gpu: improve how limits are represented

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

gpu/src/Adapter.zig

@@ -20,7 +20,7 @@
 const std = @import("std");
 
 const FeatureName = @import("feature_name.zig").FeatureName;
-const SupportedLimits = @import("supported_limits.zig").SupportedLimits;
+const Limits = @import("Limits.zig");
 const Device = @import("Device.zig");
 
 const Adapter = @This();
@@ -31,7 +31,7 @@ features: []FeatureName,
 /// The best limits which can be used to create devices on this adapter.
 ///
 /// Each adapter limit will be the same or better than its default value in supported limits.
-limits: SupportedLimits,
+limits: Limits,
 
 /// If set to true indicates that the adapter is a fallback adapter.
 ///
@@ -54,7 +54,8 @@ vtable: *const VTable,
 request_device_frame_size: usize,
 
 pub const VTable = struct {
-    // TODO:
+    // TODO: is this method actually useful over requestDevice? Doesn't appear to be available in
+    // web either:
     // WGPU_EXPORT WGPUDevice wgpuAdapterCreateDevice(WGPUAdapter adapter, WGPUDeviceDescriptor const * descriptor);
     reference: fn (ptr: *anyopaque) void,
     release: fn (ptr: *anyopaque) void,

gpu/src/Device.zig

@@ -7,6 +7,7 @@
 //! https://gpuweb.github.io/gpuweb/#devices
 //! https://gpuweb.github.io/gpuweb/#gpuadapter
 const FeatureName = @import("feature_name.zig").FeatureName;
+const Limits = @import("Limits.zig");
 
 const Device = @This();
 
@@ -56,8 +57,7 @@ pub const VTable = struct {
 pub const Descriptor = struct {
     label: ?[]const u8 = null,
     required_features: ?[]FeatureName = null,
-    // TODO:
+    required_limits: ?Limits = null,
-    //required_limits: ?RequiredLimits = null,
 };
 
 test "syntax" {

gpu/src/Limits.zig

@@ -1,9 +1,12 @@
-pub const SupportedLimits = struct {};
+// TODO: docs
+
 // TODO:
 // typedef struct WGPUSupportedLimits {
 //     WGPUChainedStructOut * nextInChain;
 //     WGPULimits limits;
 // } WGPUSupportedLimits;
+
+// TODO:
 // typedef struct WGPULimits {
 //     uint32_t maxTextureDimension1D;
 //     uint32_t maxTextureDimension2D;

gpu/src/NativeInstance.zig

@@ -2,20 +2,20 @@
 const std = @import("std");
 const c = @import("c.zig").c;
 
-pub const Interface = @import("Interface.zig");
+const Interface = @import("Interface.zig");
-pub const RequestAdapterOptions = Interface.RequestAdapterOptions;
+const RequestAdapterOptions = Interface.RequestAdapterOptions;
-pub const RequestAdapterErrorCode = Interface.RequestAdapterErrorCode;
+const RequestAdapterErrorCode = Interface.RequestAdapterErrorCode;
-pub const RequestAdapterError = Interface.RequestAdapterError;
+const RequestAdapterError = Interface.RequestAdapterError;
-pub const RequestAdapterResponse = Interface.RequestAdapterResponse;
+const RequestAdapterResponse = Interface.RequestAdapterResponse;
 
-pub const Adapter = @import("Adapter.zig");
+const Adapter = @import("Adapter.zig");
-pub const RequestDeviceErrorCode = Adapter.RequestDeviceErrorCode;
+const RequestDeviceErrorCode = Adapter.RequestDeviceErrorCode;
-pub const RequestDeviceError = Adapter.RequestDeviceError;
+const RequestDeviceError = Adapter.RequestDeviceError;
-pub const RequestDeviceResponse = Adapter.RequestDeviceResponse;
+const RequestDeviceResponse = Adapter.RequestDeviceResponse;
-
-pub const Device = @import("Device.zig");
 
+const Device = @import("Device.zig");
 const Surface = @import("Surface.zig");
+const Limits = @import("Limits.zig");
 
 const NativeInstance = @This();
 
@@ -233,12 +233,17 @@ const adapter_vtable = Adapter.VTable{
         pub fn requestDevice(ptr: *anyopaque, descriptor: *const Device.Descriptor) callconv(.Async) RequestDeviceResponse {
             const adapter = @ptrCast(c.WGPUAdapter, @alignCast(@alignOf(c.WGPUAdapter), ptr));
 
+            const required_limits = if (descriptor.required_limits) |l| c.WGPURequiredLimits{
+                .nextInChain = null,
+                .limits = convertLimits(l),
+            } else null;
+
             const desc = c.WGPUDeviceDescriptor{
                 .nextInChain = null,
                 .label = if (descriptor.label) |l| @ptrCast([*c]const u8, l) else null,
                 .requiredFeaturesCount = if (descriptor.required_features) |f| @intCast(u32, f.len) else 0,
                 .requiredFeatures = if (descriptor.required_features) |f| @ptrCast([*c]const c_uint, &f[0]) else null,
-                .requiredLimits = null, // TODO
+                .requiredLimits = if (required_limits) |*l| l else null,
             };
 
             const callback = (struct {
@@ -295,6 +300,12 @@ const device_vtable = Device.VTable{
     }).release,
 };
 
+fn convertLimits(l: Limits) c.WGPULimits {
+    // TODO: implement!
+    _ = l;
+    return std.mem.zeroes(c.WGPULimits);
+}
+
 test "syntax" {
     _ = wrap;
     _ = interface_vtable;
@@ -304,4 +315,5 @@ test "syntax" {
     _ = adapter_vtable;
     _ = wrapDevice;
     _ = device_vtable;
+    _ = convertLimits;
 }

gpu/src/TODO

@@ -955,11 +955,6 @@ typedef struct WGPURenderPassColorAttachment {
     WGPUColor clearValue;
 } WGPURenderPassColorAttachment;
 
-typedef struct WGPURequiredLimits {
-    WGPUChainedStruct const * nextInChain;
-    WGPULimits limits;
-} WGPURequiredLimits;
-
 typedef struct WGPUTextureDescriptor {
     WGPUChainedStruct const * nextInChain;
     char const * label;

gpu/src/main.zig

@@ -30,9 +30,9 @@ pub const NativeInstance = @import("NativeInstance.zig");
 pub const Adapter = @import("Adapter.zig");
 pub const Device = @import("Device.zig");
 pub const Surface = @import("Surface.zig");
+pub const Limits = @import("Limits.zig");
 
 pub const FeatureName = @import("feature_name.zig").FeatureName;
-pub const SupportedLimits = @import("supported_limits.zig").SupportedLimits;
 
 test "syntax" {
     _ = Interface;
@@ -41,7 +41,7 @@ test "syntax" {
     _ = Adapter;
     _ = Device;
     _ = Surface;
+    _ = Limits;
 
     _ = FeatureName;
-    _ = SupportedLimits;
 }