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.