518 lines
18 KiB
C++
518 lines
18 KiB
C++
/*
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Open Asset Import Library (assimp)
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----------------------------------------------------------------------
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Copyright (c) 2006-2017, assimp team
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All rights reserved.
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Redistribution and use of this software in source and binary forms,
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with or without modification, are permitted provided that the
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following conditions are met:
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* Redistributions of source code must retain the above
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copyright notice, this list of conditions and the
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following disclaimer.
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* Redistributions in binary form must reproduce the above
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copyright notice, this list of conditions and the
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following disclaimer in the documentation and/or other
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materials provided with the distribution.
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* Neither the name of the assimp team, nor the names of its
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contributors may be used to endorse or promote products
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derived from this software without specific prior
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written permission of the assimp team.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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----------------------------------------------------------------------
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*/
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/** @file BlenderTessellator.cpp
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* @brief A simple tessellation wrapper
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*/
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#ifndef ASSIMP_BUILD_NO_BLEND_IMPORTER
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#include "BlenderDNA.h"
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#include "BlenderScene.h"
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#include "BlenderBMesh.h"
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#include "BlenderTessellator.h"
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#include <stddef.h>
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static const unsigned int BLEND_TESS_MAGIC = 0x83ed9ac3;
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#if ASSIMP_BLEND_WITH_GLU_TESSELLATE
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namspace Assimp
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{
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template< > const std::string LogFunctions< BlenderTessellatorGL >::log_prefix = "BLEND_TESS_GL: ";
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}
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using namespace Assimp;
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using namespace Assimp::Blender;
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#ifndef CALLBACK
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#define CALLBACK
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#endif
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// ------------------------------------------------------------------------------------------------
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BlenderTessellatorGL::BlenderTessellatorGL( BlenderBMeshConverter& converter ):
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converter( &converter )
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{
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}
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// ------------------------------------------------------------------------------------------------
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BlenderTessellatorGL::~BlenderTessellatorGL( )
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{
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::Tessellate( const MLoop* polyLoop, int vertexCount, const std::vector< MVert >& vertices )
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{
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AssertVertexCount( vertexCount );
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std::vector< VertexGL > polyLoopGL;
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GenerateLoopVerts( polyLoopGL, polyLoop, vertexCount, vertices );
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TessDataGL tessData;
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Tesssellate( polyLoopGL, tessData );
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TriangulateDrawCalls( tessData );
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::AssertVertexCount( int vertexCount )
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{
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if ( vertexCount <= 4 )
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{
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ThrowException( "Expected more than 4 vertices for tessellation" );
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}
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::GenerateLoopVerts( std::vector< VertexGL >& polyLoopGL, const MLoop* polyLoop, int vertexCount, const std::vector< MVert >& vertices )
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{
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for ( int i = 0; i < vertexCount; ++i )
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{
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const MLoop& loopItem = polyLoop[ i ];
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const MVert& vertex = vertices[ loopItem.v ];
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polyLoopGL.push_back( VertexGL( vertex.co[ 0 ], vertex.co[ 1 ], vertex.co[ 2 ], loopItem.v, BLEND_TESS_MAGIC ) );
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}
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::Tesssellate( std::vector< VertexGL >& polyLoopGL, TessDataGL& tessData )
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{
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GLUtesselator* tessellator = gluNewTess( );
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gluTessCallback( tessellator, GLU_TESS_BEGIN_DATA, reinterpret_cast< void ( CALLBACK * )( ) >( TessellateBegin ) );
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gluTessCallback( tessellator, GLU_TESS_END_DATA, reinterpret_cast< void ( CALLBACK * )( ) >( TessellateEnd ) );
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gluTessCallback( tessellator, GLU_TESS_VERTEX_DATA, reinterpret_cast< void ( CALLBACK * )( ) >( TessellateVertex ) );
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gluTessCallback( tessellator, GLU_TESS_COMBINE_DATA, reinterpret_cast< void ( CALLBACK * )( ) >( TessellateCombine ) );
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gluTessCallback( tessellator, GLU_TESS_EDGE_FLAG_DATA, reinterpret_cast< void ( CALLBACK * )( ) >( TessellateEdgeFlag ) );
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gluTessCallback( tessellator, GLU_TESS_ERROR_DATA, reinterpret_cast< void ( CALLBACK * )( ) >( TessellateError ) );
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gluTessProperty( tessellator, GLU_TESS_WINDING_RULE, GLU_TESS_WINDING_NONZERO );
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gluTessBeginPolygon( tessellator, &tessData );
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gluTessBeginContour( tessellator );
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for ( unsigned int i = 0; i < polyLoopGL.size( ); ++i )
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{
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gluTessVertex( tessellator, reinterpret_cast< GLdouble* >( &polyLoopGL[ i ] ), &polyLoopGL[ i ] );
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}
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gluTessEndContour( tessellator );
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gluTessEndPolygon( tessellator );
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::TriangulateDrawCalls( const TessDataGL& tessData )
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{
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// NOTE - Because we are supplying a callback to GLU_TESS_EDGE_FLAG_DATA we don't technically
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// need support for GL_TRIANGLE_STRIP and GL_TRIANGLE_FAN but we'll keep it here in case
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// GLU tessellate changes or tri-strips and fans are wanted.
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// See: http://www.opengl.org/sdk/docs/man2/xhtml/gluTessCallback.xml
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for ( unsigned int i = 0; i < tessData.drawCalls.size( ); ++i )
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{
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const DrawCallGL& drawCallGL = tessData.drawCalls[ i ];
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const VertexGL* vertices = &tessData.vertices[ drawCallGL.baseVertex ];
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if ( drawCallGL.drawMode == GL_TRIANGLES )
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{
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MakeFacesFromTris( vertices, drawCallGL.vertexCount );
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}
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else if ( drawCallGL.drawMode == GL_TRIANGLE_STRIP )
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{
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MakeFacesFromTriStrip( vertices, drawCallGL.vertexCount );
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}
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else if ( drawCallGL.drawMode == GL_TRIANGLE_FAN )
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{
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MakeFacesFromTriFan( vertices, drawCallGL.vertexCount );
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}
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}
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::MakeFacesFromTris( const VertexGL* vertices, int vertexCount )
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{
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const int triangleCount = vertexCount / 3;
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for ( int i = 0; i < triangleCount; ++i )
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{
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int vertexBase = i * 3;
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converter->AddFace( vertices[ vertexBase + 0 ].index, vertices[ vertexBase + 1 ].index, vertices[ vertexBase + 2 ].index );
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}
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::MakeFacesFromTriStrip( const VertexGL* vertices, int vertexCount )
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{
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const int triangleCount = vertexCount - 2;
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for ( int i = 0; i < triangleCount; ++i )
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{
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int vertexBase = i;
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converter->AddFace( vertices[ vertexBase + 0 ].index, vertices[ vertexBase + 1 ].index, vertices[ vertexBase + 2 ].index );
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}
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::MakeFacesFromTriFan( const VertexGL* vertices, int vertexCount )
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{
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const int triangleCount = vertexCount - 2;
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for ( int i = 0; i < triangleCount; ++i )
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{
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int vertexBase = i;
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converter->AddFace( vertices[ 0 ].index, vertices[ vertexBase + 1 ].index, vertices[ vertexBase + 2 ].index );
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}
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::TessellateBegin( GLenum drawModeGL, void* userData )
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{
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TessDataGL& tessData = *reinterpret_cast< TessDataGL* >( userData );
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tessData.drawCalls.push_back( DrawCallGL( drawModeGL, tessData.vertices.size( ) ) );
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::TessellateEnd( void* )
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{
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// Do nothing
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::TessellateVertex( const void* vtxData, void* userData )
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{
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TessDataGL& tessData = *reinterpret_cast< TessDataGL* >( userData );
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const VertexGL& vertex = *reinterpret_cast< const VertexGL* >( vtxData );
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if ( vertex.magic != BLEND_TESS_MAGIC )
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{
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ThrowException( "Point returned by GLU Tessellate was probably not one of ours. This indicates we need a new way to store vertex information" );
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}
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tessData.vertices.push_back( vertex );
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if ( tessData.drawCalls.size( ) == 0 )
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{
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ThrowException( "\"Vertex\" callback received before \"Begin\"" );
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}
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++( tessData.drawCalls.back( ).vertexCount );
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::TessellateCombine( const GLdouble intersection[ 3 ], const GLdouble* [ 4 ], const GLfloat [ 4 ], GLdouble** out, void* userData )
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{
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ThrowException( "Intersected polygon loops are not yet supported" );
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::TessellateEdgeFlag( GLboolean, void* )
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{
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// Do nothing
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorGL::TessellateError( GLenum errorCode, void* )
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{
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ThrowException( reinterpret_cast< const char* >( gluErrorString( errorCode ) ) );
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}
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#endif // ASSIMP_BLEND_WITH_GLU_TESSELLATE
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#if ASSIMP_BLEND_WITH_POLY_2_TRI
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namespace Assimp
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{
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template< > const std::string LogFunctions< BlenderTessellatorP2T >::log_prefix = "BLEND_TESS_P2T: ";
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}
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using namespace Assimp;
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using namespace Assimp::Blender;
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// ------------------------------------------------------------------------------------------------
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BlenderTessellatorP2T::BlenderTessellatorP2T( BlenderBMeshConverter& converter ):
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converter( &converter )
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{
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}
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// ------------------------------------------------------------------------------------------------
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BlenderTessellatorP2T::~BlenderTessellatorP2T( )
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{
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorP2T::Tessellate( const MLoop* polyLoop, int vertexCount, const std::vector< MVert >& vertices )
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{
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AssertVertexCount( vertexCount );
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// NOTE - We have to hope that points in a Blender polygon are roughly on the same plane.
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// There may be some triangulation artifacts if they are wildly different.
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std::vector< PointP2T > points;
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Copy3DVertices( polyLoop, vertexCount, vertices, points );
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PlaneP2T plane = FindLLSQPlane( points );
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aiMatrix4x4 transform = GeneratePointTransformMatrix( plane );
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TransformAndFlattenVectices( transform, points );
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std::vector< p2t::Point* > pointRefs;
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ReferencePoints( points, pointRefs );
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p2t::CDT cdt( pointRefs );
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cdt.Triangulate( );
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std::vector< p2t::Triangle* > triangles = cdt.GetTriangles( );
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MakeFacesFromTriangles( triangles );
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorP2T::AssertVertexCount( int vertexCount )
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{
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if ( vertexCount <= 4 )
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{
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ThrowException( "Expected more than 4 vertices for tessellation" );
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}
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorP2T::Copy3DVertices( const MLoop* polyLoop, int vertexCount, const std::vector< MVert >& vertices, std::vector< PointP2T >& points ) const
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{
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points.resize( vertexCount );
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for ( int i = 0; i < vertexCount; ++i )
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{
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const MLoop& loop = polyLoop[ i ];
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const MVert& vert = vertices[ loop.v ];
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PointP2T& point = points[ i ];
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point.point3D.Set( vert.co[ 0 ], vert.co[ 1 ], vert.co[ 2 ] );
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point.index = loop.v;
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point.magic = BLEND_TESS_MAGIC;
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}
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}
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// ------------------------------------------------------------------------------------------------
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aiMatrix4x4 BlenderTessellatorP2T::GeneratePointTransformMatrix( const Blender::PlaneP2T& plane ) const
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{
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aiVector3D sideA( 1.0f, 0.0f, 0.0f );
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if ( std::fabs( plane.normal * sideA ) > 0.999f )
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{
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sideA = aiVector3D( 0.0f, 1.0f, 0.0f );
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}
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aiVector3D sideB( plane.normal ^ sideA );
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sideB.Normalize( );
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sideA = sideB ^ plane.normal;
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aiMatrix4x4 result;
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result.a1 = sideA.x;
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result.a2 = sideA.y;
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result.a3 = sideA.z;
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result.b1 = sideB.x;
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result.b2 = sideB.y;
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result.b3 = sideB.z;
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result.c1 = plane.normal.x;
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result.c2 = plane.normal.y;
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result.c3 = plane.normal.z;
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result.a4 = plane.centre.x;
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result.b4 = plane.centre.y;
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result.c4 = plane.centre.z;
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result.Inverse( );
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return result;
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorP2T::TransformAndFlattenVectices( const aiMatrix4x4& transform, std::vector< Blender::PointP2T >& vertices ) const
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{
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for ( size_t i = 0; i < vertices.size( ); ++i )
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{
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PointP2T& point = vertices[ i ];
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point.point3D = transform * point.point3D;
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point.point2D.set( point.point3D.y, point.point3D.z );
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}
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorP2T::ReferencePoints( std::vector< Blender::PointP2T >& points, std::vector< p2t::Point* >& pointRefs ) const
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{
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pointRefs.resize( points.size( ) );
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for ( size_t i = 0; i < points.size( ); ++i )
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{
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pointRefs[ i ] = &points[ i ].point2D;
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}
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}
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// ------------------------------------------------------------------------------------------------
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inline PointP2T& BlenderTessellatorP2T::GetActualPointStructure( p2t::Point& point ) const
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{
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unsigned int pointOffset = offsetof( PointP2T, point2D );
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PointP2T& pointStruct = *reinterpret_cast< PointP2T* >( reinterpret_cast< char* >( &point ) - pointOffset );
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if ( pointStruct.magic != static_cast<int>( BLEND_TESS_MAGIC ) )
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{
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ThrowException( "Point returned by poly2tri was probably not one of ours. This indicates we need a new way to store vertex information" );
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}
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return pointStruct;
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}
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// ------------------------------------------------------------------------------------------------
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void BlenderTessellatorP2T::MakeFacesFromTriangles( std::vector< p2t::Triangle* >& triangles ) const
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{
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for ( size_t i = 0; i < triangles.size( ); ++i )
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{
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p2t::Triangle& Triangle = *triangles[ i ];
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PointP2T& pointA = GetActualPointStructure( *Triangle.GetPoint( 0 ) );
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PointP2T& pointB = GetActualPointStructure( *Triangle.GetPoint( 1 ) );
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PointP2T& pointC = GetActualPointStructure( *Triangle.GetPoint( 2 ) );
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converter->AddFace( pointA.index, pointB.index, pointC.index );
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}
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}
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// ------------------------------------------------------------------------------------------------
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inline float p2tMax( float a, float b )
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{
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return a > b ? a : b;
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}
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// ------------------------------------------------------------------------------------------------
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// Adapted from: http://missingbytes.blogspot.co.uk/2012/06/fitting-plane-to-point-cloud.html
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float BlenderTessellatorP2T::FindLargestMatrixElem( const aiMatrix3x3& mtx ) const
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{
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float result = 0.0f;
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for ( unsigned int x = 0; x < 3; ++x )
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{
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for ( unsigned int y = 0; y < 3; ++y )
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{
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result = p2tMax( std::fabs( mtx[ x ][ y ] ), result );
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}
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}
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return result;
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}
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// ------------------------------------------------------------------------------------------------
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// Apparently Assimp doesn't have matrix scaling
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aiMatrix3x3 BlenderTessellatorP2T::ScaleMatrix( const aiMatrix3x3& mtx, float scale ) const
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{
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aiMatrix3x3 result;
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for ( unsigned int x = 0; x < 3; ++x )
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{
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for ( unsigned int y = 0; y < 3; ++y )
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{
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result[ x ][ y ] = mtx[ x ][ y ] * scale;
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}
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}
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return result;
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}
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// ------------------------------------------------------------------------------------------------
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// Adapted from: http://missingbytes.blogspot.co.uk/2012/06/fitting-plane-to-point-cloud.html
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aiVector3D BlenderTessellatorP2T::GetEigenVectorFromLargestEigenValue( const aiMatrix3x3& mtx ) const
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{
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const float scale = FindLargestMatrixElem( mtx );
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aiMatrix3x3 mc = ScaleMatrix( mtx, 1.0f / scale );
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mc = mc * mc * mc;
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aiVector3D v( 1.0f );
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aiVector3D lastV = v;
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for ( int i = 0; i < 100; ++i )
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{
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v = mc * v;
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v.Normalize( );
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if ( ( v - lastV ).SquareLength( ) < 1e-16f )
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{
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break;
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}
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lastV = v;
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}
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return v;
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}
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// ------------------------------------------------------------------------------------------------
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// Adapted from: http://missingbytes.blogspot.co.uk/2012/06/fitting-plane-to-point-cloud.html
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PlaneP2T BlenderTessellatorP2T::FindLLSQPlane( const std::vector< PointP2T >& points ) const
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{
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PlaneP2T result;
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aiVector3D sum( 0.0 );
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for ( size_t i = 0; i < points.size( ); ++i )
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{
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sum += points[ i ].point3D;
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}
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result.centre = sum * (ai_real)( 1.0 / points.size( ) );
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ai_real sumXX = 0.0;
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ai_real sumXY = 0.0;
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ai_real sumXZ = 0.0;
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ai_real sumYY = 0.0;
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ai_real sumYZ = 0.0;
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ai_real sumZZ = 0.0;
|
|
for ( size_t i = 0; i < points.size( ); ++i )
|
|
{
|
|
aiVector3D offset = points[ i ].point3D - result.centre;
|
|
sumXX += offset.x * offset.x;
|
|
sumXY += offset.x * offset.y;
|
|
sumXZ += offset.x * offset.z;
|
|
sumYY += offset.y * offset.y;
|
|
sumYZ += offset.y * offset.z;
|
|
sumZZ += offset.z * offset.z;
|
|
}
|
|
|
|
aiMatrix3x3 mtx( sumXX, sumXY, sumXZ, sumXY, sumYY, sumYZ, sumXZ, sumYZ, sumZZ );
|
|
|
|
const ai_real det = mtx.Determinant( );
|
|
if ( det == 0.0f )
|
|
{
|
|
result.normal = aiVector3D( 0.0f );
|
|
}
|
|
else
|
|
{
|
|
aiMatrix3x3 invMtx = mtx;
|
|
invMtx.Inverse( );
|
|
result.normal = GetEigenVectorFromLargestEigenValue( invMtx );
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
#endif // ASSIMP_BLEND_WITH_POLY_2_TRI
|
|
|
|
#endif // ASSIMP_BUILD_NO_BLEND_IMPORTER
|