Fix readTextureToTextureViews for multisampled textures (#4049)

* Fix readTextureToTextureViews for multisampled textures

I'm not sure when this bug was introduced. These tests (textureLoad:multisampled) used
to pass. Fixed the bug and added a test to hopefully find it
quicker if it breaks in the future.

Also added a test for createTextureWithRandomDataAndGetTexels
with a generator. This was fixed in a previous PR without a
a specific test as the fact that it failed other tests showed
it needed fixing but I decided it's probably best to keep
these tests too.

* Update src/webgpu/shader/execution/expression/call/builtin/texture_utils.ts

Co-authored-by: Kai Ninomiya <kainino1@gmail.com>

Author: greggman

src/webgpu/shader/execution/expression/call/builtin/texture_utils.spec.ts

@@ -4,6 +4,7 @@ Tests for texture_utils.ts
 
 import { makeTestGroup } from '../../../../../../common/framework/test_group.js';
 import { assert } from '../../../../../../common/util/util.js';
+import { isMultisampledTextureFormat, kDepthStencilFormats } from '../../../../../format_info.js';
 import { GPUTest } from '../../../../../gpu_test.js';
 import { getTextureDimensionFromView, virtualMipSize } from '../../../../../util/texture/base.js';
 import {
@@ -16,6 +17,7 @@ import {
   chooseTextureSize,
   createTextureWithRandomDataAndGetTexels,
   isSupportedViewFormatCombo,
+  makeRandomDepthComparisonTexelGenerator,
   readTextureToTexelViews,
   texelsApproximatelyEqual,
 } from './texture_utils.js';
@@ -26,6 +28,41 @@ function texelFormat(texel: Readonly<PerTexelComponent<number>>, rep: TexelRepre
   return rep.componentOrder.map(component => `${component}: ${texel[component]}`).join(', ');
 }
 
+g.test('createTextureWithRandomDataAndGetTexels_with_generator')
+  .desc(
+    `
+    Test createTextureWithRandomDataAndGetTexels with a generator. Generators
+    are only used with textureXXXCompare builtins as we need specific random
+    values to test these builtins with a depth reference value.
+    `
+  )
+  .params(u =>
+    u
+      .combine('format', kDepthStencilFormats)
+      .combine('viewDimension', ['2d', '2d-array', 'cube', 'cube-array'] as const)
+      .filter(t => isSupportedViewFormatCombo(t.format, t.viewDimension))
+  )
+  .beforeAllSubcases(t => {
+    t.skipIfTextureViewDimensionNotSupported(t.params.viewDimension);
+    t.selectDeviceForTextureFormatOrSkipTestCase(t.params.format);
+  })
+  .fn(async t => {
+    const { format, viewDimension } = t.params;
+    const size = chooseTextureSize({ minSize: 8, minBlocks: 4, format, viewDimension });
+    const descriptor: GPUTextureDescriptor = {
+      format,
+      dimension: getTextureDimensionFromView(viewDimension),
+      size,
+      mipLevelCount: 3,
+      usage: GPUTextureUsage.COPY_DST | GPUTextureUsage.TEXTURE_BINDING,
+      ...(t.isCompatibility && { textureBindingViewDimension: viewDimension }),
+    };
+    await createTextureWithRandomDataAndGetTexels(t, descriptor, {
+      generator: makeRandomDepthComparisonTexelGenerator(descriptor, 'equal'),
+    });
+    // We don't expect any particular results. We just expect no validation errors.
+  });
+
 g.test('readTextureToTexelViews')
   .desc('test readTextureToTexelViews for various formats and dimensions')
   .params(u =>
@@ -44,19 +81,26 @@ g.test('readTextureToTexelViews')
       ] as const)
       .combine('viewDimension', ['1d', '2d', '2d-array', '3d', 'cube', 'cube-array'] as const)
       .filter(t => isSupportedViewFormatCombo(t.srcFormat, t.viewDimension))
+      .combine('sampleCount', [1, 4] as const)
+      .unless(
+        t =>
+          t.sampleCount > 1 &&
+          (!isMultisampledTextureFormat(t.srcFormat) || t.viewDimension !== '2d')
+      )
   )
   .beforeAllSubcases(t => {
     t.skipIfTextureViewDimensionNotSupported(t.params.viewDimension);
   })
   .fn(async t => {
-    const { srcFormat, texelViewFormat, viewDimension } = t.params;
+    const { srcFormat, texelViewFormat, viewDimension, sampleCount } = t.params;
     const size = chooseTextureSize({ minSize: 8, minBlocks: 4, format: srcFormat, viewDimension });
     const descriptor: GPUTextureDescriptor = {
       format: srcFormat,
       dimension: getTextureDimensionFromView(viewDimension),
       size,
-      mipLevelCount: viewDimension === '1d' ? 1 : 3,
+      mipLevelCount: viewDimension === '1d' || sampleCount > 1 ? 1 : 3,
       usage: GPUTextureUsage.COPY_DST | GPUTextureUsage.TEXTURE_BINDING,
+      sampleCount,
       ...(t.isCompatibility && { textureBindingViewDimension: viewDimension }),
     };
     const { texels: expectedTexelViews, texture } = await createTextureWithRandomDataAndGetTexels(

src/webgpu/shader/execution/expression/call/builtin/texture_utils.ts

@@ -3031,11 +3031,14 @@ export async function readTextureToTexelViews(
         }
       `,
     });
-    const sampleType = isDepthTextureFormat(texture.format)
-      ? 'unfilterable-float'
-      : isStencilTextureFormat(texture.format)
+    const info = kTextureFormatInfo[texture.format];
+    const sampleType = info.depth
+      ? 'unfilterable-float' // depth only supports unfilterable-float if not a comparison.
+      : info.stencil
       ? 'uint'
-      : kTextureFormatInfo[texture.format].color?.type ?? 'unfilterable-float';
+      : info.color.type === 'float'
+      ? 'unfilterable-float'
+      : info.color.type;
     const bindGroupLayout = device.createBindGroupLayout({
       entries: [
         {
@@ -3051,6 +3054,7 @@ export async function readTextureToTexelViews(
           texture: {
             sampleType,
             viewDimension,
+            multisampled: texture.sampleCount > 1,
           },
         },
         {
@@ -3169,7 +3173,7 @@ function createTextureFromTexelViewsLocal(
 ): GPUTexture {
   const modifiedDescriptor = { ...desc };
   // If it's a depth or stencil texture we need to render to it to fill it with data.
-  if (isDepthOrStencilTextureFormat(desc.format)) {
+  if (isDepthOrStencilTextureFormat(desc.format) || desc.sampleCount! > 1) {
     modifiedDescriptor.usage = desc.usage | GPUTextureUsage.RENDER_ATTACHMENT;
   }
   return createTextureFromTexelViews(t, texelViews, modifiedDescriptor);