1 // This file is part of Eigen, a lightweight C++ template library 2 // for linear algebra. 3 // 4 // Copyright (C) 2008 Gael Guennebaud <gael.guennebaud (at) inria.fr> 5 // 6 // This Source Code Form is subject to the terms of the Mozilla 7 // Public License v. 2.0. If a copy of the MPL was not distributed 8 // with this file, You can obtain one at http://mozilla.org/MPL/2.0/. 9 10 #include "icosphere.h" 11 12 #include <GL/gl.h> 13 #include <map> 14 15 using namespace Eigen; 16 17 //-------------------------------------------------------------------------------- 18 // icosahedron data 19 //-------------------------------------------------------------------------------- 20 #define X .525731112119133606 21 #define Z .850650808352039932 22 23 static GLfloat vdata[12][3] = { 24 {-X, 0.0, Z}, {X, 0.0, Z}, {-X, 0.0, -Z}, {X, 0.0, -Z}, 25 {0.0, Z, X}, {0.0, Z, -X}, {0.0, -Z, X}, {0.0, -Z, -X}, 26 {Z, X, 0.0}, {-Z, X, 0.0}, {Z, -X, 0.0}, {-Z, -X, 0.0} 27 }; 28 29 static GLint tindices[20][3] = { 30 {0,4,1}, {0,9,4}, {9,5,4}, {4,5,8}, {4,8,1}, 31 {8,10,1}, {8,3,10}, {5,3,8}, {5,2,3}, {2,7,3}, 32 {7,10,3}, {7,6,10}, {7,11,6}, {11,0,6}, {0,1,6}, 33 {6,1,10}, {9,0,11}, {9,11,2}, {9,2,5}, {7,2,11} }; 34 //-------------------------------------------------------------------------------- 35 36 IcoSphere::IcoSphere(unsigned int levels) 37 { 38 // init with an icosahedron 39 for (int i = 0; i < 12; i++) 40 mVertices.push_back(Map<Vector3f>(vdata[i])); 41 mIndices.push_back(new std::vector<int>); 42 std::vector<int>& indices = *mIndices.back(); 43 for (int i = 0; i < 20; i++) 44 { 45 for (int k = 0; k < 3; k++) 46 indices.push_back(tindices[i][k]); 47 } 48 mListIds.push_back(0); 49 50 while(mIndices.size()<levels) 51 _subdivide(); 52 } 53 54 const std::vector<int>& IcoSphere::indices(int level) const 55 { 56 while (level>=int(mIndices.size())) 57 const_cast<IcoSphere*>(this)->_subdivide(); 58 return *mIndices[level]; 59 } 60 61 void IcoSphere::_subdivide(void) 62 { 63 typedef unsigned long long Key; 64 std::map<Key,int> edgeMap; 65 const std::vector<int>& indices = *mIndices.back(); 66 mIndices.push_back(new std::vector<int>); 67 std::vector<int>& refinedIndices = *mIndices.back(); 68 int end = indices.size(); 69 for (int i=0; i<end; i+=3) 70 { 71 int ids0[3], // indices of outer vertices 72 ids1[3]; // indices of edge vertices 73 for (int k=0; k<3; ++k) 74 { 75 int k1 = (k+1)%3; 76 int e0 = indices[i+k]; 77 int e1 = indices[i+k1]; 78 ids0[k] = e0; 79 if (e1>e0) 80 std::swap(e0,e1); 81 Key edgeKey = Key(e0) | (Key(e1)<<32); 82 std::map<Key,int>::iterator it = edgeMap.find(edgeKey); 83 if (it==edgeMap.end()) 84 { 85 ids1[k] = mVertices.size(); 86 edgeMap[edgeKey] = ids1[k]; 87 mVertices.push_back( (mVertices[e0]+mVertices[e1]).normalized() ); 88 } 89 else 90 ids1[k] = it->second; 91 } 92 refinedIndices.push_back(ids0[0]); refinedIndices.push_back(ids1[0]); refinedIndices.push_back(ids1[2]); 93 refinedIndices.push_back(ids0[1]); refinedIndices.push_back(ids1[1]); refinedIndices.push_back(ids1[0]); 94 refinedIndices.push_back(ids0[2]); refinedIndices.push_back(ids1[2]); refinedIndices.push_back(ids1[1]); 95 refinedIndices.push_back(ids1[0]); refinedIndices.push_back(ids1[1]); refinedIndices.push_back(ids1[2]); 96 } 97 mListIds.push_back(0); 98 } 99 100 void IcoSphere::draw(int level) 101 { 102 while (level>=int(mIndices.size())) 103 const_cast<IcoSphere*>(this)->_subdivide(); 104 if (mListIds[level]==0) 105 { 106 mListIds[level] = glGenLists(1); 107 glNewList(mListIds[level], GL_COMPILE); 108 glVertexPointer(3, GL_FLOAT, 0, mVertices[0].data()); 109 glNormalPointer(GL_FLOAT, 0, mVertices[0].data()); 110 glEnableClientState(GL_VERTEX_ARRAY); 111 glEnableClientState(GL_NORMAL_ARRAY); 112 glDrawElements(GL_TRIANGLES, mIndices[level]->size(), GL_UNSIGNED_INT, &(mIndices[level]->at(0))); 113 glDisableClientState(GL_VERTEX_ARRAY); 114 glDisableClientState(GL_NORMAL_ARRAY); 115 glEndList(); 116 } 117 glCallList(mListIds[level]); 118 } 119 120 121
