From acb304973978435eae2d734d323ea39eb1496663 Mon Sep 17 00:00:00 2001
From: Stephen Gutekanst <stephen@hexops.com>
Date: Fri, 18 Mar 2022 17:31:39 -0700
Subject: [PATCH] gpu: implement Device.createPipelineLayout

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
---
 gpu/src/Device.zig         | 13 ++++++-------
 gpu/src/NativeInstance.zig | 30 +++++++++++++++++++++++++-----
 2 files changed, 31 insertions(+), 12 deletions(-)

diff --git a/gpu/src/Device.zig b/gpu/src/Device.zig
index c6b80400..3c4e4b58 100644
--- a/gpu/src/Device.zig
+++ b/gpu/src/Device.zig
@@ -20,6 +20,7 @@ const BindGroup = @import("BindGroup.zig");
 const BindGroupLayout = @import("BindGroupLayout.zig");
 const Buffer = @import("Buffer.zig");
 const ExternalTexture = @import("ExternalTexture.zig");
+const PipelineLayout = @import("PipelineLayout.zig");
 
 const Device = @This();
 
@@ -43,7 +44,7 @@ pub const VTable = struct {
     ) void,
     createErrorBuffer: fn (ptr: *anyopaque) Buffer,
     createExternalTexture: fn (ptr: *anyopaque, descriptor: *const ExternalTexture.Descriptor) ExternalTexture,
-    // createPipelineLayout: fn (ptr: *anyopaque, descriptor: *const PipelineLayout.Descriptor) PipelineLayout,
+    createPipelineLayout: fn (ptr: *anyopaque, descriptor: *const PipelineLayout.Descriptor) PipelineLayout,
     // createQuerySet: fn (ptr: *anyopaque, descriptor: *const QuerySet.Descriptor) QuerySet,
     // createRenderBundleEncoder: fn (ptr: *anyopaque, descriptor: *const RenderBundleEncoder.Descriptor) RenderBundleEncoder,
     createRenderPipeline: fn (ptr: *anyopaque, descriptor: *const RenderPipeline.Descriptor) RenderPipeline,
@@ -153,11 +154,9 @@ pub inline fn createExternalTexture(device: Device, descriptor: *const ExternalT
     return device.vtable.createExternalTexture(device.ptr, descriptor);
 }
 
-// pub inline fn createPipelineLayout(device: Device, descriptor: *const PipelineLayout.Descriptor) PipelineLayout {
-//     return device.vtable.createPipelineLayout(device.ptr, descriptor);
-// }
-// createPipelineLayout: fn (ptr: *anyopaque, descriptor: *const PipelineLayout.Descriptor) PipelineLayout,
-// WGPU_EXPORT WGPUPipelineLayout wgpuDeviceCreatePipelineLayout(WGPUDevice device, WGPUPipelineLayoutDescriptor const * descriptor);
+pub inline fn createPipelineLayout(device: Device, descriptor: *const PipelineLayout.Descriptor) PipelineLayout {
+    return device.vtable.createPipelineLayout(device.ptr, descriptor);
+}
 
 // pub inline fn createQuerySet(device: Device, descriptor: *const QuerySet.Descriptor) QuerySet {
 //     return device.vtable.createQuerySet(device.ptr, descriptor);
@@ -215,7 +214,7 @@ test {
     _ = createComputePipelineAsync;
     _ = createErrorBuffer;
     _ = createExternalTexture;
-    // _ = createPipelineLayout;
+    _ = createPipelineLayout;
     // _ = createQuerySet;
     // _ = createRenderBundleEncoder;
     _ = createRenderPipeline;
diff --git a/gpu/src/NativeInstance.zig b/gpu/src/NativeInstance.zig
index 9378de3a..04fd0369 100644
--- a/gpu/src/NativeInstance.zig
+++ b/gpu/src/NativeInstance.zig
@@ -523,12 +523,32 @@ const device_vtable = Device.VTable{
             return wrapExternalTexture(c.wgpuDeviceCreateExternalTexture(@ptrCast(c.WGPUDevice, ptr), &desc));
         }
     }).createExternalTexture,
+    .createPipelineLayout = (struct {
+        pub fn createPipelineLayout(ptr: *anyopaque, descriptor: *const PipelineLayout.Descriptor) PipelineLayout {
+            var few_bind_group_layouts: [16]c.WGPUBindGroupLayout = undefined;
+            const bind_group_layouts = if (descriptor.bind_group_layouts.len <= 16) blk: {
+                for (descriptor.bind_group_layouts) |layout, i| {
+                    few_bind_group_layouts[i] = @ptrCast(c.WGPUBindGroupLayout, layout.ptr);
+                }
+                break :blk few_bind_group_layouts[0..descriptor.bind_group_layouts.len];
+            } else blk: {
+                const mem = std.heap.page_allocator.alloc(c.WGPUBindGroupLayout, descriptor.bind_group_layouts.len) catch unreachable;
+                for (descriptor.bind_group_layouts) |layout, i| {
+                    mem[i] = @ptrCast(c.WGPUBindGroupLayout, layout.ptr);
+                }
+                break :blk mem;
+            };
+            defer if (descriptor.bind_group_layouts.len > 16) std.heap.page_allocator.free(descriptor.bind_group_layouts);
 
-    // pub inline fn createPipelineLayout(device: Device, descriptor: *const PipelineLayout.Descriptor) PipelineLayout {
-    //     return device.vtable.createPipelineLayout(device.ptr);
-    // }
-    // createPipelineLayout: fn (ptr: *anyopaque, descriptor: *const PipelineLayout.Descriptor) PipelineLayout,
-    // WGPU_EXPORT WGPUPipelineLayout wgpuDeviceCreatePipelineLayout(WGPUDevice device, WGPUPipelineLayoutDescriptor const * descriptor);
+            const desc = c.WGPUPipelineLayoutDescriptor{
+                .nextInChain = null,
+                .label = if (descriptor.label) |l| l else null,
+                .bindGroupLayoutCount = @intCast(u32, bind_group_layouts.len),
+                .bindGroupLayouts = &bind_group_layouts[0],
+            };
+            return wrapPipelineLayout(c.wgpuDeviceCreatePipelineLayout(@ptrCast(c.WGPUDevice, ptr), &desc));
+        }
+    }).createPipelineLayout,
 
     // pub inline fn createQuerySet(device: Device, descriptor: *const QuerySet.Descriptor) QuerySet {
     //     return device.vtable.createQuerySet(device.ptr);