77 lines
3.2 KiB
C
77 lines
3.2 KiB
C
/****************************************************************************
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* vector.h
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*
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* This module contains macros to perform operations on vectors.
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*
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*****************************************************************************/
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/* Misc. Vector Math Macro Definitions */
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/* Vector Add */
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#define VAdd(a, b, c) {(a).x=(b).x+(c).x;(a).y=(b).y+(c).y;(a).z=(b).z+(c).z;}
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#define VAddEq(a, b) {(a).x+=(b).x;(a).y+=(b).y;(a).z+=(b).z;}
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/* Vector Subtract */
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#define VSub(a, b, c) {(a).x=(b).x-(c).x;(a).y=(b).y-(c).y;(a).z=(b).z-(c).z;}
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#define VSubEq(a, b) {(a).x-=(b).x;(a).y-=(b).y;(a).z-=(b).z;}
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/* Scale - Multiply Vector by a Scalar */
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#define VScale(a, b, k) {(a).x=(b).x*(k);(a).y=(b).y*(k);(a).z=(b).z*(k);}
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#define VScaleEq(a, k) {(a).x*=(k);(a).y*=(k);(a).z*=(k);}
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/* Inverse Scale - Divide Vector by a Scalar */
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#define VInverseScale(a, b, k) {(a).x=(b).x/(k);(a).y=(b).y/(k);(a).z=(b).z/(k);}
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#define VInverseScaleEq(a, k) {(a).x/=(k);(a).y/=(k);(a).z/=(k);}
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/* Dot Product - Gives Scalar angle (a) between two vectors (b) and (c) */
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#define VDot(a, b, c) {a=(b).x*(c).x+(b).y*(c).y+(b).z*(c).z;}
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/* Cross Product - returns Vector (a) = (b) x (c)
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WARNING: a must be different from b and c.*/
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#define VCross(a,b,c) {(a).x=(b).y*(c).z-(b).z*(c).y; \
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(a).y=(b).z*(c).x-(b).x*(c).z; \
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(a).z=(b).x*(c).y-(b).y*(c).x;}
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/* Evaluate - returns Vector (a) = Multiply Vector (b) by Vector (c) */
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#define VEvaluate(a, b, c) {(a).x=(b).x*(c).x;(a).y=(b).y*(c).y;(a).z=(b).z*(c).z;}
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#define VEvaluateEq(a, b) {(a).x*=(b).x;(a).y*=(b).y;(a).z*=(b).z;}
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/* Divide - returns Vector (a) = Divide Vector (b) by Vector (c) */
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#define VDiv(a, b, c) {(a).x=(b).x/(c).x;(a).y=(b).y/(c).y;(a).z=(b).z/(c).z;}
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#define VDivEq(a, b) {(a).x/=(b).x;(a).y/=(b).y;(a).z/=(b).z;}
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/* Square a Vector */
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#define VSqr(a) {(a).x*(a).x;(a).y*(a).y;(a).z*(a).z;}
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/* Simple Scalar Square Macro */
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#define Sqr(a) ((a)*(a))
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/* Square a Vector (b) and Assign to another Vector (a) */
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#define VSquareTerms(a, b) {(a).x=(b).x*(b).x;(a).y=(b).y*(b).y;(a).z=(b).z*(b).z;}
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/* Vector Length - returs Scalar Euclidean Length (a) of Vector (b) */
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#define VLength(a, b) {a=sqrt((b).x*(b).x+(b).y*(b).y+(b).z*(b).z);}
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/* Normalize a Vector - returns a vector (length of 1) that points at (b) */
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#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;}
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/* Compute a Vector (a) Halfway Between Two Given Vectors (b) and (c) */
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#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);}
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/* Linear Combination of vectors, A = b*B + c*C */
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#define VComb(A, b, B, c, C) {(A).x=(b)*(B).x+(c)*(C).x;(A).y=(b)*(B).y+(c)*(C).y;(A).z=(b)*(B).z+(c)*(C).z;}
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/* Add Scalar Multiple, A = b*B + C */
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#define VAddS(A, b, B, C) {(A).x=(b)*(B).x+(C).x;(A).y=(b)*(B).y+(C).y;(A).z=(b)*(B).z+(C).z;}
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/* A point on the Ray */
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#define RayPoint( ray, t, point ) VAddS(point, t, (ray)->D, (ray)->P )
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/* Copy a vector a into b */
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#define VCopy(a, b) {(b).x=(a).x;(b).y=(a).y;(b).z=(a).z;}
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/* Negate a vector */
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#define VNeg(a, b) {(a).x=-(b).x;(a).y=-(b).y;(a).z=-(b).z;}
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