diff --git a/gfx/gl.c b/gfx/gl.c
index bfb08e138c..aeec6b9056 100644
--- a/gfx/gl.c
+++ b/gfx/gl.c
@@ -31,14 +31,7 @@
 #include "config.h"
 #endif
 
-#ifdef __APPLE__
-#include <OpenGL/gl.h>
-#include <OpenGL/glext.h>
-#else
-#define GL_GLEXT_PROTOTYPES
-#include <GL/gl.h>
-#include <GL/glext.h>
-#endif
+#include "gl_common.h"
 
 #define NO_SDL_GLEXT
 #include "SDL.h"
@@ -53,7 +46,6 @@
 #include "shader_glsl.h"
 #endif
 
-#include "gl_common.h"
 
 #ifdef HAVE_FREETYPE
 #include "fonts.h"
@@ -119,6 +111,7 @@ typedef struct gl
    // Render-to-texture, multipass shaders
    GLuint fbo[MAX_SHADERS];
    GLuint fbo_texture[MAX_SHADERS];
+   struct gl_fbo_rect fbo_rect[MAX_SHADERS];
    bool render_to_tex;
    unsigned fbo_width;
    unsigned fbo_height;
@@ -264,17 +257,33 @@ static inline unsigned gl_shader_num(void)
    return num;
 }
 
-static inline bool gl_shader_filter_type(unsigned num, bool *smooth)
+static inline bool gl_shader_filter_type(unsigned index, bool *smooth)
 {
    bool valid = false;
 #ifdef HAVE_CG
    if (!valid)
-      valid = gl_cg_filter_type(num, smooth);
+      valid = gl_cg_filter_type(index, smooth);
 #endif
 
 #ifdef HAVE_XML
    if (!valid)
-      valid = gl_glsl_filter_type(num, smooth);
+      valid = gl_glsl_filter_type(index, smooth);
+#endif
+
+   return valid;
+}
+
+static inline bool gl_shader_rect(unsigned index, struct gl_fbo_rect *rect)
+{
+   bool valid = false;
+#ifdef HAVE_CG
+   if (!valid)
+      valid = gl_cg_shader_rect(index, rect);
+#endif
+
+#ifdef HAVE_XML
+   if (!valid)
+      valid = gl_glsl_shader_rect(index, rect);
 #endif
 
    return valid;
diff --git a/gfx/gl_common.h b/gfx/gl_common.h
index f03ee6a799..c0dcce57c6 100644
--- a/gfx/gl_common.h
+++ b/gfx/gl_common.h
@@ -20,6 +20,15 @@
 
 #include "general.h"
 
+#ifdef __APPLE__
+#include <OpenGL/gl.h>
+#include <OpenGL/glext.h>
+#else
+#define GL_GLEXT_PROTOTYPES
+#include <GL/gl.h>
+#include <GL/glext.h>
+#endif
+
 static inline bool gl_check_error(void)
 {
    int error = glGetError();
@@ -29,7 +38,7 @@ static inline bool gl_check_error(void)
          SSNES_ERR("GL: Invalid enum.\n");
          break;
       case GL_INVALID_VALUE:
-         SSNES_ERR("GL: Invalid value.\n");
+         SSNES_ERR("GL: Invalid value. (You're not alone.)\n");
          break;
       case GL_INVALID_OPERATION:
          SSNES_ERR("GL: Invalid operation.\n");
@@ -56,4 +65,14 @@ static inline bool gl_check_error(void)
    return false;
 }
 
+struct gl_fbo_rect
+{
+   unsigned width;
+   unsigned height;
+   unsigned tex_width;
+   unsigned tex_height;
+
+   GLfloat texcoord[8];
+};
+
 #endif
diff --git a/gfx/shader_cg.c b/gfx/shader_cg.c
index 0e890ada18..a00053012a 100644
--- a/gfx/shader_cg.c
+++ b/gfx/shader_cg.c
@@ -208,3 +208,11 @@ bool gl_cg_filter_type(unsigned index, bool *smooth)
    // We don't really care since .cg doesn't have those kinds of semantics by itself ...
    return false;
 }
+
+bool gl_cg_shader_rect(unsigned index, struct gl_fbo_rect *rect)
+{
+   (void)index;
+   (void)rect;
+   // We don't really care since .cg doesn't have those kinds of semantics by itself ...
+   return false;
+}
diff --git a/gfx/shader_cg.h b/gfx/shader_cg.h
index 54c2b08447..8dd24d6e04 100644
--- a/gfx/shader_cg.h
+++ b/gfx/shader_cg.h
@@ -20,6 +20,7 @@
 #define __SSNES_CG_H
 
 #include <stdbool.h>
+#include "gl_common.h"
 
 bool gl_cg_init(const char *path);
 
@@ -36,5 +37,6 @@ void gl_cg_use(unsigned index);
 unsigned gl_cg_num(void);
 
 bool gl_cg_filter_type(unsigned index, bool *smooth);
+bool gl_cg_shader_rect(unsigned index, struct gl_fbo_rect *rect);
 
 #endif
diff --git a/gfx/shader_glsl.c b/gfx/shader_glsl.c
index 59d2019cf6..8fd666bdd9 100644
--- a/gfx/shader_glsl.c
+++ b/gfx/shader_glsl.c
@@ -420,3 +420,10 @@ bool gl_glsl_filter_type(unsigned index, bool *smooth)
          return false;
    }
 }
+
+bool gl_glsl_shader_rect(unsigned index, struct gl_fbo_rect *rect)
+{
+   (void)index;
+   (void)rect;
+   return false;
+}
diff --git a/gfx/shader_glsl.h b/gfx/shader_glsl.h
index d570b3ebaa..78301f8b76 100644
--- a/gfx/shader_glsl.h
+++ b/gfx/shader_glsl.h
@@ -36,5 +36,6 @@ void gl_glsl_use(unsigned index);
 unsigned gl_glsl_num(void);
 
 bool gl_glsl_filter_type(unsigned index, bool *smooth);
+bool gl_glsl_shader_rect(unsigned index, struct gl_fbo_rect *rect);
 
 #endif