From 64e023c992f7e5f4c7b81fdc2aec79a68183d3ab Mon Sep 17 00:00:00 2001
From: Stephen Gutekanst <stephen@hexops.com>
Date: Sun, 6 Mar 2022 20:28:10 -0700
Subject: [PATCH] gpu: prepare to implement Surface

Signed-off-by: Stephen Gutekanst <stephen@hexops.com>
---
 gpu/src/Interface.zig      |  7 +++++-
 gpu/src/NativeInstance.zig | 27 ++++++++++++++++------
 gpu/src/Surface.zig        | 46 ++++++++++++++++++++++++++++++++++++++
 gpu/src/main.zig           |  2 ++
 4 files changed, 74 insertions(+), 8 deletions(-)
 create mode 100644 gpu/src/Surface.zig

diff --git a/gpu/src/Interface.zig b/gpu/src/Interface.zig
index e4eff7fe..22553e36 100644
--- a/gpu/src/Interface.zig
+++ b/gpu/src/Interface.zig
@@ -8,5 +8,10 @@ vtable: *const VTable,
 
 pub const VTable = struct {
     // TODO(gpu): make these *const fn once stage2 is released.
-    free: fn (ptr: *anyopaque, buf: []u8, buf_align: u29, ret_addr: usize) void,
+    deinit: fn (ptr: *anyopaque) void,
 };
+
+// TODO:
+// WGPU_EXPORT void wgpuInstanceRequestAdapter(WGPUInstance instance, WGPURequestAdapterOptions const * options, WGPURequestAdapterCallback callback, void * userdata);
+// WGPU_EXPORT void wgpuInstanceReference(WGPUInstance instance);
+// WGPU_EXPORT void wgpuInstanceRelease(WGPUInstance instance);
diff --git a/gpu/src/NativeInstance.zig b/gpu/src/NativeInstance.zig
index a02ae409..da38fe87 100644
--- a/gpu/src/NativeInstance.zig
+++ b/gpu/src/NativeInstance.zig
@@ -1,18 +1,29 @@
 //! A native webgpu.h implementation of the gpu.Interface
 const c = @import("c.zig").c;
 const Interface = @import("Interface.zig");
+const Surface = @import("Surface.zig");
 
 const NativeInstance = @This();
 
 /// The WGPUInstance that is wrapped by this native instance.
 instance: c.WGPUInstance,
 
-/// Returns the gpu.Interface for interacting with this native instance.
-pub fn interface(native: NativeInstance) Interface {
-    _ = native;
-    @panic("not implemented");
+vtable: Interface.VTable,
 
+/// Wraps a native WGPUInstance to provide an implementation of the gpu.Interface.
+pub fn wrap(instance: c.WGPUInstance) NativeInstance {
+    return .{ .instance = instance };
+}
+
+/// Returns the gpu.Interface for interacting with this native instance.
+pub fn interface(native: *const NativeInstance) Interface {
+    return .{
+        .ptr = native,
+        .vtable = native.vtable,
+    };
     // TODO: implement Interface
+    // WGPU_EXPORT void wgpuInstanceReference(WGPUInstance instance);
+    // WGPU_EXPORT void wgpuInstanceRelease(WGPUInstance instance);
 
     // TODO: implement Device interface
 
@@ -25,7 +36,9 @@ pub fn interface(native: NativeInstance) Interface {
     // WGPU_EXPORT void wgpuAdapterGetProperties(WGPUAdapter adapter, WGPUAdapterProperties * properties);
 }
 
-/// Wraps a native WGPUInstance to provide an implementation of the gpu.Interface.
-pub fn wrap(instance: c.WGPUInstance) NativeInstance {
-    return .{ .instance = instance };
+pub fn createSurface(native: *const NativeInstance, descriptor: *const Surface.Descriptor) Surface {
+    _ = native;
+    _ = descriptor;
+    // TODO:
+    // WGPU_EXPORT WGPUSurface wgpuInstanceCreateSurface(WGPUInstance instance, WGPUSurfaceDescriptor const * descriptor);
 }
diff --git a/gpu/src/Surface.zig b/gpu/src/Surface.zig
new file mode 100644
index 00000000..262b7e73
--- /dev/null
+++ b/gpu/src/Surface.zig
@@ -0,0 +1,46 @@
+//! A native WebGPU surface
+
+// typedef enum WGPUSType {
+//     WGPUSType_Invalid = 0x00000000,
+//     WGPUSType_SurfaceDescriptorFromMetalLayer = 0x00000001,
+//     WGPUSType_SurfaceDescriptorFromWindowsHWND = 0x00000002,
+//     WGPUSType_SurfaceDescriptorFromXlibWindow = 0x00000003,
+//     WGPUSType_SurfaceDescriptorFromCanvasHTMLSelector = 0x00000004,
+
+const Descriptor = struct {};
+// typedef struct WGPUSurfaceDescriptor {
+//     WGPUChainedStruct const * nextInChain;
+//     char const * label;
+// } WGPUSurfaceDescriptor;
+
+// typedef struct WGPUSurfaceDescriptorFromCanvasHTMLSelector {
+//     WGPUChainedStruct chain;
+//     char const * selector;
+// } WGPUSurfaceDescriptorFromCanvasHTMLSelector;
+
+// typedef struct WGPUSurfaceDescriptorFromMetalLayer {
+//     WGPUChainedStruct chain;
+//     void * layer;
+// } WGPUSurfaceDescriptorFromMetalLayer;
+
+// typedef struct WGPUSurfaceDescriptorFromWindowsCoreWindow {
+//     WGPUChainedStruct chain;
+//     void * coreWindow;
+// } WGPUSurfaceDescriptorFromWindowsCoreWindow;
+
+// typedef struct WGPUSurfaceDescriptorFromWindowsHWND {
+//     WGPUChainedStruct chain;
+//     void * hinstance;
+//     void * hwnd;
+// } WGPUSurfaceDescriptorFromWindowsHWND;
+
+// typedef struct WGPUSurfaceDescriptorFromWindowsSwapChainPanel {
+//     WGPUChainedStruct chain;
+//     void * swapChainPanel;
+// } WGPUSurfaceDescriptorFromWindowsSwapChainPanel;
+
+// typedef struct WGPUSurfaceDescriptorFromXlibWindow {
+//     WGPUChainedStruct chain;
+//     void * display;
+//     uint32_t window;
+// } WGPUSurfaceDescriptorFromXlibWindow;
diff --git a/gpu/src/main.zig b/gpu/src/main.zig
index 7a42857c..8c7342d4 100644
--- a/gpu/src/main.zig
+++ b/gpu/src/main.zig
@@ -21,6 +21,7 @@ const NativeInstance = @import("NativeInstance.zig");
 
 const Adapter = @import("Adapter.zig");
 const Device = @import("Device.zig");
+const Surface = @import("Surface.zig");
 
 const FeatureName = @import("feature_name.zig").FeatureName;
 const SupportedLimits = @import("supported_limits.zig").SupportedLimits;
@@ -31,6 +32,7 @@ test "syntax" {
 
     _ = Adapter;
     _ = Device;
+    _ = Surface;
 
     _ = FeatureName;
     _ = SupportedLimits;