Skip testing of stencil textures where non-readable.

Readback of stencil is not supported on vanilla ES, so we introduce a toggle to disable it. NVidia GLES drivers support NV_stencil_read and NV_depth_stencil_read extensions, so we use those where available.

It turns out ANGLE supports NV_stencil_read but not NV_depth_stencil_read (for reading from the packed depth/stencil buffers which Dawn uses), so that's the extension we check for.

Bug: dawn:667 dawn:634
Change-Id: I136674d3d47fecee2b8b390d5d219bab07e3bb64
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/41141
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Stephen White <senorblanco@chromium.org>

src/dawn_native/Toggles.cpp

@@ -129,6 +129,11 @@ namespace dawn_native {
              {"disable_snorm_read",
               "Disables reading from Snorm textures which is unsupported on some platforms.",
               "https://crbug.com/dawn/667"}},
+            {Toggle::DisableDepthStencilRead,
+             {"disable_depth_stencil_read",
+              "Disables reading from depth/stencil textures which is unsupported on some "
+              "platforms.",
+              "https://crbug.com/dawn/667"}},
             {Toggle::UseD3D12SmallShaderVisibleHeapForTesting,
              {"use_d3d12_small_shader_visible_heap",
               "Enable use of a small D3D12 shader visible heap, instead of using a large one by "

src/dawn_native/Toggles.h

@@ -41,6 +41,7 @@ namespace dawn_native {
         DisableBaseInstance,
         DisableIndexedDrawBuffers,
         DisableSnormRead,
+        DisableDepthStencilRead,
         UseD3D12SmallShaderVisibleHeapForTesting,
         UseDXC,
         DisableRobustness,

src/dawn_native/opengl/DeviceGL.cpp

@@ -71,6 +71,9 @@ namespace dawn_native { namespace opengl {
         bool supportsSnormRead =
             gl.IsAtLeastGL(4, 4) || gl.IsGLExtensionSupported("GL_EXT_render_snorm");
 
+        bool supportsDepthStencilRead =
+            gl.IsAtLeastGL(3, 0) || gl.IsGLExtensionSupported("GL_NV_read_depth_stencil");
+
         // TODO(crbug.com/dawn/343): We can support the extension variants, but need to load the EXT
         // procs without the extension suffix.
         // We'll also need emulation of shader builtins gl_BaseVertex and gl_BaseInstance.
@@ -90,6 +93,7 @@ namespace dawn_native { namespace opengl {
         SetToggle(Toggle::DisableBaseInstance, !supportsBaseInstance);
         SetToggle(Toggle::DisableIndexedDrawBuffers, !supportsIndexedDrawBuffers);
         SetToggle(Toggle::DisableSnormRead, !supportsSnormRead);
+        SetToggle(Toggle::DisableDepthStencilRead, !supportsDepthStencilRead);
         SetToggle(Toggle::FlushBeforeClientWaitSync, gl.GetVersion().IsES());
     }
 

src/tests/end2end/DepthStencilCopyTests.cpp

@@ -330,8 +330,9 @@ TEST_P(DepthStencilCopyTests, FromDepthAspect) {
 
 // Test copying the stencil-only aspect into a buffer.
 TEST_P(DepthStencilCopyTests, FromStencilAspect) {
-    // TODO(crbug.com/dawn/634): Diagnose and fix ANGLE failure.
+    // TODO(crbug.com/dawn/667): Work around the fact that some platforms are unable to read
-    DAWN_SKIP_TEST_IF(IsANGLE());
+    // stencil.
+    DAWN_SKIP_TEST_IF(HasToggleEnabled("disable_depth_stencil_read"));
 
     constexpr uint32_t kWidth = 4;
     constexpr uint32_t kHeight = 4;
@@ -358,8 +359,8 @@ TEST_P(DepthStencilCopyTests, FromNonZeroMipStencilAspect) {
     // It passes on AMD Radeon Pro and Intel HD Graphics 630.
     DAWN_SKIP_TEST_IF(IsMetal() && IsIntel());
 
-    // TODO(crbug.com/dawn/634): Diagnose and fix ANGLE failure.
+    // TODO(crbug.com/dawn/667): Work around some platforms' inability to read back stencil.
-    DAWN_SKIP_TEST_IF(IsANGLE());
+    DAWN_SKIP_TEST_IF(HasToggleEnabled("disable_depth_stencil_read"));
 
     wgpu::Texture depthStencilTexture = CreateDepthStencilTexture(
         9, 9, wgpu::TextureUsage::RenderAttachment | wgpu::TextureUsage::CopySrc, 2);
@@ -403,8 +404,8 @@ TEST_P(DepthStencilCopyTests, T2TBothAspectsThenCopyStencil) {
     // T2TBothAspectsThenCopyNonRenderableStencil does not use RenderAttachment and works correctly.
     DAWN_SKIP_TEST_IF(IsMetal() && IsIntel());
 
-    // TODO(crbug.com/dawn/634): Diagnose and fix ANGLE failure.
+    // TODO(crbug.com/dawn/667): Work around some platforms' inability to read back stencil.
-    DAWN_SKIP_TEST_IF(IsANGLE());
+    DAWN_SKIP_TEST_IF(HasToggleEnabled("disable_depth_stencil_read"));
 
     constexpr uint32_t kWidth = 4;
     constexpr uint32_t kHeight = 4;
@@ -427,8 +428,8 @@ TEST_P(DepthStencilCopyTests, T2TBothAspectsThenCopyStencil) {
 // Test that part of a non-renderable stencil aspect can be copied. Notably,
 // this test has different behavior on some platforms than T2TBothAspectsThenCopyStencil.
 TEST_P(DepthStencilCopyTests, T2TBothAspectsThenCopyNonRenderableStencil) {
-    // TODO(crbug.com/dawn/634): Diagnose and fix ANGLE failure.
+    // TODO(crbug.com/dawn/667): Work around some platforms' inability to read back stencil.
-    DAWN_SKIP_TEST_IF(IsANGLE());
+    DAWN_SKIP_TEST_IF(HasToggleEnabled("disable_depth_stencil_read"));
 
     constexpr uint32_t kWidth = 4;
     constexpr uint32_t kHeight = 4;
@@ -456,8 +457,8 @@ TEST_P(DepthStencilCopyTests, T2TBothAspectsThenCopyNonRenderableNonZeroMipStenc
     // T2TBothAspectsThenCopyNonRenderableStencil works correctly.
     DAWN_SKIP_TEST_IF(IsMetal() && IsIntel());
 
-    // TODO(crbug.com/dawn/634): Diagnose and fix ANGLE failure.
+    // TODO(crbug.com/dawn/667): Work around some platforms' inability to read back stencil.
-    DAWN_SKIP_TEST_IF(IsANGLE());
+    DAWN_SKIP_TEST_IF(HasToggleEnabled("disable_depth_stencil_read"));
 
     wgpu::Texture texture = CreateInitializeDepthStencilTextureAndCopyT2T(
         0.1f, 0.3f, 1u, 3u, 9, 9, wgpu::TextureUsage::CopySrc, 1);
@@ -508,8 +509,8 @@ TEST_P(DepthStencilCopyTests, T2TBothAspectsThenCopyNonZeroMipDepth) {
 
 // Test copying both aspects in a T2T copy, then copying stencil, then copying depth
 TEST_P(DepthStencilCopyTests, T2TBothAspectsThenCopyStencilThenDepth) {
-    // TODO(crbug.com/dawn/634): Diagnose and fix ANGLE failure.
+    // TODO(crbug.com/dawn/667): Work around some platforms' inability to read back stencil.
-    DAWN_SKIP_TEST_IF(IsANGLE());
+    DAWN_SKIP_TEST_IF(HasToggleEnabled("disable_depth_stencil_read"));
 
     constexpr uint32_t kWidth = 4;
     constexpr uint32_t kHeight = 4;
@@ -547,8 +548,9 @@ TEST_P(DepthStencilCopyTests, T2TBothAspectsThenCopyDepthThenStencil) {
     // T2TBothAspectsThenCopyStencilThenDepth which checks stencil first also passes.
     DAWN_SKIP_TEST_IF(IsMetal() && IsIntel());
 
-    // TODO(crbug.com/dawn/634): Diagnose and fix ANGLE failure.
+    // TODO(crbug.com/dawn/667): Work around the fact that some platforms are unable to read
-    DAWN_SKIP_TEST_IF(IsANGLE());
+    // stencil.
+    DAWN_SKIP_TEST_IF(HasToggleEnabled("disable_depth_stencil_read"));
 
     constexpr uint32_t kWidth = 4;
     constexpr uint32_t kHeight = 4;