docs: add procurement system presentation

docs/ppt/render-pdf.mjs

@@ -0,0 +1,50 @@
+import fs from "fs";
+import path from "path";
+import { createRequire } from "module";
+import { pathToFileURL } from "url";
+
+const require = createRequire(import.meta.url);
+const repoRoot = path.resolve(path.dirname(new URL(import.meta.url).pathname.slice(1)), "..", "..");
+const toolRoot = path.join(repoRoot, ".local", "ppt-tools", "node_modules");
+const canvasModule = require(path.join(toolRoot, "@napi-rs", "canvas"));
+
+globalThis.DOMMatrix = canvasModule.DOMMatrix;
+globalThis.ImageData = canvasModule.ImageData;
+globalThis.Path2D = canvasModule.Path2D;
+
+const pdfjsPath = path.join(toolRoot, "pdfjs-dist", "legacy", "build", "pdf.mjs");
+const pdfjs = await import(pathToFileURL(pdfjsPath).href);
+
+const [pdfArgument, outputArgument] = process.argv.slice(2);
+if (!pdfArgument || !outputArgument) {
+  throw new Error("Usage: node render-pdf.mjs <input.pdf> <output-dir>");
+}
+
+const pdfPath = path.resolve(pdfArgument);
+const outputDir = path.resolve(outputArgument);
+fs.mkdirSync(outputDir, { recursive: true });
+
+const data = new Uint8Array(fs.readFileSync(pdfPath));
+const document = await pdfjs.getDocument({
+  data,
+  disableFontFace: true,
+  isEvalSupported: false,
+  useSystemFonts: true,
+}).promise;
+
+for (let pageNumber = 1; pageNumber <= document.numPages; pageNumber += 1) {
+  const page = await document.getPage(pageNumber);
+  const baseViewport = page.getViewport({ scale: 1 });
+  const scale = 1600 / baseViewport.width;
+  const viewport = page.getViewport({ scale });
+  const canvas = canvasModule.createCanvas(
+    Math.round(viewport.width),
+    Math.round(viewport.height),
+  );
+  const context = canvas.getContext("2d");
+  await page.render({ canvasContext: context, viewport }).promise;
+  const outputPath = path.join(outputDir, `slide${pageNumber}.png`);
+  fs.writeFileSync(outputPath, canvas.toBuffer("image/png"));
+}
+
+console.log(`Rendered ${document.numPages} pages to ${outputDir}`);