expose context and display from adapter and device for egl hal

CHANGELOG.md

@@ -59,6 +59,7 @@ Bottom level categories:
 #### Hal
 
 - Allow access to queue family index in Vulkan hal by @i509VCB in [#2859](https://github.com/gfx-rs/wgpu/pull/2859)
+- Allow access to the EGLDisplay and EGLContext pointer in Gles hal Adapter and Device by @i509VCB in [#2860](https://github.com/gfx-rs/wgpu/pull/2860)
 
 ### Documentation
 - Update present_mode docs as most of them don't automatically fall back to Fifo anymore. by @Elabajaba in [#2855](https://github.com/gfx-rs/wgpu/pull/2855)

wgpu-hal/src/gles/egl.rs

@@ -282,6 +282,7 @@ fn gl_debug_message_callback(source: u32, gltype: u32, id: u32, severity: u32, m
 #[derive(Clone, Debug)]
 struct EglContext {
     instance: Arc<EglInstance>,
+    version: (i32, i32),
     display: egl::Display,
     raw: egl::Context,
     pbuffer: Option<egl::Surface>,
@@ -315,7 +316,34 @@ impl AdapterContext {
         self.egl.is_some()
     }
 
-    #[cfg(feature = "renderdoc")]
+    /// Returns a GL or an EGL extension function.
+    ///
+    /// Always returns [`None`] if the adapter was externally created.
+    ///
+    /// # Safety
+    ///
+    /// - The returned function is only valid for the lifetime of this adapter context and any devices which
+    ///   use the adapter context.
+    pub unsafe fn get_proc_address(&self, proc_name: &str) -> Option<extern "C" fn()> {
+        self.egl
+            .as_ref()
+            .and_then(|egl| egl.instance.get_proc_address(proc_name))
+    }
+
+    /// Returns the EGLDisplay corresponding to the adapter context.
+    ///
+    /// Returns [`None`] if the adapter was externally created.
+    pub fn raw_display(&self) -> Option<&egl::Display> {
+        self.egl.as_ref().map(|egl| &egl.display)
+    }
+
+    /// Returns the EGL version the adapter context was created with.
+    ///
+    /// Returns [`None`] if the adapter was externally created.
+    pub fn egl_version(&self) -> Option<(i32, i32)> {
+        self.egl.as_ref().map(|egl| egl.version)
+    }
+
     pub fn raw_context(&self) -> *mut raw::c_void {
         match self.egl {
             Some(ref egl) => egl.raw.as_ptr(),
@@ -535,6 +563,7 @@ impl Inner {
                 display,
                 raw: context,
                 pbuffer,
+                version,
             },
             version,
             supports_native_window,
@@ -881,6 +910,17 @@ impl super::Adapter {
             egl: None,
         })
     }
+
+    pub fn adapter_context(&self) -> &AdapterContext {
+        &self.shared.context
+    }
+}
+
+impl super::Device {
+    /// Returns the underlying EGL context.
+    pub fn context(&self) -> &AdapterContext {
+        &self.shared.context
+    }
 }
 
 #[derive(Debug)]