1 // Cylinder_Sky.cc - Cylindrical image mapping for Caelum.
2 //
3 // Copyright (C) 2003 Sam Varner
4 //
5 // This program is free software; you can redistribute it and/or modify
6 // it under the terms of the GNU General Public License as published by
7 // the Free Software Foundation; either version 2 of the License, or
8 // (at your option) any later version.
9 //
10 // This program is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 // GNU General Public License for more details.
14 //
15 // You should have received a copy of the GNU General Public License
16 // along with this program; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
19 #include <cassert>
20
21 #include <GL/gl.h>
22
23 #include "../geometry/Constants.h"
24
25 #include "Cylinder_Sky.h"
26
27 using Vamos_Geometry::pi;
28
Cylinder_Sky(int divisions,std::string image,int width,int height)29 Cylinder_Sky::Cylinder_Sky (int divisions, std::string image,
30 int width, int height) :
31 Sky (image, width, height),
32 m_z_divisions (divisions)
33 {
34 assert (m_z_divisions > 1);
35 }
36
37 void
draw()38 Cylinder_Sky::draw ()
39 {
40 // Draw the cylinder.
41 for (int i = 0; i < m_z_divisions; i++)
42 {
43 glBegin (GL_QUAD_STRIP);
44 for (int j = 0; j <= m_z_divisions * 2; j++)
45 {
46 double tex_x = j / (m_z_divisions * 2.0);
47 double x = cos (j * pi / m_z_divisions);
48 double y = sin (j * pi / m_z_divisions);
49 double tex_z = 1.0 - double (i) / m_z_divisions;
50 double z = (2.0 * i) / m_z_divisions - 1.0;
51
52 z = (z + z_pos ()) / z_mag ();
53 tex_x += z_rot ();
54
55 glTexCoord2d (tex_x, tex_z);
56 glVertex3d (x, y, z);
57
58 tex_z = 1.0 - (i + 1.0) / m_z_divisions;
59 z = (2.0 * (i + 1.0)) / m_z_divisions - 1.0;
60 z = (z + z_pos ()) / z_mag ();
61
62 glTexCoord2d (tex_x, tex_z);
63 glVertex3d (x, y, z);
64 }
65 glEnd ();
66 }
67 }
68