GL_KTX_buffer_region GL_KTX_buffer_region GL_KTX_FRONT_REGION 0x0 GL_KTX_BACK_REGION 0x1 GL_KTX_Z_REGION 0x2 GL_KTX_STENCIL_REGION 0x3 GLuint glBufferRegionEnabled (void) GLuint glNewBufferRegion (GLenum region) void glDeleteBufferRegion (GLenum region) void glReadBufferRegion (GLuint region, GLint x, GLint y, GLsizei width, GLsizei height) void glDrawBufferRegion (GLuint region, GLint x, GLint y, GLsizei width, GLsizei height, GLint xDest, GLint yDest)