gpu: Added helpers to BindGroup.Entry; make dynamic_offset a const slice (#215)

Helps hexops/mach#

gpu/src/BindGroup.zig

@@ -35,6 +35,34 @@ pub const Entry = struct {
     size: u64,
     sampler: ?Sampler = null,
     texture_view: ?TextureView = null,
+
+    /// Helper to create a buffer BindGroup.Entry.
+    pub fn buffer(binding: u32, buf: Buffer, offset: u64, size: u64) Entry {
+        return .{
+            .binding = binding,
+            .buffer = buf,
+            .offset = offset,
+            .size = size,
+        };
+    }
+
+    /// Helper to create a sampler BindGroup.Entry.
+    pub fn sampler(binding: u32, sam: Sampler) Entry {
+        return .{
+            .binding = binding,
+            .sampler = sam,
+            .size = 0,
+        };
+    }
+
+    /// Helper to create a texture view BindGroup.Entry.
+    pub fn textureView(binding: u32, texview: TextureView) Entry {
+        return .{
+            .binding = binding,
+            .texture_view = texview,
+            .size = 0,
+        };
+    }
 };
 
 pub const Descriptor = struct {

gpu/src/NativeInstance.zig

@@ -1298,7 +1298,7 @@ const render_pass_encoder_vtable = RenderPassEncoder.VTable{
             ptr: *anyopaque,
             group_index: u32,
             group: BindGroup,
-            dynamic_offsets: []u32,
+            dynamic_offsets: []const u32,
         ) void {
             c.wgpuRenderPassEncoderSetBindGroup(
                 @ptrCast(c.WGPURenderPassEncoder, ptr),
@@ -1495,7 +1495,7 @@ const render_bundle_encoder_vtable = RenderBundleEncoder.VTable{
             ptr: *anyopaque,
             group_index: u32,
             group: BindGroup,
-            dynamic_offsets: []u32,
+            dynamic_offsets: []const u32,
         ) void {
             c.wgpuRenderBundleEncoderSetBindGroup(
                 @ptrCast(c.WGPURenderBundleEncoder, ptr),
@@ -2157,7 +2157,7 @@ const compute_pass_encoder_vtable = ComputePassEncoder.VTable{
             ptr: *anyopaque,
             group_index: u32,
             group: BindGroup,
-            dynamic_offsets: []u32,
+            dynamic_offsets: []const u32,
         ) void {
             c.wgpuComputePassEncoderSetBindGroup(
                 @ptrCast(c.WGPUComputePassEncoder, ptr),

gpu/src/RenderPassEncoder.zig

@@ -37,7 +37,7 @@ pub const VTable = struct {
     insertDebugMarker: fn (ptr: *anyopaque, marker_label: [*:0]const u8) void,
     popDebugGroup: fn (ptr: *anyopaque) void,
     pushDebugGroup: fn (ptr: *anyopaque, group_label: [*:0]const u8) void,
-    setBindGroup: fn (ptr: *anyopaque, group_index: u32, group: BindGroup, dynamic_offsets: []u32) void,
+    setBindGroup: fn (ptr: *anyopaque, group_index: u32, group: BindGroup, dynamic_offsets: []const u32) void,
     setBlendConstant: fn (ptr: *anyopaque, color: *const Color) void,
     setIndexBuffer: fn (ptr: *anyopaque, buffer: Buffer, format: IndexFormat, offset: u64, size: u64) void,
     setLabel: fn (ptr: *anyopaque, label: [:0]const u8) void,
@@ -118,7 +118,7 @@ pub inline fn setBindGroup(
     pass: RenderPassEncoder,
     group_index: u32,
     group: BindGroup,
-    dynamic_offsets: []u32,
+    dynamic_offsets: []const u32,
 ) void {
     pass.vtable.setBindGroup(pass.ptr, group_index, group, dynamic_offsets);
 }