 #if defined(GL_ARB_shading_language_420pack)
     #extension GL_ARB_shading_language_420pack: enable
     #define EXPLICIT_TEXTURE_LAYER
+    #define RUNTIME_CONST
 #endif
 #ifdef GL_ARB_explicit_uniform_location
     #extension GL_ARB_explicit_uniform_location: enable

#define mediump
#define lowp
#endif

/* const qualifier can be used for readonly variables since GLSL 4.20, however
   it's not supported even in ES 3.0 */
#if !defined(GL_ES) && __VERSION__ >= 420
#define RUNTIME_CONST
#endif


#if defined(GL_ES) && __VERSION__ >= 300
#define EXPLICIT_ATTRIB_LOCATION
/* EXPLICIT_TEXTURE_LAYER, EXPLICIT_UNIFORM_LOCATION and RUNTIME_CONST is not
   available in OpenGL ES */
#endif

/* Precision qualifiers are not supported in GLSL 1.20 */
