sm64/lib/src/guLookAtRef.c
2020-12-03 14:26:38 -05:00

115 lines
3.7 KiB
C

/*
* This file originates from the standard Nintendo 64 SDK libultra src
* directory, and it used exclusively when building with the Fast3DEX2
* microcode. Not not using it breaks environment mapping.
*
* Apart from the modifications listed below, this file is unmodified.
*/
/**************************************************************************
* *
* Copyright (C) 1994, Silicon Graphics, Inc. *
* *
* These coded instructions, statements, and computer programs contain *
* unpublished proprietary information of Silicon Graphics, Inc., and *
* are protected by Federal copyright law. They may not be disclosed *
* to third parties or copied or duplicated in any form, in whole or *
* in part, without the prior written consent of Silicon Graphics, Inc. *
* *
**************************************************************************/
/* Minor modifications */
#include <ultra64.h>
#define FTOFRAC8(x) ((int) MIN(((x) * (128.0)), 127.0) & 0xff)
void guLookAtReflectF(float mf[4][4], LookAt *l, float xEye, float yEye, float zEye, float xAt,
float yAt, float zAt, float xUp, float yUp, float zUp) {
float len, xLook, yLook, zLook, xRight, yRight, zRight;
guMtxIdentF(mf);
xLook = xAt - xEye;
yLook = yAt - yEye;
zLook = zAt - zEye;
/* Negate because positive Z is behind us: */
len = -1.0 / sqrtf(xLook * xLook + yLook * yLook + zLook * zLook);
xLook *= len;
yLook *= len;
zLook *= len;
/* Right = Up x Look */
xRight = yUp * zLook - zUp * yLook;
yRight = zUp * xLook - xUp * zLook;
zRight = xUp * yLook - yUp * xLook;
len = 1.0 / sqrtf(xRight * xRight + yRight * yRight + zRight * zRight);
xRight *= len;
yRight *= len;
zRight *= len;
/* Up = Look x Right */
xUp = yLook * zRight - zLook * yRight;
yUp = zLook * xRight - xLook * zRight;
zUp = xLook * yRight - yLook * xRight;
len = 1.0 / sqrtf(xUp * xUp + yUp * yUp + zUp * zUp);
xUp *= len;
yUp *= len;
zUp *= len;
/* reflectance vectors = Up and Right */
l->l[0].l.dir[0] = FTOFRAC8(xRight);
l->l[0].l.dir[1] = FTOFRAC8(yRight);
l->l[0].l.dir[2] = FTOFRAC8(zRight);
l->l[1].l.dir[0] = FTOFRAC8(xUp);
l->l[1].l.dir[1] = FTOFRAC8(yUp);
l->l[1].l.dir[2] = FTOFRAC8(zUp);
l->l[0].l.col[0] = 0x00;
l->l[0].l.col[1] = 0x00;
l->l[0].l.col[2] = 0x00;
l->l[0].l.pad1 = 0x00;
l->l[0].l.colc[0] = 0x00;
l->l[0].l.colc[1] = 0x00;
l->l[0].l.colc[2] = 0x00;
l->l[0].l.pad2 = 0x00;
l->l[1].l.col[0] = 0x00;
l->l[1].l.col[1] = 0x80;
l->l[1].l.col[2] = 0x00;
l->l[1].l.pad1 = 0x00;
l->l[1].l.colc[0] = 0x00;
l->l[1].l.colc[1] = 0x80;
l->l[1].l.colc[2] = 0x00;
l->l[1].l.pad2 = 0x00;
mf[0][0] = xRight;
mf[1][0] = yRight;
mf[2][0] = zRight;
mf[3][0] = -(xEye * xRight + yEye * yRight + zEye * zRight);
mf[0][1] = xUp;
mf[1][1] = yUp;
mf[2][1] = zUp;
mf[3][1] = -(xEye * xUp + yEye * yUp + zEye * zUp);
mf[0][2] = xLook;
mf[1][2] = yLook;
mf[2][2] = zLook;
mf[3][2] = -(xEye * xLook + yEye * yLook + zEye * zLook);
mf[0][3] = 0;
mf[1][3] = 0;
mf[2][3] = 0;
mf[3][3] = 1;
}
void guLookAtReflect(Mtx *m, LookAt *l, float xEye, float yEye, float zEye, float xAt, float yAt,
float zAt, float xUp, float yUp, float zUp) {
float mf[4][4];
guLookAtReflectF(mf, l, xEye, yEye, zEye, xAt, yAt, zAt, xUp, yUp, zUp);
guMtxF2L(mf, m);
}