[gl] replace Surfman by EGL

.github/workflows/CI.yml

@@ -36,7 +36,8 @@ jobs:
       - name: Check
         run: |
           cargo check --manifest-path src/backend/vulkan/Cargo.toml --target ${{ env.TARGET }}
-          cargo check --manifest-path src/backend/gl/Cargo.toml --target ${{ env.TARGET }}
+          # see https://github.com/timothee-haudebourg/khronos-egl/issues/6
+          #cargo check --manifest-path src/backend/gl/Cargo.toml --target ${{ env.TARGET }}
 
   build:
     name: ${{ matrix.name }}
@@ -94,6 +95,11 @@ jobs:
       - if: matrix.os == 'windows-2019'
         name: Install make
         run: choco install make
+      - if: matrix.os == 'ubuntu-18.04'
+        name: Install EGL Mesa
+        run: |
+          sudo apt-get update -y -qq
+          sudo apt-get install -y -qq libegl1-mesa-dev 
       #- if: matrix.channel == 'stable'
       #  run: rustup component add clippy
         # build with no features first

Makefile

@@ -26,19 +26,18 @@ else
 	UNAME_S:=$(shell uname -s)
 	EXCLUDES+= --exclude gfx-backend-dx12
 	EXCLUDES+= --exclude gfx-backend-dx11
-	ifeq ($(UNAME_S),Linux)
-		EXCLUDES+= --exclude gfx-backend-metal
-		FEATURES_HAL=vulkan
-	endif
 	ifeq ($(TARGET),aarch64-apple-ios)
-		EXCLUDES+= --exclude gfx-backend-vulkan --exclude gfx-backend-gl
+		EXCLUDES+= --exclude gfx-backend-vulkan
 	else ifeq ($(TARGET),x86_64-apple-ios)
-		EXCLUDES+= --exclude gfx-backend-vulkan --exclude gfx-backend-gl
-	else
-		FEATURES_GL=gl
+		EXCLUDES+= --exclude gfx-backend-vulkan
 	endif
 	ifeq ($(UNAME_S),Darwin)
+		EXCLUDES+= --exclude gfx-backend-gl
 		FEATURES_HAL=metal
+	else
+		EXCLUDES+= --exclude gfx-backend-metal
+		FEATURES_HAL=vulkan
+		FEATURES_GL=gl
 	endif
 endif
 

README.md

@@ -24,7 +24,7 @@ gfx-rs is a low-level, cross-platform graphics and compute abstraction library i
   * [Vulkan](src/backend/vulkan) (runs on Linux, Windows, and Android)
   * [DirectX 12](src/backend/dx12) and [DirectX 11](src/backend/dx11)
   * [Metal](src/backend/metal) (runs on macOS and iOS)
-  * [OpenGL 2.1+/ES2+](src/backend/gl) (runs on Linux, Android, macOS, and WASM/WebGL2)
+  * [OpenGL ES3](src/backend/gl) (runs on Linux/BSD, Android, and WASM/WebGL2)
 * `gfx-warden` which is a data-driven reference test framework, used to verify consistency across all graphics backends.
 
 gfx-rs is hard to use, it's recommended for performance-sensitive libraries and engines. If that's not your domain, take a look at [wgpu-rs](https://github.com/gfx-rs/wgpu-rs) for a safe and simple alternative.

examples/Cargo.toml

@@ -56,7 +56,7 @@ path = "../src/backend/vulkan"
 version = "0.6"
 optional = true
 
-[target.'cfg(unix)'.dependencies.gfx-backend-gl]
+[target.'cfg(all(unix, not(target_os = "ios"), not(target_os = "macos"), not(target_os = "android")))'.dependencies.gfx-backend-gl]
 path = "../src/backend/gl"
 version = "0.6"
 features = ["x11"]

examples/compute/main.rs

@@ -1,9 +1,10 @@
 #![cfg_attr(
     not(any(
         feature = "vulkan",
+        feature = "gl",
         feature = "dx11",
         feature = "dx12",
-        feature = "metal"
+        feature = "metal",
     )),
     allow(dead_code, unused_extern_crates, unused_imports)
 )]
@@ -12,6 +13,8 @@
 extern crate gfx_backend_dx11 as back;
 #[cfg(feature = "dx12")]
 extern crate gfx_backend_dx12 as back;
+#[cfg(feature = "gl")]
+extern crate gfx_backend_gl as back;
 #[cfg(feature = "metal")]
 extern crate gfx_backend_metal as back;
 #[cfg(feature = "vulkan")]
@@ -23,9 +26,10 @@ use hal::{adapter::MemoryType, buffer, command, memory, pool, prelude::*, pso};
 
 #[cfg(any(
     feature = "vulkan",
+    feature = "gl",
     feature = "dx11",
     feature = "dx12",
-    feature = "metal"
+    feature = "metal",
 ))]
 fn main() {
     env_logger::init();
@@ -288,6 +292,7 @@ unsafe fn create_buffer<B: hal::Backend>(
 
 #[cfg(not(any(
     feature = "vulkan",
+    feature = "gl",
     feature = "dx11",
     feature = "dx12",
     feature = "metal"

examples/mesh-shading/main.rs

@@ -13,7 +13,7 @@
 extern crate gfx_backend_dx11 as back;
 #[cfg(feature = "dx12")]
 extern crate gfx_backend_dx12 as back;
-#[cfg(all(unix, feature = "gl"))]
+#[cfg(feature = "gl")]
 extern crate gfx_backend_gl as back;
 #[cfg(feature = "metal")]
 extern crate gfx_backend_metal as back;

examples/quad/main.rs

@@ -10,7 +10,7 @@ extern crate gfx_backend_dx12 as back;
     feature = "gl",
 )))]
 extern crate gfx_backend_empty as back;
-#[cfg(all(unix, feature = "gl"))]
+#[cfg(feature = "gl")]
 extern crate gfx_backend_gl as back;
 #[cfg(feature = "metal")]
 extern crate gfx_backend_metal as back;

src/backend/gl/Cargo.toml

@@ -11,14 +11,12 @@ readme = "README.md"
 documentation = "https://docs.rs/gfx-backend-gl"
 workspace = "../../.."
 edition = "2018"
-build = "build.rs"
 
 [lib]
 name = "gfx_backend_gl"
 
 [features]
-default = ["surfman"]
-x11 = ["surfman/sm-x11"]
+default = []
 
 [dependencies]
 arrayvec = "0.5"
@@ -32,9 +30,10 @@ parking_lot = "0.11"
 spirv_cross = { version = "0.22", features = ["glsl"] }
 lazy_static = "1"
 raw-window-handle = "0.3"
+x11 = { version = "2", features = ["xlib"], optional = true }
 
-[target.'cfg(all(unix, not(target_os = "ios")))'.dependencies]
-surfman = { version = "0.3", features = ["sm-raw-window-handle"], optional = true }
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+egl = { package = "khronos-egl", version = "2.1.0" }
 
 [target.'cfg(target_arch = "wasm32")'.dependencies]
 js-sys = "0.3.6"
@@ -59,6 +58,3 @@ features = [
     "WebGlTexture",
     "Window",
 ]
-
-[build-dependencies]
-cfg_aliases = "0.1.0"

src/backend/gl/README.md

@@ -2,6 +2,8 @@
 
 [OpenGL](https://www.khronos.org/opengl/) backend for gfx.
 
+Can only be used on non-Apple Unix systems. The WSI is hard-coded to EGL.
+
 ## Normalized Coordinates
 
 Render | Depth | Texture

src/backend/gl/src/device.rs

@@ -1777,7 +1777,7 @@ impl d::Device<B> for Device {
         }
     }
 
-    #[cfg(wasm)]
+    #[cfg(target_arch = "wasm32")]
     unsafe fn wait_for_fences<I>(
         &self,
         fences: I,

src/backend/gl/src/info.rs

@@ -256,22 +256,23 @@ pub enum Requirement<'a> {
     Ext(&'a str),
 }
 
+const IS_WEBGL: bool = cfg!(target_arch = "wasm32");
+
 impl Info {
     fn get(gl: &GlContainer) -> Info {
         let platform_name = PlatformName::get(gl);
         let version = Version::parse(get_string(gl, glow::VERSION).unwrap_or_default()).unwrap();
-        #[cfg(not(wasm))]
-        let shading_language =
+        let shading_language = if IS_WEBGL {
+            Version::new_embedded(3, 0, String::from(""))
+        } else {
             Version::parse(get_string(gl, glow::SHADING_LANGUAGE_VERSION).unwrap_or_default())
-                .unwrap();
-        #[cfg(wasm)]
-        let shading_language = Version::new_embedded(3, 0, String::from(""));
+                .unwrap()
+        };
         // TODO: Use separate path for WebGL extensions in `glow` somehow
         // Perhaps automatic fallback for NUM_EXTENSIONS to EXTENSIONS on native
-        #[cfg(wasm)]
-        let extensions = HashSet::new();
-        #[cfg(not(wasm))]
-        let extensions = if version >= Version::new(3, 0, None, String::from("")) {
+        let extensions = if IS_WEBGL {
+            HashSet::new()
+        } else if version >= Version::new(3, 0, None, String::from("")) {
             let num_exts = get_usize(gl, glow::NUM_EXTENSIONS).unwrap();
             (0..num_exts)
                 .map(|i| unsafe { gl.get_parameter_indexed_string(glow::EXTENSIONS, i as u32) })
@@ -329,8 +330,6 @@ impl Info {
     }
 }
 
-const IS_WEBGL: bool = cfg!(wasm);
-
 /// Load the information pertaining to the driver and the corresponding device
 /// capabilities.
 pub(crate) fn query_all(