api: add extra EGL and GLX extensions

This patch adds multiple new EGL extensions which are useful for
implementing Wayland applications. These have been mostly implemented
manually, since gl_generator lacks support for these newer EGL
extensions (except for `EGL_KHR_image_base`).

The following extensions were added:
 - EGL_KHR_image_base
 - EGL_WL_bind_wayland_display
 - EGL_WL_create_wayland_buffer_from_image

This also exposes EGL and GLX raw API calls on EGL and GLX displays.

Author: chrisduerr

CHANGELOG.md

@@ -3,6 +3,7 @@
 - **Breaking:** updated `raw-window-handle` dependency to `0.6`.
 - Bump MSRV from `1.65` to `1.70`.
 - Bump `windows-sys` from `0.48.0` to `0.52.0`.
+- Expose `Egl` and `Glx` raw API functions on `Egl` and `Glx` displays.
 
 # Version 0.31.3
 

glutin/src/api/egl/display.rs

@@ -214,6 +214,11 @@ impl Display {
         Device::from_ptr(self.inner.egl, device)
     }
 
+    /// Get a reference to the initialized EGL API.
+    pub fn egl(&self) -> &'static Egl {
+        self.inner.egl
+    }
+
     /// Terminate the EGL display.
     ///
     /// When the display is managed by glutin with the

glutin/src/api/egl/mod.rs

@@ -41,7 +41,9 @@ pub(crate) static EGL: Lazy<Option<Egl>> = Lazy::new(|| {
 type EglGetProcAddress = unsafe extern "C" fn(*const ffi::c_void) -> *const ffi::c_void;
 static EGL_GET_PROC_ADDRESS: OnceCell<libloading_os::Symbol<EglGetProcAddress>> = OnceCell::new();
 
-pub(crate) struct Egl(pub SymWrapper<egl::Egl>);
+/// EGL interface.
+#[allow(missing_debug_implementations)]
+pub struct Egl(SymWrapper<egl::Egl>);
 
 unsafe impl Sync for Egl {}
 unsafe impl Send for Egl {}
@@ -68,6 +70,11 @@ impl SymLoading for egl::Egl {
             }
         };
 
+        egl::BindWaylandDisplayWL::load_with(loader);
+        egl::UnbindWaylandDisplayWL::load_with(loader);
+        egl::QueryWaylandBufferWL::load_with(loader);
+        egl::CreateWaylandBufferFromImageWL::load_with(loader);
+
         Self::load_with(loader)
     }
 }

glutin/src/api/glx/display.rs

@@ -110,6 +110,11 @@ impl Display {
         Ok(Self { inner })
     }
 
+    /// Get a reference to the initialized GLX API.
+    pub fn glx(&self) -> &'static Glx {
+        self.inner.glx
+    }
+
     fn extract_display_features(
         extensions: &HashSet<&'static str>,
         version: Version,

glutin/src/api/glx/mod.rs

@@ -58,7 +58,9 @@ static GLX_EXTRA: Lazy<Option<GlxExtra>> = Lazy::new(|| {
     Some(GlxExtra::new(glx))
 });
 
-pub(crate) struct Glx(pub SymWrapper<glx::Glx>);
+/// GLX interface.
+#[allow(missing_debug_implementations)]
+pub struct Glx(pub SymWrapper<glx::Glx>);
 
 unsafe impl Sync for Glx {}
 unsafe impl Send for Glx {}

glutin/src/lib_loading.rs

@@ -15,6 +15,7 @@ pub trait SymLoading {
 }
 
 #[derive(Clone)]
+#[allow(missing_debug_implementations)]
 pub struct SymWrapper<T> {
     sym: T,
     _lib: Arc<Library>,

glutin_egl_sys/build.rs

@@ -39,6 +39,7 @@ fn main() {
             "EGL_KHR_create_context_no_error",
             "EGL_KHR_display_reference",
             "EGL_KHR_fence_sync",
+            "EGL_KHR_image_base",
             "EGL_KHR_platform_android",
             "EGL_KHR_platform_gbm",
             "EGL_KHR_platform_wayland",

glutin_egl_sys/src/egl.rs

@@ -0,0 +1,252 @@
+//! Manual implementation of EGL bindings.
+//!
+//! This is necessary since `gl_generator` is unmaintaned and incapable of
+//! generating bindings for some of the newer extensions.
+
+use std::ffi::c_uint;
+
+pub type khronos_utime_nanoseconds_t = super::khronos_utime_nanoseconds_t;
+pub type khronos_uint64_t = super::khronos_uint64_t;
+pub type khronos_ssize_t = super::khronos_ssize_t;
+pub type EGLNativeDisplayType = super::EGLNativeDisplayType;
+pub type EGLNativePixmapType = super::EGLNativePixmapType;
+pub type EGLNativeWindowType = super::EGLNativeWindowType;
+pub type EGLint = super::EGLint;
+pub type NativeDisplayType = super::EGLNativeDisplayType;
+pub type NativePixmapType = super::EGLNativePixmapType;
+pub type NativeWindowType = super::EGLNativeWindowType;
+
+include!(concat!(env!("OUT_DIR"), "/egl_bindings.rs"));
+
+// EGL_EXT_platform_xcb
+pub const PLATFORM_XCB_EXT: super::EGLenum = 0x31DC;
+pub const PLATFORM_XCB_SCREEN_EXT: super::EGLenum = 0x31DE;
+// EGL_EXT_device_query_name
+pub const RENDERER_EXT: super::EGLenum = 0x335F;
+// EGL_ANGLE_platform_angle - https://chromium.googlesource.com/angle/angle/+/HEAD/extensions/EGL_ANGLE_platform_angle.txt
+pub const PLATFORM_ANGLE_ANGLE: super::EGLenum = 0x3202;
+pub const PLATFORM_ANGLE_TYPE_ANGLE: super::EGLenum = 0x3203;
+pub const PLATFORM_ANGLE_TYPE_VULKAN_ANGLE: super::EGLenum = 0x3450;
+pub const PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE: super::EGLenum = 0x3204;
+pub const PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE: super::EGLenum = 0x3205;
+pub const PLATFORM_ANGLE_DEBUG_LAYERS_ENABLED: super::EGLenum = 0x3451;
+pub const PLATFORM_ANGLE_NATIVE_PLATFORM_TYPE_ANGLE: super::EGLenum = 0x348F;
+pub const PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE: super::EGLenum = 0x3206;
+pub const PLATFORM_ANGLE_DEVICE_TYPE_HARDWARE_ANGLE: super::EGLenum = 0x320A;
+pub const PLATFORM_ANGLE_DEVICE_TYPE_NULL_ANGLE: super::EGLenum = 0x345E;
+
+mod wayland_storage {
+    use super::FnPtr;
+    use super::__gl_imports::raw;
+
+    // EGL_WL_create_wayland_buffer_from_image
+    pub static mut CREATE_WAYLAND_BUFFER_FROM_IMAGE_WL: FnPtr =
+        FnPtr { f: super::missing_fn_panic as *const raw::c_void, is_loaded: false };
+
+    // EGL_WL_bind_wayland_display
+    pub static mut BIND_WAYLAND_DISPLAY_WL: FnPtr =
+        FnPtr { f: super::missing_fn_panic as *const raw::c_void, is_loaded: false };
+    pub static mut UNBIND_WAYLAND_DISPLAY_WL: FnPtr =
+        FnPtr { f: super::missing_fn_panic as *const raw::c_void, is_loaded: false };
+    pub static mut QUERY_WAYLAND_BUFFER_WL: FnPtr =
+        FnPtr { f: super::missing_fn_panic as *const raw::c_void, is_loaded: false };
+}
+
+impl Egl {
+    #[allow(non_snake_case, unused_variables, dead_code)]
+    #[inline]
+    pub unsafe fn CreateWaylandBufferFromImageWL(
+        &self,
+        dpy: types::EGLDisplay,
+        image: types::EGLImageKHR,
+    ) -> *mut std::ffi::c_void {
+        __gl_imports::mem::transmute::<
+            _,
+            extern "system" fn(types::EGLDisplay, types::EGLImageKHR) -> *mut std::ffi::c_void,
+        >(wayland_storage::CREATE_WAYLAND_BUFFER_FROM_IMAGE_WL.f)(dpy, image)
+    }
+
+    #[allow(non_snake_case, unused_variables, dead_code)]
+    #[inline]
+    pub unsafe fn BindWaylandDisplayWL(
+        &self,
+        dpy: types::EGLDisplay,
+        display: *mut __gl_imports::raw::c_void,
+    ) -> types::EGLBoolean {
+        __gl_imports::mem::transmute::<
+            _,
+            extern "system" fn(
+                types::EGLDisplay,
+                *mut __gl_imports::raw::c_void,
+            ) -> types::EGLBoolean,
+        >(wayland_storage::BIND_WAYLAND_DISPLAY_WL.f)(dpy, display)
+    }
+
+    #[allow(non_snake_case, unused_variables, dead_code)]
+    #[inline]
+    pub unsafe fn UnbindWaylandDisplayWL(
+        &self,
+        dpy: types::EGLDisplay,
+        display: *mut __gl_imports::raw::c_void,
+    ) -> types::EGLBoolean {
+        __gl_imports::mem::transmute::<
+            _,
+            extern "system" fn(
+                types::EGLDisplay,
+                *mut __gl_imports::raw::c_void,
+            ) -> types::EGLBoolean,
+        >(wayland_storage::UNBIND_WAYLAND_DISPLAY_WL.f)(dpy, display)
+    }
+
+    #[allow(non_snake_case, unused_variables, dead_code)]
+    #[inline]
+    pub unsafe fn QueryWaylandBufferWL(
+        &self,
+        dpy: types::EGLDisplay,
+        buffer: *mut __gl_imports::raw::c_void,
+        attribute: types::EGLint,
+        value: *mut types::EGLint,
+    ) -> types::EGLBoolean {
+        __gl_imports::mem::transmute::<
+            _,
+            extern "system" fn(
+                types::EGLDisplay,
+                *mut __gl_imports::raw::c_void,
+                types::EGLint,
+                *mut types::EGLint,
+            ) -> types::EGLBoolean,
+        >(wayland_storage::QUERY_WAYLAND_BUFFER_WL.f)(dpy, buffer, attribute, value)
+    }
+}
+
+// Extension: EGL_WL_create_wayland_buffer_from_image
+//
+
+#[allow(non_snake_case)]
+pub mod CreateWaylandBufferFromImageWL {
+    use super::__gl_imports::raw;
+    use super::{metaloadfn, wayland_storage, FnPtr};
+
+    #[inline]
+    #[allow(dead_code)]
+    pub fn is_loaded() -> bool {
+        unsafe { wayland_storage::CREATE_WAYLAND_BUFFER_FROM_IMAGE_WL.is_loaded }
+    }
+
+    #[allow(dead_code)]
+    pub fn load_with<F>(mut loadfn: F)
+    where
+        F: FnMut(&'static str) -> *const raw::c_void,
+    {
+        unsafe {
+            wayland_storage::CREATE_WAYLAND_BUFFER_FROM_IMAGE_WL =
+                FnPtr::new(metaloadfn(&mut loadfn, "eglCreateWaylandBufferFromImageWL", &[]))
+        }
+    }
+}
+
+// Extension: EGL_WL_bind_wayland_display
+//
+
+// Accepted as <target> in eglCreateImageKHR.
+pub const WAYLAND_BUFFER_WL: c_uint = 0x31D5;
+// Accepted in the <attrib_list> parameter of eglCreateImageKHR.
+pub const WAYLAND_PLANE_WL: c_uint = 0x31D6;
+// Possible values for EGL_TEXTURE_FORMAT.
+pub const TEXTURE_Y_U_V_WL: i32 = 0x31D7;
+pub const TEXTURE_Y_UV_WL: i32 = 0x31D8;
+pub const TEXTURE_Y_XUXV_WL: i32 = 0x31D9;
+pub const TEXTURE_EXTERNAL_WL: i32 = 0x31DA;
+// Accepted in the <attribute> parameter of eglQueryWaylandBufferWL.
+pub const EGL_TEXTURE_FORMAT: i32 = 0x3080;
+pub const WAYLAND_Y_INVERTED_WL: i32 = 0x31DB;
+
+#[allow(non_snake_case)]
+pub mod BindWaylandDisplayWL {
+    use super::__gl_imports::raw;
+    use super::{metaloadfn, wayland_storage, FnPtr};
+
+    #[inline]
+    #[allow(dead_code)]
+    pub fn is_loaded() -> bool {
+        unsafe { wayland_storage::BIND_WAYLAND_DISPLAY_WL.is_loaded }
+    }
+
+    #[allow(dead_code)]
+    pub fn load_with<F>(mut loadfn: F)
+    where
+        F: FnMut(&'static str) -> *const raw::c_void,
+    {
+        unsafe {
+            wayland_storage::BIND_WAYLAND_DISPLAY_WL =
+                FnPtr::new(metaloadfn(&mut loadfn, "eglBindWaylandDisplayWL", &[]))
+        }
+    }
+}
+
+#[allow(non_snake_case)]
+pub mod UnbindWaylandDisplayWL {
+    use super::__gl_imports::raw;
+    use super::{metaloadfn, wayland_storage, FnPtr};
+
+    #[inline]
+    #[allow(dead_code)]
+    pub fn is_loaded() -> bool {
+        unsafe { wayland_storage::UNBIND_WAYLAND_DISPLAY_WL.is_loaded }
+    }
+
+    #[allow(dead_code)]
+    pub fn load_with<F>(mut loadfn: F)
+    where
+        F: FnMut(&'static str) -> *const raw::c_void,
+    {
+        unsafe {
+            wayland_storage::UNBIND_WAYLAND_DISPLAY_WL =
+                FnPtr::new(metaloadfn(&mut loadfn, "eglUnbindWaylandDisplayWL", &[]))
+        }
+    }
+}
+
+#[allow(non_snake_case)]
+pub mod QueryWaylandBufferWL {
+    use super::__gl_imports::raw;
+    use super::{metaloadfn, wayland_storage, FnPtr};
+
+    #[inline]
+    #[allow(dead_code)]
+    pub fn is_loaded() -> bool {
+        unsafe { wayland_storage::QUERY_WAYLAND_BUFFER_WL.is_loaded }
+    }
+
+    #[allow(dead_code)]
+    pub fn load_with<F>(mut loadfn: F)
+    where
+        F: FnMut(&'static str) -> *const raw::c_void,
+    {
+        unsafe {
+            wayland_storage::QUERY_WAYLAND_BUFFER_WL =
+                FnPtr::new(metaloadfn(&mut loadfn, "eglQueryWaylandBufferWL", &[]))
+        }
+    }
+}
+
+/// OpenGL function loader.
+///
+/// This is based on the loader generated by `gl_generator`.
+#[inline(never)]
+fn metaloadfn(
+    loadfn: &mut dyn FnMut(&'static str) -> *const __gl_imports::raw::c_void,
+    symbol: &'static str,
+    fallbacks: &[&'static str],
+) -> *const __gl_imports::raw::c_void {
+    let mut ptr = loadfn(symbol);
+    if ptr.is_null() {
+        for &sym in fallbacks {
+            ptr = loadfn(sym);
+            if !ptr.is_null() {
+                break;
+            }
+        }
+    }
+    ptr
+}

glutin_egl_sys/src/lib.rs

@@ -12,37 +12,7 @@
 #![allow(clippy::manual_non_exhaustive)]
 #![allow(clippy::unnecessary_cast)]
 
-pub mod egl {
-    pub type khronos_utime_nanoseconds_t = super::khronos_utime_nanoseconds_t;
-    pub type khronos_uint64_t = super::khronos_uint64_t;
-    pub type khronos_ssize_t = super::khronos_ssize_t;
-    pub type EGLNativeDisplayType = super::EGLNativeDisplayType;
-    pub type EGLNativePixmapType = super::EGLNativePixmapType;
-    pub type EGLNativeWindowType = super::EGLNativeWindowType;
-    pub type EGLint = super::EGLint;
-    pub type NativeDisplayType = super::EGLNativeDisplayType;
-    pub type NativePixmapType = super::EGLNativePixmapType;
-    pub type NativeWindowType = super::EGLNativeWindowType;
-
-    include!(concat!(env!("OUT_DIR"), "/egl_bindings.rs"));
-
-    // TODO should upstream these:
-    // EGL_EXT_platform_xcb
-    pub const PLATFORM_XCB_EXT: super::EGLenum = 0x31DC;
-    pub const PLATFORM_XCB_SCREEN_EXT: super::EGLenum = 0x31DE;
-    // EGL_EXT_device_query_name
-    pub const RENDERER_EXT: super::EGLenum = 0x335F;
-    // EGL_ANGLE_platform_angle - https://chromium.googlesource.com/angle/angle/+/HEAD/extensions/EGL_ANGLE_platform_angle.txt
-    pub const PLATFORM_ANGLE_ANGLE: super::EGLenum = 0x3202;
-    pub const PLATFORM_ANGLE_TYPE_ANGLE: super::EGLenum = 0x3203;
-    pub const PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE: super::EGLenum = 0x3204;
-    pub const PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE: super::EGLenum = 0x3205;
-    pub const PLATFORM_ANGLE_DEBUG_LAYERS_ENABLED: super::EGLenum = 0x3451;
-    pub const PLATFORM_ANGLE_NATIVE_PLATFORM_TYPE_ANGLE: super::EGLenum = 0x348F;
-    pub const PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE: super::EGLenum = 0x3206;
-    pub const PLATFORM_ANGLE_DEVICE_TYPE_HARDWARE_ANGLE: super::EGLenum = 0x320A;
-    pub const PLATFORM_ANGLE_DEVICE_TYPE_NULL_ANGLE: super::EGLenum = 0x345E;
-}
+pub mod egl;
 
 pub use self::egl::types::{EGLContext, EGLDisplay};
 

glutin_examples/examples/egl_device.rs

@@ -112,7 +112,7 @@ mod example {
         }
 
         let path = Path::new(IMG_PATH);
-        let file = OpenOptions::new().write(true).create(true).open(path).unwrap();
+        let file = OpenOptions::new().write(true).truncate(true).open(path).unwrap();
 
         let mut encoder = png::Encoder::new(file, 1280, 720);
         encoder.set_depth(png::BitDepth::Eight);

glutin_examples/examples/switch_render_thread.rs

@@ -8,8 +8,8 @@ use glutin::config::ConfigTemplateBuilder;
 use glutin::context::{ContextAttributesBuilder, PossiblyCurrentContext};
 use glutin::display::GetGlDisplay;
 use glutin::error::{Error as GlutinError, ErrorKind};
-use glutin::prelude::{NotCurrentGlContext, PossiblyCurrentGlContext, *};
-use glutin::surface::{GlSurface, Surface, WindowSurface};
+use glutin::prelude::*;
+use glutin::surface::{Surface, WindowSurface};
 use glutin_examples::gl::types::GLfloat;
 use glutin_examples::{gl_config_picker, Renderer};
 use glutin_winit::{self, DisplayBuilder, GlWindow};