mirror of
https://github.com/bulletphysics/bullet3
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129 lines
3.9 KiB
C++
129 lines
3.9 KiB
C++
#include "float_math.h"
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#include "meshvolume.h"
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/*----------------------------------------------------------------------
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Copyright (c) 2004 Open Dynamics Framework Group
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www.physicstools.org
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All rights reserved.
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Redistribution and use in source and binary forms, with or without modification, are permitted provided
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that the following conditions are met:
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Redistributions of source code must retain the above copyright notice, this list of conditions
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and the following disclaimer.
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Redistributions in binary form must reproduce the above copyright notice,
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this list of conditions and the following disclaimer in the documentation
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and/or other materials provided with the distribution.
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Neither the name of the Open Dynamics Framework Group nor the names of its contributors may
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be used to endorse or promote products derived from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES,
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INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL THE INTEL OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
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IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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-----------------------------------------------------------------------*/
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// http://codesuppository.blogspot.com
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//
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// mailto: jratcliff@infiniplex.net
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//
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// http://www.amillionpixels.us
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//
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inline float det(const float *p1,const float *p2,const float *p3)
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{
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return p1[0]*p2[1]*p3[2] + p2[0]*p3[1]*p1[2] + p3[0]*p1[1]*p2[2] -p1[0]*p3[1]*p2[2] - p2[0]*p1[1]*p3[2] - p3[0]*p2[1]*p1[2];
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}
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float computeMeshVolume(const float *vertices,unsigned int tcount,const unsigned int *indices)
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{
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float volume = 0;
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for (unsigned int i=0; i<tcount; i++,indices+=3)
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{
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const float *p1 = &vertices[ indices[0]*3 ];
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const float *p2 = &vertices[ indices[1]*3 ];
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const float *p3 = &vertices[ indices[2]*3 ];
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volume+=det(p1,p2,p3); // compute the volume of the tetrahedran relative to the origin.
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}
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volume*=(1.0f/6.0f);
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if ( volume < 0 )
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volume*=-1;
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return volume;
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}
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inline void CrossProduct(const float *a,const float *b,float *cross)
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{
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cross[0] = a[1]*b[2] - a[2]*b[1];
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cross[1] = a[2]*b[0] - a[0]*b[2];
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cross[2] = a[0]*b[1] - a[1]*b[0];
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}
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inline float DotProduct(const float *a,const float *b)
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{
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return a[0] * b[0] + a[1] * b[1] + a[2] * b[2];
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}
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inline float tetVolume(const float *p0,const float *p1,const float *p2,const float *p3)
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{
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float a[3];
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float b[3];
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float c[3];
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a[0] = p1[0] - p0[0];
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a[1] = p1[1] - p0[1];
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a[2] = p1[2] - p0[2];
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b[0] = p2[0] - p0[0];
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b[1] = p2[1] - p0[1];
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b[2] = p2[2] - p0[2];
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c[0] = p3[0] - p0[0];
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c[1] = p3[1] - p0[1];
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c[2] = p3[2] - p0[2];
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float cross[3];
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CrossProduct( b, c, cross );
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float volume = DotProduct( a, cross );
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if ( volume < 0 )
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return -volume;
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return volume;
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}
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inline float det(const float *p0,const float *p1,const float *p2,const float *p3)
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{
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return p1[0]*p2[1]*p3[2] + p2[0]*p3[1]*p1[2] + p3[0]*p1[1]*p2[2] -p1[0]*p3[1]*p2[2] - p2[0]*p1[1]*p3[2] - p3[0]*p2[1]*p1[2];
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}
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float computeMeshVolume2(const float *vertices,unsigned int tcount,const unsigned int *indices)
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{
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float volume = 0;
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const float *p0 = vertices;
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for (unsigned int i=0; i<tcount; i++,indices+=3)
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{
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const float *p1 = &vertices[ indices[0]*3 ];
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const float *p2 = &vertices[ indices[1]*3 ];
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const float *p3 = &vertices[ indices[2]*3 ];
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volume+=tetVolume(p0,p1,p2,p3); // compute the volume of the tetrahdren relative to the root vertice
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}
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return volume * (1.0f / 6.0f );
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}
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