1 // Copyright (C) 2010 Tim Moore moore@bricoworks.com
2 //
3 // This library is free software; you can redistribute it and/or
4 // modify it under the terms of the GNU Library General Public
5 // License as published by the Free Software Foundation; either
6 // version 2 of the License, or (at your option) any later version.
7 //
8 // This library is distributed in the hope that it will be useful,
9 // but WITHOUT ANY WARRANTY; without even the implied warranty of
10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 // Library General Public License for more details.
12 //
13 // You should have received a copy of the GNU General Public License
14 // along with this program; if not, write to the Free Software
15 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
16 //
17
18 #ifdef HAVE_CONFIG_H
19 # include <simgear_config.h>
20 #endif
21
22 #include "project.hxx"
23
24 #include <osg/Math>
25 #include <osg/Matrixd>
26
27 namespace simgear
28 {
project(GLdouble objX,GLdouble objY,GLdouble objZ,const GLdouble * model,const GLdouble * proj,const GLint * view,GLdouble * winX,GLdouble * winY,GLdouble * winZ)29 GLint project(GLdouble objX, GLdouble objY, GLdouble objZ,
30 const GLdouble *model, const GLdouble *proj, const GLint *view,
31 GLdouble* winX, GLdouble* winY, GLdouble* winZ)
32 {
33 using namespace osg;
34 Vec4d obj(objX, objY, objZ, 1.0);
35 Matrixd Mmodel(model), Mproj(proj);
36 Matrixd Mwin = (Matrixd::translate(1.0, 1.0, 1.0)
37 * Matrixd::scale(0.5 * view[2], 0.5 * view[3], 0.5)
38 * Matrixd::translate(view[0], view[1], 0.0));
39 Vec4d result = obj * Mmodel * Mproj * Mwin;
40 if (equivalent(result.w(), 0.0))
41 return GL_FALSE;
42 result = result / result.w();
43 *winX = result.x(); *winY = result.y(); *winZ = result.z();
44 return GL_TRUE;
45 }
46
47 } // of namespace simgear
48
49