Merge pull request 'fix(web): cap /play canvas at the real 2048 wgpu limit (corrects #97)' (#98) from fix/web-canvas-cap-2048-constant into master

2026-06-24 01:14:49 +00:00
parent b3b282ec2d 8a2a22ff1b
commit 4850e9417e
1 changed files with 17 additions and 19 deletions
@@ -23,26 +23,24 @@
 <body>
    <div id="bevy-wrap"><canvas id="bevy-canvas"></canvas></div>
    <script>
-        // Clamp the Bevy canvas's backing buffer to the device's real WebGL2
-        // MAX_TEXTURE_SIZE *before* the wasm initialises. `fit_canvas_to_parent`
-        // sizes the wgpu surface to #bevy-wrap; a surface larger than the GPU
-        // limit (only 2048 on many laptop/integrated GPUs — e.g. a 2560-wide
-        // 1440p display) makes Surface::configure panic and kills the WASM
-        // thread. Querying the real maximum means only devices at the 2048 floor
-        // letterbox; everyone else still fills the viewport. Runs synchronously
-        // before the deferred module script below.
-        (function clampCanvasToGpuLimit() {
-            var max = 2048; // WebGL2 spec floor — the safe fallback
-            try {
-                var probe = document.createElement("canvas").getContext("webgl2");
-                if (probe) {
-                    var m = probe.getParameter(probe.MAX_TEXTURE_SIZE);
-                    if (m && m > 0) max = m;
-                }
-            } catch (e) { /* keep the safe 2048 floor */ }
+        // Clamp the Bevy canvas's backing buffer to 2048px *before* the wasm
+        // initialises. `fit_canvas_to_parent` sizes the wgpu surface to
+        // #bevy-wrap, and on wasm Bevy creates the device with
+        // `Limits::downlevel_webgl2_defaults()` (forced by
+        // `WgpuSettingsPriority::WebGL2` in solitaire_web/src/lib.rs), whose
+        // `max_texture_dimension_2d` is a fixed **2048** — independent of the
+        // GPU's real MAX_TEXTURE_SIZE (which is why querying the hardware limit
+        // doesn't help: a 4K/integrated GPU reports e.g. 8192 but wgpu still
+        // caps the surface at 2048). A surface wider/taller than 2048 makes
+        // Surface::configure panic and kill the WASM thread on the first frame
+        // — e.g. a 3840x2160 display at 150% scale gives a 2560x1440 logical
+        // viewport → a 2560-wide surface. So the cap is the constant 2048.
+        // Keep in sync with the wgpu limit selected in lib.rs.
+        (function clampCanvasToWebgl2Limit() {
+            var MAX = 2048; // wgpu downlevel_webgl2_defaults().max_texture_dimension_2d
            var wrap = document.getElementById("bevy-wrap");
-            wrap.style.maxWidth = max + "px";
-            wrap.style.maxHeight = max + "px";
+            wrap.style.maxWidth = MAX + "px";
+            wrap.style.maxHeight = MAX + "px";
        })();
    </script>
    <script type="module">