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