GL_3DFX_multisample
http://www.opengl.org/registry/specs/3DFX/multisample.txt
GL_MULTISAMPLE_3DFX 0x86B2
GL_SAMPLE_BUFFERS_3DFX 0x86B3
GL_SAMPLES_3DFX 0x86B4
GL_MULTISAMPLE_BIT_3DFX 0x20000000