Do not use MSAA under OpenGL ES, at least for now

MSAA will need an alternative path for GL ES using GL_EXT_multisampled_render_to_texture and GL_EXT_multisampled_render_to_texture2

Author: Shivansps

code/graphics/opengl/es_compatibility.h

@@ -24,9 +24,10 @@
 #define GLAD_GL_ARB_timer_query                 0
 #define GL_DOUBLE                               0x140A
 #define GL_TIMESTAMP							1
-#define GL_UNSIGNED_SHORT_1_5_5_5_REV			0x1CCC
-#define GL_UNSIGNED_INT_8_8_8_8_REV				0xBAAA
-#define GL_BGR									0x2CCA
+#define GL_UNSIGNED_SHORT_1_5_5_5_REV			0x8366
+#define GL_UNSIGNED_INT_8_8_8_8_REV				0x8367
+#define GL_BGR									0x80E0
+#define GL_MULTISAMPLE							0x809D
 
 //Enums
 #define GL_CLIP_DISTANCE0						GL_CLIP_DISTANCE0_EXT // GL_EXT_clip_cull_distance

code/graphics/opengl/gropengldraw.cpp

@@ -353,10 +353,15 @@ void opengl_setup_scene_textures()
 		return;
 	}
 
+#ifdef USE_OPENGL_ES
+	if (Cmdline_msaa_enabled > 0) {
+		Cmdline_msaa_enabled = 0;
+		Warning(LOCATION, "MSAA is not currently supported under OpenGL ES. Disabling MSAA.");
+	}
+#endif
+
 	if (Cmdline_msaa_enabled > 0) {
-		#ifndef USE_OPENGL_ES
 		glEnable(GL_MULTISAMPLE);
-		#endif
 
 		// Make sure our MSAA setting are valid
 		int maxSamples;