xref: /third_party/libinput/src/util-matrix.h (revision a46c0ec8)
1/*
2 * Copyright © 2008 Kristian Høgsberg
3 * Copyright © 2013-2015 Red Hat, Inc.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the next
13 * paragraph) shall be included in all copies or substantial portions of the
14 * Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
21 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
22 * DEALINGS IN THE SOFTWARE.
23 */
24
25#pragma once
26
27#include "config.h"
28
29#include <string.h>
30#include <stdbool.h>
31#include <math.h>
32
33struct matrix {
34	float val[3][3]; /* [row][col] */
35};
36
37static inline double
38deg2rad(int degree)
39{
40	return M_PI * degree / 180.0;
41}
42
43static inline void
44matrix_init_identity(struct matrix *m)
45{
46	memset(m, 0, sizeof(*m));
47	m->val[0][0] = 1;
48	m->val[1][1] = 1;
49	m->val[2][2] = 1;
50}
51
52static inline void
53matrix_from_farray6(struct matrix *m, const float values[6])
54{
55	matrix_init_identity(m);
56	m->val[0][0] = values[0];
57	m->val[0][1] = values[1];
58	m->val[0][2] = values[2];
59	m->val[1][0] = values[3];
60	m->val[1][1] = values[4];
61	m->val[1][2] = values[5];
62}
63
64static inline void
65matrix_init_scale(struct matrix *m, float sx, float sy)
66{
67	matrix_init_identity(m);
68	m->val[0][0] = sx;
69	m->val[1][1] = sy;
70}
71
72static inline void
73matrix_init_translate(struct matrix *m, float x, float y)
74{
75	matrix_init_identity(m);
76	m->val[0][2] = x;
77	m->val[1][2] = y;
78}
79
80static inline void
81matrix_init_rotate(struct matrix *m, int degrees)
82{
83	double s, c;
84
85	s = sin(deg2rad(degrees));
86	c = cos(deg2rad(degrees));
87
88	matrix_init_identity(m);
89	m->val[0][0] = c;
90	m->val[0][1] = -s;
91	m->val[1][0] = s;
92	m->val[1][1] = c;
93}
94
95static inline bool
96matrix_is_identity(const struct matrix *m)
97{
98	return (m->val[0][0] == 1 &&
99		m->val[0][1] == 0 &&
100		m->val[0][2] == 0 &&
101		m->val[1][0] == 0 &&
102		m->val[1][1] == 1 &&
103		m->val[1][2] == 0 &&
104		m->val[2][0] == 0 &&
105		m->val[2][1] == 0 &&
106		m->val[2][2] == 1);
107}
108
109static inline void
110matrix_mult(struct matrix *dest,
111	    const struct matrix *m1,
112	    const struct matrix *m2)
113{
114	struct matrix m; /* allow for dest == m1 or dest == m2 */
115	int row, col, i;
116
117	for (row = 0; row < 3; row++) {
118		for (col = 0; col < 3; col++) {
119			double v = 0;
120			for (i = 0; i < 3; i++) {
121				v += m1->val[row][i] * m2->val[i][col];
122			}
123			m.val[row][col] = v;
124		}
125	}
126
127	memcpy(dest, &m, sizeof(m));
128}
129
130static inline void
131matrix_mult_vec(const struct matrix *m, int *x, int *y)
132{
133	int tx, ty;
134
135	tx = *x * m->val[0][0] + *y * m->val[0][1] + m->val[0][2];
136	ty = *x * m->val[1][0] + *y * m->val[1][1] + m->val[1][2];
137
138	*x = tx;
139	*y = ty;
140}
141
142static inline void
143matrix_mult_vec_double(const struct matrix *m, double *x, double *y)
144{
145	double tx, ty;
146
147	tx = *x * m->val[0][0] + *y * m->val[0][1] + m->val[0][2];
148	ty = *x * m->val[1][0] + *y * m->val[1][1] + m->val[1][2];
149
150	*x = tx;
151	*y = ty;
152}
153
154static inline void
155matrix_to_farray6(const struct matrix *m, float out[6])
156{
157	out[0] = m->val[0][0];
158	out[1] = m->val[0][1];
159	out[2] = m->val[0][2];
160	out[3] = m->val[1][0];
161	out[4] = m->val[1][1];
162	out[5] = m->val[1][2];
163}
164
165static inline void
166matrix_to_relative(struct matrix *dest, const struct matrix *src)
167{
168	matrix_init_identity(dest);
169	dest->val[0][0] = src->val[0][0];
170	dest->val[0][1] = src->val[0][1];
171	dest->val[1][0] = src->val[1][0];
172	dest->val[1][1] = src->val[1][1];
173}
174