Defer blend, cull and depth test changes to draw command

Avoid unnecessary state changes and reduces the amount of OpenGL calls.
It also puts all the interesting logic at the same place, reducing the
complexity a little.

GPU/GLES/Framebuffer.cpp

@@ -28,6 +28,7 @@
 #endif
 
 #include "gfx_es2/glsl_program.h"
+#include "gfx_es2/gl_state.h"
 #include "math/lin/matrix4x4.h"
 
 #include "../../Core/Host.h"
@@ -80,9 +81,9 @@ void DisplayDrawer_Init()
 	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);	
 #endif
 
-	glDisable(GL_CULL_FACE);
-	glDisable(GL_DEPTH_TEST);
-	glDisable(GL_BLEND);
+	glstate.cullFace.disable();
+	glstate.depthTest.disable();
+	glstate.blend.disable();
 	//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 
 	glEnable(GL_TEXTURE_2D);