RetroArch/gfx/math/matrix.c
twinaphex 8487cd0204 Start using C89-style for loop initial declarations for
reusable code module parts that we reuse in other projects. It's
a huge maintenance burden having to change this stuff around everytime
when compiling in non-C99 mode
2013-10-19 19:39:38 +02:00

147 lines
3.6 KiB
C

/* RetroArch - A frontend for libretro.
* Copyright (C) 2010-2013 - Hans-Kristian Arntzen
*
* RetroArch is free software: you can redistribute it and/or modify it under the terms
* of the GNU General Public License as published by the Free Software Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* RetroArch 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 RetroArch.
* If not, see <http://www.gnu.org/licenses/>.
*/
#include "matrix.h"
#include <string.h>
#include <math.h>
void matrix_identity(math_matrix *mat)
{
unsigned i;
memset(mat, 0, sizeof(*mat));
for (i = 0; i < 4; i++)
MAT_ELEM(*mat, i, i) = 1.0f;
}
void matrix_transpose(math_matrix *out, const math_matrix *in)
{
unsigned i, j;
math_matrix mat;
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++)
MAT_ELEM(mat, j, i) = MAT_ELEM(*in, i, j);
*out = mat;
}
void matrix_rotate_x(math_matrix *mat, float rad)
{
float cosine = cosf(rad);
float sine = sinf(rad);
matrix_identity(mat);
MAT_ELEM(*mat, 1, 1) = cosine;
MAT_ELEM(*mat, 2, 2) = cosine;
MAT_ELEM(*mat, 1, 2) = -sine;
MAT_ELEM(*mat, 2, 1) = sine;
}
void matrix_rotate_y(math_matrix *mat, float rad)
{
float cosine = cosf(rad);
float sine = sinf(rad);
matrix_identity(mat);
MAT_ELEM(*mat, 0, 0) = cosine;
MAT_ELEM(*mat, 2, 2) = cosine;
MAT_ELEM(*mat, 0, 2) = -sine;
MAT_ELEM(*mat, 2, 0) = sine;
}
void matrix_rotate_z(math_matrix *mat, float rad)
{
float cosine = cosf(rad);
float sine = sinf(rad);
matrix_identity(mat);
MAT_ELEM(*mat, 0, 0) = cosine;
MAT_ELEM(*mat, 1, 1) = cosine;
MAT_ELEM(*mat, 0, 1) = -sine;
MAT_ELEM(*mat, 1, 0) = sine;
}
void matrix_ortho(math_matrix *mat,
float left, float right,
float bottom, float top,
float znear, float zfar)
{
matrix_identity(mat);
float tx = -(right + left) / (right - left);
float ty = -(top + bottom) / (top - bottom);
float tz = -(zfar + znear) / (zfar - znear);
MAT_ELEM(*mat, 0, 0) = 2.0f / (right - left);
MAT_ELEM(*mat, 1, 1) = 2.0f / (top - bottom);
MAT_ELEM(*mat, 2, 2) = -2.0f / (zfar - znear);
MAT_ELEM(*mat, 0, 3) = tx;
MAT_ELEM(*mat, 1, 3) = ty;
MAT_ELEM(*mat, 2, 3) = tz;
}
void matrix_scale(math_matrix *out, float x, float y,
float z)
{
memset(out, 0, sizeof(*out));
MAT_ELEM(*out, 0, 0) = x;
MAT_ELEM(*out, 1, 1) = y;
MAT_ELEM(*out, 2, 2) = z;
MAT_ELEM(*out, 3, 3) = 1.0f;
}
void matrix_translate(math_matrix *out, float x,
float y, float z)
{
matrix_identity(out);
MAT_ELEM(*out, 0, 3) = x;
MAT_ELEM(*out, 1, 3) = y;
MAT_ELEM(*out, 2, 3) = z;
}
void matrix_projection(math_matrix *out, float znear,
float zfar)
{
memset(out, 0, sizeof(*out));
MAT_ELEM(*out, 0, 0) = znear;
MAT_ELEM(*out, 1, 1) = zfar;
MAT_ELEM(*out, 2, 2) = (zfar + znear) / (zfar - znear);
MAT_ELEM(*out, 2, 3) = -2.0f * zfar * znear / (zfar - znear);
MAT_ELEM(*out, 3, 2) = -1.0f;
}
void matrix_multiply(math_matrix *out,
const math_matrix *a, const math_matrix *b)
{
unsigned r, c, k;
math_matrix mat;
for (r = 0; r < 4; r++)
{
for (c = 0; c < 4; c++)
{
float dot = 0.0f;
for (k = 0; k < 4; k++)
dot += MAT_ELEM(*a, r, k) * MAT_ELEM(*b, k, c);
MAT_ELEM(mat, r, c) = dot;
}
}
*out = mat;
}