feat(unstable): implement `navigator.gpu.getPreferredCanvasFormat()` (#22149)

3 files changed, 16 insertions, 0 deletions

diff --git a/cli/tests/unit/webgpu_test.ts b/cli/tests/unit/webgpu_test.ts
index bcdc6b1ff..75ae34981 100644
--- a/cli/tests/unit/webgpu_test.ts
+++ b/cli/tests/unit/webgpu_test.ts
@@ -247,6 +247,11 @@ Deno.test({
   Deno.close(Number(resources[resources.length - 1]));
 });
 
+Deno.test(function getPreferredCanvasFormat() {
+  const preferredFormat = navigator.gpu.getPreferredCanvasFormat();
+  assert(preferredFormat === "bgra8unorm" || preferredFormat === "rgba8unorm");
+});
+
 async function checkIsWsl() {
   return Deno.build.os === "linux" && await hasMicrosoftProcVersion();
 
diff --git a/cli/tsc/dts/lib.deno_webgpu.d.ts b/cli/tsc/dts/lib.deno_webgpu.d.ts
index 50d9ecfb6..74fa7c907 100644
--- a/cli/tsc/dts/lib.deno_webgpu.d.ts
+++ b/cli/tsc/dts/lib.deno_webgpu.d.ts
@@ -78,6 +78,7 @@ declare class GPU {
   requestAdapter(
     options?: GPURequestAdapterOptions,
   ): Promise<GPUAdapter | null>;
+  getPreferredCanvasFormat(): GPUTextureFormat;
 }
 
 /** @category WebGPU */
diff --git a/ext/webgpu/01_webgpu.js b/ext/webgpu/01_webgpu.js
index db0dc9264..55ca9c382 100644
--- a/ext/webgpu/01_webgpu.js
+++ b/ext/webgpu/01_webgpu.js
@@ -344,6 +344,16 @@ class GPU {
     }
   }
 
+  getPreferredCanvasFormat() {
+    // Same as Gecko.
+    //
+    // https://github.com/mozilla/gecko-dev/blob/b75080bb8b11844d18cb5f9ac6e68a866ef8e243/dom/webgpu/Instance.h#L42-L47
+    if (core.build.os == "android") {
+      return "rgba8unorm";
+    }
+    return "bgra8unorm";
+  }
+
   [SymbolFor("Deno.privateCustomInspect")](inspect, inspectOptions) {
     return `${this.constructor.name} ${inspect({}, inspectOptions)}`;
   }