return MeasureString(d.Face, s)
}
// BoundBytes returns the bounding box of s with f, drawn at a dot equal to the
// origin, as well as the advance.
//
// It is equivalent to BoundString(string(s)) but may be more efficient.
func BoundBytes(f Face, s []byte) (bounds fixed.Rectangle26_6, advance fixed.Int26_6) {
prevC := rune(-1)
for len(s) > 0 {
c, size := utf8.DecodeRune(s)
s = s[size:]
if prevC >= 0 {
advance += f.Kern(prevC, c)
}
b, a, _ := f.GlyphBounds(c)
if !b.Empty() {
b.Min.X += advance
b.Max.X += advance
bounds = bounds.Union(b)
}
advance += a
prevC = c
}
return
}
// BoundString returns the bounding box of s with f, drawn at a dot equal to the
// origin, as well as the advance.
func BoundString(f Face, s string) (bounds fixed.Rectangle26_6, advance fixed.Int26_6) {
prevC := rune(-1)
for _, c := range s {
if prevC >= 0 {
advance += f.Kern(prevC, c)
}
b, a, _ := f.GlyphBounds(c)
if !b.Empty() {
b.Min.X += advance
b.Max.X += advance
bounds = bounds.Union(b)
}
advance += a
prevC = c
}
return
}
// MeasureBytes returns how far dot would advance by drawing s with f.
//
// It is equivalent to MeasureString(string(s)) but may be more efficient.
func MeasureBytes(f Face, s []byte) (advance fixed.Int26_6) {
prevC := rune(-1)
for len(s) > 0 {
c, size := utf8.DecodeRune(s)
s = s[size:]
if prevC >= 0 {
advance += f.Kern(prevC, c)
}
a, _ := f.GlyphAdvance(c)
advance += a
prevC = c
}
return advance
}
// MeasureString returns how far dot would advance by drawing s with f.
func MeasureString(f Face, s string) (advance fixed.Int26_6) {
prevC := rune(-1)
for _, c := range s {
if prevC >= 0 {
advance += f.Kern(prevC, c)
}
a, _ := f.GlyphAdvance(c)
advance += a
prevC = c
}
return advance
}
// Hinting selects how to quantize a vector font's glyph nodes.
//
// Not all fonts support hinting.
type Hinting int
const (
HintingNone Hinting = iota
HintingVertical
HintingFull
)
// Stretch selects a normal, condensed, or expanded face.
//
// Not all fonts support stretches.
type Stretch int
const (
StretchUltraCondensed Stretch = -4
StretchExtraCondensed Stretch = -3
StretchCondensed Stretch = -2
StretchSemiCondensed Stretch = -1
StretchNormal Stretch = +0
StretchSemiExpanded Stretch = +1
StretchExpanded Stretch = +2
StretchExtraExpanded Stretch = +3
StretchUltraExpanded Stretch = +4
)
// Style selects a normal, italic, or oblique face.
//
// Not all fonts support styles.
type Style int
const (
StyleNormal Style = iota
StyleItalic
StyleOblique
)
// Weight selects a normal, light or bold face.
//
// Not all fonts support weights.
//
// The named Weight constants (e.g. WeightBold) correspond to CSS' common
// weight names (e.g. "Bold"), but the numerical values differ, so that in Go,
// the zero value means to use a normal weight. For the CSS names and values,
// see https://developer.mozilla.org/en/docs/Web/CSS/font-weight
type Weight int
const (
WeightThin Weight = -3 // CSS font-weight value 100.
WeightExtraLight Weight = -2 // CSS font-weight value 200.
WeightLight Weight = -1 // CSS font-weight value 300.
WeightNormal Weight = +0 // CSS font-weight value 400.
WeightMedium Weight = +1 // CSS font-weight value 500.
WeightSemiBold Weight = +2 // CSS font-weight value 600.
WeightBold Weight = +3 // CSS font-weight value 700.
WeightExtraBold Weight = +4 // CSS font-weight value 800.
WeightBlack Weight = +5 // CSS font-weight value 900.
)
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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package f32 implements float32 vector and matrix types.
package f32 // import "golang.org/x/image/math/f32"
// Vec2 is a 2-element vector.
type Vec2 [2]float32
// Vec3 is a 3-element vector.
type Vec3 [3]float32
// Vec4 is a 4-element vector.
type Vec4 [4]float32
// Mat3 is a 3x3 matrix in row major order.
//
// m[3*r + c] is the element in the r'th row and c'th column.
type Mat3 [9]float32
// Mat4 is a 4x4 matrix in row major order.
//
// m[4*r + c] is the element in the r'th row and c'th column.
type Mat4 [16]float32
// Aff3 is a 3x3 affine transformation matrix in row major order, where the
// bottom row is implicitly [0 0 1].
//
// m[3*r + c] is the element in the r'th row and c'th column.
type Aff3 [6]float32
// Aff4 is a 4x4 affine transformation matrix in row major order, where the
// bottom row is implicitly [0 0 0 1].
//
// m[4*r + c] is the element in the r'th row and c'th column.
type Aff4 [12]float32
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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package f64 implements float64 vector and matrix types.
package f64 // import "golang.org/x/image/math/f64"
// Vec2 is a 2-element vector.
type Vec2 [2]float64
// Vec3 is a 3-element vector.
type Vec3 [3]float64
// Vec4 is a 4-element vector.
type Vec4 [4]float64
// Mat3 is a 3x3 matrix in row major order.
//
// m[3*r + c] is the element in the r'th row and c'th column.
type Mat3 [9]float64
// Mat4 is a 4x4 matrix in row major order.
//
// m[4*r + c] is the element in the r'th row and c'th column.
type Mat4 [16]float64
// Aff3 is a 3x3 affine transformation matrix in row major order, where the
// bottom row is implicitly [0 0 1].
//
// m[3*r + c] is the element in the r'th row and c'th column.
type Aff3 [6]float64
// Aff4 is a 4x4 affine transformation matrix in row major order, where the
// bottom row is implicitly [0 0 0 1].
//
// m[4*r + c] is the element in the r'th row and c'th column.
type Aff4 [12]float64
+410
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// Copyright 2015 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package fixed implements fixed-point integer types.
package fixed // import "golang.org/x/image/math/fixed"
import (
"fmt"
)
// TODO: implement fmt.Formatter for %f and %g.
// I returns the integer value i as an Int26_6.
//
// For example, passing the integer value 2 yields Int26_6(128).
func I(i int) Int26_6 {
return Int26_6(i << 6)
}
// Int26_6 is a signed 26.6 fixed-point number.
//
// The integer part ranges from -33554432 to 33554431, inclusive. The
// fractional part has 6 bits of precision.
//
// For example, the number one-and-a-quarter is Int26_6(1<<6 + 1<<4).
type Int26_6 int32
// String returns a human-readable representation of a 26.6 fixed-point number.
//
// For example, the number one-and-a-quarter becomes "1:16".
func (x Int26_6) String() string {
const shift, mask = 6, 1<<6 - 1
if x >= 0 {
return fmt.Sprintf("%d:%02d", int32(x>>shift), int32(x&mask))
}
x = -x
if x >= 0 {
return fmt.Sprintf("-%d:%02d", int32(x>>shift), int32(x&mask))
}
return "-33554432:00" // The minimum value is -(1<<25).
}
// Floor returns the greatest integer value less than or equal to x.
//
// Its return type is int, not Int26_6.
func (x Int26_6) Floor() int { return int((x + 0x00) >> 6) }
// Round returns the nearest integer value to x. Ties are rounded up.
//
// Its return type is int, not Int26_6.
func (x Int26_6) Round() int { return int((x + 0x20) >> 6) }
// Ceil returns the least integer value greater than or equal to x.
//
// Its return type is int, not Int26_6.
func (x Int26_6) Ceil() int { return int((x + 0x3f) >> 6) }
// Mul returns x*y in 26.6 fixed-point arithmetic.
func (x Int26_6) Mul(y Int26_6) Int26_6 {
return Int26_6((int64(x)*int64(y) + 1<<5) >> 6)
}
// Int52_12 is a signed 52.12 fixed-point number.
//
// The integer part ranges from -2251799813685248 to 2251799813685247,
// inclusive. The fractional part has 12 bits of precision.
//
// For example, the number one-and-a-quarter is Int52_12(1<<12 + 1<<10).
type Int52_12 int64
// String returns a human-readable representation of a 52.12 fixed-point
// number.
//
// For example, the number one-and-a-quarter becomes "1:1024".
func (x Int52_12) String() string {
const shift, mask = 12, 1<<12 - 1
if x >= 0 {
return fmt.Sprintf("%d:%04d", int64(x>>shift), int64(x&mask))
}
x = -x
if x >= 0 {
return fmt.Sprintf("-%d:%04d", int64(x>>shift), int64(x&mask))
}
return "-2251799813685248:0000" // The minimum value is -(1<<51).
}
// Floor returns the greatest integer value less than or equal to x.
//
// Its return type is int, not Int52_12.
func (x Int52_12) Floor() int { return int((x + 0x000) >> 12) }
// Round returns the nearest integer value to x. Ties are rounded up.
//
// Its return type is int, not Int52_12.
func (x Int52_12) Round() int { return int((x + 0x800) >> 12) }
// Ceil returns the least integer value greater than or equal to x.
//
// Its return type is int, not Int52_12.
func (x Int52_12) Ceil() int { return int((x + 0xfff) >> 12) }
// Mul returns x*y in 52.12 fixed-point arithmetic.
func (x Int52_12) Mul(y Int52_12) Int52_12 {
const M, N = 52, 12
lo, hi := muli64(int64(x), int64(y))
ret := Int52_12(hi<<M | lo>>N)
ret += Int52_12((lo >> (N - 1)) & 1) // Round to nearest, instead of rounding down.
return ret
}
// muli64 multiplies two int64 values, returning the 128-bit signed integer
// result as two uint64 values.
//
// This implementation is similar to $GOROOT/src/runtime/softfloat64.go's mullu
// function, which is in turn adapted from Hacker's Delight.
func muli64(u, v int64) (lo, hi uint64) {
const (
s = 32
mask = 1<<s - 1
)
u1 := uint64(u >> s)
u0 := uint64(u & mask)
v1 := uint64(v >> s)
v0 := uint64(v & mask)
w0 := u0 * v0
t := u1*v0 + w0>>s
w1 := t & mask
w2 := uint64(int64(t) >> s)
w1 += u0 * v1
return uint64(u) * uint64(v), u1*v1 + w2 + uint64(int64(w1)>>s)
}
// P returns the integer values x and y as a Point26_6.
//
// For example, passing the integer values (2, -3) yields Point26_6{128, -192}.
func P(x, y int) Point26_6 {
return Point26_6{Int26_6(x << 6), Int26_6(y << 6)}
}
// Point26_6 is a 26.6 fixed-point coordinate pair.
//
// It is analogous to the image.Point type in the standard library.
type Point26_6 struct {
X, Y Int26_6
}
// Add returns the vector p+q.
func (p Point26_6) Add(q Point26_6) Point26_6 {
return Point26_6{p.X + q.X, p.Y + q.Y}
}
// Sub returns the vector p-q.
func (p Point26_6) Sub(q Point26_6) Point26_6 {
return Point26_6{p.X - q.X, p.Y - q.Y}
}
// Mul returns the vector p*k.
func (p Point26_6) Mul(k Int26_6) Point26_6 {
return Point26_6{p.X * k / 64, p.Y * k / 64}
}
// Div returns the vector p/k.
func (p Point26_6) Div(k Int26_6) Point26_6 {
return Point26_6{p.X * 64 / k, p.Y * 64 / k}
}
// In returns whether p is in r.
func (p Point26_6) In(r Rectangle26_6) bool {
return r.Min.X <= p.X && p.X < r.Max.X && r.Min.Y <= p.Y && p.Y < r.Max.Y
}
// Point52_12 is a 52.12 fixed-point coordinate pair.
//
// It is analogous to the image.Point type in the standard library.
type Point52_12 struct {
X, Y Int52_12
}
// Add returns the vector p+q.
func (p Point52_12) Add(q Point52_12) Point52_12 {
return Point52_12{p.X + q.X, p.Y + q.Y}
}
// Sub returns the vector p-q.
func (p Point52_12) Sub(q Point52_12) Point52_12 {
return Point52_12{p.X - q.X, p.Y - q.Y}
}
// Mul returns the vector p*k.
func (p Point52_12) Mul(k Int52_12) Point52_12 {
return Point52_12{p.X * k / 4096, p.Y * k / 4096}
}
// Div returns the vector p/k.
func (p Point52_12) Div(k Int52_12) Point52_12 {
return Point52_12{p.X * 4096 / k, p.Y * 4096 / k}
}
// In returns whether p is in r.
func (p Point52_12) In(r Rectangle52_12) bool {
return r.Min.X <= p.X && p.X < r.Max.X && r.Min.Y <= p.Y && p.Y < r.Max.Y
}
// R returns the integer values minX, minY, maxX, maxY as a Rectangle26_6.
//
// For example, passing the integer values (0, 1, 2, 3) yields
// Rectangle26_6{Point26_6{0, 64}, Point26_6{128, 192}}.
//
// Like the image.Rect function in the standard library, the returned rectangle
// has minimum and maximum coordinates swapped if necessary so that it is
// well-formed.
func R(minX, minY, maxX, maxY int) Rectangle26_6 {
if minX > maxX {
minX, maxX = maxX, minX
}
if minY > maxY {
minY, maxY = maxY, minY
}
return Rectangle26_6{
Point26_6{
Int26_6(minX << 6),
Int26_6(minY << 6),
},
Point26_6{
Int26_6(maxX << 6),
Int26_6(maxY << 6),
},
}
}
// Rectangle26_6 is a 26.6 fixed-point coordinate rectangle. The Min bound is
// inclusive and the Max bound is exclusive. It is well-formed if Min.X <=
// Max.X and likewise for Y.
//
// It is analogous to the image.Rectangle type in the standard library.
type Rectangle26_6 struct {
Min, Max Point26_6
}
// Add returns the rectangle r translated by p.
func (r Rectangle26_6) Add(p Point26_6) Rectangle26_6 {
return Rectangle26_6{
Point26_6{r.Min.X + p.X, r.Min.Y + p.Y},
Point26_6{r.Max.X + p.X, r.Max.Y + p.Y},
}
}
// Sub returns the rectangle r translated by -p.
func (r Rectangle26_6) Sub(p Point26_6) Rectangle26_6 {
return Rectangle26_6{
Point26_6{r.Min.X - p.X, r.Min.Y - p.Y},
Point26_6{r.Max.X - p.X, r.Max.Y - p.Y},
}
}
// Intersect returns the largest rectangle contained by both r and s. If the
// two rectangles do not overlap then the zero rectangle will be returned.
func (r Rectangle26_6) Intersect(s Rectangle26_6) Rectangle26_6 {
if r.Min.X < s.Min.X {
r.Min.X = s.Min.X
}
if r.Min.Y < s.Min.Y {
r.Min.Y = s.Min.Y
}
if r.Max.X > s.Max.X {
r.Max.X = s.Max.X
}
if r.Max.Y > s.Max.Y {
r.Max.Y = s.Max.Y
}
// Letting r0 and s0 be the values of r and s at the time that the method
// is called, this next line is equivalent to:
//
// if max(r0.Min.X, s0.Min.X) >= min(r0.Max.X, s0.Max.X) || likewiseForY { etc }
if r.Empty() {
return Rectangle26_6{}
}
return r
}
// Union returns the smallest rectangle that contains both r and s.
func (r Rectangle26_6) Union(s Rectangle26_6) Rectangle26_6 {
if r.Empty() {
return s
}
if s.Empty() {
return r
}
if r.Min.X > s.Min.X {
r.Min.X = s.Min.X
}
if r.Min.Y > s.Min.Y {
r.Min.Y = s.Min.Y
}
if r.Max.X < s.Max.X {
r.Max.X = s.Max.X
}
if r.Max.Y < s.Max.Y {
r.Max.Y = s.Max.Y
}
return r
}
// Empty returns whether the rectangle contains no points.
func (r Rectangle26_6) Empty() bool {
return r.Min.X >= r.Max.X || r.Min.Y >= r.Max.Y
}
// In returns whether every point in r is in s.
func (r Rectangle26_6) In(s Rectangle26_6) bool {
if r.Empty() {
return true
}
// Note that r.Max is an exclusive bound for r, so that r.In(s)
// does not require that r.Max.In(s).
return s.Min.X <= r.Min.X && r.Max.X <= s.Max.X &&
s.Min.Y <= r.Min.Y && r.Max.Y <= s.Max.Y
}
// Rectangle52_12 is a 52.12 fixed-point coordinate rectangle. The Min bound is
// inclusive and the Max bound is exclusive. It is well-formed if Min.X <=
// Max.X and likewise for Y.
//
// It is analogous to the image.Rectangle type in the standard library.
type Rectangle52_12 struct {
Min, Max Point52_12
}
// Add returns the rectangle r translated by p.
func (r Rectangle52_12) Add(p Point52_12) Rectangle52_12 {
return Rectangle52_12{
Point52_12{r.Min.X + p.X, r.Min.Y + p.Y},
Point52_12{r.Max.X + p.X, r.Max.Y + p.Y},
}
}
// Sub returns the rectangle r translated by -p.
func (r Rectangle52_12) Sub(p Point52_12) Rectangle52_12 {
return Rectangle52_12{
Point52_12{r.Min.X - p.X, r.Min.Y - p.Y},
Point52_12{r.Max.X - p.X, r.Max.Y - p.Y},
}
}
// Intersect returns the largest rectangle contained by both r and s. If the
// two rectangles do not overlap then the zero rectangle will be returned.
func (r Rectangle52_12) Intersect(s Rectangle52_12) Rectangle52_12 {
if r.Min.X < s.Min.X {
r.Min.X = s.Min.X
}
if r.Min.Y < s.Min.Y {
r.Min.Y = s.Min.Y
}
if r.Max.X > s.Max.X {
r.Max.X = s.Max.X
}
if r.Max.Y > s.Max.Y {
r.Max.Y = s.Max.Y
}
// Letting r0 and s0 be the values of r and s at the time that the method
// is called, this next line is equivalent to:
//
// if max(r0.Min.X, s0.Min.X) >= min(r0.Max.X, s0.Max.X) || likewiseForY { etc }
if r.Empty() {
return Rectangle52_12{}
}
return r
}
// Union returns the smallest rectangle that contains both r and s.
func (r Rectangle52_12) Union(s Rectangle52_12) Rectangle52_12 {
if r.Empty() {
return s
}
if s.Empty() {
return r
}
if r.Min.X > s.Min.X {
r.Min.X = s.Min.X
}
if r.Min.Y > s.Min.Y {
r.Min.Y = s.Min.Y
}
if r.Max.X < s.Max.X {
r.Max.X = s.Max.X
}
if r.Max.Y < s.Max.Y {
r.Max.Y = s.Max.Y
}
return r
}
// Empty returns whether the rectangle contains no points.
func (r Rectangle52_12) Empty() bool {
return r.Min.X >= r.Max.X || r.Min.Y >= r.Max.Y
}
// In returns whether every point in r is in s.
func (r Rectangle52_12) In(s Rectangle52_12) bool {
if r.Empty() {
return true
}
// Note that r.Max is an exclusive bound for r, so that r.In(s)
// does not require that r.Max.In(s).
return s.Min.X <= r.Min.X && r.Max.X <= s.Max.X &&
s.Min.Y <= r.Min.Y && r.Max.Y <= s.Max.Y
}
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tiff
import "io"
// buffer buffers an io.Reader to satisfy io.ReaderAt.
type buffer struct {
r io.Reader
buf []byte
}
// fill reads data from b.r until the buffer contains at least end bytes.
func (b *buffer) fill(end int) error {
m := len(b.buf)
if end > m {
if end > cap(b.buf) {
newcap := 1024
for newcap < end {
newcap *= 2
}
newbuf := make([]byte, end, newcap)
copy(newbuf, b.buf)
b.buf = newbuf
} else {
b.buf = b.buf[:end]
}
if n, err := io.ReadFull(b.r, b.buf[m:end]); err != nil {
end = m + n
b.buf = b.buf[:end]
return err
}
}
return nil
}
func (b *buffer) ReadAt(p []byte, off int64) (int, error) {
o := int(off)
end := o + len(p)
if int64(end) != off+int64(len(p)) {
return 0, io.ErrUnexpectedEOF
}
err := b.fill(end)
return copy(p, b.buf[o:end]), err
}
// Slice returns a slice of the underlying buffer. The slice contains
// n bytes starting at offset off.
func (b *buffer) Slice(off, n int) ([]byte, error) {
end := off + n
if err := b.fill(end); err != nil {
return nil, err
}
return b.buf[off:end], nil
}
// newReaderAt converts an io.Reader into an io.ReaderAt.
func newReaderAt(r io.Reader) io.ReaderAt {
if ra, ok := r.(io.ReaderAt); ok {
return ra
}
return &buffer{
r: r,
buf: make([]byte, 0, 1024),
}
}
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tiff
import (
"bufio"
"io"
)
type byteReader interface {
io.Reader
io.ByteReader
}
// unpackBits decodes the PackBits-compressed data in src and returns the
// uncompressed data.
//
// The PackBits compression format is described in section 9 (p. 42)
// of the TIFF spec.
func unpackBits(r io.Reader) ([]byte, error) {
buf := make([]byte, 128)
dst := make([]byte, 0, 1024)
br, ok := r.(byteReader)
if !ok {
br = bufio.NewReader(r)
}
for {
b, err := br.ReadByte()
if err != nil {
if err == io.EOF {
return dst, nil
}
return nil, err
}
code := int(int8(b))
switch {
case code >= 0:
n, err := io.ReadFull(br, buf[:code+1])
if err != nil {
return nil, err
}
dst = append(dst, buf[:n]...)
case code == -128:
// No-op.
default:
if b, err = br.ReadByte(); err != nil {
return nil, err
}
for j := 0; j < 1-code; j++ {
buf[j] = b
}
dst = append(dst, buf[:1-code]...)
}
}
}
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tiff
// A tiff image file contains one or more images. The metadata
// of each image is contained in an Image File Directory (IFD),
// which contains entries of 12 bytes each and is described
// on page 14-16 of the specification. An IFD entry consists of
//
// - a tag, which describes the signification of the entry,
// - the data type and length of the entry,
// - the data itself or a pointer to it if it is more than 4 bytes.
//
// The presence of a length means that each IFD is effectively an array.
const (
leHeader = "II\x2A\x00" // Header for little-endian files.
beHeader = "MM\x00\x2A" // Header for big-endian files.
ifdLen = 12 // Length of an IFD entry in bytes.
)
// Data types (p. 14-16 of the spec).
const (
dtByte = 1
dtASCII = 2
dtShort = 3
dtLong = 4
dtRational = 5
)
// The length of one instance of each data type in bytes.
var lengths = [...]uint32{0, 1, 1, 2, 4, 8}
// Tags (see p. 28-41 of the spec).
const (
tImageWidth = 256
tImageLength = 257
tBitsPerSample = 258
tCompression = 259
tPhotometricInterpretation = 262
tFillOrder = 266
tStripOffsets = 273
tSamplesPerPixel = 277
tRowsPerStrip = 278
tStripByteCounts = 279
tT4Options = 292 // CCITT Group 3 options, a set of 32 flag bits.
tT6Options = 293 // CCITT Group 4 options, a set of 32 flag bits.
tTileWidth = 322
tTileLength = 323
tTileOffsets = 324
tTileByteCounts = 325
tXResolution = 282
tYResolution = 283
tResolutionUnit = 296
tPredictor = 317
tColorMap = 320
tExtraSamples = 338
tSampleFormat = 339
)
// Compression types (defined in various places in the spec and supplements).
const (
cNone = 1
cCCITT = 2
cG3 = 3 // Group 3 Fax.
cG4 = 4 // Group 4 Fax.
cLZW = 5
cJPEGOld = 6 // Superseded by cJPEG.
cJPEG = 7
cDeflate = 8 // zlib compression.
cPackBits = 32773
cDeflateOld = 32946 // Superseded by cDeflate.
)
// Photometric interpretation values (see p. 37 of the spec).
const (
pWhiteIsZero = 0
pBlackIsZero = 1
pRGB = 2
pPaletted = 3
pTransMask = 4 // transparency mask
pCMYK = 5
pYCbCr = 6
pCIELab = 8
)
// Values for the tPredictor tag (page 64-65 of the spec).
const (
prNone = 1
prHorizontal = 2
)
// Values for the tResolutionUnit tag (page 18).
const (
resNone = 1
resPerInch = 2 // Dots per inch.
resPerCM = 3 // Dots per centimeter.
)
// imageMode represents the mode of the image.
type imageMode int
const (
mBilevel imageMode = iota
mPaletted
mGray
mGrayInvert
mRGB
mRGBA
mNRGBA
mCMYK
)
// CompressionType describes the type of compression used in Options.
type CompressionType int
// Constants for supported compression types.
const (
Uncompressed CompressionType = iota
Deflate
LZW
CCITTGroup3
CCITTGroup4
)
// specValue returns the compression type constant from the TIFF spec that
// is equivalent to c.
func (c CompressionType) specValue() uint32 {
switch c {
case LZW:
return cLZW
case Deflate:
return cDeflate
case CCITTGroup3:
return cG3
case CCITTGroup4:
return cG4
}
return cNone
}
+29
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// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build gofuzz
package tiff
import "bytes"
func Fuzz(data []byte) int {
cfg, err := DecodeConfig(bytes.NewReader(data))
if err != nil {
return 0
}
if cfg.Width*cfg.Height > 1e6 {
return 0
}
img, err := Decode(bytes.NewReader(data))
if err != nil {
return 0
}
var w bytes.Buffer
err = Encode(&w, img, nil)
if err != nil {
panic(err)
}
return 1
}
+272
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package lzw implements the Lempel-Ziv-Welch compressed data format,
// described in T. A. Welch, “A Technique for High-Performance Data
// Compression”, Computer, 17(6) (June 1984), pp 8-19.
//
// In particular, it implements LZW as used by the TIFF file format, including
// an "off by one" algorithmic difference when compared to standard LZW.
package lzw // import "golang.org/x/image/tiff/lzw"
/*
This file was branched from src/pkg/compress/lzw/reader.go in the
standard library. Differences from the original are marked with "NOTE".
The tif_lzw.c file in the libtiff C library has this comment:
----
The 5.0 spec describes a different algorithm than Aldus
implements. Specifically, Aldus does code length transitions
one code earlier than should be done (for real LZW).
Earlier versions of this library implemented the correct
LZW algorithm, but emitted codes in a bit order opposite
to the TIFF spec. Thus, to maintain compatibility w/ Aldus
we interpret MSB-LSB ordered codes to be images written w/
old versions of this library, but otherwise adhere to the
Aldus "off by one" algorithm.
----
The Go code doesn't read (invalid) TIFF files written by old versions of
libtiff, but the LZW algorithm in this package still differs from the one in
Go's standard package library to accommodate this "off by one" in valid TIFFs.
*/
import (
"bufio"
"errors"
"fmt"
"io"
)
// Order specifies the bit ordering in an LZW data stream.
type Order int
const (
// LSB means Least Significant Bits first, as used in the GIF file format.
LSB Order = iota
// MSB means Most Significant Bits first, as used in the TIFF and PDF
// file formats.
MSB
)
const (
maxWidth = 12
decoderInvalidCode = 0xffff
flushBuffer = 1 << maxWidth
)
// decoder is the state from which the readXxx method converts a byte
// stream into a code stream.
type decoder struct {
r io.ByteReader
bits uint32
nBits uint
width uint
read func(*decoder) (uint16, error) // readLSB or readMSB
litWidth int // width in bits of literal codes
err error
// The first 1<<litWidth codes are literal codes.
// The next two codes mean clear and EOF.
// Other valid codes are in the range [lo, hi] where lo := clear + 2,
// with the upper bound incrementing on each code seen.
// overflow is the code at which hi overflows the code width. NOTE: TIFF's LZW is "off by one".
// last is the most recently seen code, or decoderInvalidCode.
clear, eof, hi, overflow, last uint16
// Each code c in [lo, hi] expands to two or more bytes. For c != hi:
// suffix[c] is the last of these bytes.
// prefix[c] is the code for all but the last byte.
// This code can either be a literal code or another code in [lo, c).
// The c == hi case is a special case.
suffix [1 << maxWidth]uint8
prefix [1 << maxWidth]uint16
// output is the temporary output buffer.
// Literal codes are accumulated from the start of the buffer.
// Non-literal codes decode to a sequence of suffixes that are first
// written right-to-left from the end of the buffer before being copied
// to the start of the buffer.
// It is flushed when it contains >= 1<<maxWidth bytes,
// so that there is always room to decode an entire code.
output [2 * 1 << maxWidth]byte
o int // write index into output
toRead []byte // bytes to return from Read
}
// readLSB returns the next code for "Least Significant Bits first" data.
func (d *decoder) readLSB() (uint16, error) {
for d.nBits < d.width {
x, err := d.r.ReadByte()
if err != nil {
return 0, err
}
d.bits |= uint32(x) << d.nBits
d.nBits += 8
}
code := uint16(d.bits & (1<<d.width - 1))
d.bits >>= d.width
d.nBits -= d.width
return code, nil
}
// readMSB returns the next code for "Most Significant Bits first" data.
func (d *decoder) readMSB() (uint16, error) {
for d.nBits < d.width {
x, err := d.r.ReadByte()
if err != nil {
return 0, err
}
d.bits |= uint32(x) << (24 - d.nBits)
d.nBits += 8
}
code := uint16(d.bits >> (32 - d.width))
d.bits <<= d.width
d.nBits -= d.width
return code, nil
}
func (d *decoder) Read(b []byte) (int, error) {
for {
if len(d.toRead) > 0 {
n := copy(b, d.toRead)
d.toRead = d.toRead[n:]
return n, nil
}
if d.err != nil {
return 0, d.err
}
d.decode()
}
}
// decode decompresses bytes from r and leaves them in d.toRead.
// read specifies how to decode bytes into codes.
// litWidth is the width in bits of literal codes.
func (d *decoder) decode() {
// Loop over the code stream, converting codes into decompressed bytes.
loop:
for {
code, err := d.read(d)
if err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
d.err = err
break
}
switch {
case code < d.clear:
// We have a literal code.
d.output[d.o] = uint8(code)
d.o++
if d.last != decoderInvalidCode {
// Save what the hi code expands to.
d.suffix[d.hi] = uint8(code)
d.prefix[d.hi] = d.last
}
case code == d.clear:
d.width = 1 + uint(d.litWidth)
d.hi = d.eof
d.overflow = 1 << d.width
d.last = decoderInvalidCode
continue
case code == d.eof:
d.err = io.EOF
break loop
case code <= d.hi:
c, i := code, len(d.output)-1
if code == d.hi && d.last != decoderInvalidCode {
// code == hi is a special case which expands to the last expansion
// followed by the head of the last expansion. To find the head, we walk
// the prefix chain until we find a literal code.
c = d.last
for c >= d.clear {
c = d.prefix[c]
}
d.output[i] = uint8(c)
i--
c = d.last
}
// Copy the suffix chain into output and then write that to w.
for c >= d.clear {
d.output[i] = d.suffix[c]
i--
c = d.prefix[c]
}
d.output[i] = uint8(c)
d.o += copy(d.output[d.o:], d.output[i:])
if d.last != decoderInvalidCode {
// Save what the hi code expands to.
d.suffix[d.hi] = uint8(c)
d.prefix[d.hi] = d.last
}
default:
d.err = errors.New("lzw: invalid code")
break loop
}
d.last, d.hi = code, d.hi+1
if d.hi+1 >= d.overflow { // NOTE: the "+1" is where TIFF's LZW differs from the standard algorithm.
if d.width == maxWidth {
d.last = decoderInvalidCode
} else {
d.width++
d.overflow <<= 1
}
}
if d.o >= flushBuffer {
break
}
}
// Flush pending output.
d.toRead = d.output[:d.o]
d.o = 0
}
var errClosed = errors.New("lzw: reader/writer is closed")
func (d *decoder) Close() error {
d.err = errClosed // in case any Reads come along
return nil
}
// NewReader creates a new io.ReadCloser.
// Reads from the returned io.ReadCloser read and decompress data from r.
// If r does not also implement io.ByteReader,
// the decompressor may read more data than necessary from r.
// It is the caller's responsibility to call Close on the ReadCloser when
// finished reading.
// The number of bits to use for literal codes, litWidth, must be in the
// range [2,8] and is typically 8. It must equal the litWidth
// used during compression.
func NewReader(r io.Reader, order Order, litWidth int) io.ReadCloser {
d := new(decoder)
switch order {
case LSB:
d.read = (*decoder).readLSB
case MSB:
d.read = (*decoder).readMSB
default:
d.err = errors.New("lzw: unknown order")
return d
}
if litWidth < 2 || 8 < litWidth {
d.err = fmt.Errorf("lzw: litWidth %d out of range", litWidth)
return d
}
if br, ok := r.(io.ByteReader); ok {
d.r = br
} else {
d.r = bufio.NewReader(r)
}
d.litWidth = litWidth
d.width = 1 + uint(litWidth)
d.clear = uint16(1) << uint(litWidth)
d.eof, d.hi = d.clear+1, d.clear+1
d.overflow = uint16(1) << d.width
d.last = decoderInvalidCode
return d
}
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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package tiff implements a TIFF image decoder and encoder.
//
// The TIFF specification is at http://partners.adobe.com/public/developer/en/tiff/TIFF6.pdf
package tiff // import "golang.org/x/image/tiff"
import (
"bytes"
"compress/zlib"
"encoding/binary"
"fmt"
"image"
"image/color"
"io"
"math"
"golang.org/x/image/ccitt"
"golang.org/x/image/tiff/lzw"
)
// A FormatError reports that the input is not a valid TIFF image.
type FormatError string
func (e FormatError) Error() string {
return "tiff: invalid format: " + string(e)
}
// An UnsupportedError reports that the input uses a valid but
// unimplemented feature.
type UnsupportedError string
func (e UnsupportedError) Error() string {
return "tiff: unsupported feature: " + string(e)
}
var (
errNoPixels = FormatError("not enough pixel data")
errInvalidColorIndex = FormatError("invalid color index")
)
const maxChunkSize = 10 << 20 // 10M
// safeReadAt is a verbatim copy of internal/saferio.ReadDataAt from the
// standard library, which is used to read data from a reader using a length
// provided by untrusted data, without allocating the entire slice ahead of time
// if it is large (>maxChunkSize). This allows us to avoid allocating giant
// slices before learning that we can't actually read that much data from the
// reader.
func safeReadAt(r io.ReaderAt, n uint64, off int64) ([]byte, error) {
if int64(n) < 0 || n != uint64(int(n)) {
// n is too large to fit in int, so we can't allocate
// a buffer large enough. Treat this as a read failure.
return nil, io.ErrUnexpectedEOF
}
if n < maxChunkSize {
buf := make([]byte, n)
_, err := r.ReadAt(buf, off)
if err != nil {
// io.SectionReader can return EOF for n == 0,
// but for our purposes that is a success.
if err != io.EOF || n > 0 {
return nil, err
}
}
return buf, nil
}
var buf []byte
buf1 := make([]byte, maxChunkSize)
for n > 0 {
next := n
if next > maxChunkSize {
next = maxChunkSize
}
_, err := r.ReadAt(buf1[:next], off)
if err != nil {
return nil, err
}
buf = append(buf, buf1[:next]...)
n -= next
off += int64(next)
}
return buf, nil
}
type decoder struct {
r io.ReaderAt
byteOrder binary.ByteOrder
config image.Config
mode imageMode
bpp uint
features map[int][]uint
palette []color.Color
buf []byte
off int // Current offset in buf.
v uint32 // Buffer value for reading with arbitrary bit depths.
nbits uint // Remaining number of bits in v.
}
// firstVal returns the first uint of the features entry with the given tag,
// or 0 if the tag does not exist.
func (d *decoder) firstVal(tag int) uint {
f := d.features[tag]
if len(f) == 0 {
return 0
}
return f[0]
}
// ifdUint decodes the IFD entry in p, which must be of the Byte, Short
// or Long type, and returns the decoded uint values.
func (d *decoder) ifdUint(p []byte) (u []uint, err error) {
var raw []byte
if len(p) < ifdLen {
return nil, FormatError("bad IFD entry")
}
datatype := d.byteOrder.Uint16(p[2:4])
if dt := int(datatype); dt <= 0 || dt >= len(lengths) {
return nil, UnsupportedError("IFD entry datatype")
}
count := d.byteOrder.Uint32(p[4:8])
if count > math.MaxInt32/lengths[datatype] {
return nil, FormatError("IFD data too large")
}
if datalen := lengths[datatype] * count; datalen > 4 {
// The IFD contains a pointer to the real value.
raw, err = safeReadAt(d.r, uint64(datalen), int64(d.byteOrder.Uint32(p[8:12])))
} else {
raw = p[8 : 8+datalen]
}
if err != nil {
return nil, err
}
u = make([]uint, count)
switch datatype {
case dtByte:
for i := uint32(0); i < count; i++ {
u[i] = uint(raw[i])
}
case dtShort:
for i := uint32(0); i < count; i++ {
u[i] = uint(d.byteOrder.Uint16(raw[2*i : 2*(i+1)]))
}
case dtLong:
for i := uint32(0); i < count; i++ {
u[i] = uint(d.byteOrder.Uint32(raw[4*i : 4*(i+1)]))
}
default:
return nil, UnsupportedError("data type")
}
return u, nil
}
// parseIFD decides whether the IFD entry in p is "interesting" and
// stows away the data in the decoder. It returns the tag number of the
// entry and an error, if any.
func (d *decoder) parseIFD(p []byte) (int, error) {
tag := d.byteOrder.Uint16(p[0:2])
switch tag {
case tBitsPerSample,
tExtraSamples,
tPhotometricInterpretation,
tCompression,
tPredictor,
tStripOffsets,
tStripByteCounts,
tRowsPerStrip,
tTileWidth,
tTileLength,
tTileOffsets,
tTileByteCounts,
tImageLength,
tImageWidth,
tFillOrder,
tT4Options,
tT6Options:
val, err := d.ifdUint(p)
if err != nil {
return 0, err
}
d.features[int(tag)] = val
case tColorMap:
val, err := d.ifdUint(p)
if err != nil {
return 0, err
}
numcolors := len(val) / 3
if len(val)%3 != 0 || numcolors <= 0 || numcolors > 256 {
return 0, FormatError("bad ColorMap length")
}
d.palette = make([]color.Color, numcolors)
for i := 0; i < numcolors; i++ {
d.palette[i] = color.RGBA64{
uint16(val[i]),
uint16(val[i+numcolors]),
uint16(val[i+2*numcolors]),
0xffff,
}
}
case tSampleFormat:
// Page 27 of the spec: If the SampleFormat is present and
// the value is not 1 [= unsigned integer data], a Baseline
// TIFF reader that cannot handle the SampleFormat value
// must terminate the import process gracefully.
val, err := d.ifdUint(p)
if err != nil {
return 0, err
}
for _, v := range val {
if v != 1 {
return 0, UnsupportedError("sample format")
}
}
}
return int(tag), nil
}
// readBits reads n bits from the internal buffer starting at the current offset.
func (d *decoder) readBits(n uint) (v uint32, ok bool) {
for d.nbits < n {
d.v <<= 8
if d.off >= len(d.buf) {
return 0, false
}
d.v |= uint32(d.buf[d.off])
d.off++
d.nbits += 8
}
d.nbits -= n
rv := d.v >> d.nbits
d.v &^= rv << d.nbits
return rv, true
}
// flushBits discards the unread bits in the buffer used by readBits.
// It is used at the end of a line.
func (d *decoder) flushBits() {
d.v = 0
d.nbits = 0
}
// minInt returns the smaller of x or y.
func minInt(a, b int) int {
if a <= b {
return a
}
return b
}
// decode decodes the raw data of an image.
// It reads from d.buf and writes the strip or tile into dst.
func (d *decoder) decode(dst image.Image, xmin, ymin, xmax, ymax int) error {
d.off = 0
// Apply horizontal predictor if necessary.
// In this case, p contains the color difference to the preceding pixel.
// See page 64-65 of the spec.
if d.firstVal(tPredictor) == prHorizontal {
switch d.bpp {
case 16:
var off int
n := 2 * len(d.features[tBitsPerSample]) // bytes per sample times samples per pixel
for y := ymin; y < ymax; y++ {
off += n
for x := 0; x < (xmax-xmin-1)*n; x += 2 {
if off+2 > len(d.buf) {
return errNoPixels
}
v0 := d.byteOrder.Uint16(d.buf[off-n : off-n+2])
v1 := d.byteOrder.Uint16(d.buf[off : off+2])
d.byteOrder.PutUint16(d.buf[off:off+2], v1+v0)
off += 2
}
}
case 8:
var off int
n := 1 * len(d.features[tBitsPerSample]) // bytes per sample times samples per pixel
for y := ymin; y < ymax; y++ {
off += n
for x := 0; x < (xmax-xmin-1)*n; x++ {
if off >= len(d.buf) {
return errNoPixels
}
d.buf[off] += d.buf[off-n]
off++
}
}
case 1:
return UnsupportedError("horizontal predictor with 1 BitsPerSample")
}
}
rMaxX := minInt(xmax, dst.Bounds().Max.X)
rMaxY := minInt(ymax, dst.Bounds().Max.Y)
switch d.mode {
case mGray, mGrayInvert:
if d.bpp == 16 {
img := dst.(*image.Gray16)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
if d.off+2 > len(d.buf) {
return errNoPixels
}
v := d.byteOrder.Uint16(d.buf[d.off : d.off+2])
d.off += 2
if d.mode == mGrayInvert {
v = 0xffff - v
}
img.SetGray16(x, y, color.Gray16{v})
}
if rMaxX == img.Bounds().Max.X {
d.off += 2 * (xmax - img.Bounds().Max.X)
}
}
} else {
img := dst.(*image.Gray)
max := uint32((1 << d.bpp) - 1)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
v, ok := d.readBits(d.bpp)
if !ok {
return errNoPixels
}
v = v * 0xff / max
if d.mode == mGrayInvert {
v = 0xff - v
}
img.SetGray(x, y, color.Gray{uint8(v)})
}
d.flushBits()
}
}
case mPaletted:
img := dst.(*image.Paletted)
pLen := len(d.palette)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
v, ok := d.readBits(d.bpp)
if !ok {
return errNoPixels
}
idx := uint8(v)
if int(idx) >= pLen {
return errInvalidColorIndex
}
img.SetColorIndex(x, y, idx)
}
d.flushBits()
}
case mRGB:
if d.bpp == 16 {
img := dst.(*image.RGBA64)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
if d.off+6 > len(d.buf) {
return errNoPixels
}
r := d.byteOrder.Uint16(d.buf[d.off+0 : d.off+2])
g := d.byteOrder.Uint16(d.buf[d.off+2 : d.off+4])
b := d.byteOrder.Uint16(d.buf[d.off+4 : d.off+6])
d.off += 6
img.SetRGBA64(x, y, color.RGBA64{r, g, b, 0xffff})
}
}
} else {
img := dst.(*image.RGBA)
for y := ymin; y < rMaxY; y++ {
min := img.PixOffset(xmin, y)
max := img.PixOffset(rMaxX, y)
off := (y - ymin) * (xmax - xmin) * 3
for i := min; i < max; i += 4 {
if off+3 > len(d.buf) {
return errNoPixels
}
img.Pix[i+0] = d.buf[off+0]
img.Pix[i+1] = d.buf[off+1]
img.Pix[i+2] = d.buf[off+2]
img.Pix[i+3] = 0xff
off += 3
}
}
}
case mNRGBA:
if d.bpp == 16 {
img := dst.(*image.NRGBA64)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
if d.off+8 > len(d.buf) {
return errNoPixels
}
r := d.byteOrder.Uint16(d.buf[d.off+0 : d.off+2])
g := d.byteOrder.Uint16(d.buf[d.off+2 : d.off+4])
b := d.byteOrder.Uint16(d.buf[d.off+4 : d.off+6])
a := d.byteOrder.Uint16(d.buf[d.off+6 : d.off+8])
d.off += 8
img.SetNRGBA64(x, y, color.NRGBA64{r, g, b, a})
}
}
} else {
img := dst.(*image.NRGBA)
for y := ymin; y < rMaxY; y++ {
min := img.PixOffset(xmin, y)
max := img.PixOffset(rMaxX, y)
i0, i1 := (y-ymin)*(xmax-xmin)*4, (y-ymin+1)*(xmax-xmin)*4
if i1 > len(d.buf) {
return errNoPixels
}
copy(img.Pix[min:max], d.buf[i0:i1])
}
}
case mRGBA:
if d.bpp == 16 {
img := dst.(*image.RGBA64)
for y := ymin; y < rMaxY; y++ {
for x := xmin; x < rMaxX; x++ {
if d.off+8 > len(d.buf) {
return errNoPixels
}
r := d.byteOrder.Uint16(d.buf[d.off+0 : d.off+2])
g := d.byteOrder.Uint16(d.buf[d.off+2 : d.off+4])
b := d.byteOrder.Uint16(d.buf[d.off+4 : d.off+6])
a := d.byteOrder.Uint16(d.buf[d.off+6 : d.off+8])
d.off += 8
img.SetRGBA64(x, y, color.RGBA64{r, g, b, a})
}
}
} else {
img := dst.(*image.RGBA)
for y := ymin; y < rMaxY; y++ {
min := img.PixOffset(xmin, y)
max := img.PixOffset(rMaxX, y)
i0, i1 := (y-ymin)*(xmax-xmin)*4, (y-ymin+1)*(xmax-xmin)*4
if i1 > len(d.buf) {
return errNoPixels
}
copy(img.Pix[min:max], d.buf[i0:i1])
}
}
}
return nil
}
func newDecoder(r io.Reader) (*decoder, error) {
d := &decoder{
r: newReaderAt(r),
features: make(map[int][]uint),
}
p := make([]byte, 8)
if _, err := d.r.ReadAt(p, 0); err != nil {
if err == io.EOF {
err = io.ErrUnexpectedEOF
}
return nil, err
}
switch string(p[0:4]) {
case leHeader:
d.byteOrder = binary.LittleEndian
case beHeader:
d.byteOrder = binary.BigEndian
default:
return nil, FormatError("malformed header")
}
ifdOffset := int64(d.byteOrder.Uint32(p[4:8]))
// The first two bytes contain the number of entries (12 bytes each).
if _, err := d.r.ReadAt(p[0:2], ifdOffset); err != nil {
return nil, err
}
numItems := int(d.byteOrder.Uint16(p[0:2]))
// All IFD entries are read in one chunk.
var err error
p, err = safeReadAt(d.r, uint64(ifdLen*numItems), ifdOffset+2)
if err != nil {
return nil, err
}
prevTag := -1
for i := 0; i < len(p); i += ifdLen {
tag, err := d.parseIFD(p[i : i+ifdLen])
if err != nil {
return nil, err
}
if tag <= prevTag {
return nil, FormatError("tags are not sorted in ascending order")
}
prevTag = tag
}
d.config.Width = int(d.firstVal(tImageWidth))
d.config.Height = int(d.firstVal(tImageLength))
if _, ok := d.features[tBitsPerSample]; !ok {
// Default is 1 per specification.
d.features[tBitsPerSample] = []uint{1}
}
d.bpp = d.firstVal(tBitsPerSample)
switch d.bpp {
case 0:
return nil, FormatError("BitsPerSample must not be 0")
case 1, 8, 16:
// Nothing to do, these are accepted by this implementation.
default:
return nil, UnsupportedError(fmt.Sprintf("BitsPerSample of %v", d.bpp))
}
// Determine the image mode.
switch d.firstVal(tPhotometricInterpretation) {
case pRGB:
if d.bpp == 16 {
for _, b := range d.features[tBitsPerSample] {
if b != 16 {
return nil, FormatError("wrong number of samples for 16bit RGB")
}
}
} else {
for _, b := range d.features[tBitsPerSample] {
if b != 8 {
return nil, FormatError("wrong number of samples for 8bit RGB")
}
}
}
// RGB images normally have 3 samples per pixel.
// If there are more, ExtraSamples (p. 31-32 of the spec)
// gives their meaning (usually an alpha channel).
//
// This implementation does not support extra samples
// of an unspecified type.
switch len(d.features[tBitsPerSample]) {
case 3:
d.mode = mRGB
if d.bpp == 16 {
d.config.ColorModel = color.RGBA64Model
} else {
d.config.ColorModel = color.RGBAModel
}
case 4:
switch d.firstVal(tExtraSamples) {
case 1:
d.mode = mRGBA
if d.bpp == 16 {
d.config.ColorModel = color.RGBA64Model
} else {
d.config.ColorModel = color.RGBAModel
}
case 2:
d.mode = mNRGBA
if d.bpp == 16 {
d.config.ColorModel = color.NRGBA64Model
} else {
d.config.ColorModel = color.NRGBAModel
}
default:
return nil, FormatError("wrong number of samples for RGB")
}
default:
return nil, FormatError("wrong number of samples for RGB")
}
case pPaletted:
d.mode = mPaletted
d.config.ColorModel = color.Palette(d.palette)
case pWhiteIsZero:
d.mode = mGrayInvert
if d.bpp == 16 {
d.config.ColorModel = color.Gray16Model
} else {
d.config.ColorModel = color.GrayModel
}
case pBlackIsZero:
d.mode = mGray
if d.bpp == 16 {
d.config.ColorModel = color.Gray16Model
} else {
d.config.ColorModel = color.GrayModel
}
default:
return nil, UnsupportedError("color model")
}
if d.firstVal(tPhotometricInterpretation) != pRGB {
if len(d.features[tBitsPerSample]) != 1 {
return nil, UnsupportedError("extra samples")
}
}
return d, nil
}
// DecodeConfig returns the color model and dimensions of a TIFF image without
// decoding the entire image.
func DecodeConfig(r io.Reader) (image.Config, error) {
d, err := newDecoder(r)
if err != nil {
return image.Config{}, err
}
return d.config, nil
}
func ccittFillOrder(tiffFillOrder uint) ccitt.Order {
if tiffFillOrder == 2 {
return ccitt.LSB
}
return ccitt.MSB
}
// Decode reads a TIFF image from r and returns it as an image.Image.
// The type of Image returned depends on the contents of the TIFF.
func Decode(r io.Reader) (img image.Image, err error) {
d, err := newDecoder(r)
if err != nil {
return
}
blockPadding := false
blockWidth := d.config.Width
blockHeight := d.config.Height
blocksAcross := 1
blocksDown := 1
if d.config.Width == 0 {
blocksAcross = 0
}
if d.config.Height == 0 {
blocksDown = 0
}
var blockOffsets, blockCounts []uint
if int(d.firstVal(tTileWidth)) != 0 {
blockPadding = true
blockWidth = int(d.firstVal(tTileWidth))
blockHeight = int(d.firstVal(tTileLength))
// The specification says that tile widths and lengths must be a multiple of 16.
// We currently permit invalid sizes, but reject anything too small to limit the
// amount of work a malicious input can force us to perform.
if blockWidth < 8 || blockHeight < 8 {
return nil, FormatError("tile size is too small")
}
if blockWidth != 0 {
blocksAcross = (d.config.Width + blockWidth - 1) / blockWidth
}
if blockHeight != 0 {
blocksDown = (d.config.Height + blockHeight - 1) / blockHeight
}
blockCounts = d.features[tTileByteCounts]
blockOffsets = d.features[tTileOffsets]
} else {
if int(d.firstVal(tRowsPerStrip)) != 0 {
blockHeight = int(d.firstVal(tRowsPerStrip))
}
if blockHeight != 0 {
blocksDown = (d.config.Height + blockHeight - 1) / blockHeight
}
blockOffsets = d.features[tStripOffsets]
blockCounts = d.features[tStripByteCounts]
}
// Check if we have the right number of strips/tiles, offsets and counts.
if n := blocksAcross * blocksDown; len(blockOffsets) < n || len(blockCounts) < n {
return nil, FormatError("inconsistent header")
}
imgRect := image.Rect(0, 0, d.config.Width, d.config.Height)
switch d.mode {
case mGray, mGrayInvert:
if d.bpp == 16 {
img = image.NewGray16(imgRect)
} else {
img = image.NewGray(imgRect)
}
case mPaletted:
img = image.NewPaletted(imgRect, d.palette)
case mNRGBA:
if d.bpp == 16 {
img = image.NewNRGBA64(imgRect)
} else {
img = image.NewNRGBA(imgRect)
}
case mRGB, mRGBA:
if d.bpp == 16 {
img = image.NewRGBA64(imgRect)
} else {
img = image.NewRGBA(imgRect)
}
}
if blocksAcross == 0 || blocksDown == 0 {
return
}
// Maximum data per pixel is 8 bytes (RGBA64).
blockMaxDataSize := int64(blockWidth) * int64(blockHeight) * 8
for i := 0; i < blocksAcross; i++ {
blkW := blockWidth
if !blockPadding && i == blocksAcross-1 && d.config.Width%blockWidth != 0 {
blkW = d.config.Width % blockWidth
}
for j := 0; j < blocksDown; j++ {
blkH := blockHeight
if !blockPadding && j == blocksDown-1 && d.config.Height%blockHeight != 0 {
blkH = d.config.Height % blockHeight
}
offset := int64(blockOffsets[j*blocksAcross+i])
n := int64(blockCounts[j*blocksAcross+i])
switch d.firstVal(tCompression) {
// According to the spec, Compression does not have a default value,
// but some tools interpret a missing Compression value as none so we do
// the same.
case cNone, 0:
if b, ok := d.r.(*buffer); ok {
d.buf, err = b.Slice(int(offset), int(n))
} else {
d.buf, err = safeReadAt(d.r, uint64(n), offset)
}
case cG3:
inv := d.firstVal(tPhotometricInterpretation) == pWhiteIsZero
order := ccittFillOrder(d.firstVal(tFillOrder))
r := ccitt.NewReader(io.NewSectionReader(d.r, offset, n), order, ccitt.Group3, blkW, blkH, &ccitt.Options{Invert: inv, Align: false})
d.buf, err = readBuf(r, d.buf, blockMaxDataSize)
case cG4:
inv := d.firstVal(tPhotometricInterpretation) == pWhiteIsZero
order := ccittFillOrder(d.firstVal(tFillOrder))
r := ccitt.NewReader(io.NewSectionReader(d.r, offset, n), order, ccitt.Group4, blkW, blkH, &ccitt.Options{Invert: inv, Align: false})
d.buf, err = readBuf(r, d.buf, blockMaxDataSize)
case cLZW:
r := lzw.NewReader(io.NewSectionReader(d.r, offset, n), lzw.MSB, 8)
d.buf, err = readBuf(r, d.buf, blockMaxDataSize)
r.Close()
case cDeflate, cDeflateOld:
var r io.ReadCloser
r, err = zlib.NewReader(io.NewSectionReader(d.r, offset, n))
if err != nil {
return nil, err
}
d.buf, err = readBuf(r, d.buf, blockMaxDataSize)
r.Close()
case cPackBits:
d.buf, err = unpackBits(io.NewSectionReader(d.r, offset, n))
default:
err = UnsupportedError(fmt.Sprintf("compression value %d", d.firstVal(tCompression)))
}
if err != nil {
return nil, err
}
xmin := i * blockWidth
ymin := j * blockHeight
xmax := xmin + blkW
ymax := ymin + blkH
err = d.decode(img, xmin, ymin, xmax, ymax)
if err != nil {
return nil, err
}
}
}
return
}
func readBuf(r io.Reader, buf []byte, lim int64) ([]byte, error) {
b := bytes.NewBuffer(buf[:0])
_, err := b.ReadFrom(io.LimitReader(r, lim))
return b.Bytes(), err
}
func init() {
image.RegisterFormat("tiff", leHeader, Decode, DecodeConfig)
image.RegisterFormat("tiff", beHeader, Decode, DecodeConfig)
}
+441
View File
@@ -0,0 +1,441 @@
// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tiff
import (
"bytes"
"compress/zlib"
"encoding/binary"
"errors"
"image"
"io"
"sort"
)
// The TIFF format allows to choose the order of the different elements freely.
// The basic structure of a TIFF file written by this package is:
//
// 1. Header (8 bytes).
// 2. Image data.
// 3. Image File Directory (IFD).
// 4. "Pointer area" for larger entries in the IFD.
// We only write little-endian TIFF files.
var enc = binary.LittleEndian
// An ifdEntry is a single entry in an Image File Directory.
// A value of type dtRational is composed of two 32-bit values,
// thus data contains two uints (numerator and denominator) for a single number.
type ifdEntry struct {
tag int
datatype int
data []uint32
}
func (e ifdEntry) putData(p []byte) {
for _, d := range e.data {
switch e.datatype {
case dtByte, dtASCII:
p[0] = byte(d)
p = p[1:]
case dtShort:
enc.PutUint16(p, uint16(d))
p = p[2:]
case dtLong, dtRational:
enc.PutUint32(p, uint32(d))
p = p[4:]
}
}
}
type byTag []ifdEntry
func (d byTag) Len() int { return len(d) }
func (d byTag) Less(i, j int) bool { return d[i].tag < d[j].tag }
func (d byTag) Swap(i, j int) { d[i], d[j] = d[j], d[i] }
func encodeGray(w io.Writer, pix []uint8, dx, dy, stride int, predictor bool) error {
if !predictor {
return writePix(w, pix, dy, dx, stride)
}
buf := make([]byte, dx)
for y := 0; y < dy; y++ {
min := y*stride + 0
max := y*stride + dx
off := 0
var v0 uint8
for i := min; i < max; i++ {
v1 := pix[i]
buf[off] = v1 - v0
v0 = v1
off++
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
func encodeGray16(w io.Writer, pix []uint8, dx, dy, stride int, predictor bool) error {
buf := make([]byte, dx*2)
for y := 0; y < dy; y++ {
min := y*stride + 0
max := y*stride + dx*2
off := 0
var v0 uint16
for i := min; i < max; i += 2 {
// An image.Gray16's Pix is in big-endian order.
v1 := uint16(pix[i])<<8 | uint16(pix[i+1])
if predictor {
v0, v1 = v1, v1-v0
}
// We only write little-endian TIFF files.
buf[off+0] = byte(v1)
buf[off+1] = byte(v1 >> 8)
off += 2
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
func encodeRGBA(w io.Writer, pix []uint8, dx, dy, stride int, predictor bool) error {
if !predictor {
return writePix(w, pix, dy, dx*4, stride)
}
buf := make([]byte, dx*4)
for y := 0; y < dy; y++ {
min := y*stride + 0
max := y*stride + dx*4
off := 0
var r0, g0, b0, a0 uint8
for i := min; i < max; i += 4 {
r1, g1, b1, a1 := pix[i+0], pix[i+1], pix[i+2], pix[i+3]
buf[off+0] = r1 - r0
buf[off+1] = g1 - g0
buf[off+2] = b1 - b0
buf[off+3] = a1 - a0
off += 4
r0, g0, b0, a0 = r1, g1, b1, a1
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
func encodeRGBA64(w io.Writer, pix []uint8, dx, dy, stride int, predictor bool) error {
buf := make([]byte, dx*8)
for y := 0; y < dy; y++ {
min := y*stride + 0
max := y*stride + dx*8
off := 0
var r0, g0, b0, a0 uint16
for i := min; i < max; i += 8 {
// An image.RGBA64's Pix is in big-endian order.
r1 := uint16(pix[i+0])<<8 | uint16(pix[i+1])
g1 := uint16(pix[i+2])<<8 | uint16(pix[i+3])
b1 := uint16(pix[i+4])<<8 | uint16(pix[i+5])
a1 := uint16(pix[i+6])<<8 | uint16(pix[i+7])
if predictor {
r0, r1 = r1, r1-r0
g0, g1 = g1, g1-g0
b0, b1 = b1, b1-b0
a0, a1 = a1, a1-a0
}
// We only write little-endian TIFF files.
buf[off+0] = byte(r1)
buf[off+1] = byte(r1 >> 8)
buf[off+2] = byte(g1)
buf[off+3] = byte(g1 >> 8)
buf[off+4] = byte(b1)
buf[off+5] = byte(b1 >> 8)
buf[off+6] = byte(a1)
buf[off+7] = byte(a1 >> 8)
off += 8
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
func encode(w io.Writer, m image.Image, predictor bool) error {
bounds := m.Bounds()
buf := make([]byte, 4*bounds.Dx())
for y := bounds.Min.Y; y < bounds.Max.Y; y++ {
off := 0
if predictor {
var r0, g0, b0, a0 uint8
for x := bounds.Min.X; x < bounds.Max.X; x++ {
r, g, b, a := m.At(x, y).RGBA()
r1 := uint8(r >> 8)
g1 := uint8(g >> 8)
b1 := uint8(b >> 8)
a1 := uint8(a >> 8)
buf[off+0] = r1 - r0
buf[off+1] = g1 - g0
buf[off+2] = b1 - b0
buf[off+3] = a1 - a0
off += 4
r0, g0, b0, a0 = r1, g1, b1, a1
}
} else {
for x := bounds.Min.X; x < bounds.Max.X; x++ {
r, g, b, a := m.At(x, y).RGBA()
buf[off+0] = uint8(r >> 8)
buf[off+1] = uint8(g >> 8)
buf[off+2] = uint8(b >> 8)
buf[off+3] = uint8(a >> 8)
off += 4
}
}
if _, err := w.Write(buf); err != nil {
return err
}
}
return nil
}
// writePix writes the internal byte array of an image to w. It is less general
// but much faster then encode. writePix is used when pix directly
// corresponds to one of the TIFF image types.
func writePix(w io.Writer, pix []byte, nrows, length, stride int) error {
if length == stride {
_, err := w.Write(pix[:nrows*length])
return err
}
for ; nrows > 0; nrows-- {
if _, err := w.Write(pix[:length]); err != nil {
return err
}
pix = pix[stride:]
}
return nil
}
func writeIFD(w io.Writer, ifdOffset int, d []ifdEntry) error {
var buf [ifdLen]byte
// Make space for "pointer area" containing IFD entry data
// longer than 4 bytes.
parea := make([]byte, 1024)
pstart := ifdOffset + ifdLen*len(d) + 6
var o int // Current offset in parea.
// The IFD has to be written with the tags in ascending order.
sort.Sort(byTag(d))
// Write the number of entries in this IFD.
if err := binary.Write(w, enc, uint16(len(d))); err != nil {
return err
}
for _, ent := range d {
enc.PutUint16(buf[0:2], uint16(ent.tag))
enc.PutUint16(buf[2:4], uint16(ent.datatype))
count := uint32(len(ent.data))
if ent.datatype == dtRational {
count /= 2
}
enc.PutUint32(buf[4:8], count)
datalen := int(count * lengths[ent.datatype])
if datalen <= 4 {
ent.putData(buf[8:12])
} else {
if (o + datalen) > len(parea) {
newlen := len(parea) + 1024
for (o + datalen) > newlen {
newlen += 1024
}
newarea := make([]byte, newlen)
copy(newarea, parea)
parea = newarea
}
ent.putData(parea[o : o+datalen])
enc.PutUint32(buf[8:12], uint32(pstart+o))
o += datalen
}
if _, err := w.Write(buf[:]); err != nil {
return err
}
}
// The IFD ends with the offset of the next IFD in the file,
// or zero if it is the last one (page 14).
if err := binary.Write(w, enc, uint32(0)); err != nil {
return err
}
_, err := w.Write(parea[:o])
return err
}
// Options are the encoding parameters.
type Options struct {
// Compression is the type of compression used.
Compression CompressionType
// Predictor determines whether a differencing predictor is used;
// if true, instead of each pixel's color, the color difference to the
// preceding one is saved. This improves the compression for certain
// types of images and compressors. For example, it works well for
// photos with Deflate compression.
Predictor bool
}
// Encode writes the image m to w. opt determines the options used for
// encoding, such as the compression type. If opt is nil, an uncompressed
// image is written.
func Encode(w io.Writer, m image.Image, opt *Options) error {
d := m.Bounds().Size()
compression := uint32(cNone)
predictor := false
if opt != nil {
compression = opt.Compression.specValue()
// The predictor field is only used with LZW. See page 64 of the spec.
predictor = opt.Predictor && compression == cLZW
}
_, err := io.WriteString(w, leHeader)
if err != nil {
return err
}
// Compressed data is written into a buffer first, so that we
// know the compressed size.
var buf bytes.Buffer
// dst holds the destination for the pixel data of the image --
// either w or a writer to buf.
var dst io.Writer
// imageLen is the length of the pixel data in bytes.
// The offset of the IFD is imageLen + 8 header bytes.
var imageLen int
switch compression {
case cNone:
dst = w
// Write IFD offset before outputting pixel data.
switch m.(type) {
case *image.Paletted:
imageLen = d.X * d.Y * 1
case *image.Gray:
imageLen = d.X * d.Y * 1
case *image.Gray16:
imageLen = d.X * d.Y * 2
case *image.RGBA64:
imageLen = d.X * d.Y * 8
case *image.NRGBA64:
imageLen = d.X * d.Y * 8
default:
imageLen = d.X * d.Y * 4
}
err = binary.Write(w, enc, uint32(imageLen+8))
if err != nil {
return err
}
case cDeflate:
dst = zlib.NewWriter(&buf)
default:
return errors.New("tiff: unsupported compression")
}
pr := uint32(prNone)
photometricInterpretation := uint32(pRGB)
samplesPerPixel := uint32(4)
bitsPerSample := []uint32{8, 8, 8, 8}
extraSamples := uint32(0)
colorMap := []uint32{}
if predictor {
pr = prHorizontal
}
switch m := m.(type) {
case *image.Paletted:
photometricInterpretation = pPaletted
samplesPerPixel = 1
bitsPerSample = []uint32{8}
colorMap = make([]uint32, 256*3)
for i := 0; i < 256 && i < len(m.Palette); i++ {
r, g, b, _ := m.Palette[i].RGBA()
colorMap[i+0*256] = uint32(r)
colorMap[i+1*256] = uint32(g)
colorMap[i+2*256] = uint32(b)
}
err = encodeGray(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.Gray:
photometricInterpretation = pBlackIsZero
samplesPerPixel = 1
bitsPerSample = []uint32{8}
err = encodeGray(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.Gray16:
photometricInterpretation = pBlackIsZero
samplesPerPixel = 1
bitsPerSample = []uint32{16}
err = encodeGray16(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.NRGBA:
extraSamples = 2 // Unassociated alpha.
err = encodeRGBA(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.NRGBA64:
extraSamples = 2 // Unassociated alpha.
bitsPerSample = []uint32{16, 16, 16, 16}
err = encodeRGBA64(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.RGBA:
extraSamples = 1 // Associated alpha.
err = encodeRGBA(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
case *image.RGBA64:
extraSamples = 1 // Associated alpha.
bitsPerSample = []uint32{16, 16, 16, 16}
err = encodeRGBA64(dst, m.Pix, d.X, d.Y, m.Stride, predictor)
default:
extraSamples = 1 // Associated alpha.
err = encode(dst, m, predictor)
}
if err != nil {
return err
}
if compression != cNone {
if err = dst.(io.Closer).Close(); err != nil {
return err
}
imageLen = buf.Len()
if err = binary.Write(w, enc, uint32(imageLen+8)); err != nil {
return err
}
if _, err = buf.WriteTo(w); err != nil {
return err
}
}
ifd := []ifdEntry{
{tImageWidth, dtShort, []uint32{uint32(d.X)}},
{tImageLength, dtShort, []uint32{uint32(d.Y)}},
{tBitsPerSample, dtShort, bitsPerSample},
{tCompression, dtShort, []uint32{compression}},
{tPhotometricInterpretation, dtShort, []uint32{photometricInterpretation}},
{tStripOffsets, dtLong, []uint32{8}},
{tSamplesPerPixel, dtShort, []uint32{samplesPerPixel}},
{tRowsPerStrip, dtShort, []uint32{uint32(d.Y)}},
{tStripByteCounts, dtLong, []uint32{uint32(imageLen)}},
// There is currently no support for storing the image
// resolution, so give a bogus value of 72x72 dpi.
{tXResolution, dtRational, []uint32{72, 1}},
{tYResolution, dtRational, []uint32{72, 1}},
{tResolutionUnit, dtShort, []uint32{resPerInch}},
}
if pr != prNone {
ifd = append(ifd, ifdEntry{tPredictor, dtShort, []uint32{pr}})
}
if len(colorMap) != 0 {
ifd = append(ifd, ifdEntry{tColorMap, dtShort, colorMap})
}
if extraSamples > 0 {
ifd = append(ifd, ifdEntry{tExtraSamples, dtShort, []uint32{extraSamples}})
}
return writeIFD(w, imageLen+8, ifd)
}
+29
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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build !appengine && gc && !noasm
package vector
func haveSSE4_1() bool
var haveAccumulateSIMD = haveSSE4_1()
//go:noescape
func fixedAccumulateOpOverSIMD(dst []uint8, src []uint32)
//go:noescape
func fixedAccumulateOpSrcSIMD(dst []uint8, src []uint32)
//go:noescape
func fixedAccumulateMaskSIMD(buf []uint32)
//go:noescape
func floatingAccumulateOpOverSIMD(dst []uint8, src []float32)
//go:noescape
func floatingAccumulateOpSrcSIMD(dst []uint8, src []float32)
//go:noescape
func floatingAccumulateMaskSIMD(dst []uint32, src []float32)
+1028
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+16
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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:build !amd64 || appengine || !gc || noasm
package vector
const haveAccumulateSIMD = false
func fixedAccumulateOpOverSIMD(dst []uint8, src []uint32) {}
func fixedAccumulateOpSrcSIMD(dst []uint8, src []uint32) {}
func fixedAccumulateMaskSIMD(buf []uint32) {}
func floatingAccumulateOpOverSIMD(dst []uint8, src []float32) {}
func floatingAccumulateOpSrcSIMD(dst []uint8, src []float32) {}
func floatingAccumulateMaskSIMD(dst []uint32, src []float32) {}
+170
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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// +build !appengine
// +build gc
// +build !noasm
#include "textflag.h"
// fl is short for floating point math. fx is short for fixed point math.
DATA flAlmost65536<>+0x00(SB)/8, $0x477fffff477fffff
DATA flAlmost65536<>+0x08(SB)/8, $0x477fffff477fffff
DATA flOne<>+0x00(SB)/8, $0x3f8000003f800000
DATA flOne<>+0x08(SB)/8, $0x3f8000003f800000
DATA flSignMask<>+0x00(SB)/8, $0x7fffffff7fffffff
DATA flSignMask<>+0x08(SB)/8, $0x7fffffff7fffffff
// scatterAndMulBy0x101 is a PSHUFB mask that brings the low four bytes of an
// XMM register to the low byte of that register's four uint32 values. It
// duplicates those bytes, effectively multiplying each uint32 by 0x101.
//
// It transforms a little-endian 16-byte XMM value from
// ijkl????????????
// to
// ii00jj00kk00ll00
DATA scatterAndMulBy0x101<>+0x00(SB)/8, $0x8080010180800000
DATA scatterAndMulBy0x101<>+0x08(SB)/8, $0x8080030380800202
// gather is a PSHUFB mask that brings the second-lowest byte of the XMM
// register's four uint32 values to the low four bytes of that register.
//
// It transforms a little-endian 16-byte XMM value from
// ?i???j???k???l??
// to
// ijkl000000000000
DATA gather<>+0x00(SB)/8, $0x808080800d090501
DATA gather<>+0x08(SB)/8, $0x8080808080808080
DATA fxAlmost65536<>+0x00(SB)/8, $0x0000ffff0000ffff
DATA fxAlmost65536<>+0x08(SB)/8, $0x0000ffff0000ffff
DATA inverseFFFF<>+0x00(SB)/8, $0x8000800180008001
DATA inverseFFFF<>+0x08(SB)/8, $0x8000800180008001
GLOBL flAlmost65536<>(SB), (NOPTR+RODATA), $16
GLOBL flOne<>(SB), (NOPTR+RODATA), $16
GLOBL flSignMask<>(SB), (NOPTR+RODATA), $16
GLOBL scatterAndMulBy0x101<>(SB), (NOPTR+RODATA), $16
GLOBL gather<>(SB), (NOPTR+RODATA), $16
GLOBL fxAlmost65536<>(SB), (NOPTR+RODATA), $16
GLOBL inverseFFFF<>(SB), (NOPTR+RODATA), $16
// func haveSSE4_1() bool
TEXT ·haveSSE4_1(SB), NOSPLIT, $0
MOVQ $1, AX
CPUID
SHRQ $19, CX
ANDQ $1, CX
MOVB CX, ret+0(FP)
RET
// ----------------------------------------------------------------------------
// func {{.LongName}}SIMD({{.Args}})
//
// XMM registers. Variable names are per
// https://github.com/google/font-rs/blob/master/src/accumulate.c
//
// xmm0 scratch
// xmm1 x
// xmm2 y, z
// xmm3 {{.XMM3}}
// xmm4 {{.XMM4}}
// xmm5 {{.XMM5}}
// xmm6 {{.XMM6}}
// xmm7 offset
// xmm8 {{.XMM8}}
// xmm9 {{.XMM9}}
// xmm10 {{.XMM10}}
TEXT ·{{.LongName}}SIMD(SB), NOSPLIT, ${{.FrameSize}}-{{.ArgsSize}}
{{.LoadArgs}}
// R10 = len(src) &^ 3
// R11 = len(src)
MOVQ R10, R11
ANDQ $-4, R10
{{.Setup}}
{{.LoadXMMRegs}}
// offset := XMM(0x00000000 repeated four times) // Cumulative sum.
XORPS X7, X7
// i := 0
MOVQ $0, R9
{{.ShortName}}Loop4:
// for i < (len(src) &^ 3)
CMPQ R9, R10
JAE {{.ShortName}}Loop1
// x = XMM(s0, s1, s2, s3)
//
// Where s0 is src[i+0], s1 is src[i+1], etc.
MOVOU (SI), X1
// scratch = XMM(0, s0, s1, s2)
// x += scratch // yields x == XMM(s0, s0+s1, s1+s2, s2+s3)
MOVOU X1, X0
PSLLO $4, X0
{{.Add}} X0, X1
// scratch = XMM(0, 0, 0, 0)
// scratch = XMM(scratch@0, scratch@0, x@0, x@1) // yields scratch == XMM(0, 0, s0, s0+s1)
// x += scratch // yields x == XMM(s0, s0+s1, s0+s1+s2, s0+s1+s2+s3)
XORPS X0, X0
SHUFPS $0x40, X1, X0
{{.Add}} X0, X1
// x += offset
{{.Add}} X7, X1
{{.ClampAndScale}}
{{.ConvertToInt32}}
{{.Store4}}
// offset = XMM(x@3, x@3, x@3, x@3)
MOVOU X1, X7
SHUFPS $0xff, X1, X7
// i += 4
// dst = dst[4:]
// src = src[4:]
ADDQ $4, R9
ADDQ ${{.DstElemSize4}}, DI
ADDQ $16, SI
JMP {{.ShortName}}Loop4
{{.ShortName}}Loop1:
// for i < len(src)
CMPQ R9, R11
JAE {{.ShortName}}End
// x = src[i] + offset
MOVL (SI), X1
{{.Add}} X7, X1
{{.ClampAndScale}}
{{.ConvertToInt32}}
{{.Store1}}
// offset = x
MOVOU X1, X7
// i += 1
// dst = dst[1:]
// src = src[1:]
ADDQ $1, R9
ADDQ ${{.DstElemSize1}}, DI
ADDQ $4, SI
JMP {{.ShortName}}Loop1
{{.ShortName}}End:
RET
+330
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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vector
// This file contains a fixed point math implementation of the vector
// graphics rasterizer.
const (
// ϕ is the number of binary digits after the fixed point.
//
// For example, if ϕ == 10 (and int1ϕ is based on the int32 type) then we
// are using 22.10 fixed point math.
//
// When changing this number, also change the assembly code (search for ϕ
// in the .s files).
ϕ = 9
fxOne int1ϕ = 1 << ϕ
fxOneAndAHalf int1ϕ = 1<<ϕ + 1<<(ϕ-1)
fxOneMinusIota int1ϕ = 1<<ϕ - 1 // Used for rounding up.
)
// int1ϕ is a signed fixed-point number with 1*ϕ binary digits after the fixed
// point.
type int1ϕ int32
// int2ϕ is a signed fixed-point number with 2*ϕ binary digits after the fixed
// point.
//
// The Rasterizer's bufU32 field, nominally of type []uint32 (since that slice
// is also used by other code), can be thought of as a []int2ϕ during the
// fixedLineTo method. Lines of code that are actually like:
//
// buf[i] += uint32(etc) // buf has type []uint32.
//
// can be thought of as
//
// buf[i] += int2ϕ(etc) // buf has type []int2ϕ.
type int2ϕ int32
func fixedMax(x, y int1ϕ) int1ϕ {
if x > y {
return x
}
return y
}
func fixedMin(x, y int1ϕ) int1ϕ {
if x < y {
return x
}
return y
}
func fixedFloor(x int1ϕ) int32 { return int32(x >> ϕ) }
func fixedCeil(x int1ϕ) int32 { return int32((x + fxOneMinusIota) >> ϕ) }
func (z *Rasterizer) fixedLineTo(bx, by float32) {
ax, ay := z.penX, z.penY
z.penX, z.penY = bx, by
dir := int1ϕ(1)
if ay > by {
dir, ax, ay, bx, by = -1, bx, by, ax, ay
}
// Horizontal line segments yield no change in coverage. Almost horizontal
// segments would yield some change, in ideal math, but the computation
// further below, involving 1 / (by - ay), is unstable in fixed point math,
// so we treat the segment as if it was perfectly horizontal.
if by-ay <= 0.000001 {
return
}
dxdy := (bx - ax) / (by - ay)
ayϕ := int1ϕ(ay * float32(fxOne))
byϕ := int1ϕ(by * float32(fxOne))
x := int1ϕ(ax * float32(fxOne))
y := fixedFloor(ayϕ)
yMax := fixedCeil(byϕ)
if yMax > int32(z.size.Y) {
yMax = int32(z.size.Y)
}
width := int32(z.size.X)
for ; y < yMax; y++ {
dy := fixedMin(int1ϕ(y+1)<<ϕ, byϕ) - fixedMax(int1ϕ(y)<<ϕ, ayϕ)
xNext := x + int1ϕ(float32(dy)*dxdy)
if y < 0 {
x = xNext
continue
}
buf := z.bufU32[y*width:]
d := dy * dir // d ranges up to ±1<<(1*ϕ).
x0, x1 := x, xNext
if x > xNext {
x0, x1 = x1, x0
}
x0i := fixedFloor(x0)
x0Floor := int1ϕ(x0i) << ϕ
x1i := fixedCeil(x1)
x1Ceil := int1ϕ(x1i) << ϕ
if x1i <= x0i+1 {
xmf := (x+xNext)>>1 - x0Floor
if i := clamp(x0i+0, width); i < uint(len(buf)) {
buf[i] += uint32(d * (fxOne - xmf))
}
if i := clamp(x0i+1, width); i < uint(len(buf)) {
buf[i] += uint32(d * xmf)
}
} else {
oneOverS := x1 - x0
twoOverS := 2 * oneOverS
x0f := x0 - x0Floor
oneMinusX0f := fxOne - x0f
oneMinusX0fSquared := oneMinusX0f * oneMinusX0f
x1f := x1 - x1Ceil + fxOne
x1fSquared := x1f * x1f
// These next two variables are unused, as rounding errors are
// minimized when we delay the division by oneOverS for as long as
// possible. These lines of code (and the "In ideal math" comments
// below) are commented out instead of deleted in order to aid the
// comparison with the floating point version of the rasterizer.
//
// a0 := ((oneMinusX0f * oneMinusX0f) >> 1) / oneOverS
// am := ((x1f * x1f) >> 1) / oneOverS
if i := clamp(x0i, width); i < uint(len(buf)) {
// In ideal math: buf[i] += uint32(d * a0)
D := oneMinusX0fSquared // D ranges up to ±1<<(2*ϕ).
D *= d // D ranges up to ±1<<(3*ϕ).
D /= twoOverS
buf[i] += uint32(D)
}
if x1i == x0i+2 {
if i := clamp(x0i+1, width); i < uint(len(buf)) {
// In ideal math: buf[i] += uint32(d * (fxOne - a0 - am))
//
// (x1i == x0i+2) and (twoOverS == 2 * (x1 - x0)) implies
// that twoOverS ranges up to +1<<(1*ϕ+2).
D := twoOverS<<ϕ - oneMinusX0fSquared - x1fSquared // D ranges up to ±1<<(2*ϕ+2).
D *= d // D ranges up to ±1<<(3*ϕ+2).
D /= twoOverS
buf[i] += uint32(D)
}
} else {
// This is commented out for the same reason as a0 and am.
//
// a1 := ((fxOneAndAHalf - x0f) << ϕ) / oneOverS
if i := clamp(x0i+1, width); i < uint(len(buf)) {
// In ideal math:
// buf[i] += uint32(d * (a1 - a0))
// or equivalently (but better in non-ideal, integer math,
// with respect to rounding errors),
// buf[i] += uint32(A * d / twoOverS)
// where
// A = (a1 - a0) * twoOverS
// = a1*twoOverS - a0*twoOverS
// Noting that twoOverS/oneOverS equals 2, substituting for
// a0 and then a1, given above, yields:
// A = a1*twoOverS - oneMinusX0fSquared
// = (fxOneAndAHalf-x0f)<<(ϕ+1) - oneMinusX0fSquared
// = fxOneAndAHalf<<(ϕ+1) - x0f<<(ϕ+1) - oneMinusX0fSquared
//
// This is a positive number minus two non-negative
// numbers. For an upper bound on A, the positive number is
// P = fxOneAndAHalf<<(ϕ+1)
// < (2*fxOne)<<(ϕ+1)
// = fxOne<<(ϕ+2)
// = 1<<(2*ϕ+2)
//
// For a lower bound on A, the two non-negative numbers are
// N = x0f<<(ϕ+1) + oneMinusX0fSquared
// ≤ x0f<<(ϕ+1) + fxOne*fxOne
// = x0f<<(ϕ+1) + 1<<(2*ϕ)
// < x0f<<(ϕ+1) + 1<<(2*ϕ+1)
// ≤ fxOne<<(ϕ+1) + 1<<(2*ϕ+1)
// = 1<<(2*ϕ+1) + 1<<(2*ϕ+1)
// = 1<<(2*ϕ+2)
//
// Thus, A ranges up to ±1<<(2*ϕ+2). It is possible to
// derive a tighter bound, but this bound is sufficient to
// reason about overflow.
D := (fxOneAndAHalf-x0f)<<(ϕ+1) - oneMinusX0fSquared // D ranges up to ±1<<(2*ϕ+2).
D *= d // D ranges up to ±1<<(3*ϕ+2).
D /= twoOverS
buf[i] += uint32(D)
}
dTimesS := uint32((d << (2 * ϕ)) / oneOverS)
for xi := x0i + 2; xi < x1i-1; xi++ {
if i := clamp(xi, width); i < uint(len(buf)) {
buf[i] += dTimesS
}
}
// This is commented out for the same reason as a0 and am.
//
// a2 := a1 + (int1ϕ(x1i-x0i-3)<<(2*ϕ))/oneOverS
if i := clamp(x1i-1, width); i < uint(len(buf)) {
// In ideal math:
// buf[i] += uint32(d * (fxOne - a2 - am))
// or equivalently (but better in non-ideal, integer math,
// with respect to rounding errors),
// buf[i] += uint32(A * d / twoOverS)
// where
// A = (fxOne - a2 - am) * twoOverS
// = twoOverS<<ϕ - a2*twoOverS - am*twoOverS
// Noting that twoOverS/oneOverS equals 2, substituting for
// am and then a2, given above, yields:
// A = twoOverS<<ϕ - a2*twoOverS - x1f*x1f
// = twoOverS<<ϕ - a1*twoOverS - (int1ϕ(x1i-x0i-3)<<(2*ϕ))*2 - x1f*x1f
// = twoOverS<<ϕ - a1*twoOverS - int1ϕ(x1i-x0i-3)<<(2*ϕ+1) - x1f*x1f
// Substituting for a1, given above, yields:
// A = twoOverS<<ϕ - ((fxOneAndAHalf-x0f)<<ϕ)*2 - int1ϕ(x1i-x0i-3)<<(2*ϕ+1) - x1f*x1f
// = twoOverS<<ϕ - (fxOneAndAHalf-x0f)<<(ϕ+1) - int1ϕ(x1i-x0i-3)<<(2*ϕ+1) - x1f*x1f
// = B<<ϕ - x1f*x1f
// where
// B = twoOverS - (fxOneAndAHalf-x0f)<<1 - int1ϕ(x1i-x0i-3)<<(ϕ+1)
// = (x1-x0)<<1 - (fxOneAndAHalf-x0f)<<1 - int1ϕ(x1i-x0i-3)<<(ϕ+1)
//
// Re-arranging the defintions given above:
// x0Floor := int1ϕ(x0i) << ϕ
// x0f := x0 - x0Floor
// x1Ceil := int1ϕ(x1i) << ϕ
// x1f := x1 - x1Ceil + fxOne
// combined with fxOne = 1<<ϕ yields:
// x0 = x0f + int1ϕ(x0i)<<ϕ
// x1 = x1f + int1ϕ(x1i-1)<<ϕ
// so that expanding (x1-x0) yields:
// B = (x1f-x0f + int1ϕ(x1i-x0i-1)<<ϕ)<<1 - (fxOneAndAHalf-x0f)<<1 - int1ϕ(x1i-x0i-3)<<(ϕ+1)
// = (x1f-x0f)<<1 + int1ϕ(x1i-x0i-1)<<(ϕ+1) - (fxOneAndAHalf-x0f)<<1 - int1ϕ(x1i-x0i-3)<<(ϕ+1)
// A large part of the second and fourth terms cancel:
// B = (x1f-x0f)<<1 - (fxOneAndAHalf-x0f)<<1 - int1ϕ(-2)<<(ϕ+1)
// = (x1f-x0f)<<1 - (fxOneAndAHalf-x0f)<<1 + 1<<(ϕ+2)
// = (x1f - fxOneAndAHalf)<<1 + 1<<(ϕ+2)
// The first term, (x1f - fxOneAndAHalf)<<1, is a negative
// number, bounded below by -fxOneAndAHalf<<1, which is
// greater than -fxOne<<2, or -1<<(ϕ+2). Thus, B ranges up
// to ±1<<(ϕ+2). One final simplification:
// B = x1f<<1 + (1<<(ϕ+2) - fxOneAndAHalf<<1)
const C = 1<<(ϕ+2) - fxOneAndAHalf<<1
D := x1f<<1 + C // D ranges up to ±1<<(1*ϕ+2).
D <<= ϕ // D ranges up to ±1<<(2*ϕ+2).
D -= x1fSquared // D ranges up to ±1<<(2*ϕ+3).
D *= d // D ranges up to ±1<<(3*ϕ+3).
D /= twoOverS
buf[i] += uint32(D)
}
}
if i := clamp(x1i, width); i < uint(len(buf)) {
// In ideal math: buf[i] += uint32(d * am)
D := x1fSquared // D ranges up to ±1<<(2*ϕ).
D *= d // D ranges up to ±1<<(3*ϕ).
D /= twoOverS
buf[i] += uint32(D)
}
}
x = xNext
}
}
func fixedAccumulateOpOver(dst []uint8, src []uint32) {
// Sanity check that len(dst) >= len(src).
if len(dst) < len(src) {
return
}
acc := int2ϕ(0)
for i, v := range src {
acc += int2ϕ(v)
a := acc
if a < 0 {
a = -a
}
a >>= 2*ϕ - 16
if a > 0xffff {
a = 0xffff
}
// This algorithm comes from the standard library's image/draw package.
dstA := uint32(dst[i]) * 0x101
maskA := uint32(a)
outA := dstA*(0xffff-maskA)/0xffff + maskA
dst[i] = uint8(outA >> 8)
}
}
func fixedAccumulateOpSrc(dst []uint8, src []uint32) {
// Sanity check that len(dst) >= len(src).
if len(dst) < len(src) {
return
}
acc := int2ϕ(0)
for i, v := range src {
acc += int2ϕ(v)
a := acc
if a < 0 {
a = -a
}
a >>= 2*ϕ - 8
if a > 0xff {
a = 0xff
}
dst[i] = uint8(a)
}
}
func fixedAccumulateMask(buf []uint32) {
acc := int2ϕ(0)
for i, v := range buf {
acc += int2ϕ(v)
a := acc
if a < 0 {
a = -a
}
a >>= 2*ϕ - 16
if a > 0xffff {
a = 0xffff
}
buf[i] = uint32(a)
}
}
+220
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// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package vector
// This file contains a floating point math implementation of the vector
// graphics rasterizer.
import (
"math"
)
func floatingMax(x, y float32) float32 {
if x > y {
return x
}
return y
}
func floatingMin(x, y float32) float32 {
if x < y {
return x
}
return y
}
func floatingFloor(x float32) int32 { return int32(math.Floor(float64(x))) }
func floatingCeil(x float32) int32 { return int32(math.Ceil(float64(x))) }
func (z *Rasterizer) floatingLineTo(bx, by float32) {
ax, ay := z.penX, z.penY
z.penX, z.penY = bx, by
dir := float32(1)
if ay > by {
dir, ax, ay, bx, by = -1, bx, by, ax, ay
}
// Horizontal line segments yield no change in coverage. Almost horizontal
// segments would yield some change, in ideal math, but the computation
// further below, involving 1 / (by - ay), is unstable in floating point
// math, so we treat the segment as if it was perfectly horizontal.
if by-ay <= 0.000001 {
return
}
dxdy := (bx - ax) / (by - ay)
x := ax
y := floatingFloor(ay)
yMax := floatingCeil(by)
if yMax > int32(z.size.Y) {
yMax = int32(z.size.Y)
}
width := int32(z.size.X)
for ; y < yMax; y++ {
dy := floatingMin(float32(y+1), by) - floatingMax(float32(y), ay)
// The "float32" in expressions like "float32(foo*bar)" here and below
// look redundant, since foo and bar already have type float32, but are
// explicit in order to disable the compiler's Fused Multiply Add (FMA)
// instruction selection, which can improve performance but can result
// in different rounding errors in floating point computations.
//
// This package aims to have bit-exact identical results across all
// GOARCHes, and across pure Go code and assembly, so it disables FMA.
//
// See the discussion at
// https://groups.google.com/d/topic/golang-dev/Sti0bl2xUXQ/discussion
xNext := x + float32(dy*dxdy)
if y < 0 {
x = xNext
continue
}
buf := z.bufF32[y*width:]
d := float32(dy * dir)
x0, x1 := x, xNext
if x > xNext {
x0, x1 = x1, x0
}
x0i := floatingFloor(x0)
x0Floor := float32(x0i)
x1i := floatingCeil(x1)
x1Ceil := float32(x1i)
if x1i <= x0i+1 {
xmf := float32(0.5*(x+xNext)) - x0Floor
if i := clamp(x0i+0, width); i < uint(len(buf)) {
buf[i] += d - float32(d*xmf)
}
if i := clamp(x0i+1, width); i < uint(len(buf)) {
buf[i] += float32(d * xmf)
}
} else {
s := 1 / (x1 - x0)
x0f := x0 - x0Floor
oneMinusX0f := 1 - x0f
a0 := float32(0.5 * s * oneMinusX0f * oneMinusX0f)
x1f := x1 - x1Ceil + 1
am := float32(0.5 * s * x1f * x1f)
if i := clamp(x0i, width); i < uint(len(buf)) {
buf[i] += float32(d * a0)
}
if x1i == x0i+2 {
if i := clamp(x0i+1, width); i < uint(len(buf)) {
buf[i] += float32(d * (1 - a0 - am))
}
} else {
a1 := float32(s * (1.5 - x0f))
if i := clamp(x0i+1, width); i < uint(len(buf)) {
buf[i] += float32(d * (a1 - a0))
}
dTimesS := float32(d * s)
for xi := x0i + 2; xi < x1i-1; xi++ {
if i := clamp(xi, width); i < uint(len(buf)) {
buf[i] += dTimesS
}
}
a2 := a1 + float32(s*float32(x1i-x0i-3))
if i := clamp(x1i-1, width); i < uint(len(buf)) {
buf[i] += float32(d * (1 - a2 - am))
}
}
if i := clamp(x1i, width); i < uint(len(buf)) {
buf[i] += float32(d * am)
}
}
x = xNext
}
}
const (
// almost256 scales a floating point value in the range [0, 1] to a uint8
// value in the range [0x00, 0xff].
//
// 255 is too small. Floating point math accumulates rounding errors, so a
// fully covered src value that would in ideal math be float32(1) might be
// float32(1-ε), and uint8(255 * (1-ε)) would be 0xfe instead of 0xff. The
// uint8 conversion rounds to zero, not to nearest.
//
// 256 is too big. If we multiplied by 256, below, then a fully covered src
// value of float32(1) would translate to uint8(256 * 1), which can be 0x00
// instead of the maximal value 0xff.
//
// math.Float32bits(almost256) is 0x437fffff.
almost256 = 255.99998
// almost65536 scales a floating point value in the range [0, 1] to a
// uint16 value in the range [0x0000, 0xffff].
//
// math.Float32bits(almost65536) is 0x477fffff.
almost65536 = almost256 * 256
)
func floatingAccumulateOpOver(dst []uint8, src []float32) {
// Sanity check that len(dst) >= len(src).
if len(dst) < len(src) {
return
}
acc := float32(0)
for i, v := range src {
acc += v
a := acc
if a < 0 {
a = -a
}
if a > 1 {
a = 1
}
// This algorithm comes from the standard library's image/draw package.
dstA := uint32(dst[i]) * 0x101
maskA := uint32(almost65536 * a)
outA := dstA*(0xffff-maskA)/0xffff + maskA
dst[i] = uint8(outA >> 8)
}
}
func floatingAccumulateOpSrc(dst []uint8, src []float32) {
// Sanity check that len(dst) >= len(src).
if len(dst) < len(src) {
return
}
acc := float32(0)
for i, v := range src {
acc += v
a := acc
if a < 0 {
a = -a
}
if a > 1 {
a = 1
}
dst[i] = uint8(almost256 * a)
}
}
func floatingAccumulateMask(dst []uint32, src []float32) {
// Sanity check that len(dst) >= len(src).
if len(dst) < len(src) {
return
}
acc := float32(0)
for i, v := range src {
acc += v
a := acc
if a < 0 {
a = -a
}
if a > 1 {
a = 1
}
dst[i] = uint32(almost65536 * a)
}
}
+472
View File
@@ -0,0 +1,472 @@
// Copyright 2016 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
//go:generate go run gen.go
//go:generate asmfmt -w acc_amd64.s
// asmfmt is https://github.com/klauspost/asmfmt
// Package vector provides a rasterizer for 2-D vector graphics.
package vector // import "golang.org/x/image/vector"
// The rasterizer's design follows
// https://medium.com/@raphlinus/inside-the-fastest-font-renderer-in-the-world-75ae5270c445
//
// Proof of concept code is in
// https://github.com/google/font-go
//
// See also:
// http://nothings.org/gamedev/rasterize/
// http://projects.tuxee.net/cl-vectors/section-the-cl-aa-algorithm
// https://people.gnome.org/~mathieu/libart/internals.html#INTERNALS-SCANLINE
import (
"image"
"image/color"
"image/draw"
"math"
)
// floatingPointMathThreshold is the width or height above which the rasterizer
// chooses to used floating point math instead of fixed point math.
//
// Both implementations of line segmentation rasterization (see raster_fixed.go
// and raster_floating.go) implement the same algorithm (in ideal, infinite
// precision math) but they perform differently in practice. The fixed point
// math version is roughtly 1.25x faster (on GOARCH=amd64) on the benchmarks,
// but at sufficiently large scales, the computations will overflow and hence
// show rendering artifacts. The floating point math version has more
// consistent quality over larger scales, but it is significantly slower.
//
// This constant determines when to use the faster implementation and when to
// use the better quality implementation.
//
// The rationale for this particular value is that TestRasterizePolygon in
// vector_test.go checks the rendering quality of polygon edges at various
// angles, inscribed in a circle of diameter 512. It may be that a higher value
// would still produce acceptable quality, but 512 seems to work.
const floatingPointMathThreshold = 512
func lerp(t, px, py, qx, qy float32) (x, y float32) {
return px + t*(qx-px), py + t*(qy-py)
}
func clamp(i, width int32) uint {
if i < 0 {
return 0
}
if i < width {
return uint(i)
}
return uint(width)
}
// NewRasterizer returns a new Rasterizer whose rendered mask image is bounded
// by the given width and height.
func NewRasterizer(w, h int) *Rasterizer {
z := &Rasterizer{}
z.Reset(w, h)
return z
}
// Raster is a 2-D vector graphics rasterizer.
//
// The zero value is usable, in that it is a Rasterizer whose rendered mask
// image has zero width and zero height. Call Reset to change its bounds.
type Rasterizer struct {
// bufXxx are buffers of float32 or uint32 values, holding either the
// individual or cumulative area values.
//
// We don't actually need both values at any given time, and to conserve
// memory, the integration of the individual to the cumulative could modify
// the buffer in place. In other words, we could use a single buffer, say
// of type []uint32, and add some math.Float32bits and math.Float32frombits
// calls to satisfy the compiler's type checking. As of Go 1.7, though,
// there is a performance penalty between:
// bufF32[i] += x
// and
// bufU32[i] = math.Float32bits(x + math.Float32frombits(bufU32[i]))
//
// See golang.org/issue/17220 for some discussion.
bufF32 []float32
bufU32 []uint32
useFloatingPointMath bool
size image.Point
firstX float32
firstY float32
penX float32
penY float32
// DrawOp is the operator used for the Draw method.
//
// The zero value is draw.Over.
DrawOp draw.Op
// TODO: an exported field equivalent to the mask point in the
// draw.DrawMask function in the stdlib image/draw package?
}
// Reset resets a Rasterizer as if it was just returned by NewRasterizer.
//
// This includes setting z.DrawOp to draw.Over.
func (z *Rasterizer) Reset(w, h int) {
z.size = image.Point{w, h}
z.firstX = 0
z.firstY = 0
z.penX = 0
z.penY = 0
z.DrawOp = draw.Over
z.setUseFloatingPointMath(w > floatingPointMathThreshold || h > floatingPointMathThreshold)
}
func (z *Rasterizer) setUseFloatingPointMath(b bool) {
z.useFloatingPointMath = b
// Make z.bufF32 or z.bufU32 large enough to hold width * height samples.
if z.useFloatingPointMath {
if n := z.size.X * z.size.Y; n > cap(z.bufF32) {
z.bufF32 = make([]float32, n)
} else {
z.bufF32 = z.bufF32[:n]
for i := range z.bufF32 {
z.bufF32[i] = 0
}
}
} else {
if n := z.size.X * z.size.Y; n > cap(z.bufU32) {
z.bufU32 = make([]uint32, n)
} else {
z.bufU32 = z.bufU32[:n]
for i := range z.bufU32 {
z.bufU32[i] = 0
}
}
}
}
// Size returns the width and height passed to NewRasterizer or Reset.
func (z *Rasterizer) Size() image.Point {
return z.size
}
// Bounds returns the rectangle from (0, 0) to the width and height passed to
// NewRasterizer or Reset.
func (z *Rasterizer) Bounds() image.Rectangle {
return image.Rectangle{Max: z.size}
}
// Pen returns the location of the path-drawing pen: the last argument to the
// most recent XxxTo call.
func (z *Rasterizer) Pen() (x, y float32) {
return z.penX, z.penY
}
// ClosePath closes the current path.
func (z *Rasterizer) ClosePath() {
z.LineTo(z.firstX, z.firstY)
}
// MoveTo starts a new path and moves the pen to (ax, ay).
//
// The coordinates are allowed to be out of the Rasterizer's bounds.
func (z *Rasterizer) MoveTo(ax, ay float32) {
z.firstX = ax
z.firstY = ay
z.penX = ax
z.penY = ay
}
// LineTo adds a line segment, from the pen to (bx, by), and moves the pen to
// (bx, by).
//
// The coordinates are allowed to be out of the Rasterizer's bounds.
func (z *Rasterizer) LineTo(bx, by float32) {
if z.useFloatingPointMath {
z.floatingLineTo(bx, by)
} else {
z.fixedLineTo(bx, by)
}
}
// QuadTo adds a quadratic Bézier segment, from the pen via (bx, by) to (cx,
// cy), and moves the pen to (cx, cy).
//
// The coordinates are allowed to be out of the Rasterizer's bounds.
func (z *Rasterizer) QuadTo(bx, by, cx, cy float32) {
ax, ay := z.penX, z.penY
devsq := devSquared(ax, ay, bx, by, cx, cy)
if devsq >= 0.333 {
const tol = 3
n := 1 + int(math.Sqrt(math.Sqrt(tol*float64(devsq))))
t, nInv := float32(0), 1/float32(n)
for i := 0; i < n-1; i++ {
t += nInv
abx, aby := lerp(t, ax, ay, bx, by)
bcx, bcy := lerp(t, bx, by, cx, cy)
z.LineTo(lerp(t, abx, aby, bcx, bcy))
}
}
z.LineTo(cx, cy)
}
// CubeTo adds a cubic Bézier segment, from the pen via (bx, by) and (cx, cy)
// to (dx, dy), and moves the pen to (dx, dy).
//
// The coordinates are allowed to be out of the Rasterizer's bounds.
func (z *Rasterizer) CubeTo(bx, by, cx, cy, dx, dy float32) {
ax, ay := z.penX, z.penY
devsq := devSquared(ax, ay, bx, by, dx, dy)
if devsqAlt := devSquared(ax, ay, cx, cy, dx, dy); devsq < devsqAlt {
devsq = devsqAlt
}
if devsq >= 0.333 {
const tol = 3
n := 1 + int(math.Sqrt(math.Sqrt(tol*float64(devsq))))
t, nInv := float32(0), 1/float32(n)
for i := 0; i < n-1; i++ {
t += nInv
abx, aby := lerp(t, ax, ay, bx, by)
bcx, bcy := lerp(t, bx, by, cx, cy)
cdx, cdy := lerp(t, cx, cy, dx, dy)
abcx, abcy := lerp(t, abx, aby, bcx, bcy)
bcdx, bcdy := lerp(t, bcx, bcy, cdx, cdy)
z.LineTo(lerp(t, abcx, abcy, bcdx, bcdy))
}
}
z.LineTo(dx, dy)
}
// devSquared returns a measure of how curvy the sequence (ax, ay) to (bx, by)
// to (cx, cy) is. It determines how many line segments will approximate a
// Bézier curve segment.
//
// http://lists.nongnu.org/archive/html/freetype-devel/2016-08/msg00080.html
// gives the rationale for this evenly spaced heuristic instead of a recursive
// de Casteljau approach:
//
// The reason for the subdivision by n is that I expect the "flatness"
// computation to be semi-expensive (it's done once rather than on each
// potential subdivision) and also because you'll often get fewer subdivisions.
// Taking a circular arc as a simplifying assumption (ie a spherical cow),
// where I get n, a recursive approach would get 2^⌈lg n⌉, which, if I haven't
// made any horrible mistakes, is expected to be 33% more in the limit.
func devSquared(ax, ay, bx, by, cx, cy float32) float32 {
devx := ax - 2*bx + cx
devy := ay - 2*by + cy
return devx*devx + devy*devy
}
// Draw implements the Drawer interface from the standard library's image/draw
// package.
//
// The vector paths previously added via the XxxTo calls become the mask for
// drawing src onto dst.
func (z *Rasterizer) Draw(dst draw.Image, r image.Rectangle, src image.Image, sp image.Point) {
// TODO: adjust r and sp (and mp?) if src.Bounds() doesn't contain
// r.Add(sp.Sub(r.Min)).
if src, ok := src.(*image.Uniform); ok {
srcR, srcG, srcB, srcA := src.RGBA()
switch dst := dst.(type) {
case *image.Alpha:
// Fast path for glyph rendering.
if srcA == 0xffff {
if z.DrawOp == draw.Over {
z.rasterizeDstAlphaSrcOpaqueOpOver(dst, r)
} else {
z.rasterizeDstAlphaSrcOpaqueOpSrc(dst, r)
}
return
}
case *image.RGBA:
if z.DrawOp == draw.Over {
z.rasterizeDstRGBASrcUniformOpOver(dst, r, srcR, srcG, srcB, srcA)
} else {
z.rasterizeDstRGBASrcUniformOpSrc(dst, r, srcR, srcG, srcB, srcA)
}
return
}
}
if z.DrawOp == draw.Over {
z.rasterizeOpOver(dst, r, src, sp)
} else {
z.rasterizeOpSrc(dst, r, src, sp)
}
}
func (z *Rasterizer) accumulateMask() {
if z.useFloatingPointMath {
if n := z.size.X * z.size.Y; n > cap(z.bufU32) {
z.bufU32 = make([]uint32, n)
} else {
z.bufU32 = z.bufU32[:n]
}
if haveAccumulateSIMD {
floatingAccumulateMaskSIMD(z.bufU32, z.bufF32)
} else {
floatingAccumulateMask(z.bufU32, z.bufF32)
}
} else {
if haveAccumulateSIMD {
fixedAccumulateMaskSIMD(z.bufU32)
} else {
fixedAccumulateMask(z.bufU32)
}
}
}
func (z *Rasterizer) rasterizeDstAlphaSrcOpaqueOpOver(dst *image.Alpha, r image.Rectangle) {
// TODO: non-zero vs even-odd winding?
if r == dst.Bounds() && r == z.Bounds() {
// We bypass the z.accumulateMask step and convert straight from
// z.bufF32 or z.bufU32 to dst.Pix.
if z.useFloatingPointMath {
if haveAccumulateSIMD {
floatingAccumulateOpOverSIMD(dst.Pix, z.bufF32)
} else {
floatingAccumulateOpOver(dst.Pix, z.bufF32)
}
} else {
if haveAccumulateSIMD {
fixedAccumulateOpOverSIMD(dst.Pix, z.bufU32)
} else {
fixedAccumulateOpOver(dst.Pix, z.bufU32)
}
}
return
}
z.accumulateMask()
pix := dst.Pix[dst.PixOffset(r.Min.X, r.Min.Y):]
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
ma := z.bufU32[y*z.size.X+x]
i := y*dst.Stride + x
// This formula is like rasterizeOpOver's, simplified for the
// concrete dst type and opaque src assumption.
a := 0xffff - ma
pix[i] = uint8((uint32(pix[i])*0x101*a/0xffff + ma) >> 8)
}
}
}
func (z *Rasterizer) rasterizeDstAlphaSrcOpaqueOpSrc(dst *image.Alpha, r image.Rectangle) {
// TODO: non-zero vs even-odd winding?
if r == dst.Bounds() && r == z.Bounds() {
// We bypass the z.accumulateMask step and convert straight from
// z.bufF32 or z.bufU32 to dst.Pix.
if z.useFloatingPointMath {
if haveAccumulateSIMD {
floatingAccumulateOpSrcSIMD(dst.Pix, z.bufF32)
} else {
floatingAccumulateOpSrc(dst.Pix, z.bufF32)
}
} else {
if haveAccumulateSIMD {
fixedAccumulateOpSrcSIMD(dst.Pix, z.bufU32)
} else {
fixedAccumulateOpSrc(dst.Pix, z.bufU32)
}
}
return
}
z.accumulateMask()
pix := dst.Pix[dst.PixOffset(r.Min.X, r.Min.Y):]
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
ma := z.bufU32[y*z.size.X+x]
// This formula is like rasterizeOpSrc's, simplified for the
// concrete dst type and opaque src assumption.
pix[y*dst.Stride+x] = uint8(ma >> 8)
}
}
}
func (z *Rasterizer) rasterizeDstRGBASrcUniformOpOver(dst *image.RGBA, r image.Rectangle, sr, sg, sb, sa uint32) {
z.accumulateMask()
pix := dst.Pix[dst.PixOffset(r.Min.X, r.Min.Y):]
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
ma := z.bufU32[y*z.size.X+x]
// This formula is like rasterizeOpOver's, simplified for the
// concrete dst type and uniform src assumption.
a := 0xffff - (sa * ma / 0xffff)
i := y*dst.Stride + 4*x
pix[i+0] = uint8(((uint32(pix[i+0])*0x101*a + sr*ma) / 0xffff) >> 8)
pix[i+1] = uint8(((uint32(pix[i+1])*0x101*a + sg*ma) / 0xffff) >> 8)
pix[i+2] = uint8(((uint32(pix[i+2])*0x101*a + sb*ma) / 0xffff) >> 8)
pix[i+3] = uint8(((uint32(pix[i+3])*0x101*a + sa*ma) / 0xffff) >> 8)
}
}
}
func (z *Rasterizer) rasterizeDstRGBASrcUniformOpSrc(dst *image.RGBA, r image.Rectangle, sr, sg, sb, sa uint32) {
z.accumulateMask()
pix := dst.Pix[dst.PixOffset(r.Min.X, r.Min.Y):]
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
ma := z.bufU32[y*z.size.X+x]
// This formula is like rasterizeOpSrc's, simplified for the
// concrete dst type and uniform src assumption.
i := y*dst.Stride + 4*x
pix[i+0] = uint8((sr * ma / 0xffff) >> 8)
pix[i+1] = uint8((sg * ma / 0xffff) >> 8)
pix[i+2] = uint8((sb * ma / 0xffff) >> 8)
pix[i+3] = uint8((sa * ma / 0xffff) >> 8)
}
}
}
func (z *Rasterizer) rasterizeOpOver(dst draw.Image, r image.Rectangle, src image.Image, sp image.Point) {
z.accumulateMask()
out := color.RGBA64{}
outc := color.Color(&out)
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
sr, sg, sb, sa := src.At(sp.X+x, sp.Y+y).RGBA()
ma := z.bufU32[y*z.size.X+x]
// This algorithm comes from the standard library's image/draw
// package.
dr, dg, db, da := dst.At(r.Min.X+x, r.Min.Y+y).RGBA()
a := 0xffff - (sa * ma / 0xffff)
out.R = uint16((dr*a + sr*ma) / 0xffff)
out.G = uint16((dg*a + sg*ma) / 0xffff)
out.B = uint16((db*a + sb*ma) / 0xffff)
out.A = uint16((da*a + sa*ma) / 0xffff)
dst.Set(r.Min.X+x, r.Min.Y+y, outc)
}
}
}
func (z *Rasterizer) rasterizeOpSrc(dst draw.Image, r image.Rectangle, src image.Image, sp image.Point) {
z.accumulateMask()
out := color.RGBA64{}
outc := color.Color(&out)
for y, y1 := 0, r.Max.Y-r.Min.Y; y < y1; y++ {
for x, x1 := 0, r.Max.X-r.Min.X; x < x1; x++ {
sr, sg, sb, sa := src.At(sp.X+x, sp.Y+y).RGBA()
ma := z.bufU32[y*z.size.X+x]
// This algorithm comes from the standard library's image/draw
// package.
out.R = uint16(sr * ma / 0xffff)
out.G = uint16(sg * ma / 0xffff)
out.B = uint16(sb * ma / 0xffff)
out.A = uint16(sa * ma / 0xffff)
dst.Set(r.Min.X+x, r.Min.Y+y, outc)
}
}
}