From e95481db2196069dce42da1e0e54a96d8e076953 Mon Sep 17 00:00:00 2001
From: Stephen Gutekanst <stephen@hexops.com>
Date: Tue, 16 Aug 2022 18:57:05 -0700
Subject: [PATCH] gpu: add ProgrammableStageDescriptor slice helper

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
---
 gpu/README.md     |  1 +
 gpu/src/types.zig | 17 ++++++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/gpu/README.md b/gpu/README.md
index c90c285a..e63ca339 100644
--- a/gpu/README.md
+++ b/gpu/README.md
@@ -176,6 +176,7 @@ And, to initialize data structures with slices in them, the following helpers ar
 * `Texture.Descriptor.init`
 * `ComputePassDescriptor.init`
 * `RenderPassDescriptor.init`
+* `ProgrammableStageDescriptor.init`
 
 ### Typed callbacks
 
diff --git a/gpu/src/types.zig b/gpu/src/types.zig
index 56ac536c..ba9b5ba5 100644
--- a/gpu/src/types.zig
+++ b/gpu/src/types.zig
@@ -655,9 +655,24 @@ pub const ProgrammableStageDescriptor = extern struct {
     next_in_chain: ?*const ChainedStruct = null,
     module: *ShaderModule,
     entry_point: [*:0]const u8,
-    // TODO: slice helper
     constant_count: u32 = 0,
     constants: ?[*]const ConstantEntry = null,
+
+    /// Provides a slightly friendlier Zig API to initialize this structure.
+    pub inline fn init(v: struct {
+        next_in_chain: ?*const ChainedStruct = null,
+        module: *ShaderModule,
+        entry_point: [*:0]const u8,
+        constants: ?[]const ConstantEntry = null,
+    }) ComputePassDescriptor {
+        return .{
+            .next_in_chain = v.next_in_chain,
+            .module = v.module,
+            .entry_point = v.entry_point,
+            .constant_count = if (v.timestamp_writes) |e| @intCast(u32, e.len) else 0,
+            .constants = if (v.constants) |e| e.ptr else null,
+        };
+    }
 };
 
 pub const RenderPassColorAttachment = extern struct {