graPHIGS Programming Interface: Subroutine Reference

The graPHIGS Programming Interface : Subroutine Reference

GPDFCO - Define Coordinate System

GPDFCO (origin, zplane, up, matrix)

Purpose

Use GPDFCO to compute a three-dimensional, homogeneous transformation matrix.

This matrix mathematically represents a change of coordinates from the default World Coordinate (WC) system to the coordinate system described by the specified input parameters (origin,z plane, up) This matrix represents the change of coordinate systems by a rotation operation followed by a translation operation.

Parameters

origin -- specified by user, 3 short floating-point numbers (WC)

Point of origin of new coordinate system.

z plane -- specified by user, 3 short floating-point numbers (WC)

z plane normal vector of new coordinate system.

up -- specified by user, 3 short floating-point numbers (WC)

Up vector of new coordinate system.

matrix -- returned by the graPHIGS API, 16 short floating-point numbers

Transformation matrix. The elements are returned in the following order for the transformation matrix:

                 
  |m11 m12 m13 m14|
  |m21 m22 m23 m24| ---> (m11,m12,m13,m14,m21,m22,...m44)
  |m31 m32 m33 m34|
  |m41 m42 m43 m44|

Error Codes

58: UP AND PLANE NORMAL VECTORS ARE PARALLEL

Related Subroutines

None

RCP code

201330953 (X'0C001109')