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Diffstat (limited to 'src/m4f-3dx.h')
| -rw-r--r-- | src/m4f-3dx.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/src/m4f-3dx.h b/src/m4f-3dx.h new file mode 100644 index 0000000..384641b --- /dev/null +++ b/src/m4f-3dx.h @@ -0,0 +1,122 @@ +/* + * Copyright (C) 2018-2020 - Vito Caputo - <vcaputo@pengaru.com> + * + * This program is free software: you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 3 as published + * by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef _M4F_3DX_H +#define _M4F_3DX_H + +#include <math.h> + +#include "m4f.h" +#include "v3f.h" + +/* helpers for manipulating 3D transformation matrices */ + +/* XXX: note this is column-major */ + +/* adjust the matrix m to translate by v, returning the resulting matrix */ +/* if m is NULL the identity vector is assumed */ +static inline m4f_t m4f_translate(const m4f_t *m, const v3f_t *v) +{ + m4f_t identity = m4f_identity(); + m4f_t translate = m4f_identity(); + + if (!m) + m = &identity; + + translate.m[3][0] = v->x; + translate.m[3][1] = v->y; + translate.m[3][2] = v->z; + + return m4f_mult(m, &translate); +} + + +/* adjust the matrix m to scale by v, returning the resulting matrix */ +/* if m is NULL the identity vector is assumed */ +static inline m4f_t m4f_scale(const m4f_t *m, const v3f_t *v) +{ + m4f_t identity = m4f_identity(); + m4f_t scale = {}; + + if (!m) + m = &identity; + + scale.m[0][0] = v->x; + scale.m[1][1] = v->y; + scale.m[2][2] = v->z; + scale.m[3][3] = 1.f; + + return m4f_mult(m, &scale); +} + + +/* adjust the matrix m to rotate around the specified axis by radians, returning the resulting matrix */ +/* axis is expected to be a unit vector */ +/* if m is NULL the identity vector is assumed */ +static inline m4f_t m4f_rotate(const m4f_t *m, const v3f_t *axis, float radians) +{ + m4f_t identity = m4f_identity(); + float cos_r = cosf(radians); + float sin_r = sinf(radians); + m4f_t rotate; + + if (!m) + m = &identity; + + rotate.m[0][0] = cos_r + axis->x * axis->x * (1.f - cos_r); + rotate.m[0][1] = axis->y * axis->x * (1.f - cos_r) + axis->z * sin_r; + rotate.m[0][2] = axis->z * axis->x * (1.f - cos_r) - axis->y * sin_r; + rotate.m[0][3] = 0.f; + + rotate.m[1][0] = axis->x * axis->y * (1.f - cos_r) - axis->z * sin_r; + rotate.m[1][1] = cos_r + axis->y * axis->y * (1.f - cos_r); + rotate.m[1][2] = axis->z * axis->y * (1.f - cos_r) + axis->x * sin_r; + rotate.m[1][3] = 0.f; + + rotate.m[2][0] = axis->x * axis->z * (1.f - cos_r) + axis->y * sin_r; + rotate.m[2][1] = axis->y * axis->z * (1.f - cos_r) - axis->x * sin_r; + rotate.m[2][2] = cos_r + axis->z * axis->z * (1.f - cos_r); + rotate.m[2][3] = 0.f; + + rotate.m[3][0] = 0.f; + rotate.m[3][1] = 0.f; + rotate.m[3][2] = 0.f; + rotate.m[3][3] = 1.f; + + return m4f_mult(m, &rotate); +} + + +/* this is a simple perpsective projection matrix taken from an opengl tutorial */ +static inline m4f_t m4f_frustum(float bot, float top, float left, float right, float nnear, float ffar) +{ + m4f_t m = {}; + + m.m[0][0] = 2 * nnear / (right - left); + + m.m[1][1] = 2 * nnear / (top - bot); + + m.m[2][0] = (right + left) / (right - left);; + m.m[2][1] = (top + bot) / (top - bot); + m.m[2][2] = -(ffar + nnear) / (ffar - nnear); + m.m[2][3] = -1; + + m.m[3][2] = -2 * ffar * nnear / (ffar - nnear); + + return m; +} + +#endif |