GL_APPLE_object_purgeable http://www.opengl.org/registry/specs/APPLE/object_purgeable.txt GL_APPLE_object_purgeable GL_BUFFER_OBJECT_APPLE 0x85B3 GL_RELEASED_APPLE 0x8A19 GL_VOLATILE_APPLE 0x8A1A GL_RETAINED_APPLE 0x8A1B GL_UNDEFINED_APPLE 0x8A1C GL_PURGEABLE_APPLE 0x8A1D void glGetObjectParameterivAPPLE (GLenum objectType, GLuint name, GLenum pname, GLint* params) GLenum glObjectPurgeableAPPLE (GLenum objectType, GLuint name, GLenum option) GLenum glObjectUnpurgeableAPPLE (GLenum objectType, GLuint name, GLenum option)