GPPHE - Polyhedron Edge

Purpose

Use GPPHE to insert a Polyhedron Edge structure element into the open structure following the element pointer or to replace the element pointed at by the element pointer with a Polyhedron Edge structure element depending on the current edit mode.

You can use this primitive to simulate the edge of a polyhedron type object. The two normals identify the orientation of the faces which intersect and result in the line segment defined by the two endpoints.

During structure traversal, the graPHIGS API uses the polyline attributes and Polyhedron Edge Culling mode (GPPHEC) from the traversal state list to render each line segment defined by two end points. The Polyhedron Edge Culling mode along with two associated normals within an edgelist entry may suppress rendering of this line segment.

All normal vectors are normalized by the graPHIGS API If the application later inquires the content of this structure element, then the graPHIGS API returns the normalized vectors not the original vectors specified on this subroutine.

GPPHE is identified as GDP 1037.

Note:

Not all GDPs are supported on all workstations. (GPQGD) subroutine to determine the GDPs supported by an opened workstation. See also the workstation description in The graPHIGS Programming Interface: Technical Reference

Parameters