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comparison: gfx/qcms/matrix.c
gfx/qcms/matrix.c
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| 1 /* vim: set ts=8 sw=8 noexpandtab: */ | |
| 2 // qcms | |
| 3 // Copyright (C) 2009 Mozilla Foundation | |
| 4 // Copyright (C) 1998-2007 Marti Maria | |
| 5 // | |
| 6 // Permission is hereby granted, free of charge, to any person obtaining | |
| 7 // a copy of this software and associated documentation files (the "Software"), | |
| 8 // to deal in the Software without restriction, including without limitation | |
| 9 // the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
| 10 // and/or sell copies of the Software, and to permit persons to whom the Software | |
| 11 // is furnished to do so, subject to the following conditions: | |
| 12 // | |
| 13 // The above copyright notice and this permission notice shall be included in | |
| 14 // all copies or substantial portions of the Software. | |
| 15 // | |
| 16 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, | |
| 17 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO | |
| 18 // THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND | |
| 19 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE | |
| 20 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION | |
| 21 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION | |
| 22 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. | |
| 23 | |
| 24 #include <stdlib.h> | |
| 25 #include "qcmsint.h" | |
| 26 #include "matrix.h" | |
| 27 | |
| 28 struct vector matrix_eval(struct matrix mat, struct vector v) | |
| 29 { | |
| 30 struct vector result; | |
| 31 result.v[0] = mat.m[0][0]*v.v[0] + mat.m[0][1]*v.v[1] + mat.m[0][2]*v.v[2]; | |
| 32 result.v[1] = mat.m[1][0]*v.v[0] + mat.m[1][1]*v.v[1] + mat.m[1][2]*v.v[2]; | |
| 33 result.v[2] = mat.m[2][0]*v.v[0] + mat.m[2][1]*v.v[1] + mat.m[2][2]*v.v[2]; | |
| 34 return result; | |
| 35 } | |
| 36 | |
| 37 //XXX: should probably pass by reference and we could | |
| 38 //probably reuse this computation in matrix_invert | |
| 39 float matrix_det(struct matrix mat) | |
| 40 { | |
| 41 float det; | |
| 42 det = mat.m[0][0]*mat.m[1][1]*mat.m[2][2] + | |
| 43 mat.m[0][1]*mat.m[1][2]*mat.m[2][0] + | |
| 44 mat.m[0][2]*mat.m[1][0]*mat.m[2][1] - | |
| 45 mat.m[0][0]*mat.m[1][2]*mat.m[2][1] - | |
| 46 mat.m[0][1]*mat.m[1][0]*mat.m[2][2] - | |
| 47 mat.m[0][2]*mat.m[1][1]*mat.m[2][0]; | |
| 48 return det; | |
| 49 } | |
| 50 | |
| 51 /* from pixman and cairo and Mathematics for Game Programmers */ | |
| 52 /* lcms uses gauss-jordan elimination with partial pivoting which is | |
| 53 * less efficient and not as numerically stable. See Mathematics for | |
| 54 * Game Programmers. */ | |
| 55 struct matrix matrix_invert(struct matrix mat) | |
| 56 { | |
| 57 struct matrix dest_mat; | |
| 58 int i,j; | |
| 59 static int a[3] = { 2, 2, 1 }; | |
| 60 static int b[3] = { 1, 0, 0 }; | |
| 61 | |
| 62 /* inv (A) = 1/det (A) * adj (A) */ | |
| 63 float det = matrix_det(mat); | |
| 64 | |
| 65 if (det == 0) { | |
| 66 dest_mat.invalid = true; | |
| 67 } else { | |
| 68 dest_mat.invalid = false; | |
| 69 } | |
| 70 | |
| 71 det = 1/det; | |
| 72 | |
| 73 for (j = 0; j < 3; j++) { | |
| 74 for (i = 0; i < 3; i++) { | |
| 75 double p; | |
| 76 int ai = a[i]; | |
| 77 int aj = a[j]; | |
| 78 int bi = b[i]; | |
| 79 int bj = b[j]; | |
| 80 | |
| 81 p = mat.m[ai][aj] * mat.m[bi][bj] - | |
| 82 mat.m[ai][bj] * mat.m[bi][aj]; | |
| 83 if (((i + j) & 1) != 0) | |
| 84 p = -p; | |
| 85 | |
| 86 dest_mat.m[j][i] = det * p; | |
| 87 } | |
| 88 } | |
| 89 return dest_mat; | |
| 90 } | |
| 91 | |
| 92 struct matrix matrix_identity(void) | |
| 93 { | |
| 94 struct matrix i; | |
| 95 i.m[0][0] = 1; | |
| 96 i.m[0][1] = 0; | |
| 97 i.m[0][2] = 0; | |
| 98 i.m[1][0] = 0; | |
| 99 i.m[1][1] = 1; | |
| 100 i.m[1][2] = 0; | |
| 101 i.m[2][0] = 0; | |
| 102 i.m[2][1] = 0; | |
| 103 i.m[2][2] = 1; | |
| 104 i.invalid = false; | |
| 105 return i; | |
| 106 } | |
| 107 | |
| 108 struct matrix matrix_invalid(void) | |
| 109 { | |
| 110 struct matrix inv = matrix_identity(); | |
| 111 inv.invalid = true; | |
| 112 return inv; | |
| 113 } | |
| 114 | |
| 115 | |
| 116 /* from pixman */ | |
| 117 /* MAT3per... */ | |
| 118 struct matrix matrix_multiply(struct matrix a, struct matrix b) | |
| 119 { | |
| 120 struct matrix result; | |
| 121 int dx, dy; | |
| 122 int o; | |
| 123 for (dy = 0; dy < 3; dy++) { | |
| 124 for (dx = 0; dx < 3; dx++) { | |
| 125 double v = 0; | |
| 126 for (o = 0; o < 3; o++) { | |
| 127 v += a.m[dy][o] * b.m[o][dx]; | |
| 128 } | |
| 129 result.m[dy][dx] = v; | |
| 130 } | |
| 131 } | |
| 132 result.invalid = a.invalid || b.invalid; | |
| 133 return result; | |
| 134 } | |
| 135 | |
| 136 |
