gpu: implement Device.createBindGroup

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

gpu/src/Device.zig

@@ -15,6 +15,7 @@ const SwapChain = @import("SwapChain.zig");
 const RenderPipeline = @import("RenderPipeline.zig");
 const CommandEncoder = @import("CommandEncoder.zig");
 const ComputePipeline = @import("ComputePipeline.zig");
+const BindGroup = @import("BindGroup.zig");
 
 const Device = @This();
 
@@ -24,9 +25,9 @@ ptr: *anyopaque,
 vtable: *const VTable,
 
 pub const VTable = struct {
-    // TODO:
+    reference: fn (ptr: *anyopaque) void,
-    // createBindGroup: fn (ptr: *anyopaque, descriptor: *const BindGroup.Descriptor) BindGroup,
+    release: fn (ptr: *anyopaque) void,
-    // WGPU_EXPORT WGPUBindGroup wgpuDeviceCreateBindGroup(WGPUDevice device, WGPUBindGroupDescriptor const * descriptor);
+    createBindGroup: fn (ptr: *anyopaque, descriptor: *const BindGroup.Descriptor) BindGroup,
     // createBindGroupLayout: fn (ptr: *anyopaque, descriptor: *const BindGroupLayout.Descriptor) BindGroupLayout,
     // WGPU_EXPORT WGPUBindGroupLayout wgpuDeviceCreateBindGroupLayout(WGPUDevice device, WGPUBindGroupLayoutDescriptor const * descriptor);
     // createBuffer: fn (ptr: *anyopaque, descriptor: *const Buffer.Descriptor) Buffer,
@@ -88,15 +89,8 @@ pub const VTable = struct {
     // WGPU_EXPORT void wgpuDeviceSetUncapturedErrorCallback(WGPUDevice device, WGPUErrorCallback callback, void * userdata);
     // tick: fn (ptr: *anyopaque) void,
     // WGPU_EXPORT void wgpuDeviceTick(WGPUDevice device);
-
-    reference: fn (ptr: *anyopaque) void,
-    release: fn (ptr: *anyopaque) void,
 };
 
-pub inline fn getQueue(device: Device) Queue {
-    return device.vtable.getQueue(device.ptr);
-}
-
 pub inline fn reference(device: Device) void {
     device.vtable.reference(device.ptr);
 }
@@ -105,6 +99,14 @@ pub inline fn release(device: Device) void {
     device.vtable.release(device.ptr);
 }
 
+pub inline fn getQueue(device: Device) Queue {
+    return device.vtable.getQueue(device.ptr);
+}
+
+pub inline fn createBindGroup(device: Device, descriptor: *const BindGroup.Descriptor) void {
+    device.vtable.createBindGroup(device.ptr, descriptor);
+}
+
 pub inline fn createShaderModule(device: Device, descriptor: *const ShaderModule.Descriptor) ShaderModule {
     return device.vtable.createShaderModule(device.ptr, descriptor);
 }

gpu/src/NativeInstance.zig

@@ -321,6 +321,50 @@ const device_vtable = Device.VTable{
             return wrapQueue(c.wgpuDeviceGetQueue(@ptrCast(c.WGPUDevice, ptr)));
         }
     }).getQueue,
+    .createBindGroup = (struct {
+        pub fn createBindGroup(ptr: *anyopaque, descriptor: *const BindGroup.Descriptor) BindGroup {
+            var few_entries: [16]c.WGPUBindGroupEntry = undefined;
+            const entries = if (descriptor.entries.len <= 8) blk: {
+                for (descriptor.entries) |entry, i| {
+                    few_entries[i] = c.WGPUBindGroupEntry{
+                        .nextInChain = null,
+                        .binding = entry.binding,
+                        .buffer = @ptrCast(c.WGPUBuffer, entry.buffer.ptr),
+                        .offset = entry.offset,
+                        .size = entry.size,
+                        .sampler = @ptrCast(c.WGPUSampler, entry.sampler.ptr),
+                        .textureView = @ptrCast(c.WGPUTextureView, entry.texture_view.ptr),
+                    };
+                }
+                break :blk few_entries[0..descriptor.entries.len];
+            } else blk: {
+                const mem = std.heap.page_allocator.alloc(c.WGPUBindGroupEntry, descriptor.entries.len) catch unreachable;
+                for (descriptor.entries) |entry, i| {
+                    mem[i] = c.WGPUBindGroupEntry{
+                        .nextInChain = null,
+                        .binding = entry.binding,
+                        .buffer = @ptrCast(c.WGPUBuffer, entry.buffer.ptr),
+                        .offset = entry.offset,
+                        .size = entry.size,
+                        .sampler = @ptrCast(c.WGPUSampler, entry.sampler.ptr),
+                        .textureView = @ptrCast(c.WGPUTextureView, entry.texture_view.ptr),
+                    };
+                }
+                break :blk mem;
+            };
+            defer if (entries.len > 8) std.heap.page_allocator.free(entries);
+
+            const desc = c.WGPUBindGroupDescriptor{
+                .nextInChain = null,
+                .label = if (descriptor.label) |l| l else null,
+                .layout = @ptrCast(c.WGPUBindGroupLayout, descriptor.layout.ptr),
+                .entryCount = @intCast(u32, entries.len),
+                .entries = &entries[0],
+            };
+
+            return wrapBindGroup(c.wgpuDeviceCreateBindGroup(@ptrCast(c.WGPUDevice, ptr), &desc));
+        }
+    }).createBindGroup,
     .createShaderModule = (struct {
         pub fn createShaderModule(ptr: *anyopaque, descriptor: *const ShaderModule.Descriptor) ShaderModule {
             switch (descriptor.code) {