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/*
* 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_H
#define _M4F_H
#include <assert.h>
#include "v4f.h"
#include "v3f.h"
typedef struct m4f_t {
float m[4][4];
} m4f_t;
/* XXX: note this is column-major, which reflects OpenGL expectations. */
/* returns an identity matrix */
static inline m4f_t m4f_identity(void)
{
return (m4f_t){ .m = {
{ 1.f, 0.f, 0.f, 0.f },
{ 0.f, 1.f, 0.f, 0.f },
{ 0.f, 0.f, 1.f, 0.f },
{ 0.f, 0.f, 0.f, 1.f },
}};
}
/* 4x4 X 4x4 matrix multiply */
static inline m4f_t m4f_mult(const m4f_t *a, const m4f_t *b)
{
m4f_t r;
/* In matrix multiplication the output has the number of rows from a and number
* of columns from b, and a must have the same number of columns as b has rows.
*
* So this covers a very specific form of matrix multiplication that is of limitd
* use. It's desirable to be able to have inputs of m4f_t and v4f_t with a v4f_t
* output. I think that will be moved into a combined matrix+vector header
* that will depend on m4f.h and v4f.h.
*/
r.m[0][0] = (a->m[0][0] * b->m[0][0]) + (a->m[1][0] * b->m[0][1]) + (a->m[2][0] * b->m[0][2]) + (a->m[3][0] * b->m[0][3]);
r.m[0][1] = (a->m[0][1] * b->m[0][0]) + (a->m[1][1] * b->m[0][1]) + (a->m[2][1] * b->m[0][2]) + (a->m[3][1] * b->m[0][3]);
r.m[0][2] = (a->m[0][2] * b->m[0][0]) + (a->m[1][2] * b->m[0][1]) + (a->m[2][2] * b->m[0][2]) + (a->m[3][2] * b->m[0][3]);
r.m[0][3] = (a->m[0][3] * b->m[0][0]) + (a->m[1][3] * b->m[0][1]) + (a->m[2][3] * b->m[0][2]) + (a->m[3][3] * b->m[0][3]);
r.m[1][0] = (a->m[0][0] * b->m[1][0]) + (a->m[1][0] * b->m[1][1]) + (a->m[2][0] * b->m[1][2]) + (a->m[3][0] * b->m[1][3]);
r.m[1][1] = (a->m[0][1] * b->m[1][0]) + (a->m[1][1] * b->m[1][1]) + (a->m[2][1] * b->m[1][2]) + (a->m[3][1] * b->m[1][3]);
r.m[1][2] = (a->m[0][2] * b->m[1][0]) + (a->m[1][2] * b->m[1][1]) + (a->m[2][2] * b->m[1][2]) + (a->m[3][2] * b->m[1][3]);
r.m[1][3] = (a->m[0][3] * b->m[1][0]) + (a->m[1][3] * b->m[1][1]) + (a->m[2][3] * b->m[1][2]) + (a->m[3][3] * b->m[1][3]);
r.m[2][0] = (a->m[0][0] * b->m[2][0]) + (a->m[1][0] * b->m[2][1]) + (a->m[2][0] * b->m[2][2]) + (a->m[3][0] * b->m[2][3]);
r.m[2][1] = (a->m[0][1] * b->m[2][0]) + (a->m[1][1] * b->m[2][1]) + (a->m[2][1] * b->m[2][2]) + (a->m[3][1] * b->m[2][3]);
r.m[2][2] = (a->m[0][2] * b->m[2][0]) + (a->m[1][2] * b->m[2][1]) + (a->m[2][2] * b->m[2][2]) + (a->m[3][2] * b->m[2][3]);
r.m[2][3] = (a->m[0][3] * b->m[2][0]) + (a->m[1][3] * b->m[2][1]) + (a->m[2][3] * b->m[2][2]) + (a->m[3][3] * b->m[2][3]);
r.m[3][0] = (a->m[0][0] * b->m[3][0]) + (a->m[1][0] * b->m[3][1]) + (a->m[2][0] * b->m[3][2]) + (a->m[3][0] * b->m[3][3]);
r.m[3][1] = (a->m[0][1] * b->m[3][0]) + (a->m[1][1] * b->m[3][1]) + (a->m[2][1] * b->m[3][2]) + (a->m[3][1] * b->m[3][3]);
r.m[3][2] = (a->m[0][2] * b->m[3][0]) + (a->m[1][2] * b->m[3][1]) + (a->m[2][2] * b->m[3][2]) + (a->m[3][2] * b->m[3][3]);
r.m[3][3] = (a->m[0][3] * b->m[3][0]) + (a->m[1][3] * b->m[3][1]) + (a->m[2][3] * b->m[3][2]) + (a->m[3][3] * b->m[3][3]);
return r;
}
/* 4x4 X 1x4 matrix multiply */
static inline v4f_t m4f_mult_v4f(const m4f_t *a, const v4f_t *b)
{
v4f_t v;
v.x = (a->m[0][0] * b->x) + (a->m[1][0] * b->y) + (a->m[2][0] * b->z) + (a->m[3][0] * b->w);
v.y = (a->m[0][1] * b->x) + (a->m[1][1] * b->y) + (a->m[2][1] * b->z) + (a->m[3][1] * b->w);
v.z = (a->m[0][2] * b->x) + (a->m[1][2] * b->y) + (a->m[2][2] * b->z) + (a->m[3][2] * b->w);
v.w = (a->m[0][3] * b->x) + (a->m[1][3] * b->y) + (a->m[2][3] * b->z) + (a->m[3][3] * b->w);
return v;
}
/* 4x4 X 1x3 matrix multiply */
static inline v3f_t m4f_mult_v3f(const m4f_t *a, const v3f_t *b)
{
v3f_t v;
/* TODO: verify correctness/sanity of this */
v.x = (a->m[0][0] * b->x) + (a->m[1][0] * b->y) + (a->m[2][0] * b->z) + (a->m[3][0]);
v.y = (a->m[0][1] * b->x) + (a->m[1][1] * b->y) + (a->m[2][1] * b->z) + (a->m[3][1]);
v.z = (a->m[0][2] * b->x) + (a->m[1][2] * b->y) + (a->m[2][2] * b->z) + (a->m[3][2]);
return v;
}
/* 4x4 square matrix inversion */
static inline m4f_t m4f_invert(const m4f_t *m)
{
m4f_t inv;
float det;
inv.m[0][0] = m->m[1][1] * m->m[2][2] * m->m[3][3] -
m->m[1][1] * m->m[2][3] * m->m[3][2] -
m->m[2][1] * m->m[1][2] * m->m[3][3] +
m->m[2][1] * m->m[1][3] * m->m[3][2] +
m->m[3][1] * m->m[1][2] * m->m[2][3] -
m->m[3][1] * m->m[1][3] * m->m[2][2];
inv.m[1][0] = -m->m[1][0] * m->m[2][2] * m->m[3][3] +
m->m[1][0] * m->m[2][3] * m->m[3][2] +
m->m[2][0] * m->m[1][2] * m->m[3][3] -
m->m[2][0] * m->m[1][3] * m->m[3][2] -
m->m[3][0] * m->m[1][2] * m->m[2][3] +
m->m[3][0] * m->m[1][3] * m->m[2][2];
inv.m[2][0] = m->m[1][0] * m->m[2][1] * m->m[3][3] -
m->m[1][0] * m->m[8][3] * m->m[3][1] -
m->m[2][0] * m->m[1][1] * m->m[3][3] +
m->m[2][0] * m->m[1][3] * m->m[3][1] +
m->m[3][0] * m->m[1][1] * m->m[2][3] -
m->m[3][0] * m->m[1][3] * m->m[2][1];
inv.m[3][0] = -m->m[1][0] * m->m[2][1] * m->m[3][2] +
m->m[1][0] * m->m[2][2] * m->m[3][1] +
m->m[2][0] * m->m[1][1] * m->m[3][2] -
m->m[2][0] * m->m[1][2] * m->m[3][1] -
m->m[3][0] * m->m[1][1] * m->m[2][2] +
m->m[3][0] * m->m[1][2] * m->m[2][1];
inv.m[0][1] = -m->m[0][1] * m->m[2][2] * m->m[3][3] +
m->m[0][1] * m->m[2][3] * m->m[3][2] +
m->m[2][1] * m->m[0][2] * m->m[3][3] -
m->m[2][1] * m->m[0][3] * m->m[3][2] -
m->m[3][1] * m->m[0][2] * m->m[2][3] +
m->m[3][1] * m->m[0][3] * m->m[2][2];
inv.m[1][1] = m->m[0][0] * m->m[2][2] * m->m[3][3] -
m->m[0][0] * m->m[2][3] * m->m[3][2] -
m->m[2][0] * m->m[0][2] * m->m[3][3] +
m->m[2][0] * m->m[0][3] * m->m[3][2] +
m->m[3][0] * m->m[0][2] * m->m[2][3] -
m->m[3][0] * m->m[0][3] * m->m[2][2];
inv.m[2][1] = -m->m[0][0] * m->m[2][1] * m->m[3][3] +
m->m[0][0] * m->m[2][3] * m->m[3][1] +
m->m[2][0] * m->m[0][1] * m->m[3][3] -
m->m[2][0] * m->m[0][3] * m->m[3][1] -
m->m[3][0] * m->m[0][1] * m->m[2][3] +
m->m[3][0] * m->m[0][3] * m->m[2][1];
inv.m[3][1] = m->m[0][0] * m->m[2][1] * m->m[3][2] -
m->m[0][0] * m->m[2][2] * m->m[3][1] -
m->m[2][0] * m->m[0][1] * m->m[3][2] +
m->m[2][0] * m->m[0][2] * m->m[3][1] +
m->m[3][0] * m->m[0][1] * m->m[2][2] -
m->m[3][0] * m->m[0][2] * m->m[2][1];
inv.m[0][2] = m->m[0][1] * m->m[1][2] * m->m[3][3] -
m->m[0][1] * m->m[1][3] * m->m[3][2] -
m->m[1][1] * m->m[0][2] * m->m[3][3] +
m->m[1][1] * m->m[0][3] * m->m[3][2] +
m->m[2][1] * m->m[0][2] * m->m[1][3] -
m->m[2][1] * m->m[0][3] * m->m[1][2];
inv.m[1][2] = -m->m[0][0] * m->m[1][2] * m->m[3][3] +
m->m[0][0] * m->m[1][3] * m->m[3][2] +
m->m[1][0] * m->m[0][2] * m->m[3][3] -
m->m[1][0] * m->m[0][3] * m->m[3][2] -
m->m[3][0] * m->m[0][2] * m->m[1][3] +
m->m[3][0] * m->m[0][3] * m->m[1][2];
inv.m[2][2] = m->m[0][0] * m->m[1][1] * m->m[3][3] -
m->m[0][0] * m->m[1][3] * m->m[3][1] -
m->m[1][0] * m->m[0][1] * m->m[3][3] +
m->m[1][0] * m->m[0][3] * m->m[3][1] +
m->m[3][0] * m->m[0][1] * m->m[1][3] -
m->m[3][0] * m->m[0][3] * m->m[1][1];
inv.m[3][2] = -m->m[0][0] * m->m[1][1] * m->m[3][2] +
m->m[0][0] * m->m[1][2] * m->m[3][1] +
m->m[1][0] * m->m[0][1] * m->m[3][2] -
m->m[1][0] * m->m[0][2] * m->m[3][1] -
m->m[3][0] * m->m[0][1] * m->m[1][2] +
m->m[3][0] * m->m[0][2] * m->m[1][1];
inv.m[0][3] = -m->m[0][1] * m->m[1][2] * m->m[2][3] +
m->m[0][1] * m->m[1][3] * m->m[2][2] +
m->m[1][1] * m->m[0][2] * m->m[2][3] -
m->m[1][1] * m->m[0][3] * m->m[2][2] -
m->m[2][1] * m->m[0][2] * m->m[1][3] +
m->m[2][1] * m->m[0][3] * m->m[1][2];
inv.m[1][3] = m->m[0][0] * m->m[1][2] * m->m[2][3] -
m->m[0][0] * m->m[1][3] * m->m[2][2] -
m->m[1][0] * m->m[0][2] * m->m[2][3] +
m->m[1][0] * m->m[0][3] * m->m[2][2] +
m->m[2][0] * m->m[0][2] * m->m[1][3] -
m->m[2][0] * m->m[0][3] * m->m[1][2];
inv.m[2][3] = -m->m[0][0] * m->m[1][1] * m->m[2][3] +
m->m[0][0] * m->m[1][3] * m->m[2][1] +
m->m[1][0] * m->m[0][1] * m->m[2][3] -
m->m[1][0] * m->m[0][3] * m->m[2][1] -
m->m[2][0] * m->m[0][1] * m->m[1][3] +
m->m[2][0] * m->m[0][3] * m->m[1][1];
inv.m[3][3] = m->m[0][0] * m->m[1][1] * m->m[2][2] -
m->m[0][0] * m->m[1][2] * m->m[2][1] -
m->m[1][0] * m->m[0][1] * m->m[2][2] +
m->m[1][0] * m->m[0][2] * m->m[2][1] +
m->m[2][0] * m->m[0][1] * m->m[1][2] -
m->m[2][0] * m->m[0][2] * m->m[1][1];
det = m->m[0][0] * inv.m[0][0] + m->m[0][1] * inv.m[1][0] + m->m[0][2] * inv.m[2][0] + m->m[0][3] * inv.m[3][0];
/* XXX: this could instead return a success/fail status, but in games it's not
* like anything useful will be possible when it's non-invertible, hence the assert
*/
assert(det != 0.f);
det = 1.f / det;
inv.m[0][0] *= det;
inv.m[0][1] *= det;
inv.m[0][2] *= det;
inv.m[0][3] *= det;
inv.m[1][0] *= det;
inv.m[1][1] *= det;
inv.m[1][2] *= det;
inv.m[1][3] *= det;
inv.m[2][0] *= det;
inv.m[2][1] *= det;
inv.m[2][2] *= det;
inv.m[2][3] *= det;
inv.m[3][0] *= det;
inv.m[3][1] *= det;
inv.m[3][2] *= det;
inv.m[3][3] *= det;
return inv;
}
#endif
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