Add WGL context creation and OpenGL support

CHANGELOG.md

@@ -44,6 +44,12 @@ Bottom level categories:
 
 - Update Naga to 9eb3a1dc (2023-10-12), which includes support for WGSL constant expressions. By @jimblandy in [#4233](https://github.com/gfx-rs/wgpu/pull/4233)
 
+#### Support desktop OpenGL via WGL on Windows
+
+Added creating of full OpenGL contexts to the GLES backend using WGL to support older devices.
+
+By @Zoxc in [#4248](https://github.com/gfx-rs/wgpu/pull/4248)
+
 #### Pass timestamp queries
 
 Addition of `TimestampWrites` to compute and render passes to allow profiling.

README.md

@@ -70,14 +70,14 @@ We have a [wiki](https://github.com/gfx-rs/wgpu/wiki) that serves as a knowledge
 
 ## Supported Platforms
 
-| API       | Windows                        | Linux & Android    | macOS & iOS               | Web (wasm)                |
-| --------- | ------------------------------ | ------------------ | ------------------------- | ------------------------- |
-| Vulkan    | :white_check_mark:             | :white_check_mark: | :ok: (vulkan-portability) |                           |
-| Metal     |                                |                    | :white_check_mark:        |                           |
-| DX12      | :white_check_mark: (W10+ only) |                    |                           |                           |
-| DX11      | :hammer_and_wrench:            |                    |                           |                           |
-| GLES3     | :ok: (angle)                   | :ok:               | :ok: (angle; macOS only)  | :ok: (WebGL2 Only)        |
-| WebGPU    |                                |                    |                           | :white_check_mark:        |
+| API         | Windows                        | Linux & Android    | macOS & iOS               | Web (wasm)                |
+| ----------- | ------------------------------ | ------------------ | ------------------------- | ------------------------- |
+| Vulkan      | :white_check_mark:             | :white_check_mark: | :ok: (vulkan-portability) |                           |
+| Metal       |                                |                    | :white_check_mark:        |                           |
+| DX12        | :white_check_mark: (W10+ only) |                    |                           |                           |
+| DX11        | :hammer_and_wrench:            |                    |                           |                           |
+| OpenGL      |  :ok: (Desktop GL 3.3+)        | :ok: (GL ES 3.0+)  | :ok: (angle; GL ES 3.0+)  | :ok: (WebGL2)             |
+| WebGPU      |                                |                    |                           | :white_check_mark:        |
 
 :white_check_mark: = First Class Support — :ok: = Best Effort Support — :hammer_and_wrench: = Unsupported, but support in progress
 
@@ -148,6 +148,7 @@ We have multiple methods of testing, each of which tests different qualities abo
 | DX11/Windows 10  | :construction:     | —                  | using WARP                            |
 | Metal/MacOS      | :heavy_check_mark: | —                  | using hardware runner                 |
 | Vulkan/Linux     | :heavy_check_mark: | -                  | using swiftshader                     |
+| GL/Windows       |                    | —                  |                                       |
 | GLES/Linux       | :heavy_check_mark: | —                  | using llvmpipe                        |
 | WebGL/Chrome     | :heavy_check_mark: | —                  | using swiftshader                     |
 

tests/tests/multi-instance.rs

@@ -0,0 +1,33 @@
+#![cfg(not(target_arch = "wasm32"))]
+
+async fn get() -> wgpu::Adapter {
+    let adapter = {
+        let instance = wgpu::Instance::new(wgpu::InstanceDescriptor {
+            backends: wgpu::util::backend_bits_from_env().unwrap_or_else(wgpu::Backends::all),
+            ..Default::default()
+        });
+        instance
+            .request_adapter(&wgpu::RequestAdapterOptions::default())
+            .await
+            .unwrap()
+    };
+
+    log::info!("Selected adapter: {:?}", adapter.get_info());
+
+    adapter
+}
+
+#[test]
+fn multi_instance() {
+    {
+        env_logger::init();
+
+        // Sequential instances.
+        for _ in 0..3 {
+            pollster::block_on(get());
+        }
+
+        // Concurrent instances
+        let _instances: Vec<_> = (0..3).map(|_| pollster::block_on(get())).collect();
+    }
+}

wgpu-hal/Cargo.toml

@@ -36,7 +36,7 @@ targets = [
 default = ["link"]
 metal = ["naga/msl-out", "block"]
 vulkan = ["naga/spv-out", "ash", "gpu-alloc", "gpu-descriptor", "libloading", "smallvec"]
-gles = ["naga/glsl-out", "glow", "khronos-egl", "libloading"]
+gles = ["naga/glsl-out", "glow", "glutin_wgl_sys", "khronos-egl", "libloading"]
 dx11 = ["naga/hlsl-out", "d3d12", "libloading", "winapi/d3d11", "winapi/std", "winapi/d3d11_1", "winapi/d3d11_2", "winapi/d3d11sdklayers", "winapi/dxgi1_6"]
 dx12 = ["naga/hlsl-out", "d3d12", "bit-set", "libloading", "range-alloc", "winapi/std", "winapi/winbase", "winapi/d3d12", "winapi/d3d12shader", "winapi/d3d12sdklayers", "winapi/dxgi1_6"]
 # TODO: This is a separate feature until Mozilla okays windows-rs, see https://github.com/gfx-rs/wgpu/issues/3207 for the tracking issue.
@@ -59,6 +59,7 @@ parking_lot = ">=0.11,<0.13"
 profiling = { version = "1", default-features = false }
 raw-window-handle = "0.5"
 thiserror = "1"
+once_cell = "1.18.0"
 
 # backends common
 arrayvec = "0.7"
@@ -95,6 +96,8 @@ bit-set = { version = "0.5", optional = true }
 range-alloc = { version = "0.1", optional = true }
 gpu-allocator = { version = "0.23", default_features = false, features = ["d3d12", "public-winapi"], optional = true }
 hassle-rs = { version = "0.10", optional = true }
+# backend: Gles
+glutin_wgl_sys = { version = "0.4", optional = true }
 
 winapi = { version = "0.3", features = ["profileapi", "libloaderapi", "windef", "winuser", "dcomp"] }
 d3d12 = { version = "0.7", features = ["libloading"], optional = true }

wgpu-hal/examples/raw-gles.rs

@@ -10,7 +10,7 @@
 
 extern crate wgpu_hal as hal;
 
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(not(any(windows, target_arch = "wasm32")))]
 fn main() {
     env_logger::init();
     println!("Initializing external GL context");
@@ -116,10 +116,10 @@ fn main() {
     fill_screen(&exposed, 640, 400);
 }
 
-#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
+#[cfg(any(windows, all(target_arch = "wasm32", not(target_os = "emscripten"))))]
 fn main() {}
 
-#[cfg(any(not(target_arch = "wasm32"), target_os = "emscripten"))]
+#[cfg(any(not(any(windows, target_arch = "wasm32")), target_os = "emscripten"))]
 fn fill_screen(exposed: &hal::ExposedAdapter<hal::api::Gles>, width: u32, height: u32) {
     use hal::{Adapter as _, CommandEncoder as _, Device as _, Queue as _};