Shrink the default max binding index to 640 and expose it in Limits.

Following the corresponding changes happening in WebGPU.

wgpu-core/src/device/mod.rs

@@ -32,9 +32,6 @@ pub mod queue;
 #[cfg(any(feature = "trace", feature = "replay"))]
 pub mod trace;
 
-// Per WebGPU specification.
-pub const MAX_BINDING_INDEX: u32 = 65535;
-
 pub const SHADER_STAGE_COUNT: usize = 3;
 // Should be large enough for the largest possible texture row. This value is enough for a 16k texture with float4 format.
 pub(crate) const ZERO_BUFFER_SIZE: BufferAddress = 512 << 10;
@@ -4128,10 +4125,10 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
 
             let mut entry_map = FastHashMap::default();
             for entry in desc.entries.iter() {
-                if entry.binding > MAX_BINDING_INDEX {
+                if entry.binding > device.limits.max_bindings_per_bind_group {
                     break 'outer binding_model::CreateBindGroupLayoutError::InvalidBindingIndex {
                         binding: entry.binding,
-                        maximum: MAX_BINDING_INDEX,
+                        maximum: device.limits.max_bindings_per_bind_group,
                     };
                 }
                 if entry_map.insert(entry.binding, *entry).is_some() {

wgpu-hal/src/dx11/adapter.rs

@@ -198,6 +198,7 @@ impl super::Adapter {
             max_texture_dimension_3d,
             max_texture_array_layers: max_texture_dimension_3d,
             max_bind_groups: u32::MAX,
+            max_bindings_per_bind_group: 65535,
             max_dynamic_uniform_buffers_per_pipeline_layout: max_constant_buffers,
             max_dynamic_storage_buffers_per_pipeline_layout: 0,
             max_sampled_textures_per_shader_stage: max_sampled_textures,

wgpu-hal/src/dx12/adapter.rs

@@ -245,6 +245,7 @@ impl super::Adapter {
                     max_texture_dimension_3d: d3d12::D3D12_REQ_TEXTURE3D_U_V_OR_W_DIMENSION,
                     max_texture_array_layers: d3d12::D3D12_REQ_TEXTURE2D_ARRAY_AXIS_DIMENSION,
                     max_bind_groups: crate::MAX_BIND_GROUPS as u32,
+                    max_bindings_per_bind_group: 65535,
                     // dynamic offsets take a root constant, so we expose the minimum here
                     max_dynamic_uniform_buffers_per_pipeline_layout: base
                         .max_dynamic_uniform_buffers_per_pipeline_layout,

wgpu-hal/src/gles/adapter.rs

@@ -426,6 +426,7 @@ impl super::Adapter {
             max_texture_dimension_3d: max_texture_3d_size,
             max_texture_array_layers: gl.get_parameter_i32(glow::MAX_ARRAY_TEXTURE_LAYERS) as u32,
             max_bind_groups: crate::MAX_BIND_GROUPS as u32,
+            max_bindings_per_bind_group: 65535,
             max_dynamic_uniform_buffers_per_pipeline_layout: max_uniform_buffers_per_shader_stage,
             max_dynamic_storage_buffers_per_pipeline_layout: max_storage_buffers_per_shader_stage,
             max_sampled_textures_per_shader_stage: super::MAX_TEXTURE_SLOTS as u32,

wgpu-hal/src/metal/adapter.rs

@@ -823,6 +823,7 @@ impl super::PrivateCapabilities {
                 max_texture_dimension_3d: self.max_texture_3d_size as u32,
                 max_texture_array_layers: self.max_texture_layers as u32,
                 max_bind_groups: 8,
+                max_bindings_per_bind_group: 65535,
                 max_dynamic_uniform_buffers_per_pipeline_layout: base
                     .max_dynamic_uniform_buffers_per_pipeline_layout,
                 max_dynamic_storage_buffers_per_pipeline_layout: base

wgpu-hal/src/vulkan/adapter.rs

@@ -673,6 +673,7 @@ impl PhysicalDeviceCapabilities {
             max_bind_groups: limits
                 .max_bound_descriptor_sets
                 .min(crate::MAX_BIND_GROUPS as u32),
+            max_bindings_per_bind_group: 640,
             max_dynamic_uniform_buffers_per_pipeline_layout: limits
                 .max_descriptor_set_uniform_buffers_dynamic,
             max_dynamic_storage_buffers_per_pipeline_layout: limits

wgpu-info/src/main.rs

@@ -156,6 +156,7 @@ mod inner {
             max_texture_dimension_3d,
             max_texture_array_layers,
             max_bind_groups,
+            max_bindings_per_bind_group,
             max_dynamic_uniform_buffers_per_pipeline_layout,
             max_dynamic_storage_buffers_per_pipeline_layout,
             max_sampled_textures_per_shader_stage,
@@ -185,6 +186,7 @@ mod inner {
         println!("\t\t                        Max Texture Dimension 3d: {}", max_texture_dimension_3d);
         println!("\t\t                        Max Texture Array Layers: {}", max_texture_array_layers);
         println!("\t\t                                 Max Bind Groups: {}", max_bind_groups);
+        println!("\t\t                     Max Bindings Per Bind Group: {}", max_bindings_per_bind_group);
         println!("\t\t Max Dynamic Uniform Buffers Per Pipeline Layout: {}", max_dynamic_uniform_buffers_per_pipeline_layout);
         println!("\t\t Max Dynamic Storage Buffers Per Pipeline Layout: {}", max_dynamic_storage_buffers_per_pipeline_layout);
         println!("\t\t           Max Sampled Textures Per Shader Stage: {}", max_sampled_textures_per_shader_stage);

wgpu-types/src/lib.rs

@@ -710,6 +710,8 @@ pub struct Limits {
     pub max_texture_array_layers: u32,
     /// Amount of bind groups that can be attached to a pipeline at the same time. Defaults to 4. Higher is "better".
     pub max_bind_groups: u32,
+    /// Maximum binding index allowed in `create_bind_group_layout`. Defaults to 640.
+    pub max_bindings_per_bind_group: u32,
     /// Amount of uniform buffer bindings that can be dynamic in a single pipeline. Defaults to 8. Higher is "better".
     pub max_dynamic_uniform_buffers_per_pipeline_layout: u32,
     /// Amount of storage buffer bindings that can be dynamic in a single pipeline. Defaults to 4. Higher is "better".
@@ -792,6 +794,7 @@ impl Default for Limits {
             max_texture_dimension_3d: 2048,
             max_texture_array_layers: 256,
             max_bind_groups: 4,
+            max_bindings_per_bind_group: 640,
             max_dynamic_uniform_buffers_per_pipeline_layout: 8,
             max_dynamic_storage_buffers_per_pipeline_layout: 4,
             max_sampled_textures_per_shader_stage: 16,
@@ -828,6 +831,7 @@ impl Limits {
             max_texture_dimension_3d: 256,
             max_texture_array_layers: 256,
             max_bind_groups: 4,
+            max_bindings_per_bind_group: 640,
             max_dynamic_uniform_buffers_per_pipeline_layout: 8,
             max_dynamic_storage_buffers_per_pipeline_layout: 4,
             max_sampled_textures_per_shader_stage: 16,

wgpu/src/backend/web.rs

@@ -1156,6 +1156,7 @@ impl crate::Context for Context {
             max_texture_dimension_3d: limits.max_texture_dimension_3d(),
             max_texture_array_layers: limits.max_texture_array_layers(),
             max_bind_groups: limits.max_bind_groups(),
+            max_bindings_per_bind_group: limits.max_bindings_per_bind_group(),
             max_dynamic_uniform_buffers_per_pipeline_layout: limits
                 .max_dynamic_uniform_buffers_per_pipeline_layout(),
             max_dynamic_storage_buffers_per_pipeline_layout: limits