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A lightweight C++ OpenGL middleware for 2D/3D graphics

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# D:/VL/BuildSystem/VL_DISTRO/Visualization_Library_SDK/src/vlGraphics/Extrusion.cpp

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    00001 /**************************************************************************************/
    00002 /*                                                                                    */
    00003 /*  Visualization Library                                                             */
    00004 /*  http://www.visualizationlibrary.org                                               */
    00005 /*                                                                                    */
    00006 /*  Copyright (c) 2005-2010, Michele Bosi                                             */
    00007 /*  All rights reserved.                                                              */
    00008 /*                                                                                    */
    00009 /*  Redistribution and use in source and binary forms, with or without modification,  */
    00010 /*  are permitted provided that the following conditions are met:                     */
    00011 /*                                                                                    */
    00012 /*  - Redistributions of source code must retain the above copyright notice, this     */
    00013 /*  list of conditions and the following disclaimer.                                  */
    00014 /*                                                                                    */
    00015 /*  - Redistributions in binary form must reproduce the above copyright notice, this  */
    00016 /*  list of conditions and the following disclaimer in the documentation and/or       */
    00017 /*  other materials provided with the distribution.                                   */
    00018 /*                                                                                    */
    00019 /*  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND   */
    00020 /*  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED     */
    00021 /*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE            */
    00022 /*  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR  */
    00023 /*  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    */
    00024 /*  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;      */
    00025 /*  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON    */
    00026 /*  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT           */
    00027 /*  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS     */
    00028 /*  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                      */
    00029 /*                                                                                    */
    00030 /**************************************************************************************/
    00031
    00032 #include <vlGraphics/Extrusion.hpp>
    00033 #include <vlGraphics/Tessellator.hpp>
    00034 #include <vlCore/glsl_math.hpp>
    00035
    00036 using namespace vl;
    00037
    00038 ref<Geometry> Extrusion::extrude()
    00039 {
    00040   if (silhouette().empty())
    00041   {
    00042     Log::error("Extrusion::extrude(): no silhouette defined.\n");
    00043     return NULL;
    00044   }
    00045   if (positionPath().empty())
    00046   {
    00047     Log::error("Extrusion::extrude() needs at least a non empty positionPath().\n");
    00048     return NULL;
    00049   }
    00050   if (!scalingPath().empty() && scalingPath().size() != positionPath().size()-2)
    00051   {
    00052     Log::error("Extrusion::extrude(): scalingPath() must have the same number of control points as positionPath().\n");
    00053     return NULL;
    00054   }
    00055   if (!rotationPath().empty() && rotationPath().size() != positionPath().size()-2)
    00056   {
    00057     Log::error("Extrusion::extrude(): rotationPath() must have the same number of control points as positionPath().\n");
    00058     return NULL;
    00059   }
    00060   if (!colorPath().empty() && colorPath().size() != positionPath().size()-2)
    00061   {
    00062     Log::error("Extrusion::extrude(): colorPath() must have the same number of control points as positionPath().\n");
    00063     return NULL;
    00064   }
    00065
    00066   ref<Geometry> geom = new Geometry;
    00067
    00068   size_t segments = positionPath().size()-2;
    00069
    00070   std::vector<fvec3> verts;
    00071   verts.resize( silhouette().size() * segments );
    00072
    00073   vl::fmat4 m = fmat4::getRotation(fvec3(0,1,0),positionPath()[1]-positionPath()[0]);
    00074
    00075   // initialize silhouette on the x/z plane
    00076   std::vector<vl::fvec3> projected_sil;
    00077   projected_sil.resize(silhouette().size());
    00078   for(unsigned i=0; i<silhouette().size(); ++i)
    00079   {
    00080     projected_sil[i] = m * vl::fvec3(silhouette()[i].x(),0,silhouette()[i].y()) + positionPath()[0];
    00081   }
    00082
    00083   // initialize plane normals from 1 to n-1 (end points are excluded)
    00084   std::vector<fvec3> plane_normals;
    00085   plane_normals.resize(positionPath().size());
    00086   for(unsigned i=1; i<plane_normals.size()-1; ++i)
    00087   {
    00088     fvec3 p0 = positionPath()[i-1] - positionPath()[i];
    00089     fvec3 p1 = positionPath()[i+1] - positionPath()[i];
    00090     p0.normalize();
    00091     p1.normalize();
    00092     plane_normals[i] = (p1-p0).normalize();
    00093   }
    00094
    00095   for(unsigned i=1; i<positionPath().size()-1; ++i)
    00096   {
    00097     for(int j=0; j<(int)silhouette().size(); ++j)
    00098     {
    00099       fvec3 V = (positionPath()[i] - positionPath()[i-1]).normalize();
    00100       const fvec3& P = projected_sil[j];
    00101       const fvec3& orig = positionPath()[i];
    00102       const fvec3& N = plane_normals [i];
    00103       float d = dot(N,orig);
    00104       float t = dot(V,N) ? (d-dot(P,N))/dot(V,N) : 0 /*error*/;
    00105       // project current projected_sil on next plane along p0->p1 vector
    00106       verts.at(j+silhouette().size()*(i-1)) = projected_sil[j] = P + V*t;
    00107     }
    00108   }
    00109
    00110   // rotation
    00111   if(!rotationPath().empty())
    00112   {
    00113     for(unsigned i=1; i<positionPath().size()-1; ++i)
    00114     {
    00115       fvec3 r = (positionPath()[i+1] - positionPath()[i]).normalize();
    00116       fmat4 mat = vl::fmat4::getRotation(rotationPath()[i-1],r);
    00117       fvec3 c;
    00118       for(int j=0; j<(int)silhouette().size(); ++j)
    00119         c += verts.at(j+silhouette().size()*(i-1));
    00120       c /= (float)silhouette().size();
    00121       for(int j=0; j<(int)silhouette().size(); ++j)
    00122         verts.at(j+silhouette().size()*(i-1)) = (mat*(verts.at(j+silhouette().size()*(i-1))-c))+c;
    00123     }
    00124   }
    00125
    00126   // scaling
    00127   if(!scalingPath().empty())
    00128   {
    00129     for(unsigned i=1; i<positionPath().size()-1; ++i)
    00130     {
    00131       float s = scalingPath()[i-1];
    00132       fvec3 c;
    00133       for(int j=0; j<(int)silhouette().size(); ++j)
    00134         c += verts.at(j+silhouette().size()*(i-1));
    00135       c /= (float)silhouette().size();
    00136       for(int j=0; j<(int)silhouette().size(); ++j)
    00137         verts.at(j+silhouette().size()*(i-1)) = (s*(verts.at(j+silhouette().size()*(i-1))-c))+c;
    00138     }
    00139   }
    00140
    00141   int prof_count = silhouetteMode() == SilhouetteClosed ? (int)silhouette().size() : (int)silhouette().size()-1;
    00142   ref<DrawElementsUInt> de = new DrawElementsUInt(PT_QUADS);
    00143   geom->drawCalls()->push_back(de.get());
    00144   de->indexBuffer()->resize(4 * prof_count * (segments-1));
    00145   for(size_t iseg=0; iseg<segments-1; ++iseg)
    00146   {
    00147     for(int iquad=0; iquad<prof_count; ++iquad)
    00148     {
    00149       de->indexBuffer()->at(iquad*4+iseg*4*prof_count + 3) = (iseg + 0) * (GLuint)silhouette().size() + iquad;
    00150       de->indexBuffer()->at(iquad*4+iseg*4*prof_count + 2) = (iseg + 0) * (GLuint)silhouette().size() + (iquad+1)%silhouette().size();
    00151       de->indexBuffer()->at(iquad*4+iseg*4*prof_count + 1) = (iseg + 1) * (GLuint)silhouette().size() + (iquad+1)%silhouette().size();
    00152       de->indexBuffer()->at(iquad*4+iseg*4*prof_count + 0) = (iseg + 1) * (GLuint)silhouette().size() + iquad;
    00153     }
    00154   }
    00155
    00156   // bottom/top caps
    00157
    00158   size_t tess_bottom_count = 0;
    00159   size_t tess_top_count    = 0;
    00160
    00161   if(fillBottom())
    00162   {
    00163     size_t start = verts.size();
    00164     Tessellator tessellator;
    00165     tessellator.contours().push_back((int)silhouette().size());
    00166     for(unsigned i=0; i<silhouette().size(); ++i)
    00167       tessellator.contourVerts().push_back((dvec3)verts[i]);
    00168     tessellator.setWindingRule(vl::TW_TESS_WINDING_NONZERO);
    00169     tessellator.tessellate();
    00170     for(unsigned i=0; i<tessellator.tessellatedTris().size(); ++i)
    00171       verts.push_back(tessellator.tessellatedTris()[i]);
    00172     if (tessellator.tessellatedTris().size())
    00173       geom->drawCalls()->push_back( new DrawArrays(PT_TRIANGLES, start, tessellator.tessellatedTris().size()) );
    00174     tess_bottom_count = tessellator.tessellatedTris().size();
    00175   }
    00176   if(fillTop())
    00177   {
    00178     size_t start = verts.size();
    00179     Tessellator tessellator;
    00180     tessellator.contours().push_back(silhouette().size());
    00181     for(unsigned i=0; i<silhouette().size(); ++i)
    00182       tessellator.contourVerts().push_back((dvec3)verts[verts.size()-i-1-tess_bottom_count]);
    00183     tessellator.setWindingRule(vl::TW_TESS_WINDING_NONZERO);
    00184     tessellator.tessellate();
    00185     for(unsigned i=0; i<tessellator.tessellatedTris().size(); ++i)
    00186       verts.push_back(tessellator.tessellatedTris()[i]);
    00187     if (tessellator.tessellatedTris().size())
    00188       geom->drawCalls()->push_back( new DrawArrays(PT_TRIANGLES, start, tessellator.tessellatedTris().size()) );
    00189     tess_top_count = tessellator.tessellatedTris().size();
    00190   }
    00191
    00192   ref<ArrayFloat3> vert_array = new ArrayFloat3;
    00193   geom->setVertexArray( vert_array.get() );
    00194   vert_array->initFrom(verts);
    00195
    00196   if (!colorPath().empty())
    00197   {
    00198     ref<ArrayFloat4> col_array = new ArrayFloat4;
    00199     geom->setColorArray(col_array.get());
    00200     col_array->resize(geom->vertexArray()->size());
    00201     int offs = 0;
    00202     for(size_t iseg=0; iseg<segments; ++iseg)
    00203     {
    00204       for(unsigned j=0; j<silhouette().size(); ++j, ++offs)
    00205         col_array->at(offs) = colorPath()[iseg];
    00206     }
    00207     if (fillBottom())
    00208     {
    00209       for(unsigned j=0; j<tess_bottom_count; ++j, ++offs)
    00210         col_array->at(offs) = colorPath()[0];
    00211     }
    00212     if (fillTop())
    00213     {
    00214       for(unsigned j=0; j<tess_top_count; ++j, ++offs)
    00215         col_array->at(offs) = colorPath().back();
    00216     }
    00217   }
    00218
    00219   if (!smooth())
    00220     geom->convertDrawCallToDrawArrays();
    00221
    00222   geom->computeNormals();
    00223
    00224   return geom;
    00225 }

Visualization Library v2011.09.1162 Reference Documentation
Copyright 2005-2011 Michele Bosi. All rights reserved.
Updated on Thu Jan 26 2012 00:43:37.
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