summaryrefslogtreecommitdiffstats
path: root/src/MathUtil.cpp
blob: 8ea35998d88c96c04fd659b5294aa6f6e9a86e61 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
/*
 * MathUtil.cpp
 *
 * Copyright (C) 2009 Matthias Schiffer <matthias@gamezock.de>
 *
 * This program is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#include "MathUtil.h"
#include <cmath>

namespace Zoom {

const float MathUtil::EPSILON = 1E-6;

vmml::vec3f MathUtil::Plane::intersection(const vmml::vec3f &p, const vmml::vec3f &dir) const {
  float r = (d - p.dot(normal))/dir.dot(normal);

  return p + r*dir;
}


vmml::mat4f MathUtil::perspective(float fovy, float aspect, float zNear) {
  float f = 1/std::tan(fovy*M_PI/360);

  vmml::mat4f ret(vmml::mat4f::ZERO);
  ret[0][0] = f/aspect;
  ret[1][1] = f;
  ret[2][2] = EPSILON-1;
  ret[2][3] = (EPSILON-2)*zNear;
  ret[3][2] = -1;

  return ret;
}

}