108 lines
3.4 KiB
C++
108 lines
3.4 KiB
C++
/*
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* osgDB::wrl - a VRML 1.0 loader for OpenSceneGraph
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* Copyright (C) 2002 Ruben Lopez <ryu@gpul.org>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <osg/Matrix>
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#include "normals.h"
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#define CREASE_ANGLE 3.14159265356 * 45 / 180
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float difAng(osg::Vec3 a, osg::Vec3 b) {
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float div = a.length() * b.length();
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return (div != 0.0f ? acosf( (a*b) / div) : 0.0f );
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}
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osg::Vec3 calcNormal(osg::Vec3 &a, osg::Vec3 &b, osg::Vec3 &c) {
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osg::Vec3 norm;
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osg::Vec3 v1;
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osg::Vec3 v2;
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v1=b-c;
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v2=a-b;
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norm=v1 ^ v2; // cross product
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norm.normalize();
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return norm;
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}
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void get3v(VertexList &vertices, VertexIndexList &vindex, int &a, int &b, int &c) {
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unsigned tam=vindex.size();
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unsigned i;
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b=0;c=0;
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a=vindex[0];
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for (i=1;i<tam;i++) {
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if (vertices[vindex[i]] != vertices[a]) { b=vindex[i];break; }
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}
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for (i=1;i<tam;i++) {
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if (vertices[vindex[i]] != vertices[a] && vertices[vindex[i]] != vertices[b]) { c=vindex[i];break; }
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}
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}
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osg::Vec3 *calcNormals(VertexList &vertices, PolygonList &polygons, unsigned nvert_total) {
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unsigned nPoly=polygons.size();
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osg::Vec3 *normales_polys = new osg::Vec3[nPoly];
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osg::Vec3 *normales = new osg::Vec3[nvert_total];
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unsigned pos=0;
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unsigned poly;
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/* Phase 1: Get flat normals */
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for (poly=0;poly<nPoly;poly++) {
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VertexIndexList vindex=*polygons[poly];
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if (vindex.size() > 2) {
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int v0,v1,v2;
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get3v(vertices,vindex,v0,v1,v2);
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if (v0 == v1 || v0 == v2) {
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std::cerr << "ERROR: Vertices alineados: nv=" << vindex.size() << std::endl;
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}
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normales_polys[poly] = calcNormal(vertices[v0],
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vertices[v1],
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vertices[v2]);
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if (normales_polys[poly] == osg::Vec3(0,0,0) && vindex.size() > 2) {
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std::cerr << "##***" << "Normal nula VERTICES=" << vindex.size() << " " << vertices[v0] << " " << vertices[v1] << " " << vertices[v2] << std::endl;
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}
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}
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}
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/* Phase 2: Selective smooth depending on crease angle */
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for (poly=0;poly<nPoly;poly++) {
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VertexIndexList vindex=*polygons[poly];
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unsigned j;
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osg::Vec3 pnormal=normales_polys[poly];
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for (j=0;j<vindex.size();j++) {
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int vertice=vindex[j];
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normales[pos]=osg::Vec3(pnormal[0],pnormal[1],pnormal[2]);
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unsigned poly2;
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for (poly2=0;poly2<nPoly;poly2++) {
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if (poly2 == poly) continue;
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VertexIndexList vindex2=*polygons[poly2];
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unsigned k;
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osg::Vec3 pnormal2=normales_polys[poly2];
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for (k=0;k<vindex2.size();k++) {
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if (vindex2[k] == vertice) {
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float ang=difAng(pnormal,pnormal2);
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if (ang < CREASE_ANGLE) {
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normales[pos]+=osg::Vec3(pnormal2[0],pnormal2[1],pnormal2[2]);
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}
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}
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}
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}
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normales[pos].normalize();
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pos++;
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}
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}
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/* Phase 3: All done ;) */
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return normales;
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}
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