Specifies which of the two materials is being queried. GL_FRONT or GL_BACK are accepted, representing the front and back materials, respectively.

Specifies the material parameter to return. GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR, GL_EMISSION, GL_SHININESS, and GL_COLOR_INDEXES are accepted.

Returns the requested data.

params returns four integer or floating-point values representing the ambient reflectance of the material. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and $-1.0$ maps to the most negative representable integer value. If the internal value is outside the range $\left[-1,1\right]$, the corresponding integer return value is undefined. The initial value is (0.2, 0.2, 0.2, 1.0)

params returns four integer or floating-point values representing the diffuse reflectance of the material. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and $-1.0$ maps to the most negative representable integer value. If the internal value is outside the range $\left[-1,1\right]$, the corresponding integer return value is undefined. The initial value is (0.8, 0.8, 0.8, 1.0).

params returns four integer or floating-point values representing the specular reflectance of the material. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and $-1.0$ maps to the most negative representable integer value. If the internal value is outside the range $\left[-1,1\right]$, the corresponding integer return value is undefined. The initial value is (0, 0, 0, 1).

params returns four integer or floating-point values representing the emitted light intensity of the material. Integer values, when requested, are linearly mapped from the internal floating-point representation such that 1.0 maps to the most positive representable integer value, and $-1.0$ maps to the most negative representable integer value. If the internal value is outside the range $\left[-1,1\right]$, the corresponding integer return value is undefined. The initial value is (0, 0, 0, 1).

params returns one integer or floating-point value representing the specular exponent of the material. Integer values, when requested, are computed by rounding the internal floating-point value to the nearest integer value. The initial value is 0.

params returns three integer or floating-point values representing the ambient, diffuse, and specular indices of the material. These indices are used only for color index lighting. (All the other parameters are used only for RGBA lighting.) Integer values, when requested, are computed by rounding the internal floating-point values to the nearest integer values.