glColorMaterial

GL_COLOR_MATERIAL is a feature of OpenGL's fixed-function pipeline that links the current color state to material properties used in lighting calculations. When enabled, colors specified with glColor* calls can automatically update certain material attributes of the drawn geometry, reducing the need to call glMaterial for each property.

To use GL_COLOR_MATERIAL, the state is enabled with glEnable(GL_COLOR_MATERIAL) and configured with glColorMaterial(face, mode). The face parameter selects which polygons are affected: GL_FRONT, GL_BACK, or GL_FRONT_AND_BACK. The mode parameter selects which material properties are updated by glColor calls. Typical modes include GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR, GL_EMISSION, and GL_AMBIENT_AND_DIFFUSE, with GL_AMBIENT_AND_DIFFUSE applying the current color to both ambient and diffuse properties. In color-index mode, color indices may also influence material properties.

When GL_COLOR_MATERIAL is active, subsequent glColor calls set the specified material properties for the chosen faces, subject to the current lighting state. This can simplify shading by allowing a single color specification to drive multiple material components. If both color-material and explicit glMaterial calls affect the same properties, the last value set applies.

GL_COLOR_MATERIAL remains part of the compatibility profile and is associated with the fixed-function pipeline. In modern OpenGL, which uses shaders, material properties are typically passed as uniforms, and GL_COLOR_MATERIAL is not used.