NAME

gleTwistExtrusion - Extrude arbitrary 2D contour along arbitrary 3D path, specifying local rotations (twists).

SYNTAX

void gleTwistExtrusion (int ncp,


                gleDouble contour[][2],


                gleDouble cont_normal[][2],


                gleDouble up[3],


                int npoints,


                gleDouble point_array[][3],


                float color_array[][3],


                gleDouble twist_array[]);

ARGUMENTS

ncp

number of contour points

contour

2D contour

cont_normal

2D contour normals

up

up vector for contour

npoints

numpoints in poly-line

point_array

polyline vertices

color_array

colors at polyline verts

twist_array

contour twists (in degrees)

DESCRIPTION

Extrude arbitrary 2D contour along arbitrary 3D path, specifying local rotations (twists). As the contour is extruded, it will be twisted by the amount specified in the array "twist_array". The angles are measured in degrees, and the rotation is about the origin of the contour coordinate system.

The argument "contour" specifies the 2D contour to be extruded, while the argument "point_array" specifies the path along which to extrude. The vector "up" defines the orientation of the contour y-axis in real 3D space.

Note that neither the very first segment, nor the very last segment are drawn. The first and last segments serve only to define the angle of the join at the very ends of the polyline. Thus, to draw one segment, three must be specified. To draw two segments, four must be specified, etc.

The normal array may be NULL. If it is, normal vectors will NOT be automatically generated, and the object will look terrible when lit.

The color array may be NULL. If NULL, the current color is used. If not NULL, the glColor3f() routine is used to set the color; therefore, specifying the glColorMaterial() subroutine before this primitive can be used to set diffuse, specular, ambient, etc. colors.

SEE ALSO

gleExtrusion, gleSuperExtrusion

AUTHOR

Linas Vepstas (linas@linas.org)