
/**************************************************************************
 *									  *
 *		 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 *  unpublished  proprietary  information of Silicon Graphics, Inc., and  *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.  *
 *									  *
 **************************************************************************/

#include <libultra/types.h>
#include "PR/guint.h"

extern f32 __cosf(f32);
extern f32 __sinf(f32);

void guPerspectiveF(float mf[4][4], u16* perspNorm, float fovy, float aspect, float near, float far, float scale) {
    float cot;
    int i, j;

    guMtxIdentF(mf);

    fovy *= 3.1415926 / 180.0;
    cot = __cosf(fovy / 2) / __sinf(fovy / 2);

    mf[0][0] = cot / aspect;
    mf[1][1] = cot;
    mf[2][2] = (near + far) / (near - far);
    mf[2][3] = -1;
    mf[3][2] = (2 * near * far) / (near - far);
    mf[3][3] = 0;

    for (i = 0; i < 4; i++) {
        for (j = 0; j < 4; j++) {
            mf[i][j] *= scale;
        }
    }

    if (perspNorm != (u16*) NULL) {
        if (near + far <= 2.0) {
            *perspNorm = (u16) 0xFFFF;
        } else {
            *perspNorm = (u16) ((2.0 * 65536.0) / (near + far));
            if (*perspNorm <= 0) {
                *perspNorm = (u16) 0x0001;
            }
        }
    }
}

void guPerspective(Mtx* m, u16* perspNorm, float fovy, float aspect, float near, float far, float scale) {
    Matrix mf;

    guPerspectiveF(mf, perspNorm, fovy, aspect, near, far, scale);
    guMtxF2L(mf, m);
}
