frohlich
e417903c23
Modified Files: SGGeometryTest.cxx SGIntersect.hxx SGLineSegment.hxx SGTriangle.hxx
106 lines
2.9 KiB
C++
106 lines
2.9 KiB
C++
// Copyright (C) 2006 Mathias Froehlich - Mathias.Froehlich@web.de
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//
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// This library is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Library General Public
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// License as published by the Free Software Foundation; either
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// version 2 of the License, or (at your option) any later version.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// Library General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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//
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#ifndef SGTriangle_H
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#define SGTrianlge_H
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template<typename T>
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class SGTriangle {
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public:
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SGTriangle()
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{ }
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SGTriangle(const SGVec3<T>& v0, const SGVec3<T>& v1, const SGVec3<T>& v2)
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{ set(v0, v1, v2); }
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SGTriangle(const SGVec3<T> v[3])
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{ set(v); }
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void set(const SGVec3<T>& v0, const SGVec3<T>& v1, const SGVec3<T>& v2)
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{
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_v0 = v0;
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_d[0] = v1 - v0;
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_d[1] = v2 - v0;
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}
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void set(const SGVec3<T> v[3])
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{
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_v0 = v[0];
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_d[0] = v[1] - v[0];
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_d[1] = v[2] - v[0];
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}
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SGVec3<T> getCenter() const
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{ return _v0 + T(1)/T(3)*(_d[0] + _d[1]); }
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// note that the index is unchecked
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SGVec3<T> getVertex(unsigned i) const
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{
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if (0 < i)
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return _v0 + _d[i-1];
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return _v0;
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}
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/// return the normalized surface normal
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SGVec3<T> getNormal() const
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{ return normalize(cross(_d[0], _d[1])); }
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const SGVec3<T>& getBaseVertex() const
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{ return _v0; }
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void setBaseVertex(const SGVec3<T>& v)
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{ _v0 = v; }
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const SGVec3<T>& getEdge(unsigned i) const
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{ return _d[i]; }
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void setEdge(unsigned i, const SGVec3<T>& d)
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{ _d[i] = d; }
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// flip the positive side
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void flip()
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{
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SGVec3<T> tmp = _d[0];
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_d[0] = _d[1];
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_d[1] = tmp;
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}
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SGTriangle<T> transform(const SGMatrix<T>& matrix) const
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{
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SGTriangle<T> triangle;
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triangle._v0 = matrix.xformPt(_v0);
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triangle._d[0] = matrix.xformVec(_d[0]);
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triangle._d[1] = matrix.xformVec(_d[1]);
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return triangle;
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}
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private:
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/// Store one vertex directly, _d is the offset of the other two
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/// vertices wrt the base vertex
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/// For fast intersection tests this format prooves usefull. For that same
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/// purpose also cache the cross product of the _d[i].
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SGVec3<T> _v0;
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SGVec3<T> _d[2];
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};
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/// Output to an ostream
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template<typename char_type, typename traits_type, typename T>
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inline
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std::basic_ostream<char_type, traits_type>&
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operator<<(std::basic_ostream<char_type, traits_type>& s,
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const SGTriangle<T>& triangle)
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{
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return s << "triangle: v0 = " << triangle.getVertex(0)
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<< ", v1 = " << triangle.getVertex(1)
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<< ", v2 = " << triangle.getVertex(2);
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}
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#endif
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