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							120 lines
						
					
					
						
							3.8 KiB
						
					
					
				| // This file is part of Eigen, a lightweight C++ template library | |
| // for linear algebra. | |
| // | |
| // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr> | |
| // | |
| // This Source Code Form is subject to the terms of the Mozilla | |
| // Public License v. 2.0. If a copy of the MPL was not distributed | |
| // with this file, You can obtain one at http://mozilla.org/MPL/2.0/. | |
|  | |
| #include "icosphere.h" | |
|  | |
| #include <GL/gl.h> | |
| #include <map> | |
|  | |
| using namespace Eigen; | |
| 
 | |
| //-------------------------------------------------------------------------------- | |
| // icosahedron data | |
| //-------------------------------------------------------------------------------- | |
| #define X .525731112119133606 | |
| #define Z .850650808352039932 | |
|  | |
| static GLfloat vdata[12][3] = { | |
|    {-X, 0.0, Z}, {X, 0.0, Z}, {-X, 0.0, -Z}, {X, 0.0, -Z}, | |
|    {0.0, Z, X}, {0.0, Z, -X}, {0.0, -Z, X}, {0.0, -Z, -X}, | |
|    {Z, X, 0.0}, {-Z, X, 0.0}, {Z, -X, 0.0}, {-Z, -X, 0.0} | |
| }; | |
| 
 | |
| static GLint tindices[20][3] = { | |
|    {0,4,1}, {0,9,4}, {9,5,4}, {4,5,8}, {4,8,1}, | |
|    {8,10,1}, {8,3,10}, {5,3,8}, {5,2,3}, {2,7,3}, | |
|    {7,10,3}, {7,6,10}, {7,11,6}, {11,0,6}, {0,1,6}, | |
|    {6,1,10}, {9,0,11}, {9,11,2}, {9,2,5}, {7,2,11} }; | |
| //-------------------------------------------------------------------------------- | |
|  | |
| IcoSphere::IcoSphere(unsigned int levels) | |
| { | |
|   // init with an icosahedron | |
|   for (int i = 0; i < 12; i++) | |
|     mVertices.push_back(Map<Vector3f>(vdata[i])); | |
|   mIndices.push_back(new std::vector<int>); | |
|   std::vector<int>& indices = *mIndices.back(); | |
|   for (int i = 0; i < 20; i++) | |
|   { | |
|     for (int k = 0; k < 3; k++) | |
|       indices.push_back(tindices[i][k]); | |
|   } | |
|   mListIds.push_back(0); | |
| 
 | |
|   while(mIndices.size()<levels) | |
|     _subdivide(); | |
| } | |
| 
 | |
| const std::vector<int>& IcoSphere::indices(int level) const | |
| { | |
|   while (level>=int(mIndices.size())) | |
|     const_cast<IcoSphere*>(this)->_subdivide(); | |
|   return *mIndices[level]; | |
| } | |
| 
 | |
| void IcoSphere::_subdivide(void) | |
| { | |
|   typedef unsigned long long Key; | |
|   std::map<Key,int> edgeMap; | |
|   const std::vector<int>& indices = *mIndices.back(); | |
|   mIndices.push_back(new std::vector<int>); | |
|   std::vector<int>& refinedIndices = *mIndices.back(); | |
|   int end = indices.size(); | |
|   for (int i=0; i<end; i+=3) | |
|   { | |
|     int ids0[3],  // indices of outer vertices | |
|         ids1[3];  // indices of edge vertices | |
|     for (int k=0; k<3; ++k) | |
|     { | |
|       int k1 = (k+1)%3; | |
|       int e0 = indices[i+k]; | |
|       int e1 = indices[i+k1]; | |
|       ids0[k] = e0; | |
|       if (e1>e0) | |
|         std::swap(e0,e1); | |
|       Key edgeKey = Key(e0) | (Key(e1)<<32); | |
|       std::map<Key,int>::iterator it = edgeMap.find(edgeKey); | |
|       if (it==edgeMap.end()) | |
|       { | |
|         ids1[k] = mVertices.size(); | |
|         edgeMap[edgeKey] = ids1[k]; | |
|         mVertices.push_back( (mVertices[e0]+mVertices[e1]).normalized() ); | |
|       } | |
|       else | |
|         ids1[k] = it->second; | |
|     } | |
|     refinedIndices.push_back(ids0[0]); refinedIndices.push_back(ids1[0]); refinedIndices.push_back(ids1[2]); | |
|     refinedIndices.push_back(ids0[1]); refinedIndices.push_back(ids1[1]); refinedIndices.push_back(ids1[0]); | |
|     refinedIndices.push_back(ids0[2]); refinedIndices.push_back(ids1[2]); refinedIndices.push_back(ids1[1]); | |
|     refinedIndices.push_back(ids1[0]); refinedIndices.push_back(ids1[1]); refinedIndices.push_back(ids1[2]); | |
|   } | |
|   mListIds.push_back(0); | |
| } | |
| 
 | |
| void IcoSphere::draw(int level) | |
| { | |
|   while (level>=int(mIndices.size())) | |
|     const_cast<IcoSphere*>(this)->_subdivide(); | |
|   if (mListIds[level]==0) | |
|   { | |
|     mListIds[level] = glGenLists(1); | |
|     glNewList(mListIds[level], GL_COMPILE); | |
|       glVertexPointer(3, GL_FLOAT, 0, mVertices[0].data()); | |
|       glNormalPointer(GL_FLOAT, 0, mVertices[0].data()); | |
|       glEnableClientState(GL_VERTEX_ARRAY); | |
|       glEnableClientState(GL_NORMAL_ARRAY); | |
|       glDrawElements(GL_TRIANGLES, mIndices[level]->size(), GL_UNSIGNED_INT, &(mIndices[level]->at(0))); | |
|       glDisableClientState(GL_VERTEX_ARRAY); | |
|       glDisableClientState(GL_NORMAL_ARRAY); | |
|     glEndList(); | |
|   } | |
|   glCallList(mListIds[level]); | |
| } | |
| 
 | |
| 
 |