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/* Copyright (c) Mark J. Kilgard, 1997. */
/* This program is freely distributable without licensing fees
and is provided without guarantee or warrantee expressed or
implied. This program is -not- in the public domain. */
/* Simple 3D vector routines. This file is meant to be included in
a .c file, hence all the routines are defined statically. A
good C compiler should be able to automatically inline all
these routines. */
#include <math.h>
static void
vnorm(float vec[3])
{
float len;
len = sqrt(vec[0] * vec[0] + vec[1] * vec[1] + vec[2] * vec[2]);
vec[0] = vec[0] / len;
vec[1] = vec[1] / len;
vec[2] = vec[2] / len;
}
static float
vdot(float a[3], float b[3])
{
return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
}
static void
vdiff(float dst[3], float a[3], float b[3])
{
dst[0] = a[0] - b[0];
dst[1] = a[1] - b[1];
dst[2] = a[2] - b[2];
}
static void
vadd(float dst[3], float a[3], float b[3])
{
dst[0] = a[0] + b[0];
dst[1] = a[1] + b[1];
dst[2] = a[2] + b[2];
}
static void
vcopy(float dst[3], float src[3])
{
dst[0] = src[0];
dst[1] = src[1];
dst[2] = src[2];
}
static void
vscale(float dst[3], float src[3], float scale)
{
dst[0] = src[0] * scale;
dst[1] = src[1] * scale;
dst[2] = src[2] * scale;
}
static void
vcross(float cross[3], const float v1[3], const float v2[3])
{
float tmp[3];
tmp[0] = (v1[1] * v2[2]) - (v1[2] * v2[1]);
tmp[1] = (v1[2] * v2[0]) - (v1[0] * v2[2]);
tmp[2] = (v1[0] * v2[1]) - (v1[1] * v2[0]);
vcopy(cross, tmp);
}
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