Add new BindingResource type SamplerArray (#2113)

* implemented SamplerArray

* modified shaders

* fixed doc

* fixed code format

wgpu-core/src/binding_model.rs

@@ -663,6 +663,7 @@ pub enum BindingResource<'a> {
     Buffer(BufferBinding),
     BufferArray(Cow<'a, [BufferBinding]>),
     Sampler(SamplerId),
+    SamplerArray(Cow<'a, [SamplerId]>),
     TextureView(TextureViewId),
     TextureViewArray(Cow<'a, [TextureViewId]>),
 }

wgpu-core/src/device/mod.rs

@@ -1202,7 +1202,10 @@ impl<A: HalApi> Device<A> {
                         false => WritableStorage::Yes,
                     },
                 ),
-                Bt::Sampler { .. } => (None, WritableStorage::No),
+                Bt::Sampler { .. } => (
+                    Some(wgt::Features::TEXTURE_BINDING_ARRAY),
+                    WritableStorage::No,
+                ),
                 Bt::Texture { .. } => (
                     Some(wgt::Features::TEXTURE_BINDING_ARRAY),
                     WritableStorage::No,
@@ -1618,6 +1621,21 @@ impl<A: HalApi> Device<A> {
                         }
                     }
                 }
+                Br::SamplerArray(ref bindings_array) => {
+                    let num_bindings = bindings_array.len();
+                    Self::check_array_binding(self.features, decl.count, num_bindings)?;
+
+                    let res_index = hal_samplers.len();
+                    for &id in bindings_array.iter() {
+                        let sampler = used
+                            .samplers
+                            .use_extend(&*sampler_guard, id, (), ())
+                            .map_err(|_| Error::InvalidSampler(id))?;
+                        hal_samplers.push(&sampler.raw);
+                    }
+
+                    (res_index, num_bindings)
+                }
                 Br::TextureView(id) => {
                     let view = used
                         .views

wgpu/examples/texture-arrays/constant.frag

@@ -5,13 +5,13 @@ layout(location = 1) flat in int v_Index;  // dynamically non-uniform
 layout(location = 0) out vec4 o_Color;
 
 layout(set = 0, binding = 0) uniform texture2D u_Textures[2];
-layout(set = 0, binding = 1) uniform sampler u_Sampler;
+layout(set = 0, binding = 1) uniform sampler u_Sampler[2];
 
 void main() {
     if (v_Index == 0) {
-        o_Color = vec4(texture(sampler2D(u_Textures[0], u_Sampler), v_TexCoord).rgb, 1.0);
+        o_Color = vec4(texture(sampler2D(u_Textures[0], u_Sampler[0]), v_TexCoord).rgb, 1.0);
     } else if (v_Index == 1) {
-        o_Color = vec4(texture(sampler2D(u_Textures[1], u_Sampler), v_TexCoord).rgb, 1.0);
+        o_Color = vec4(texture(sampler2D(u_Textures[1], u_Sampler[1]), v_TexCoord).rgb, 1.0);
     } else {
         // We need to write something to output color
         o_Color = vec4(0.0, 0.0, 1.0, 0.0);

wgpu/examples/texture-arrays/main.rs

@@ -189,7 +189,7 @@ impl framework::Example for Example {
                     binding: 1,
                     visibility: wgpu::ShaderStages::FRAGMENT,
                     ty: wgpu::BindingType::Sampler(wgpu::SamplerBindingType::Filtering),
-                    count: None,
+                    count: NonZeroU32::new(2),
                 },
             ],
         });
@@ -205,7 +205,7 @@ impl framework::Example for Example {
                 },
                 wgpu::BindGroupEntry {
                     binding: 1,
-                    resource: wgpu::BindingResource::Sampler(&sampler),
+                    resource: wgpu::BindingResource::SamplerArray(&[&sampler, &sampler]),
                 },
             ],
             layout: &bind_group_layout,

wgpu/examples/texture-arrays/non-uniform.frag

@@ -7,8 +7,8 @@ layout(location = 1) nonuniformEXT flat in int v_Index;  // dynamically non-unif
 layout(location = 0) out vec4 o_Color;
 
 layout(set = 0, binding = 0) uniform texture2D u_Textures[2];
-layout(set = 0, binding = 1) uniform sampler u_Sampler;
+layout(set = 0, binding = 1) uniform sampler u_Sampler[2];
 
 void main() {
-    o_Color = vec4(texture(sampler2D(u_Textures[v_Index], u_Sampler), v_TexCoord).rgb, 1.0);
+    o_Color = vec4(texture(sampler2D(u_Textures[v_Index], u_Sampler[v_Index]), v_TexCoord).rgb, 1.0);
 }

wgpu/examples/texture-arrays/uniform.frag

@@ -5,11 +5,11 @@ layout(location = 1) flat in int v_Index;  // dynamically non-uniform
 layout(location = 0) out vec4 o_Color;
 
 layout(set = 0, binding = 0) uniform texture2D u_Textures[2];
-layout(set = 0, binding = 1) uniform sampler u_Sampler;
+layout(set = 0, binding = 1) uniform sampler u_Sampler[2];
 layout(push_constant) uniform Uniforms {
     int u_Index;  // dynamically uniform
 };
 
 void main() {
-    o_Color = vec4(texture(sampler2D(u_Textures[u_Index], u_Sampler), v_TexCoord).rgb, 1.0);
+    o_Color = vec4(texture(sampler2D(u_Textures[u_Index], u_Sampler[u_Index]), v_TexCoord).rgb, 1.0);
 }

wgpu/examples/texture-arrays/unsized-non-uniform.frag

@@ -7,8 +7,8 @@ layout(location = 1) nonuniformEXT flat in int v_Index;  // dynamically non-unif
 layout(location = 0) out vec4 o_Color;
 
 layout(set = 0, binding = 0) uniform texture2D u_Textures[];
-layout(set = 0, binding = 1) uniform sampler u_Sampler;
+layout(set = 0, binding = 1) uniform sampler u_Sampler[];
 
 void main() {
-    o_Color = vec4(texture(sampler2D(u_Textures[v_Index], u_Sampler), v_TexCoord).rgb, 1.0);
+    o_Color = vec4(texture(sampler2D(u_Textures[v_Index], u_Sampler[v_Index]), v_TexCoord).rgb, 1.0);
 }

wgpu/src/backend/direct.rs

@@ -1114,15 +1114,20 @@ impl crate::Context for Context {
         use wgc::binding_model as bm;
 
         let mut arrayed_texture_views = Vec::new();
+        let mut arrayed_samplers = Vec::new();
         if device.features.contains(Features::TEXTURE_BINDING_ARRAY) {
             // gather all the array view IDs first
             for entry in desc.entries.iter() {
                 if let BindingResource::TextureViewArray(array) = entry.resource {
                     arrayed_texture_views.extend(array.iter().map(|view| view.id));
                 }
+                if let BindingResource::SamplerArray(array) = entry.resource {
+                    arrayed_samplers.extend(array.iter().map(|sampler| sampler.id));
+                }
             }
         }
         let mut remaining_arrayed_texture_views = &arrayed_texture_views[..];
+        let mut remaining_arrayed_samplers = &arrayed_samplers[..];
 
         let mut arrayed_buffer_bindings = Vec::new();
         if device.features.contains(Features::BUFFER_BINDING_ARRAY) {
@@ -1161,6 +1166,11 @@ impl crate::Context for Context {
                         bm::BindingResource::BufferArray(Borrowed(slice))
                     }
                     BindingResource::Sampler(sampler) => bm::BindingResource::Sampler(sampler.id),
+                    BindingResource::SamplerArray(array) => {
+                        let slice = &remaining_arrayed_samplers[..array.len()];
+                        remaining_arrayed_samplers = &remaining_arrayed_samplers[array.len()..];
+                        bm::BindingResource::SamplerArray(Borrowed(slice))
+                    }
                     BindingResource::TextureView(texture_view) => {
                         bm::BindingResource::TextureView(texture_view.id)
                     }

wgpu/src/backend/web.rs

@@ -1380,6 +1380,9 @@ impl crate::Context for Context {
                         panic!("Web backend does not support arrays of buffers")
                     }
                     crate::BindingResource::Sampler(sampler) => JsValue::from(sampler.id.0.clone()),
+                    crate::BindingResource::SamplerArray(..) => {
+                        panic!("Web backend does not support arrays of samplers")
+                    }
                     crate::BindingResource::TextureView(texture_view) => {
                         JsValue::from(texture_view.id.0.clone())
                     }

wgpu/src/lib.rs

@@ -1005,6 +1005,13 @@ pub enum BindingResource<'a> {
     ///
     /// Corresponds to [`wgt::BindingType::Sampler`] with [`BindGroupLayoutEntry::count`] set to None.
     Sampler(&'a Sampler),
+    /// Binding is backed by an array of samplers.
+    ///
+    /// [`Features::TEXTURE_BINDING_ARRAY`] must be supported to use this feature.
+    ///
+    /// Corresponds to [`wgt::BindingType::Sampler`] with [`BindGroupLayoutEntry::count`] set
+    /// to Some.
+    SamplerArray(&'a [&'a Sampler]),
     /// Binding is backed by a texture.
     ///
     /// Corresponds to [`wgt::BindingType::Texture`] and [`wgt::BindingType::StorageTexture`] with