72 lines
3.0 KiB
C++
72 lines
3.0 KiB
C++
/****************************************************************************
|
|
* VCGLib o o *
|
|
* Visual and Computer Graphics Library o o *
|
|
* _ O _ *
|
|
* Copyright(C) 2004 \/)\/ *
|
|
* Visual Computing Lab /\/| *
|
|
* ISTI - Italian National Research Council | *
|
|
* \ *
|
|
* All rights reserved. *
|
|
* *
|
|
* This program is free software; you can redistribute it and/or modify *
|
|
* it under the terms of the GNU General Public License as published by *
|
|
* the Free Software Foundation; either version 2 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 General Public License (http://www.gnu.org/licenses/gpl.txt) *
|
|
* for more details. *
|
|
* *
|
|
****************************************************************************/
|
|
#ifndef IO_FAN_TESSELLATOR_H
|
|
#define IO_FAN_TESSELLATOR_H
|
|
|
|
namespace vcg {
|
|
namespace tri {
|
|
namespace io {
|
|
|
|
/*
|
|
* A face polygon composed of more than three vertices is triangulated
|
|
* according to the following schema:
|
|
* v5
|
|
* / \
|
|
* / \
|
|
* / \
|
|
* v1------v4
|
|
* |\ /
|
|
* | \ /
|
|
* | \ /
|
|
* v2---v3
|
|
*
|
|
* As shown above, the 5 vertices polygon (v1,v2,v3,v4,v5)
|
|
* has been split into the triangles (v1,v2,v3), (v1,v3,v4) e (v1,v4,v5).
|
|
* This way vertex v1 becomes the common vertex of all newly generated
|
|
* triangles, and this may lead to the creation of very thin triangles.
|
|
*
|
|
* This function is intended as a trivial fallback when glutessellator is not available.
|
|
* it assumes just ONE outline
|
|
*/
|
|
template < class PointType>
|
|
void FanTessellator(const std::vector< std::vector<PointType> > & outlines, std::vector<int> & indices)
|
|
{
|
|
indices.clear();
|
|
if(outlines.empty()) return;
|
|
const std::vector<PointType> &points=outlines[0];
|
|
|
|
for(size_t i=0;i<points.size()-2;++i)
|
|
{
|
|
indices.push_back(0);
|
|
indices.push_back(i+1);
|
|
indices.push_back(i+2);
|
|
}
|
|
}
|
|
|
|
} // end Namespace tri
|
|
} // end Namespace io
|
|
} // end Namespace vcg
|
|
|
|
|
|
#endif // IO_FAN_TESSELLATOR_H
|