Fix glium support

src/backend/glium.rs

@@ -1,7 +1,9 @@
 use glium::backend::Backend;
 use glium::SwapBuffersError as GliumSwapBuffersError;
 
-use ::backend::graphics::opengl::{OpenglRenderer, SwapBuffersError};
+use std::os::raw::c_void;
+
+use ::backend::graphics::opengl::{OpenglGraphicsBackend, SwapBuffersError};
 
 impl From<SwapBuffersError> for GliumSwapBuffersError
 {
@@ -13,26 +15,41 @@ impl From<SwapBuffersError> for GliumSwapBuffersError
     }
 }
 
-impl<T: OpenglRenderer> Backend for T
+pub struct GliumGraphicBackend<T: OpenglGraphicsBackend>(T);
+
+pub trait IntoGlium: OpenglGraphicsBackend + Sized
 {
-    fn swap_buffers(&self) -> Result<(), SwapBuffersError> {
-        self.swap_buffers().map_err(|x| x.into)
+    fn into_glium(self) -> GliumGraphicBackend<Self>;
+}
+
+impl<T: OpenglGraphicsBackend> IntoGlium for T
+{
+    fn into_glium(self) -> GliumGraphicBackend<Self>
+    {
+        GliumGraphicBackend(self)
+    }
+}
+
+unsafe impl<T: OpenglGraphicsBackend> Backend for GliumGraphicBackend<T>
+{
+    fn swap_buffers(&self) -> Result<(), GliumSwapBuffersError> {
+        self.0.swap_buffers().map_err(Into::into)
     }
 
     unsafe fn get_proc_address(&self, symbol: &str) -> *const c_void
     {
-        self.get_proc_address(symbol)
+        self.0.get_proc_address(symbol) as *const c_void
     }
 
     fn get_framebuffer_dimensions(&self) -> (u32, u32) {
-        self.get_framebuffer_dimensions()
+        self.0.get_framebuffer_dimensions()
     }
 
     fn is_current(&self) -> bool {
-        self.is_current()
+        self.0.is_current()
     }
 
     unsafe fn make_current(&self) {
-        self.make_current()
+        self.0.make_current()
     }
 }