Rustification of Extensions and SamplerDescriptor

wgpu-core/src/device/mod.rs

@@ -1003,16 +1003,15 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
         let (device_guard, mut token) = hub.devices.read(&mut token);
         let device = &device_guard[device_id];
 
-        if desc.anisotropy_clamp > 1 {
+        if let Some(clamp) = desc.anisotropy_clamp {
             assert!(
-                device.extensions.anisotropic_filtering,
+                device.extensions.contains(wgt::Extensions::ANISOTROPIC_FILTERING),
                 "Anisotropic clamp may only be used when the anisotropic filtering extension is enabled"
             );
-            let valid_clamp = desc.anisotropy_clamp <= MAX_ANISOTROPY
-                && conv::is_power_of_two(desc.anisotropy_clamp as u32);
+            let valid_clamp = clamp <= MAX_ANISOTROPY && conv::is_power_of_two(clamp as u32);
             assert!(
                 valid_clamp,
-                "Anisotropic clamp must be one of the values: 0, 1, 2, 4, 8, or 16"
+                "Anisotropic clamp must be one of the values: 1, 2, 4, 8, or 16"
             );
         }
 
@@ -1027,14 +1026,10 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             ),
             lod_bias: hal::image::Lod(0.0),
             lod_range: hal::image::Lod(desc.lod_min_clamp)..hal::image::Lod(desc.lod_max_clamp),
-            comparison: conv::map_compare_function(desc.compare),
+            comparison: desc.compare.and_then(conv::map_compare_function),
             border: hal::image::PackedColor(0),
             normalized: true,
-            anisotropy_clamp: if desc.anisotropy_clamp > 1 {
-                Some(desc.anisotropy_clamp)
-            } else {
-                None
-            },
+            anisotropy_clamp: desc.anisotropy_clamp,
         };
 
         let sampler = resource::Sampler {

wgpu-core/src/instance.rs

@@ -534,9 +534,12 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
 
         let features = adapter.raw.physical_device.features();
 
-        wgt::Extensions {
-            anisotropic_filtering: features.contains(hal::Features::SAMPLER_ANISOTROPY),
-        }
+        let mut extensions = wgt::Extensions::default();
+        extensions.set(
+            wgt::Extensions::ANISOTROPIC_FILTERING,
+            features.contains(hal::Features::SAMPLER_ANISOTROPY),
+        );
+        extensions
     }
 
     pub fn adapter_limits<B: GfxBackend>(&self, adapter_id: AdapterId) -> wgt::Limits {
@@ -601,7 +604,10 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
             }
 
             // Check features needed by extensions
-            if desc.extensions.anisotropic_filtering {
+            if desc
+                .extensions
+                .contains(wgt::Extensions::ANISOTROPIC_FILTERING)
+            {
                 assert!(
                     available_features.contains(hal::Features::SAMPLER_ANISOTROPY),
                     "Missing feature SAMPLER_ANISOTROPY for anisotropic filtering extension"

wgpu-types/src/lib.rs

@@ -100,16 +100,18 @@ impl From<Backend> for BackendBit {
     }
 }
 
-#[repr(C)]
-#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
+bitflags::bitflags! {
+    #[repr(transparent)]
+    #[derive(Default)]
     #[cfg_attr(feature = "trace", derive(Serialize))]
     #[cfg_attr(feature = "replay", derive(Deserialize))]
-pub struct Extensions {
+    pub struct Extensions: u64 {
         /// This is a native only extension. Support is planned to be added to webgpu,
         /// but it is not yet implemented.
         ///
         /// https://github.com/gpuweb/gpuweb/issues/696
-    pub anisotropic_filtering: bool,
+        const ANISOTROPIC_FILTERING = 0x01;
+    }
 }
 
 #[repr(C)]
@@ -939,7 +941,6 @@ impl Default for FilterMode {
     }
 }
 
-#[repr(C)]
 #[derive(Clone, Debug, PartialEq)]
 #[cfg_attr(feature = "trace", derive(Serialize))]
 #[cfg_attr(feature = "replay", derive(Deserialize))]
@@ -953,12 +954,12 @@ pub struct SamplerDescriptor<L> {
     pub mipmap_filter: FilterMode,
     pub lod_min_clamp: f32,
     pub lod_max_clamp: f32,
-    pub compare: CompareFunction,
+    pub compare: Option<CompareFunction>,
     /// Anisotropic filtering extension must be enabled if this value is
-    /// anything other than 0 and 1.
+    /// anything other than 0 or 1.
     ///
-    /// Valid values are 0, 1, 2, 4, 8, and 16.
-    pub anisotropy_clamp: u8,
+    /// Valid values: 1, 2, 4, 8, and 16.
+    pub anisotropy_clamp: Option<u8>,
 }
 
 impl<L> SamplerDescriptor<L> {