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Diffstat (limited to 'src/matrix.c')
| -rw-r--r-- | src/matrix.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/src/matrix.c b/src/matrix.c new file mode 100644 index 0000000..c71471f --- /dev/null +++ b/src/matrix.c @@ -0,0 +1,102 @@ +/* + * Copyright © 2011 Intel Corporation + * + * Permission to use, copy, modify, distribute, and sell this software and + * its documentation for any purpose is hereby granted without fee, provided + * that the above copyright notice appear in all copies and that both that + * copyright notice and this permission notice appear in supporting + * documentation, and that the name of the copyright holders not be used in + * advertising or publicity pertaining to distribution of the software + * without specific, written prior permission. The copyright holders make + * no representations about the suitability of this software for any + * purpose. It is provided "as is" without express or implied warranty. + * + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS + * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY + * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER + * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF + * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include <string.h> +#include <stdlib.h> +#include <GLES2/gl2.h> +#include <wayland-server.h> + +#include "matrix.h" + +/* + * Matrices are stored in column-major order, that is the array indices are: + * 0 4 8 12 + * 1 5 9 13 + * 2 6 10 14 + * 3 7 11 15 + */ + +WL_EXPORT void +weston_matrix_init(struct weston_matrix *matrix) +{ + static const struct weston_matrix identity = { + { 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 } + }; + + memcpy(matrix, &identity, sizeof identity); +} + +/* m <- n * m, that is, m is multiplied on the LEFT. */ +WL_EXPORT void +weston_matrix_multiply(struct weston_matrix *m, const struct weston_matrix *n) +{ + struct weston_matrix tmp; + const GLfloat *row, *column; + div_t d; + int i, j; + + for (i = 0; i < 16; i++) { + tmp.d[i] = 0; + d = div(i, 4); + row = m->d + d.quot * 4; + column = n->d + d.rem; + for (j = 0; j < 4; j++) + tmp.d[i] += row[j] * column[j * 4]; + } + memcpy(m, &tmp, sizeof tmp); +} + +WL_EXPORT void +weston_matrix_translate(struct weston_matrix *matrix, GLfloat x, GLfloat y, GLfloat z) +{ + struct weston_matrix translate = { + { 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, x, y, z, 1 } + }; + + weston_matrix_multiply(matrix, &translate); +} + +WL_EXPORT void +weston_matrix_scale(struct weston_matrix *matrix, GLfloat x, GLfloat y, GLfloat z) +{ + struct weston_matrix scale = { + { x, 0, 0, 0, 0, y, 0, 0, 0, 0, z, 0, 0, 0, 0, 1 } + }; + + weston_matrix_multiply(matrix, &scale); +} + +/* v <- m * v */ +WL_EXPORT void +weston_matrix_transform(struct weston_matrix *matrix, struct weston_vector *v) +{ + int i, j; + struct weston_vector t; + + for (i = 0; i < 4; i++) { + t.f[i] = 0; + for (j = 0; j < 4; j++) + t.f[i] += v->f[j] * matrix->d[i + j * 4]; + } + + *v = t; +} |