summaryrefslogtreecommitdiff
path: root/lib/igt_matrix.c
blob: 6ba59d47dc4b4c11c9349b981ef019b15733e507 (plain)
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
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
/*
 * Copyright © 2018 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include "igt_core.h"
#include "igt_matrix.h"

/**
 * SECTION:igt_matrix
 * @short_description: Matrix math library
 * @title: Matrix
 * @include: igt.h
 *
 * This library contains helper functions for basic matrix math.
 * The library operates on #igt_mat4 and #igt_vec4 structures.
 */

/**
 * igt_matrix_print:
 * @m: the matrix
 *
 * Print out the matrix elements.
 */
void igt_matrix_print(const struct igt_mat4 *m)
{
	for (int row = 0; row < 4; row++) {
		igt_info("|");
		for (int col = 0; col < 4; col++) {
			igt_info("%4.4f,", m->d[m(row, col)]);
		}
		igt_info("|\n");
	}
}

/**
 * igt_matrix_identity:
 *
 * Returns:
 * An identity matrix.
 */
struct igt_mat4 igt_matrix_identity(void)
{
	static const struct igt_mat4 ret = {
		.d[m(0, 0)] = 1.0f,
		.d[m(1, 1)] = 1.0f,
		.d[m(2, 2)] = 1.0f,
		.d[m(3, 3)] = 1.0f,
	};

	return ret;
}

/**
 * igt_matrix_scale:
 * @x: x scaling amount
 * @y: y scaling amount
 * @z: z scaling amount
 *
 * Returns:
 * An scaling matrix.
 */
struct igt_mat4 igt_matrix_scale(float x, float y, float z)
{
	struct igt_mat4 ret = {
		.d[m(0, 0)] = x,
		.d[m(1, 1)] = y,
		.d[m(2, 2)] = z,
		.d[m(3, 3)] = 1.0f,
	};

	return ret;
}

/**
 * igt_matrix_translate:
 * @x: x translation amount
 * @y: y translation amount
 * @z: z translation amount
 *
 * Returns:
 * A translation matrix.
 */
struct igt_mat4 igt_matrix_translate(float x, float y, float z)
{
	struct igt_mat4 ret = {
		.d[m(0, 0)] = 1.0f,
		.d[m(1, 1)] = 1.0f,
		.d[m(2, 2)] = 1.0f,
		.d[m(0, 3)] = x,
		.d[m(1, 3)] = y,
		.d[m(2, 3)] = z,
		.d[m(3, 3)] = 1.0f,
	};

	return ret;
}

/**
 * igt_matrix_multiply:
 * @a: Left matrix
 * @b: Right matrix
 *
 * Multiply two matrices together. @a is on the left,
 * @b on the right.
 *
 * Returns:
 * The resulting matrix.
 */
struct igt_mat4 igt_matrix_multiply(const struct igt_mat4 *a,
				    const struct igt_mat4 *b)
{
	struct igt_mat4 ret = {};

	for (int col = 0; col < 4; col++) {
		for (int row = 0; row < 4; row++) {
			for (int i = 0; i < 4; i++)
				ret.d[m(row, col)] += a->d[m(row, i)] * b->d[m(i, col)];
		}
	}

	return ret;
}