GL_ATI_draw_buffers
http://www.opengl.org/registry/specs/ATI/draw_buffers.txt
GL_ATI_draw_buffers
	GL_MAX_DRAW_BUFFERS_ATI 0x8824
	GL_DRAW_BUFFER0_ATI 0x8825
	GL_DRAW_BUFFER1_ATI 0x8826
	GL_DRAW_BUFFER2_ATI 0x8827
	GL_DRAW_BUFFER3_ATI 0x8828
	GL_DRAW_BUFFER4_ATI 0x8829
	GL_DRAW_BUFFER5_ATI 0x882A
	GL_DRAW_BUFFER6_ATI 0x882B
	GL_DRAW_BUFFER7_ATI 0x882C
	GL_DRAW_BUFFER8_ATI 0x882D
	GL_DRAW_BUFFER9_ATI 0x882E
	GL_DRAW_BUFFER10_ATI 0x882F
	GL_DRAW_BUFFER11_ATI 0x8830
	GL_DRAW_BUFFER12_ATI 0x8831
	GL_DRAW_BUFFER13_ATI 0x8832
	GL_DRAW_BUFFER14_ATI 0x8833
	GL_DRAW_BUFFER15_ATI 0x8834
	void glDrawBuffersATI (GLsizei n, const GLenum* bufs)