1/* Copyright (c) 2005 - 2012 G-Truc Creation (www.g-truc.net)
2 * Copyright © 2012 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a copy
5 * of this software and associated documentation files (the "Software"), to deal
6 * in the Software without restriction, including without limitation the rights
7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 * copies of the Software, and to permit persons to whom the Software is
9 * furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice shall be included in
12 * all copies or substantial portions of the Software.
13 *
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20 * THE SOFTWARE.
21 */
22
23#version 120
24mat2 inverse(mat2 m)
25{
26   mat2 adj;
27   adj[0][0] = m[1][1];
28   adj[0][1] = -m[0][1];
29   adj[1][0] = -m[1][0];
30   adj[1][1] = m[0][0];
31   float det = m[0][0] * m[1][1] - m[1][0] * m[0][1];
32   return adj / det;
33}
34
35mat3 inverse(mat3 m)
36{
37   mat3 adj;
38   adj[0][0] = + (m[1][1] * m[2][2] - m[2][1] * m[1][2]);
39   adj[1][0] = - (m[1][0] * m[2][2] - m[2][0] * m[1][2]);
40   adj[2][0] = + (m[1][0] * m[2][1] - m[2][0] * m[1][1]);
41   adj[0][1] = - (m[0][1] * m[2][2] - m[2][1] * m[0][2]);
42   adj[1][1] = + (m[0][0] * m[2][2] - m[2][0] * m[0][2]);
43   adj[2][1] = - (m[0][0] * m[2][1] - m[2][0] * m[0][1]);
44   adj[0][2] = + (m[0][1] * m[1][2] - m[1][1] * m[0][2]);
45   adj[1][2] = - (m[0][0] * m[1][2] - m[1][0] * m[0][2]);
46   adj[2][2] = + (m[0][0] * m[1][1] - m[1][0] * m[0][1]);
47
48   float det = (+ m[0][0] * (m[1][1] * m[2][2] - m[1][2] * m[2][1])
49		- m[0][1] * (m[1][0] * m[2][2] - m[1][2] * m[2][0])
50		+ m[0][2] * (m[1][0] * m[2][1] - m[1][1] * m[2][0]));
51
52   return adj / det;
53}
54
55mat4 inverse(mat4 m)
56{
57   float SubFactor00 = m[2][2] * m[3][3] - m[3][2] * m[2][3];
58   float SubFactor01 = m[2][1] * m[3][3] - m[3][1] * m[2][3];
59   float SubFactor02 = m[2][1] * m[3][2] - m[3][1] * m[2][2];
60   float SubFactor03 = m[2][0] * m[3][3] - m[3][0] * m[2][3];
61   float SubFactor04 = m[2][0] * m[3][2] - m[3][0] * m[2][2];
62   float SubFactor05 = m[2][0] * m[3][1] - m[3][0] * m[2][1];
63   float SubFactor06 = m[1][2] * m[3][3] - m[3][2] * m[1][3];
64   float SubFactor07 = m[1][1] * m[3][3] - m[3][1] * m[1][3];
65   float SubFactor08 = m[1][1] * m[3][2] - m[3][1] * m[1][2];
66   float SubFactor09 = m[1][0] * m[3][3] - m[3][0] * m[1][3];
67   float SubFactor10 = m[1][0] * m[3][2] - m[3][0] * m[1][2];
68   float SubFactor11 = m[1][1] * m[3][3] - m[3][1] * m[1][3];
69   float SubFactor12 = m[1][0] * m[3][1] - m[3][0] * m[1][1];
70   float SubFactor13 = m[1][2] * m[2][3] - m[2][2] * m[1][3];
71   float SubFactor14 = m[1][1] * m[2][3] - m[2][1] * m[1][3];
72   float SubFactor15 = m[1][1] * m[2][2] - m[2][1] * m[1][2];
73   float SubFactor16 = m[1][0] * m[2][3] - m[2][0] * m[1][3];
74   float SubFactor17 = m[1][0] * m[2][2] - m[2][0] * m[1][2];
75   float SubFactor18 = m[1][0] * m[2][1] - m[2][0] * m[1][1];
76
77   mat4 adj;
78
79   adj[0][0] = + (m[1][1] * SubFactor00 - m[1][2] * SubFactor01 + m[1][3] * SubFactor02);
80   adj[1][0] = - (m[1][0] * SubFactor00 - m[1][2] * SubFactor03 + m[1][3] * SubFactor04);
81   adj[2][0] = + (m[1][0] * SubFactor01 - m[1][1] * SubFactor03 + m[1][3] * SubFactor05);
82   adj[3][0] = - (m[1][0] * SubFactor02 - m[1][1] * SubFactor04 + m[1][2] * SubFactor05);
83
84   adj[0][1] = - (m[0][1] * SubFactor00 - m[0][2] * SubFactor01 + m[0][3] * SubFactor02);
85   adj[1][1] = + (m[0][0] * SubFactor00 - m[0][2] * SubFactor03 + m[0][3] * SubFactor04);
86   adj[2][1] = - (m[0][0] * SubFactor01 - m[0][1] * SubFactor03 + m[0][3] * SubFactor05);
87   adj[3][1] = + (m[0][0] * SubFactor02 - m[0][1] * SubFactor04 + m[0][2] * SubFactor05);
88
89   adj[0][2] = + (m[0][1] * SubFactor06 - m[0][2] * SubFactor07 + m[0][3] * SubFactor08);
90   adj[1][2] = - (m[0][0] * SubFactor06 - m[0][2] * SubFactor09 + m[0][3] * SubFactor10);
91   adj[2][2] = + (m[0][0] * SubFactor11 - m[0][1] * SubFactor09 + m[0][3] * SubFactor12);
92   adj[3][2] = - (m[0][0] * SubFactor08 - m[0][1] * SubFactor10 + m[0][2] * SubFactor12);
93
94   adj[0][3] = - (m[0][1] * SubFactor13 - m[0][2] * SubFactor14 + m[0][3] * SubFactor15);
95   adj[1][3] = + (m[0][0] * SubFactor13 - m[0][2] * SubFactor16 + m[0][3] * SubFactor17);
96   adj[2][3] = - (m[0][0] * SubFactor14 - m[0][1] * SubFactor16 + m[0][3] * SubFactor18);
97   adj[3][3] = + (m[0][0] * SubFactor15 - m[0][1] * SubFactor17 + m[0][2] * SubFactor18);
98
99   float det = (+ m[0][0] * adj[0][0]
100		+ m[0][1] * adj[1][0]
101		+ m[0][2] * adj[2][0]
102		+ m[0][3] * adj[3][0]);
103
104   return adj / det;
105}
106
107