glGetMaterialfv,
glGetMaterialiv
[New
- Windows 95, OEM Service Release 2]
The glGetMaterialfv
and glGetMaterialiv functions return material parameters.
void glGetMaterialfv(
GLenum face, |
|
GLenum pname, |
|
GLfloat * params |
|
); |
|
void glGetMaterialiv(
GLenum face, |
|
GLenum pname, |
|
GLint * params |
|
); |
|
Parameters
face
Specifies
which of the two materials is being queried. GL_FRONT or GL_BACK are accepted,
representing the front and back materials, respectively.
pname
The material
parameter to return. The following values are accepted:
GL_AMBIENT
The params
parameter 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 [-1,1], the corresponding integer return value is
undefined.
GL_DIFFUSE
The params
parameter 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 [-1,1], the corresponding integer return value is
undefined.
GL_SPECULAR
The params
parameter 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 [-1,1], the corresponding integer return value is
undefined.
GL_EMISSION
The params
parameter 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 [-1,1], the corresponding integer return value is
undefined.
GL_SHININESS
The params
parameter 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.
GL_COLOR_INDEXES
The params
parameter returns three integer or floating-point values representing the
ambient, diffuse, and specular indexes of the material. Use these indexes only
for color-index lighting. (The other parameters are all used only for RGBA
lighting.) Integer values, when requested, are computed by rounding the
internal floating-point values to the nearest integer values.
params
Returns the
requested data.
Remarks
The glGetMaterial
function returns in params the value or values of parameter pname
of material face.
If an error
is generated, no change is made to the contents of params.
Error Codes
The following
are the error codes generated and their conditions.
Error
Code |
Condition |
GL_INVALID_ENUM
|
face or pname was not an accepted value. |
GL_INVALID_OPERATION
|
glGetMaterial was called between a call to glBegin and the
corresponding call to glEnd. |
See Also