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- /****************************************************************************
- * vector.h
- *
- * This module contains macros to perform operations on vectors.
- *
- * from Persistence of Vision Raytracer
- * Copyright 1992 Persistence of Vision Team
- *---------------------------------------------------------------------------
- * Copying, distribution and legal info is in the file povlegal.doc which
- * should be distributed with this file. If povlegal.doc is not available
- * or for more info please contact:
- *
- * Drew Wells [POV-Team Leader]
- * CIS: 73767,1244 Internet: 73767.1244@compuserve.com
- * Phone: (213) 254-4041
- *
- * This program is based on the popular DKB raytracer version 2.12.
- * DKBTrace was originally written by David K. Buck.
- * DKBTrace Ver 2.0-2.12 were written by David K. Buck & Aaron A. Collins.
- *
- *****************************************************************************/
-
-
- /* Misc. Vector Math Macro Definitions */
-
- extern DBL VTemp;
-
- /* Vector Add */
- #define VAdd(a, b, c) {(a).x=(b).x+(c).x;(a).y=(b).y+(c).y;(a).z=(b).z+(c).z;}
-
- /* Vector Subtract */
- #define VSub(a, b, c) {(a).x=(b).x-(c).x;(a).y=(b).y-(c).y;(a).z=(b).z-(c).z;}
-
- /* Scale - Multiply Vector by a Scalar */
- #define VScale(a, b, k) {(a).x=(b).x*(k);(a).y=(b).y*(k);(a).z=(b).z*(k);}
-
- /* Inverse Scale - Divide Vector by a Scalar */
- #define VInverseScale(a, b, k) {(a).x=(b).x/(k);(a).y=(b).y/(k);(a).z=(b).z/(k);}
-
- /* Dot Product - Gives Scalar angle (a) between two vectors (b) and (c) */
- #define VDot(a, b, c) {a=(b).x*(c).x+(b).y*(c).y+(b).z*(c).z;}
-
- /* Cross Product - returns Vector (a) = (b) x (c)
- WARNING: a must be different from b and c.*/
- #define VCross(a,b,c) {(a).x=(b).y*(c).z-(b).z*(c).y; \
- (a).y=(b).z*(c).x-(b).x*(c).z; \
- (a).z=(b).x*(c).y-(b).y*(c).x;}
-
- /* Evaluate - returns Vector (a) = Multiply Vector (b) by Vector (c) */
- #define VEvaluate(a, b, c) {(a).x=(b).x*(c).x;(a).y=(b).y*(c).y;(a).z=(b).z*(c).z;}
-
- /* Square a Vector */
- #define VSqr(a) {(a).x*(a).x;(a).y*(a).y;(a).z*(a).z;}
-
- /* Simple Scalar Square Macro */
- #define Sqr(a) ((a)*(a))
-
- /* Square a Vector (b) and Assign to another Vector (a) */
- #define VSquareTerms(a, b) {(a).x=(b).x*(b).x;(a).y=(b).y*(b).y;(a).z=(b).z*(b).z;}
-
- /* Vector Length - returs Scalar Euclidean Length (a) of Vector (b) */
- #define VLength(a, b) {a=sqrt((b).x*(b).x+(b).y*(b).y+(b).z*(b).z);}
-
- /* Normalize a Vector - returns a vector (length of 1) that points at (b) */
- #define VNormalize(a,b) {VTemp=sqrt((b).x*(b).x+(b).y*(b).y+(b).z*(b).z);(a).x=(b).x/VTemp;(a).y=(b).y/VTemp;(a).z=(b).z/VTemp;}
-
- /* Compute a Vector (a) Halfway Between Two Given Vectors (b) and (c) */
- #define VHalf(a, b, c) {(a).x=0.5*((b).x+(c).x);(a).y=0.5*((b).y+(c).y);(a).z=0.5*((b).z+(c).z);}
-