Make paint function accept anything implementing Surface trait (#681)

* Make paint function accept anything implementing Surface trait

* Remove unused imports

egui_glium/src/lib.rs

@@ -631,10 +631,10 @@ impl EguiGlium {
         (needs_repaint, shapes)
     }
 
-    pub fn paint(
+    pub fn paint<T: glium::Surface>(
         &mut self,
         display: &glium::Display,
-        target: &mut glium::Frame,
+        target: &mut T,
         shapes: Vec<egui::epaint::ClippedShape>,
     ) {
         let clipped_meshes = self.egui_ctx.tessellate(shapes);

egui_glium/src/painter.rs

@@ -12,7 +12,6 @@ use {
         texture::{self, srgb_texture2d::SrgbTexture2d},
         uniform,
         uniforms::{MagnifySamplerFilter, SamplerWrapFunction},
-        Frame, Surface,
     },
 };
 
@@ -95,10 +94,10 @@ impl Painter {
     /// Main entry-point for painting a frame.
     /// You should call `target.clear_color(..)` before
     /// and `target.finish()` after this.
-    pub fn paint_meshes(
+    pub fn paint_meshes<T: glium::Surface>(
         &mut self,
         display: &glium::Display,
-        target: &mut Frame,
+        target: &mut T,
         pixels_per_point: f32,
         cipped_meshes: Vec<egui::ClippedMesh>,
         egui_texture: &egui::Texture,
@@ -112,9 +111,9 @@ impl Painter {
     }
 
     #[inline(never)] // Easier profiling
-    pub fn paint_mesh(
+    pub fn paint_mesh<T: glium::Surface>(
         &mut self,
-        target: &mut Frame,
+        target: &mut T,
         display: &glium::Display,
         pixels_per_point: f32,
         clip_rect: Rect,