michael@0: /* vim: set ts=8 sw=8 noexpandtab: */
michael@0: //  qcms
michael@0: //  Copyright (C) 2009 Mozilla Foundation
michael@0: //  Copyright (C) 1998-2007 Marti Maria
michael@0: //
michael@0: // Permission is hereby granted, free of charge, to any person obtaining 
michael@0: // a copy of this software and associated documentation files (the "Software"), 
michael@0: // to deal in the Software without restriction, including without limitation 
michael@0: // the rights to use, copy, modify, merge, publish, distribute, sublicense, 
michael@0: // and/or sell copies of the Software, and to permit persons to whom the Software 
michael@0: // is furnished to do so, subject to the following conditions:
michael@0: //
michael@0: // The above copyright notice and this permission notice shall be included in 
michael@0: // all copies or substantial portions of the Software.
michael@0: //
michael@0: // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
michael@0: // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO 
michael@0: // THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
michael@0: // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 
michael@0: // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 
michael@0: // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 
michael@0: // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
michael@0: 
michael@0: #include <stdlib.h>
michael@0: #include "qcmsint.h"
michael@0: #include "matrix.h"
michael@0: 
michael@0: struct vector matrix_eval(struct matrix mat, struct vector v)
michael@0: {
michael@0: 	struct vector result;
michael@0: 	result.v[0] = mat.m[0][0]*v.v[0] + mat.m[0][1]*v.v[1] + mat.m[0][2]*v.v[2];
michael@0: 	result.v[1] = mat.m[1][0]*v.v[0] + mat.m[1][1]*v.v[1] + mat.m[1][2]*v.v[2];
michael@0: 	result.v[2] = mat.m[2][0]*v.v[0] + mat.m[2][1]*v.v[1] + mat.m[2][2]*v.v[2];
michael@0: 	return result;
michael@0: }
michael@0: 
michael@0: //XXX: should probably pass by reference and we could
michael@0: //probably reuse this computation in matrix_invert
michael@0: float matrix_det(struct matrix mat)
michael@0: {
michael@0: 	float det;
michael@0: 	det = mat.m[0][0]*mat.m[1][1]*mat.m[2][2] +
michael@0: 		mat.m[0][1]*mat.m[1][2]*mat.m[2][0] +
michael@0: 		mat.m[0][2]*mat.m[1][0]*mat.m[2][1] -
michael@0: 		mat.m[0][0]*mat.m[1][2]*mat.m[2][1] -
michael@0: 		mat.m[0][1]*mat.m[1][0]*mat.m[2][2] -
michael@0: 		mat.m[0][2]*mat.m[1][1]*mat.m[2][0];
michael@0: 	return det;
michael@0: }
michael@0: 
michael@0: /* from pixman and cairo and Mathematics for Game Programmers */
michael@0: /* lcms uses gauss-jordan elimination with partial pivoting which is
michael@0:  * less efficient and not as numerically stable. See Mathematics for
michael@0:  * Game Programmers. */
michael@0: struct matrix matrix_invert(struct matrix mat)
michael@0: {
michael@0: 	struct matrix dest_mat;
michael@0: 	int i,j;
michael@0: 	static int a[3] = { 2, 2, 1 };
michael@0: 	static int b[3] = { 1, 0, 0 };
michael@0: 
michael@0: 	/* inv  (A) = 1/det (A) * adj (A) */
michael@0: 	float det = matrix_det(mat);
michael@0: 
michael@0: 	if (det == 0) {
michael@0: 		dest_mat.invalid = true;
michael@0: 	} else {
michael@0: 		dest_mat.invalid = false;
michael@0: 	}
michael@0: 
michael@0: 	det = 1/det;
michael@0: 
michael@0: 	for (j = 0; j < 3; j++) {
michael@0: 		for (i = 0; i < 3; i++) {
michael@0: 			double p;
michael@0: 			int ai = a[i];
michael@0: 			int aj = a[j];
michael@0: 			int bi = b[i];
michael@0: 			int bj = b[j];
michael@0: 
michael@0: 			p = mat.m[ai][aj] * mat.m[bi][bj] -
michael@0: 				mat.m[ai][bj] * mat.m[bi][aj];
michael@0: 			if (((i + j) & 1) != 0)
michael@0: 				p = -p;
michael@0: 
michael@0: 			dest_mat.m[j][i] = det * p;
michael@0: 		}
michael@0: 	}
michael@0: 	return dest_mat;
michael@0: }
michael@0: 
michael@0: struct matrix matrix_identity(void)
michael@0: {
michael@0: 	struct matrix i;
michael@0: 	i.m[0][0] = 1;
michael@0: 	i.m[0][1] = 0;
michael@0: 	i.m[0][2] = 0;
michael@0: 	i.m[1][0] = 0;
michael@0: 	i.m[1][1] = 1;
michael@0: 	i.m[1][2] = 0;
michael@0: 	i.m[2][0] = 0;
michael@0: 	i.m[2][1] = 0;
michael@0: 	i.m[2][2] = 1;
michael@0: 	i.invalid = false;
michael@0: 	return i;
michael@0: }
michael@0: 
michael@0: struct matrix matrix_invalid(void)
michael@0: {
michael@0: 	struct matrix inv = matrix_identity();
michael@0: 	inv.invalid = true;
michael@0: 	return inv;
michael@0: }
michael@0: 
michael@0: 
michael@0: /* from pixman */
michael@0: /* MAT3per... */
michael@0: struct matrix matrix_multiply(struct matrix a, struct matrix b)
michael@0: {
michael@0: 	struct matrix result;
michael@0: 	int dx, dy;
michael@0: 	int o;
michael@0: 	for (dy = 0; dy < 3; dy++) {
michael@0: 		for (dx = 0; dx < 3; dx++) {
michael@0: 			double v = 0;
michael@0: 			for (o = 0; o < 3; o++) {
michael@0: 				v += a.m[dy][o] * b.m[o][dx];
michael@0: 			}
michael@0: 			result.m[dy][dx] = v;
michael@0: 		}
michael@0: 	}
michael@0: 	result.invalid = a.invalid || b.invalid;
michael@0: 	return result;
michael@0: }
michael@0: 
michael@0: