Enable ray tracing example tests on metal (#9324)

Author: Vecvec

examples/features/src/ray_cube_compute/mod.rs

@@ -471,7 +471,7 @@ pub static TEST: crate::framework::ExampleTestParams = crate::framework::Example
     optional_features: wgpu::Features::default(),
     base_test_parameters: wgpu_test::TestParameters::default()
         // https://github.com/gfx-rs/wgpu/issues/9100
-        .expect_fail(wgpu_test::FailureCase::backend(wgpu::Backends::METAL)),
+        .disable_mtl_shader_validation(),
     comparisons: &[wgpu_test::ComparisonType::Mean(0.02)],
     _phantom: std::marker::PhantomData::<Example>,
 };

examples/features/src/ray_cube_fragment/mod.rs

@@ -357,7 +357,7 @@ pub static TEST: crate::framework::ExampleTestParams = crate::framework::Example
     optional_features: wgpu::Features::default(),
     base_test_parameters: wgpu_test::TestParameters::default()
         // https://github.com/gfx-rs/wgpu/issues/9100
-        .expect_fail(wgpu_test::FailureCase::backend(wgpu::Backends::METAL)),
+        .disable_mtl_shader_validation(),
     comparisons: &[wgpu_test::ComparisonType::Mean(0.02)],
     _phantom: std::marker::PhantomData::<Example>,
 };

examples/features/src/ray_scene/mod.rs

@@ -537,7 +537,7 @@ pub static TEST: crate::framework::ExampleTestParams = crate::framework::Example
     optional_features: wgpu::Features::default(),
     base_test_parameters: wgpu_test::TestParameters::default()
         // https://github.com/gfx-rs/wgpu/issues/9100
-        .expect_fail(wgpu_test::FailureCase::backend(wgpu::Backends::METAL)),
+        .disable_mtl_shader_validation(),
     comparisons: &[wgpu_test::ComparisonType::Mean(0.02)],
     _phantom: std::marker::PhantomData::<Example>,
 };

examples/features/src/ray_shadows/mod.rs

@@ -354,7 +354,7 @@ pub static TEST: crate::framework::ExampleTestParams = crate::framework::Example
     optional_features: wgpu::Features::default(),
     base_test_parameters: wgpu_test::TestParameters::default()
         // https://github.com/gfx-rs/wgpu/issues/9100
-        .expect_fail(wgpu_test::FailureCase::backend(wgpu::Backends::METAL)),
+        .disable_mtl_shader_validation(),
     comparisons: &[wgpu_test::ComparisonType::Mean(0.02)],
     _phantom: std::marker::PhantomData::<Example>,
 };

examples/features/src/ray_traced_triangle/mod.rs

@@ -440,7 +440,7 @@ pub static TEST: crate::framework::ExampleTestParams = crate::framework::Example
     optional_features: wgpu::Features::default(),
     base_test_parameters: wgpu_test::TestParameters::default()
         // https://github.com/gfx-rs/wgpu/issues/9100
-        .expect_fail(wgpu_test::FailureCase::backend(wgpu::Backends::METAL)),
+        .disable_mtl_shader_validation(),
     comparisons: &[wgpu_test::ComparisonType::Mean(0.02)],
     _phantom: std::marker::PhantomData::<Example>,
 };

tests/src/native.rs

@@ -62,9 +62,15 @@ impl NativeTest {
 
                 let env_value = if metal_validation { "1" } else { "0" };
                 std::env::set_var("MTL_DEBUG_LAYER", env_value);
-                if std::env::var("GITHUB_ACTIONS").as_deref() != Ok("true") {
+                if std::env::var("GITHUB_ACTIONS").as_deref() != Ok("true")
+                    && !config.params.disable_mtl_shader_validation
+                {
                     // Metal Shader Validation is entirely broken in the paravirtualized CI environment.
                     std::env::set_var("MTL_SHADER_VALIDATION", env_value);
+                } else if config.params.disable_mtl_shader_validation {
+                    // For ray tracing, where MTL_SHADER_VALIDATION causes acceleration structure ids to be
+                    // completely incorrect.
+                    std::env::set_var("MTL_SHADER_VALIDATION", "0");
                 }
 
                 execute_test(Some(&adapter_report), config, Some(test_info)).await;

tests/src/params.rs

@@ -31,6 +31,10 @@ pub struct TestParameters {
 
     /// Conditions under which this test should be run, but is expected to fail.
     pub failures: Vec<FailureCase>,
+
+    /// For certain features (ray tracing), metal shader validation is completely
+    /// broken
+    pub disable_mtl_shader_validation: bool,
 }
 
 impl Default for TestParameters {
@@ -45,6 +49,7 @@ impl Default for TestParameters {
             // parameters ask us to remove it.
             skips: vec![FailureCase::backend(wgpu::Backends::NOOP)],
             failures: Vec::new(),
+            disable_mtl_shader_validation: false,
         }
     }
 }
@@ -106,6 +111,15 @@ impl TestParameters {
             .retain(|case| *case != FailureCase::backend(wgpu::Backends::NOOP));
         self
     }
+
+    /// Disable metal shader validation.
+    ///
+    /// Metal shader validation can cause features (ray tracing specifically)
+    /// to break. This disables it so it can be tested.
+    pub fn disable_mtl_shader_validation(mut self) -> Self {
+        self.disable_mtl_shader_validation = true;
+        self
+    }
 }
 
 /// Information about a test, including if if it should be skipped.

tests/tests/wgpu-gpu/ray_tracing/shader.rs

@@ -115,7 +115,7 @@ static PREVENT_INVALID_RAY_QUERY_CALLS: GpuTestConfiguration = GpuTestConfigurat
             .features(wgpu::Features::EXPERIMENTAL_RAY_QUERY)
             // Otherwise, mistakes in the generated code won't be caught.
             .instance_flags(InstanceFlags::GPU_BASED_VALIDATION)
-            // not yet implemented in directx12
+            // not yet implemented in metal
             .skip(FailureCase::backend(Backends::METAL)),
     )
     .run_sync(prevent_invalid_ray_query_calls);

wgpu-types/src/limits.rs

@@ -725,7 +725,8 @@ impl Limits {
             max_blas_geometry_count: (1 << 24) - 1, // 2^24 - 1: Vulkan's minimum
             max_tlas_instance_count: (1 << 24) - 1, // 2^24 - 1: Vulkan's minimum
             max_blas_primitive_count: 1 << 28,      // 2^28: Metal's minimum
-            max_acceleration_structures_per_shader_stage: 16, // Vulkan's minimum
+            // On metal acceleration structures are limited because they share buffer slots
+            max_acceleration_structures_per_shader_stage: 1,
             ..self
         }
     }