/******************************************************************************
	libx42make - skinned vertex animation library (exporter utilities)
	Copyright (C) 2007 HermitWorks Entertainment Corporation

	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
	for more details.

	You should have received a copy of the GNU General Public License along
	with this program; if not, write to the
	
		Free Software Foundation, Inc.
		51 Franklin Street, Fifth Floor
		Boston, MA  02110-1301, USA.
******************************************************************************/

#include "local.h"

namespace x42
{
namespace make
{

void Adjacency::Init( const std::vector< index > &tris )
{
	entries.resize( tris.size() / 3 );
	
	values.clear();
	values.reserve( tris.size() );

	//for each triangle
	for( uint t = 0; t < entries.size(); t++ )
	{
		entries[t].begin = (uint)values.size();

		//skip degenerates
		if( tris[t * 3 + 0] == tris[t * 3 + 1] ||
			tris[t * 3 + 1] == tris[t * 3 + 2] ||
			tris[t * 3 + 2] == tris[t * 3 + 0] )
			continue;

		//for each edge
		for( uint e = 0; e < 3; e++ )
		{
			uint es = tris[t * 3 + e];
			uint ee = tris[t * 3 + ((e + 1) % 3)];

			//for each other triangle
			for( uint ot = 0; ot < entries.size(); ot++ )
			{
				if( ot == t )
					continue;

				//skip degenerates
				if( tris[ot * 3 + 0] == tris[ot * 3 + 1] ||
					tris[ot * 3 + 1] == tris[ot * 3 + 2] ||
					tris[ot * 3 + 2] == tris[ot * 3 + 0] )
					continue;

				//for each other edge
				for( uint oe = 0; oe < 3; oe++ )
				{
					uint oes = tris[ot * 3 + oe];
					uint oee = tris[ot * 3 + ((oe + 1) % 3)];

					if( es == oee && ee == oes )
						values.push_back( ot );
				}
			}
		}

		entries[t].length = (uint)values.size() - entries[t].begin;
	}
}

};
};