From 8df0c70c69857ce6ce65a859eb1391ed0e694805 Mon Sep 17 00:00:00 2001
From: Stephen Gutekanst <stephen@hexops.com>
Date: Fri, 18 Mar 2022 18:21:54 -0700
Subject: [PATCH] gpu: implement Device.popErrorScope

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
---
 gpu/src/Device.zig         | 10 +++++++---
 gpu/src/NativeInstance.zig | 28 ++++++++++++++++++++++++++++
 gpu/src/structs.zig        | 24 ++++++++++++++++++++++++
 3 files changed, 59 insertions(+), 3 deletions(-)

diff --git a/gpu/src/Device.zig b/gpu/src/Device.zig
index a83521e1..d4af19fe 100644
--- a/gpu/src/Device.zig
+++ b/gpu/src/Device.zig
@@ -10,6 +10,7 @@ const Feature = @import("enums.zig").Feature;
 const ErrorType = @import("enums.zig").ErrorType;
 const ErrorFilter = @import("enums.zig").ErrorFilter;
 const Limits = @import("data.zig").Limits;
+const ErrorCallback = @import("structs.zig").ErrorCallback;
 const Queue = @import("Queue.zig");
 const ShaderModule = @import("ShaderModule.zig");
 const Surface = @import("Surface.zig");
@@ -72,9 +73,7 @@ pub const VTable = struct {
     // WGPU_EXPORT bool wgpuDeviceHasFeature(WGPUDevice device, WGPUFeature feature);
     injectError: fn (ptr: *anyopaque, type: ErrorType, message: [*:0]const u8) void,
     loseForTesting: fn (ptr: *anyopaque) void,
-    // TODO: callback
-    // popErrorScope: fn (ptr: *anyopaque, callback: ErrorCallback) bool,
-    // WGPU_EXPORT bool wgpuDevicePopErrorScope(WGPUDevice device, WGPUErrorCallback callback, void * userdata);
+    popErrorScope: fn (ptr: *anyopaque, callback: *ErrorCallback) bool,
     pushErrorScope: fn (ptr: *anyopaque, filter: ErrorFilter) void,
     // TODO: callback
     // setDeviceLostCallback: fn (ptr: *anyopaque, callback: DeviceLostCallback) void,
@@ -108,6 +107,10 @@ pub inline fn loseForTesting(device: Device) void {
     device.vtable.loseForTesting(device.ptr);
 }
 
+pub inline fn popErrorScope(device: Device, callback: *ErrorCallback) bool {
+    return device.vtable.popErrorScope(device.ptr, callback);
+}
+
 pub inline fn pushErrorScope(device: Device, filter: ErrorFilter) void {
     device.vtable.pushErrorScope(device.ptr, filter);
 }
@@ -217,6 +220,7 @@ test {
     _ = getQueue;
     _ = injectError;
     _ = loseForTesting;
+    _ = popErrorScope;
     _ = createBindGroup;
     _ = pushErrorScope;
     _ = createBindGroupLayout;
diff --git a/gpu/src/NativeInstance.zig b/gpu/src/NativeInstance.zig
index 5c10be7f..792a645a 100644
--- a/gpu/src/NativeInstance.zig
+++ b/gpu/src/NativeInstance.zig
@@ -49,6 +49,7 @@ const ErrorFilter = @import("enums.zig").ErrorFilter;
 
 const ImageCopyBuffer = @import("structs.zig").ImageCopyBuffer;
 const ImageCopyTexture = @import("structs.zig").ImageCopyTexture;
+const ErrorCallback = @import("structs.zig").ErrorCallback;
 
 const NativeInstance = @This();
 
@@ -333,6 +334,33 @@ const device_vtable = Device.VTable{
             c.wgpuDeviceLoseForTesting(@ptrCast(c.WGPUDevice, ptr));
         }
     }).loseForTesting,
+    .popErrorScope = (struct {
+        pub fn popErrorScope(
+            ptr: *anyopaque,
+            callback: *ErrorCallback,
+        ) bool {
+            const cCallback = (struct {
+                pub fn cCallback(
+                    typ: c.WGPUErrorType,
+                    message: [*c]const u8,
+                    userdata: ?*anyopaque,
+                ) callconv(.C) void {
+                    const callback_info = @ptrCast(*ErrorCallback, @alignCast(@alignOf(*ErrorCallback), userdata));
+                    callback_info.type_erased_callback(
+                        callback_info.type_erased_ctx,
+                        @intToEnum(ErrorType, typ),
+                        std.mem.span(message),
+                    );
+                }
+            }).cCallback;
+
+            return c.wgpuDevicePopErrorScope(
+                @ptrCast(c.WGPUDevice, ptr),
+                cCallback,
+                callback,
+            );
+        }
+    }).popErrorScope,
     .createBindGroup = (struct {
         pub fn createBindGroup(ptr: *anyopaque, descriptor: *const BindGroup.Descriptor) BindGroup {
             var few_entries: [16]c.WGPUBindGroupEntry = undefined;
diff --git a/gpu/src/structs.zig b/gpu/src/structs.zig
index 454cb69e..67eb1d4e 100644
--- a/gpu/src/structs.zig
+++ b/gpu/src/structs.zig
@@ -21,6 +21,7 @@ const RenderPassTimestampLocation = @import("enums.zig").RenderPassTimestampLoca
 const LoadOp = @import("enums.zig").LoadOp;
 const StoreOp = @import("enums.zig").StoreOp;
 const ColorWriteMask = @import("enums.zig").ColorWriteMask;
+const ErrorType = @import("enums.zig").ErrorType;
 
 pub const MultisampleState = struct {
     count: u32,
@@ -136,6 +137,28 @@ pub const ImageCopyTexture = struct {
     aspect: Texture.Aspect,
 };
 
+pub const ErrorCallback = struct {
+    type_erased_ctx: *anyopaque,
+    type_erased_callback: fn (ctx: *anyopaque, typ: ErrorType, message: [*:0]const u8) callconv(.Inline) void,
+
+    pub fn init(
+        comptime Context: type,
+        ctx: *Context,
+        comptime callback: fn (ctx: *Context, typ: ErrorType, message: [*:0]const u8) void,
+    ) ErrorCallback {
+        const erased = (struct {
+            pub inline fn erased(type_erased_ctx: *anyopaque, typ: ErrorType, message: [*:0]const u8) void {
+                callback(@ptrCast(*Context, @alignCast(@alignOf(*Context), type_erased_ctx)), typ, message);
+            }
+        }).erased;
+
+        return .{
+            .type_erased_ctx = ctx,
+            .type_erased_callback = erased,
+        };
+    }
+};
+
 test {
     _ = MultisampleState;
     _ = PrimitiveState;
@@ -151,4 +174,5 @@ test {
     _ = FragmentState;
     _ = ImageCopyBuffer;
     _ = ImageCopyTexture;
+    _ = ErrorCallback;
 }