[api-minor] Make isOffscreenCanvasSupported configurable via the API (issue 14952)

This patch first of all makes `isOffscreenCanvasSupported` configurable, defaulting to `true` in browsers and `false` in Node.js environments, with a new `getDocument` parameter. While you normally want to use this, in order to improve performance, it should still be possible for users to control it (similar to e.g. `isEvalSupported`).

The specific problem, as reported in issue 14952, is that the SVG back-end doesn't support the new ImageMask data-format that's introduced in PR 14754. In particular:
 - When the SVG back-end is used in Node.js environments, this patch will "just work" without the user needing to make any code changes.
 - If the SVG back-end is used in browsers, this patch will require that `isOffscreenCanvasSupported: false` is added to the `getDocument`-call.

src/core/evaluator.js

@@ -84,6 +84,7 @@ const DefaultPartialEvaluatorOptions = Object.freeze({
   disableFontFace: false,
   ignoreErrors: false,
   isEvalSupported: true,
+  isOffscreenCanvasSupported: true,
   fontExtraProperties: false,
   useSystemFonts: true,
   cMapUrl: null,
@@ -652,6 +653,7 @@ class PartialEvaluator {
         imageIsFromDecodeStream: image instanceof DecodeStream,
         inverseDecode: !!decode && decode[0] > 0,
         interpolate,
+        isOffscreenCanvasSupported: this.options.isOffscreenCanvasSupported,
       });
 
       if (imgData.isSingleOpaquePixel) {

src/core/image.js

@@ -356,6 +356,7 @@ class PDFImage {
     imageIsFromDecodeStream,
     inverseDecode,
     interpolate,
+    isOffscreenCanvasSupported = true,
   }) {
     const isSingleOpaquePixel =
       width === 1 &&
@@ -366,7 +367,7 @@ class PDFImage {
       return { isSingleOpaquePixel };
     }
 
-    if (FeatureTest.isOffscreenCanvasSupported) {
+    if (isOffscreenCanvasSupported && FeatureTest.isOffscreenCanvasSupported) {
       const canvas = new OffscreenCanvas(width, height);
       const ctx = canvas.getContext("2d");
       const imgData = ctx.createImageData(width, height);

src/core/worker.js

@@ -410,6 +410,7 @@ class WorkerMessageHandler {
         disableFontFace: data.disableFontFace,
         ignoreErrors: data.ignoreErrors,
         isEvalSupported: data.isEvalSupported,
+        isOffscreenCanvasSupported: data.isOffscreenCanvasSupported,
         fontExtraProperties: data.fontExtraProperties,
         useSystemFonts: data.useSystemFonts,
         cMapUrl: data.cMapUrl,

src/display/api.js

@@ -189,6 +189,10 @@ function setPDFNetworkStreamFactory(pdfNetworkStreamFactory) {
  * @property {boolean} [isEvalSupported] - Determines if we can evaluate strings
  *   as JavaScript. Primarily used to improve performance of font rendering, and
  *   when parsing PDF functions. The default value is `true`.
+ * @property {boolean} [isOffscreenCanvasSupported] - Determines if we can use
+ *   `OffscreenCanvas` in the worker. Primarily used to improve performance of
+ *   image conversion/rendering.
+ *   The default value is `true` in web environments and `false` in Node.js.
  * @property {boolean} [disableFontFace] - By default fonts are converted to
  *   OpenType fonts and loaded via the Font Loading API or `@font-face` rules.
  *   If disabled, fonts will be rendered using a built-in font renderer that
@@ -365,6 +369,9 @@ function getDocument(src) {
   if (typeof params.isEvalSupported !== "boolean") {
     params.isEvalSupported = true;
   }
+  if (typeof params.isOffscreenCanvasSupported !== "boolean") {
+    params.isOffscreenCanvasSupported = !isNodeJS;
+  }
   if (typeof params.disableFontFace !== "boolean") {
     params.disableFontFace = isNodeJS;
   }
@@ -516,6 +523,7 @@ async function _fetchDocument(worker, source, pdfDataRangeTransport, docId) {
       docBaseUrl: source.docBaseUrl,
       ignoreErrors: source.ignoreErrors,
       isEvalSupported: source.isEvalSupported,
+      isOffscreenCanvasSupported: source.isOffscreenCanvasSupported,
       fontExtraProperties: source.fontExtraProperties,
       enableXfa: source.enableXfa,
       useSystemFonts: source.useSystemFonts,

src/display/svg.js

@@ -495,6 +495,15 @@ if (
       }
     }
 
+    getObject(data, fallback = null) {
+      if (typeof data === "string") {
+        return data.startsWith("g_")
+          ? this.commonObjs.get(data)
+          : this.objs.get(data);
+      }
+      return fallback;
+    }
+
     save() {
       this.transformStack.push(this.transformMatrix);
       const old = this.current;
@@ -1586,9 +1595,7 @@ if (
     }
 
     paintImageXObject(objId) {
-      const imgData = objId.startsWith("g_")
-        ? this.commonObjs.get(objId)
-        : this.objs.get(objId);
+      const imgData = this.getObject(objId);
       if (!imgData) {
         warn(`Dependent image with object ID ${objId} is not ready yet`);
         return;
@@ -1627,7 +1634,15 @@ if (
       }
     }
 
-    paintImageMaskXObject(imgData) {
+    paintImageMaskXObject(img) {
+      const imgData = this.getObject(img.data, img);
+      if (imgData.bitmap) {
+        warn(
+          "paintImageMaskXObject: ImageBitmap support is not implemented, " +
+            "ensure that the `isOffscreenCanvasSupported` API parameter is disabled."
+        );
+        return;
+      }
       const current = this.current;
       const width = imgData.width;
       const height = imgData.height;

web/app_options.js

@@ -242,6 +242,11 @@ const defaultOptions = {
     value: true,
     kind: OptionKind.API,
   },
+  isOffscreenCanvasSupported: {
+    /** @type {boolean} */
+    value: true,
+    kind: OptionKind.API,
+  },
   maxImageSize: {
     /** @type {number} */
     value: -1,