| GL_EXT_texture_env_combine | |
| http://oss.sgi.com/projects/ogl-sample/registry/EXT/texture_env_combine.txt | |
| GL_COMBINE_EXT 0x8570 | |
| GL_COMBINE_RGB_EXT 0x8571 | |
| GL_COMBINE_ALPHA_EXT 0x8572 | |
| GL_RGB_SCALE_EXT 0x8573 | |
| GL_ADD_SIGNED_EXT 0x8574 | |
| GL_INTERPOLATE_EXT 0x8575 | |
| GL_CONSTANT_EXT 0x8576 | |
| GL_PRIMARY_COLOR_EXT 0x8577 | |
| GL_PREVIOUS_EXT 0x8578 | |
| GL_SOURCE0_RGB_EXT 0x8580 | |
| GL_SOURCE1_RGB_EXT 0x8581 | |
| GL_SOURCE2_RGB_EXT 0x8582 | |
| GL_SOURCE0_ALPHA_EXT 0x8588 | |
| GL_SOURCE1_ALPHA_EXT 0x8589 | |
| GL_SOURCE2_ALPHA_EXT 0x858A | |
| GL_OPERAND0_RGB_EXT 0x8590 | |
| GL_OPERAND1_RGB_EXT 0x8591 | |
| GL_OPERAND2_RGB_EXT 0x8592 | |
| GL_OPERAND0_ALPHA_EXT 0x8598 | |
| GL_OPERAND1_ALPHA_EXT 0x8599 | |
| GL_OPERAND2_ALPHA_EXT 0x859A |