matrix.c

   1 /*-
   2  * Copyright (C) 2011, 2012 glevand <geoffrey.levand@mail.ru>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer,
  10  *    without modification, immediately at the beginning of the file.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  *
  26  * $FreeBSD$
  27  */
  28
  29 #include <string.h>
  30
  31 #include "matrix.h"
  32
  33 void
  34 matrix_ident(matrix_t m)
  35 {
  36         memset(m, 0, sizeof(m));
  37         MATRIX_ELEM(m, 0, 0) = 1.0f;
  38         MATRIX_ELEM(m, 1, 1) = 1.0f;
  39         MATRIX_ELEM(m, 2, 2) = 1.0f;
  40         MATRIX_ELEM(m, 3, 3) = 1.0f;
  41 }
  42
  43 void
  44 matrix_trans(matrix_t m, float x, float y, float z)
  45 {
  46         matrix_ident(m);
  47         MATRIX_ELEM(m, 0, 3) = x;
  48         MATRIX_ELEM(m, 1, 3) = y;
  49         MATRIX_ELEM(m, 2, 3) = z;
  50 }
  51
  52 void
  53 matrix_mult(matrix_t m, const matrix_t m1, const matrix_t m2)
  54 {
  55         int i, j;
  56
  57         for (i = 0; i < 4; i++) {
  58                 for (j = 0; j < 4; j++) {
  59                         MATRIX_ELEM(m, i, j) =
  60                             MATRIX_ELEM(m1, i, 0) * MATRIX_ELEM(m2, 0, j) +
  61                             MATRIX_ELEM(m1, i, 1) * MATRIX_ELEM(m2, 1, j) +
  62                             MATRIX_ELEM(m1, i, 2) * MATRIX_ELEM(m2, 2, j) +
  63                             MATRIX_ELEM(m1, i, 3) * MATRIX_ELEM(m2, 3, j);
  64                 }
  65         }
  66 }
  67
  68 void
  69 matrix_proj(matrix_t m, float top, float bottom, float left, float right,
  70     float near, float far)
  71 {
  72         memset(m, 0, sizeof(m));
  73         MATRIX_ELEM(m, 0, 0) = (2.0f * near) / (right - left);
  74         MATRIX_ELEM(m, 0, 2) = (right + left) / (right - left);
  75         MATRIX_ELEM(m, 1, 1) = (2.0f * near) / (bottom - top);
  76         MATRIX_ELEM(m, 1, 2) = (top + bottom) / (top - bottom);
  77         MATRIX_ELEM(m, 2, 2) = -(far + near) / (far - near);
  78         MATRIX_ELEM(m, 2, 3) = -(2.0f *far * near) / (far - near);
  79         MATRIX_ELEM(m, 3, 2) = -1.0f;
  80 }