Graphics.Rendering.OpenGL.Raw.ARB.TextureEnvCombine
gl_COMBINE
gl_COMBINE_RGB
gl_COMBINE_ALPHA
gl_SOURCE0_RGB
gl_SOURCE1_RGB
gl_SOURCE2_RGB
gl_SOURCE0_ALPHA
gl_SOURCE1_ALPHA
gl_SOURCE2_ALPHA
gl_OPERAND0_RGB
gl_OPERAND1_RGB
gl_OPERAND2_RGB
gl_OPERAND0_ALPHA
gl_OPERAND1_ALPHA
gl_OPERAND2_ALPHA
gl_RGB_SCALE
gl_ALPHA_SCALE
gl_REPLACE
gl_MODULATE
gl_ADD
gl_ADD_SIGNED
gl_INTERPOLATE
gl_SUBTRACT
gl_TEXTURE
gl_CONSTANT
gl_PRIMARY_COLOR
gl_PREVIOUS
gl_SRC_COLOR
gl_ONE_MINUS_SRC_COLOR
gl_SRC_ALPHA
gl_ONE_MINUS_SRC_ALPHA