/**************************************************************************** * 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. * * * ****************************************************************************/ /**************************************************************************** History $Log: not supported by cvs2svn $ Revision 1.21 2007/12/02 07:39:19 cignoni disambiguated sqrt call Revision 1.20 2007/11/26 14:11:38 ponchio Added Mean Ratio metric for triangle quality. Revision 1.19 2007/11/19 17:04:05 ponchio QualityRadii values fixed. Revision 1.18 2007/11/18 19:12:54 ponchio Typo (missing comma). Revision 1.17 2007/11/16 14:22:35 ponchio Added qualityRadii: computes inradius /circumradius. (ok the name is ugly...) Revision 1.16 2007/10/10 15:11:30 ponchio Added Circumcenter function. Revision 1.15 2007/05/10 09:31:15 cignoni Corrected InterpolationParameters invocation Revision 1.14 2007/05/04 16:33:27 ganovelli moved InterpolationParamaters out the class Triangle Revision 1.13 2007/04/04 23:23:55 pietroni - corrected and renamed distance to point ( function TrianglePointDistance) Revision 1.12 2007/01/13 00:25:23 cignoni Added (Normalized) Normal version templated on three points (instead forcing the creation of a new triangle) Revision 1.11 2006/10/17 06:51:33 fiorin In function Barycenter, replaced calls to (the inexistent) cP(i) with P(i) Revision 1.10 2006/10/10 09:33:47 cignoni added quality for triangle wrap Revision 1.9 2006/09/14 08:44:07 ganovelli changed t.P(*) in t.cP() nella funzione Barycenter Revision 1.8 2006/06/01 08:38:58 pietroni added PointDistance function Revision 1.7 2006/03/01 15:35:09 pietroni compiled InterspolationParameters function Revision 1.6 2006/01/22 10:00:56 cignoni Very Important Change: Area->DoubleArea (and no more Area function) Revision 1.5 2005/09/23 14:18:27 ganovelli added constructor Revision 1.4 2005/04/14 11:35:09 ponchio *** empty log message *** Revision 1.3 2004/07/15 13:22:37 cignoni Added the standard P() access function instead of the shortcut P0() Revision 1.2 2004/07/15 10:17:42 pietroni correct access to point funtions call in usage of triangle3 (ex. t.P(0) in t.P0(0)) Revision 1.1 2004/03/08 01:13:31 cignoni Initial commit ****************************************************************************/ #ifndef __VCG_TRIANGLE3 #define __VCG_TRIANGLE3 #include #include #include #include #include namespace vcg { /** \addtogroup space */ /*@{*/ /** Templated class for storing a generic triangle in a 3D space. Note the relation with the Face class of TriMesh complex, both classes provide the P(i) access functions to their points and therefore they share the algorithms on it (e.g. area, normal etc...) */ template class Triangle3 { public: typedef ScalarTriangleType ScalarType; typedef Point3< ScalarType > CoordType; /// The bounding box type typedef Box3 BoxType; /********************************************* blah blah **/ Triangle3(){} Triangle3(const CoordType & c0,const CoordType & c1,const CoordType & c2){_v[0]=c0;_v[1]=c1;_v[2]=c2;} protected: /// Vector of vertex pointer incident in the face Point3 _v[3]; public: /// Shortcut per accedere ai punti delle facce inline CoordType & P( const int j ) { return _v[j];} inline CoordType & P0( const int j ) { return _v[j];} inline CoordType & P1( const int j ) { return _v[(j+1)%3];} inline CoordType & P2( const int j ) { return _v[(j+2)%3];} inline const CoordType & P( const int j ) const { return _v[j];} inline const CoordType & P0( const int j ) const { return _v[j];} inline const CoordType & P1( const int j ) const { return _v[(j+1)%3];} inline const CoordType & P2( const int j ) const { return _v[(j+2)%3];} inline const CoordType & cP0( const int j ) const { return _v[j];} inline const CoordType & cP1( const int j ) const { return _v[(j+1)%3];} inline const CoordType & cP2( const int j ) const { return _v[(j+2)%3];} bool InterpolationParameters(const CoordType & bq, ScalarType &a, ScalarType &b, ScalarType &_c ) const{ return InterpolationParameters(*this, bq, a, b,_c ); } /// Return the _q of the face, the return value is in [0,sqrt(3)/2] = [0 - 0.866.. ] ScalarType QualityFace( ) const { return Quality(P(0), P(1), P(2)); } }; //end Class /// Returns the normal to the plane passing through p0,p1,p2 template typename TriangleType::ScalarType QualityFace(const TriangleType &t) { return Quality(t.cP(0), t.cP(1), t.cP(2)); } // More robust function to computing barycentric coords of a point inside a triangle. // it requires the knowledge of what is the direction that is more orthogonal to the face plane. // Usually this info can be stored in a bit of the face flags (see updateFlags::FaceProjection(MeshType &m) ) // and accessing the field with // if(fp->Flags() & FaceType::NORMX ) axis = 0; // else if(fp->Flags() & FaceType::NORMY ) axis = 1; // else axis =2; // InterpolationParameters(*fp,axis,Point,Bary); // This direction is used to project the triangle in 2D and solve the problem in 2D where it is well defined. template bool InterpolationParameters(const TriangleType t, const int Axis, const Point3 & P, Point3 & L) { Point2 test; typedef Point2 P2; if(Axis==0) return InterpolationParameters2( P2(t.P(0)[1],t.P(0)[2]), P2(t.P(1)[1],t.P(1)[2]), P2(t.P(2)[1],t.P(2)[2]), P2(P[1],P[2]), L); if(Axis==1) return InterpolationParameters2( P2(t.P(0)[0],t.P(0)[2]), P2(t.P(1)[0],t.P(1)[2]), P2(t.P(2)[0],t.P(2)[2]), P2(P[0],P[2]), L); if(Axis==2) return InterpolationParameters2( P2(t.P(0)[0],t.P(0)[1]), P2(t.P(1)[0],t.P(1)[1]), P2(t.P(2)[0],t.P(2)[1]), P2(P[0],P[1]), L); return false; } /// Handy Wrapper of the above one that uses the passed normal N to choose the right orientation template bool InterpolationParameters(const TriangleType t, const Point3 & N, const Point3 & P, Point3 & L) { if(N[0]>N[1]) { if(N[0]>N[2]) return InterpolationParameters(t,0,P,L); /* 0 > 1 ? 2 */ else return InterpolationParameters(t,2,P,L); /* 2 > 1 ? 2 */ } else { if(N[1]>N[2]) return InterpolationParameters(t,1,P,L); /* 1 > 0 ? 2 */ else return InterpolationParameters(t,2,P,L); /* 2 > 1 ? 2 */ } } // Function that computes the barycentric coords of a 2D triangle. Used by the above function. // Algorithm: simply find a base for the frame of the triangle, assuming v3 as origin (matrix T) invert it and apply to P-v3. template bool InterpolationParameters2(const Point2 &V1, const Point2 &V2, const Point2 &V3, const Point2 &P, Point3 &L) { ScalarType T00 = V1[0]-V3[0]; ScalarType T01 = V2[0]-V3[0]; ScalarType T10 = V1[1]-V3[1]; ScalarType T11 = V2[1]-V3[1]; ScalarType Det = T00 * T11 - T01*T10; if(fabs(Det) < 0.0000001) return false; ScalarType IT00 = T11/Det; ScalarType IT01 = -T01/Det; ScalarType IT10 = -T10/Det; ScalarType IT11 = T00/Det; Point2 Delta = P-V3; L[0] = IT00*Delta[0] + IT01*Delta[1]; L[1] = IT10*Delta[0] + IT11*Delta[1]; if(L[0]<0) L[0]=0; if(L[1]<0) L[1]=0; if(L[0]>1.) L[0]=1; if(L[1]>1.) L[1]=1; L[2] = 1. - L[1] - L[0]; if(L[2]<0) L[2]=0; assert(L[2] >= -0.00001); return true; } /** Calcola i coefficienti della combinazione convessa. @param bq Punto appartenente alla faccia @param a Valore di ritorno per il vertice V(0) @param b Valore di ritorno per il vertice V(1) @param _c Valore di ritorno per il vertice V(2) @return true se bq appartiene alla faccia, false altrimenti */ template bool InterpolationParameters(const TriangleType t,const Point3 & N,const Point3 & bq, ScalarType &a, ScalarType &b, ScalarType &c ) { Point3 bary; bool done= InterpolationParameters(t,N,bq,bary); a=bary[0]; b=bary[1]; c=bary[2]; return done; } /// Compute a shape quality measure of the triangle composed by points p0,p1,p2 /// It Returns 2*AreaTri/(MaxEdge^2), /// the range is range [0.0, 0.866] /// e.g. Equilateral triangle sqrt(3)/2, halfsquare: 1/2, ... up to a line that has zero quality. template P3ScalarType Quality( Point3 const &p0, Point3 const & p1, Point3 const & p2) { Point3 d10=p1-p0; Point3 d20=p2-p0; Point3 d12=p1-p2; Point3 x = d10^d20; P3ScalarType a = Norm( x ); if(a==0) return 0; // Area zero triangles have surely quality==0; P3ScalarType b = SquaredNorm( d10 ); P3ScalarType t = b; t = SquaredNorm( d20 ); if ( b P3ScalarType QualityRadii(Point3 const &p0, Point3 const &p1, Point3 const &p2) { P3ScalarType a=(p1-p0).Norm(); P3ScalarType b=(p2-p0).Norm(); P3ScalarType c=(p1-p2).Norm(); P3ScalarType sum = (a + b + c)*0.5; P3ScalarType area2 = sum*(a+b-sum)*(a+c-sum)*(b+c-sum); if(area2 <= 0) return 0; //circumradius: (a*b*c)/(4*sqrt(area2)) //inradius: (a*b*c)/(4*circumradius*sum) => sqrt(area2)/sum; return (8*area2)/(a*b*c*sum); } /// Compute a shape quality measure of the triangle composed by points p0,p1,p2 /// It Returns mean ratio 2sqrt(a, b)/(a+b) where a+b are the eigenvalues of the M^tM of the /// transformation matrix into a regular simplex /// the range is range [0, 1] template P3ScalarType QualityMeanRatio(Point3 const &p0, Point3 const &p1, Point3 const &p2) { P3ScalarType a=(p1-p0).Norm(); P3ScalarType b=(p2-p0).Norm(); P3ScalarType c=(p1-p2).Norm(); P3ScalarType sum = (a + b + c)*0.5; //semiperimeter P3ScalarType area2 = sum*(a+b-sum)*(a+c-sum)*(b+c-sum); if(area2 <= 0) return 0; return (4.0*sqrt(3.0)*sqrt(area2))/(a*a + b*b + c*c); } /// Returns the normal to the plane passing through p0,p1,p2 template Point3 Normal(const TriangleType &t) { return (( t.P(1) - t.P(0)) ^ (t.P(2) - t.P(0))); } template Point3Type Normal( Point3Type const &p0, Point3Type const & p1, Point3Type const & p2) { return (( p1 - p0) ^ (p2 - p0)); } /// Like the above, it returns the normal to the plane passing through p0,p1,p2, but normalized. template Point3 NormalizedNormal(const TriangleType &t) { return (( t.P(1) - t.P(0)) ^ (t.P(2) - t.P(0))).Normalize(); } template Point3Type NormalizedNormal( Point3Type const &p0, Point3Type const & p1, Point3Type const & p2) { return (( p1 - p0) ^ (p2 - p0)).Normalize(); } /// Handy Wrapper of the above one that calculate the normal on the triangle template bool InterpolationParameters(const TriangleType t, const Point3 & P, Point3 & L) { vcg::Point3 N=vcg::Normal(t); return (InterpolationParameters(t,N,P,L)); } /// Return the Double of area of the triangle // NOTE the old Area function has been removed to intentionally // cause compiling error that will help people to check their code... // A some people used Area assuming that it returns the double and some not. // So please check your codes!!! // And please DO NOT Insert any Area named function here! template typename TriangleType::ScalarType DoubleArea(const TriangleType &t) { return Norm( (t.P(1) - t.P(0)) ^ (t.P(2) - t.P(0)) ); } template typename TriangleType::ScalarType CosWedge(const TriangleType &t, int k) { typename TriangleType::CoordType e0 = t.P((k+1)%3) - t.P(k), e1 = t.P((k+2)%3) - t.P(k); return (e0*e1)/(e0.Norm()*e1.Norm()); } template Point3 Barycenter(const TriangleType &t) { return ((t.P(0)+t.P(1)+t.P(2))/(typename TriangleType::ScalarType) 3.0); } template typename TriangleType::ScalarType Perimeter(const TriangleType &t) { return Distance(t.P(0),t.P(1))+ Distance(t.P(1),t.P(2))+ Distance(t.P(2),t.P(0)); } template Point3 Circumcenter(const TriangleType &t) { typename TriangleType::ScalarType a2 = (t.P(1) - t.P(2)).SquaredNorm(); typename TriangleType::ScalarType b2 = (t.P(2) - t.P(0)).SquaredNorm(); typename TriangleType::ScalarType c2 = (t.P(0) - t.P(1)).SquaredNorm(); Point3c = t.P(0)*a2*(-a2 + b2 + c2) + t.P(1)*b2*( a2 - b2 + c2) + t.P(2)*c2*( a2 + b2 - c2); c /= 2*(a2*b2 + a2*c2 + b2*c2) - a2*a2 - b2*b2 - c2*c2; return c; } } // end namespace #endif