00001 #include <gra/camera/PerspProj.h>
00002
00003 using namespace gra;
00004
00005 PerspProj::PerspProj(double left,
00006 double right,
00007 double bottom,
00008 double top,
00009 double nr,
00010 double fr)
00011 : Projection(left, right, bottom, top, nr, fr)
00012 {
00013 if (_left == _right) {
00014 cerr << "PerspProj(): invalid left and right clipping planes;" << endl;
00015 cerr << " switching to -1, 1" << endl;
00016 _left = -1.0;
00017 _right = 1.0;
00018 }
00019
00020 if (_bottom == _top) {
00021 cerr << "PerspProj(): invalid bottom and top clipping planes;" << endl;
00022 cerr << " switching to -1, 1" << endl;
00023 _bottom = -1.0;
00024 _top = 1.0;
00025 }
00026
00027 if (_near == _far) {
00028 cerr << "PerspProj(): invalid near and far clipping planes;" << endl;
00029 cerr << " switching to 1, 10" << endl;
00030 _near = 1.0;
00031 _far = 10.0;
00032 }
00033
00034 if (_near <= 0.0) {
00035 cerr << "PerspProj(): near clipping plane mus be positive;" << endl;
00036 cerr << " switching to 1" << endl;
00037 _near = 1.0;
00038 }
00039
00040 if (_far <= 0.0) {
00041 cerr << "PerspProj(): far clipping plane mus be positive;" << endl;
00042 cerr << " switching to 10" << endl;
00043 _far = 10.0;
00044 }
00045
00046 float rl = _right - _left;
00047 float tb = _top - _bottom;
00048 float fn = _far - _near;
00049 float n2 = 2 * _near;
00050
00051 _projMat.set(n2/rl, 0.0, (_right+_left)/rl, 0.0,
00052 0.0, n2/tb, (_top+_bottom)/tb, 0.0,
00053 0.0, 0.0, (-_far-_near)/fn, -(n2*_far)/fn,
00054 0.0, 0.0, -1.0, 0.0);
00055 }
00056
00057 Projection* PerspProj::clone() const
00058 {
00059 return new PerspProj(*this);
00060 }
00061
00062 Vector3 PerspProj::getProjectionDirection(const Vector2& point)
00063 {
00064 Vector3 pdir(_left + point.x, _bottom + point.y, -_near);
00065 pdir.normalize();
00066 return pdir;
00067 }
