gluLoadSamplingMatrices function
The gluLoadSamplingMatrices function loads Non-Uniform Rational B-Spline (NURBS) sampling and culling matrices.
Syntax
void WINAPI gluLoadSamplingMatrices(
GLUnurbs *nobj,
const GLfloat modelMatrix[16],
const GLfloat projMatrix[16],
const GLint viewport[4]
);
Parameters
-
nobj
-
The NURBS object (created with gluNewNurbsRenderer).
-
modelMatrix
-
A modelview matrix (as from a glGetFloatv call).
-
projMatrix
-
A projection matrix (as from a glGetFloatv call).
-
viewport
-
A viewport (as from a glGetIntegerv call).
Return value
This function does not return a value.
Remarks
The gluLoadSamplingMatrices function uses modelMatrix, projMatrix, and viewport to recompute the sampling and culling matrices stored in nobj. The sampling matrix determines how finely a NURBS curve or surface must be tessellated to satisfy the sampling tolerance (as determined by the GLU_SAMPLING_TOLERANCE property). The culling matrix is used in deciding if a NURBS curve or surface should be culled before rendering (when the GLU_CULLING property is turned on).
The gluLoadSamplingMatrices function is necessary only if the GLU_AUTO_LOAD_MATRIX property is turned off (see gluNurbsProperty). Although it can be convenient to leave the GLU_AUTO_LOAD_MATRIX property turned on, doing so necessitates a round trip to the OpenGL server to get the current values of the modelview matrix, projection matrix, and viewport.)
Requirements
Requirement | Value |
---|---|
Minimum supported client |
Windows 2000 Professional [desktop apps only] |
Minimum supported server |
Windows 2000 Server [desktop apps only] |
Header |
|
Library |
|
DLL |
|