NAME

C SPECIFICATION

#include <cx/Geometry.h>

enum cxGeoBindingLevel
{
 CX_GEO_PER_DEFAULT,
 CX_GEO_PER_OBJECT,
 CX_GEO_PER_PART,
 CX_GEO_PER_FACE,
 CX_GEO_PER_FACE_INDEXED,
 CX_GEO_PER_VERTEX,
 CX_GEO_PER_VERTEX_INDEXED
};

void cxGeoNormalAdd(
 int n,
 float *normal,
 cxGeoBindingLevel per )

FORTRAN SPECIFICATION

integer CX_GEO_PER_DEFAULT
integer CX_GEO_PER_OBJECT
integer CX_GEO_PER_PART
integer CX_GEO_PER_FACE
integer CX_GEO_PER_FACE_INDEXED
integer CX_GEO_PER_VERTEX
integer CX_GEO_PER_VERTEX_INDEXED

parameter (CX_GEO_PER_DEFAULT  = 0)
parameter (CX_GEO_PER_OBJECT  = 1)
parameter (CX_GEO_PER_PART  = 2)
parameter (CX_GEO_PER_FACE  = 3)
parameter (CX_GEO_PER_FACE_INDEXED = 4)
parameter (CX_GEO_PER_VERTEX  = 5)
parameter (CX_GEO_PER_VERTEX_INDEXED = 6)

subroutine cxGeoNormalAdd(n,normal,per)
integer n
real normal(3, n)
integer per

PARAMETERS

n

Number of normals.

normal

An array of normalized XYZ triples.

per

A flag indicating how normals are to be applied.

DESCRIPTION

Colors may be applied in different ways, depending on the setting of the per flag:

CX_GEO_PER_OBJECT

a single attribute is used over the entire object

CX_GEO_PER_FACE

a different attribute is applied on each face (valid for polygons, triangles, and grids)

CX_GEO_PER_VERTEX

a different attribute is applied per vertex (valid for points, lines, polygons, triangles, and grids)

CX_GEO_PER_VERTEX_INDEXED

a different attribute is applied on each reference to a vertex (valid for lines, polygons, and triangles)

The normals are expected to have been normalized to unit length.

Polygons specified by cxGeoPolysDefine must have their vertices supplied in a counter-clockwise fashion so that the implicit frontfacing/backfacing normal for the polygon is computed correctly according to the "right-hand rule". You cannot use cxGeoNormalAdd to override this frontfacing/backfacing normal computation for purposes of rendering.

SEE ALSO