[html5] Fix canvas size functions with OffscreenCanvas

src/lib/libhtml5.js

@@ -2104,21 +2104,24 @@ var LibraryHTML5 = {
     }
     return setCanvasElementSizeMainThread(target, width, height);
   },
-#else
+#else // PTHREADS
   emscripten_set_canvas_element_size: (target, width, height) => {
 #if GL_DEBUG
     dbg(`emscripten_set_canvas_element_size(target=${target},width=${width},height=${height}`);
 #endif
     var canvas = findCanvasEventTarget(target);
     if (!canvas) return {{{ cDefs.EMSCRIPTEN_RESULT_UNKNOWN_TARGET }}};
+#if OFFSCREENCANVAS_SUPPORT
+    if (canvas.offscreenCanvas) canvas = canvas.offscreenCanvas;
+#endif
     canvas.width = width;
     canvas.height = height;
 #if OFFSCREEN_FRAMEBUFFER
     if (canvas.GLctxObject) GL.resizeOffscreenFramebuffer(canvas.GLctxObject);
 #endif
     return {{{ cDefs.EMSCRIPTEN_RESULT_SUCCESS }}};
   },
-#endif
+#endif // !PTHREADS
 
   $setCanvasElementSize: (target, width, height) => {
 #if GL_DEBUG
@@ -2178,14 +2181,18 @@ var LibraryHTML5 = {
     }
     return getCanvasSizeMainThread(target, width, height);
   },
-#else
+#else // PTHREADS
   emscripten_get_canvas_element_size: (target, width, height) => {
     var canvas = findCanvasEventTarget(target);
     if (!canvas) return {{{ cDefs.EMSCRIPTEN_RESULT_UNKNOWN_TARGET }}};
+#if OFFSCREENCANVAS_SUPPORT
+    if (canvas.offscreenCanvas) canvas = canvas.offscreenCanvas;
+#endif
     {{{ makeSetValue('width', '0', 'canvas.width', 'i32') }}};
     {{{ makeSetValue('height', '0', 'canvas.height', 'i32') }}};
+    return {{{ cDefs.EMSCRIPTEN_RESULT_SUCCESS }}};
   },
-#endif
+#endif // !PTHREADS
 
   // JavaScript-friendly API, returns pair [width, height]
   $getCanvasElementSize: (target) => {

src/lib/libhtml5_webgl.js

@@ -57,9 +57,6 @@ var LibraryHtml5WebGL = {
   });`,
 #endif
 
-#if OFFSCREENCANVAS_SUPPORT
-  _emscripten_webgl_do_create_context__deps: ['malloc'],
-#endif
   // This function performs proxying manually, depending on the style of context that is to be created.
   _emscripten_webgl_do_create_context: (target, attributes) => {
 #if ASSERTIONS
@@ -104,10 +101,6 @@ var LibraryHtml5WebGL = {
 #endif
 
     var canvas = findCanvasEventTarget(target);
-#if OFFSCREENCANVAS_SUPPORT
-    // If our canvas from findCanvasEventTarget is actually an offscreen canvas record, we should extract the inner canvas.
-    if (canvas?.canvas) { canvas = canvas.canvas; }
-#endif
 #if GL_DEBUG
     var targetStr = UTF8ToString(target);
 #endif
@@ -175,8 +168,7 @@ var LibraryHtml5WebGL = {
 #endif
         if (!canvas.controlTransferredOffscreen) {
           GL.offscreenCanvases[canvas.id] = {
-            canvas: canvas.transferControlToOffscreen(),
-            canvasSharedPtr: _malloc(12),
+            offscreenCanvas: canvas.transferControlToOffscreen(),
             id: canvas.id
           };
           canvas.controlTransferredOffscreen = true;
@@ -186,7 +178,7 @@ var LibraryHtml5WebGL = {
 #endif
           return 0;
         }
-        canvas = GL.offscreenCanvases[canvas.id].canvas;
+        canvas = GL.offscreenCanvases[canvas.id].offscreenCanvas;
       }
     }
 #else // !OFFSCREENCANVAS_SUPPORT

test/browser/webgl_create_context_swapcontrol.c

@@ -23,6 +23,24 @@ int main() {
   EMSCRIPTEN_RESULT res = emscripten_webgl_make_context_current(context);
   assert(res == EMSCRIPTEN_RESULT_SUCCESS);
   assert(emscripten_webgl_get_current_context() == context);
+
+  int w, h;
+  res = emscripten_get_canvas_element_size("#canvas", &w, &h);
+  assert(res == EMSCRIPTEN_RESULT_SUCCESS);
+  assert(w == 300);
+  assert(h == 150);
+
+  res = emscripten_set_canvas_element_size("#canvas", 400, 200);
+  assert(res == EMSCRIPTEN_RESULT_SUCCESS);
+  res = emscripten_get_canvas_element_size("#canvas", &w, &h);
+  assert(res == EMSCRIPTEN_RESULT_SUCCESS);
+  assert(w == 400);
+  assert(h == 200);
+  res = emscripten_webgl_get_drawing_buffer_size(context, &w, &h);
+  assert(res == EMSCRIPTEN_RESULT_SUCCESS);
+  assert(w == 400);
+  assert(h == 200);
+
   emscripten_webgl_destroy_context(context);
   assert(emscripten_webgl_get_current_context() == 0);
   // Test that creating a context for a canvas that's already been used once succeeds

test/codesize/test_codesize_hello_dylink_all.json

@@ -1,7 +1,7 @@
 {
-  "a.out.js": 272917,
+  "a.out.js": 272926,
   "a.out.nodebug.wasm": 589443,
-  "total": 862360,
+  "total": 862369,
   "sent": [
     "IMG_Init",
     "IMG_Load",