/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

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All rights reserved.

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with or without modification, are permitted provided that the 
following conditions are met:

* Redistributions of source code must retain the above
  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
  copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other
  materials provided with the distribution.

* Neither the name of the assimp team, nor the names of its
  contributors may be used to endorse or promote products
  derived from this software without specific prior
  written permission of the assimp team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*/

/** @file  BlenderBMesh.cpp
 *  @brief Conversion of Blender's new BMesh stuff
 */

#include "AssimpPCH.h"

#ifndef ASSIMP_BUILD_NO_BLEND_IMPORTER

#include "BlenderDNA.h"
#include "BlenderScene.h"
#include "BlenderBMesh.h"
#include "BlenderTessellator.h"

namespace Assimp
{
	template< > const std::string LogFunctions< BlenderBMeshConverter >::log_prefix = "BLEND_BMESH: ";
}

using namespace Assimp;
using namespace Assimp::Blender;
using namespace Assimp::Formatter;

// ------------------------------------------------------------------------------------------------
BlenderBMeshConverter::BlenderBMeshConverter( const Mesh* mesh ):
	BMesh( mesh ),
	triMesh( NULL )
{
	AssertValidMesh( );
}

// ------------------------------------------------------------------------------------------------
BlenderBMeshConverter::~BlenderBMeshConverter( )
{
	DestroyTriMesh( );
}

// ------------------------------------------------------------------------------------------------
bool BlenderBMeshConverter::ContainsBMesh( ) const
{
	// TODO - Should probably do some additional verification here
	return BMesh->totpoly && BMesh->totloop && BMesh->totvert;
}

// ------------------------------------------------------------------------------------------------
const Mesh* BlenderBMeshConverter::TriangulateBMesh( )
{
	AssertValidMesh( );
	AssertValidSizes( );
	PrepareTriMesh( );

	for ( int i = 0; i < BMesh->totpoly; ++i )
	{
		const MPoly& poly = BMesh->mpoly[ i ];
		ConvertPolyToFaces( poly );
	}

	return triMesh;
}

// ------------------------------------------------------------------------------------------------
void BlenderBMeshConverter::AssertValidMesh( )
{
	if ( !ContainsBMesh( ) )
	{
		ThrowException( "BlenderBMeshConverter requires a BMesh with \"polygons\" - please call BlenderBMeshConverter::ContainsBMesh to check this first" );
	}
}

// ------------------------------------------------------------------------------------------------
void BlenderBMeshConverter::AssertValidSizes( )
{
	if ( BMesh->totpoly != static_cast<int>( BMesh->mpoly.size( ) ) )
	{
		ThrowException( "BMesh poly array has incorrect size" );
	}
	if ( BMesh->totloop != static_cast<int>( BMesh->mloop.size( ) ) )
	{
		ThrowException( "BMesh loop array has incorrect size" );
	}
}

// ------------------------------------------------------------------------------------------------
void BlenderBMeshConverter::PrepareTriMesh( )
{
	if ( triMesh )
	{
		DestroyTriMesh( );
	}

	triMesh = new Mesh( *BMesh );
	triMesh->totface = 0;
	triMesh->mface.clear( );
}

// ------------------------------------------------------------------------------------------------
void BlenderBMeshConverter::DestroyTriMesh( )
{
	delete triMesh;
	triMesh = NULL;
}

// ------------------------------------------------------------------------------------------------
void BlenderBMeshConverter::ConvertPolyToFaces( const MPoly& poly )
{
	const MLoop* polyLoop = &BMesh->mloop[ poly.loopstart ];
	if ( poly.totloop == 3 || poly.totloop == 4 )
	{
		AddFace( polyLoop[ 0 ].v, polyLoop[ 1 ].v, polyLoop[ 2 ].v, poly.totloop == 4 ? polyLoop[ 3 ].v : 0 );
	}
	else if ( poly.totloop > 4 )
	{
#if ASSIMP_BLEND_WITH_GLU_TESSELLATE
		BlenderTessellatorGL tessGL( *this );
		tessGL.Tessellate( polyLoop, poly.totloop, triMesh->mvert );
#elif ASSIMP_BLEND_WITH_POLY_2_TRI
		BlenderTessellatorP2T tessP2T( *this );
		tessP2T.Tessellate( polyLoop, poly.totloop, triMesh->mvert );
#endif
	}
}

// ------------------------------------------------------------------------------------------------
void BlenderBMeshConverter::AddFace( int v1, int v2, int v3, int v4 )
{
	MFace face;
	face.v1 = v1;
	face.v2 = v2;
	face.v3 = v3;
	face.v4 = v4;
	// TODO - Work out how materials work
	face.mat_nr = 0;
	triMesh->mface.push_back( face );
	triMesh->totface = triMesh->mface.size( );
}

#endif // ASSIMP_BUILD_NO_BLEND_IMPORTER
