GNU/Linux |
CentOS 5.3 |
|
![]() |
gluNurbsCurve(3gl) |
![]() |
gluNurbsCurve − define the shape of a NURBS curve
void gluNurbsCurve( GLUnurbs* nurb,
GLint knotCount, | |
GLfloat *knots, | |
GLint stride, | |
GLfloat *control, | |
GLint order, | |
GLenum type ) |
nurb |
Specifies the NURBS object (created with gluNewNurbsRenderer). | ||
knotCount |
Specifies the number of knots in knots. knotCount equals the number of control points plus the order. | ||
knots |
Specifies an array of knotCount nondecreasing knot values. | ||
stride |
Specifies the offset (as a number of single-precision floating-point values) between successive curve control points. | ||
control |
Specifies a pointer to an array of control points. The coordinates must agree with type, specified below. | ||
order |
Specifies the order of the NURBS curve. order equals degree + 1, hence a cubic curve has an order of 4. | ||
type |
Specifies the type of the curve. If this curve is defined within a gluBeginCurve/gluEndCurve pair, then the type can be any of the valid one-dimensional evaluator types (such as GL_MAP1_VERTEX_3 or GL_MAP1_COLOR_4). Between a gluBeginTrim/gluEndTrim pair, the only valid types are GLU_MAP1_TRIM_2 and GLU_MAP1_TRIM_3. |
Use gluNurbsCurve to describe a NURBS curve.
When gluNurbsCurve appears between a gluBeginCurve/gluEndCurve pair, it is used to describe a curve to be rendered. Positional, texture, and color coordinates are associated by presenting each as a separate gluNurbsCurve between a gluBeginCurve/gluEndCurve pair. No more than one call to gluNurbsCurve for each of color, position, and texture data can be made within a single gluBeginCurve/gluEndCurve pair. Exactly one call must be made to describe the position of the curve (a type of GL_MAP1_VERTEX_3 or GL_MAP1_VERTEX_4).
When gluNurbsCurve appears between a gluBeginTrim/gluEndTrim pair, it is used to describe a trimming curve on a NURBS surface. If type is GLU_MAP1_TRIM_2, then it describes a curve in two-dimensional (u and v) parameter space. If it is GLU_MAP1_TRIM_3, then it describes a curve in two-dimensional homogeneous (u, v, and w) parameter space. See the gluBeginTrim reference page for more discussion about trimming curves.
The following commands render a textured NURBS curve with normals:
gluBeginCurve(nobj);
gluNurbsCurve(nobj, ..., GL_MAP1_TEXTURE_COORD_2);
gluNurbsCurve(nobj, ..., GL_MAP1_NORMAL);
gluNurbsCurve(nobj, ..., GL_MAP1_VERTEX_4);
gluEndCurve(nobj);
To define trim curves which stitch well, use gluPwlCurve.
gluBeginCurve(3G), gluBeginTrim(3G), gluNewNurbsRenderer(3G), gluPwlCurve(3G)
![]() |
gluNurbsCurve(3gl) | ![]() |