gpu: use PowerPreference

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

gpu/examples/sample_utils.zig

@@ -74,7 +74,9 @@ pub fn setup(allocator: std.mem.Allocator) !Setup {
     try discoverAdapters(instance, window, backend_type);
 
     // Request an adapter.
-    const backend_adapter = switch (nosuspend gpu_interface.requestAdapter(&.{})) {
+    const backend_adapter = switch (nosuspend gpu_interface.requestAdapter(&.{
+        .power_preference = .high_performance,
+    })) {
         .adapter => |v| v,
         .err => |err| {
             std.debug.print("failed to get adapter: error={} {s}\n", .{ err.code, err.message });

gpu/src/BindGroupLayout.zig

@@ -34,7 +34,6 @@ pub const Descriptor = struct {
     entries: []const Entry,
 };
 
-// TODO: can this be extern struct / ABI compatible?
 pub const Entry = struct {
     binding: u32,
     visibility: ShaderStage,

gpu/src/Interface.zig

@@ -5,6 +5,7 @@ const std = @import("std");
 
 const Surface = @import("Surface.zig");
 const Adapter = @import("Adapter.zig");
+const PowerPreference = @import("enums.zig").PowerPreference;
 
 const Interface = @This();
 
@@ -30,8 +31,7 @@ pub inline fn release(interface: Interface) void {
 }
 
 pub const RequestAdapterOptions = struct {
-    // TODO:
-    //power_preference: PowerPreference,
+    power_preference: PowerPreference,
     force_fallback_adapter: bool = false,
 
     /// Only respected by native WebGPU implementations.

gpu/src/NativeInstance.zig

@@ -69,9 +69,7 @@ const interface_vtable = Interface.VTable{
             const opt = c.WGPURequestAdapterOptions{
                 .nextInChain = null,
                 .compatibleSurface = if (options.compatible_surface) |surface| @ptrCast(c.WGPUSurface, surface.ptr) else null,
-                // TODO:
-                //.powerPreference = power_preference,
-                .powerPreference = c.WGPUPowerPreference_Undefined,
+                .powerPreference = @enumToInt(options.power_preference),
                 .forceFallbackAdapter = options.force_fallback_adapter,
             };