Replaced the GLee OpenGL function loader with a modified version of GLAD (resolves issue #728.)

--HG--
branch : minor

src/modules/graphics/opengl/OpenGL.h

@@ -21,13 +21,14 @@
 #ifndef LOVE_GRAPHICS_OPENGL_OPENGL_H
 #define LOVE_GRAPHICS_OPENGL_OPENGL_H
 
-#include "GLee.h"
-
 // LOVE
 #include "graphics/Color.h"
 #include "graphics/Texture.h"
 #include "common/Matrix.h"
 
+// GLAD
+#include "libraries/glad/gladfuncs.hpp"
+
 // C++
 #include <vector>
 #include <stack>
@@ -42,6 +43,11 @@ namespace graphics
 namespace opengl
 {
 
+// Awful, but the library uses the namespace in order to use the functions sanely
+// with proper autocomplete in IDEs while having name mangling safety -
+// no clashes with other GL libraries when linking, etc.
+using namespace glad;
+
 /**
  * Thin layer between OpenGL and the rest of the program.
  * Internally shadows some OpenGL context state for improved efficiency and
@@ -138,7 +144,7 @@ public:
 	/**
 	 * Initializes the active OpenGL context.
 	 **/
-	void initContext();
+	bool initContext();
 
 	/**
 	 * Sets up some required context state based on current and default OpenGL