rotate.c
1.31 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
/**************************************************************************
* *
* 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* unpublished proprietary information of Silicon Graphics, Inc., and *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 "guint.h"
void guRotateF(float mf[4][4], float a, float x, float y, float z)
{
static float dtor = 3.1415926 / 180.0;
float sine;
float cosine;
float ab, bc, ca, t;
guNormalize(&x, &y, &z);
a *= dtor;
sine = sinf(a);
cosine = cosf(a);
t = (1-cosine);
ab = x*y*t;
bc = y*z*t;
ca = z*x*t;
guMtxIdentF(mf);
t = x*x;
mf[0][0] = t+cosine*(1-t);
mf[2][1] = bc-x*sine;
mf[1][2] = bc+x*sine;
t = y*y;
mf[1][1] = t+cosine*(1-t);
mf[2][0] = ca+y*sine;
mf[0][2] = ca-y*sine;
t = z*z;
mf[2][2] = t+cosine*(1-t);
mf[1][0] = ab-z*sine;
mf[0][1] = ab+z*sine;
}
void guRotate(Mtx *m, float a, float x, float y, float z)
{
Matrix mf;
guRotateF(mf, a, x, y, z);
guMtxF2L(mf, m);
}