Gl.GetMaterialfv (gb.opengl)
Static Function GetMaterialfv ( Face As Integer, Pname As Integer ) As Float[]
Return material parameters.
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
-
Specifies the material parameter to return.
Gl.AMBIENT,
Gl.DIFFUSE,
Gl.SPECULAR,
Gl.EMISSION,
Gl.SHININESS, and
Gl.COLOR_INDEXES
are accepted.
- params
-
Returns the requested data.
Description
Gl.GetMaterial returns in
params the value or values of parameter
pname
of material
face. Six parameters are defined:
- Gl.AMBIENT
-
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
maps to the most negative representable integer value.
If the internal value is outside the range
,
the corresponding integer return value is undefined. The initial value is
(0.2, 0.2, 0.2, 1.0)
- Gl.DIFFUSE
-
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
maps to the most negative representable integer value.
If the internal value is outside the range
,
the corresponding integer return value is undefined. The initial value is
(0.8, 0.8, 0.8, 1.0).
- Gl.SPECULAR
-
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
maps to the most negative representable integer value.
If the internal value is outside the range
,
the corresponding integer return value is undefined. The initial value is
(0, 0, 0, 1).
- Gl.EMISSION
-
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
maps to the most negative representable integer value.
If the internal value is outside the range
,
the corresponding integer return value is undefined. The initial value is
(0, 0, 0, 1).
- Gl.SHININESS
-
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.
- Gl.COLOR_INDEXES
-
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.
Notes
If an error is generated,
no change is made to the contents of
params.
Errors
Gl.INVALID_ENUM is generated if
face or
pname is not an
accepted value.
Gl.INVALID_OPERATION is generated if
Gl.GetMaterial
is executed between the execution of Gl.Begin
and the corresponding execution of Gl.End.
See also
See original documentation on OpenGL website