gpu: add PipelineLayout.Descriptor

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>

gpu/TODO-webgpu.h

@@ -1,10 +1,3 @@
-typedef struct WGPUPipelineLayoutDescriptor {
-    next_in_chain: *const ChainedStruct,
-    label: ?[*:0]const u8 = null,
-    uint32_t bindGroupLayoutCount;
-    WGPUBindGroupLayout const * bindGroupLayouts;
-} WGPUPipelineLayoutDescriptor;
-
 typedef struct WGPUPrimitiveDepthClampingState {
     WGPUChainedStruct chain;
     clamp_depth: bool,

gpu/src/external_texture.zig

@@ -1,5 +1,5 @@
-pub const ChainedStruct = @import("types.zig").ChainedStruct;
-pub const TextureView = @import("texture_view.zig").TextureView;
+const ChainedStruct = @import("types.zig").ChainedStruct;
+const TextureView = @import("texture_view.zig").TextureView;
 
 pub const ExternalTexture = enum(usize) {
     _,

gpu/src/instance.zig

@@ -1,4 +1,4 @@
-pub const ChainedStruct = @import("types.zig").ChainedStruct;
+const ChainedStruct = @import("types.zig").ChainedStruct;
 
 pub const Instance = enum(usize) {
     _,

gpu/src/pipeline_layout.zig

@@ -1,6 +1,16 @@
+const ChainedStruct = @import("types.zig").ChainedStruct;
+const BindGroupLayout = @import("bind_group_layout.zig").BindGroupLayout;
+
 pub const PipelineLayout = enum(usize) {
     _,
 
     // TODO: verify there is a use case for nullable value of this type.
     pub const none: PipelineLayout = @intToEnum(PipelineLayout, 0);
+
+    pub const Descriptor = extern struct {
+        next_in_chain: *const ChainedStruct,
+        label: ?[*:0]const u8 = null,
+        bind_group_layout_count: u32,
+        bind_group_layouts: [*]const BindGroupLayout,
+    };
 };