353 lines
14 KiB
C++
353 lines
14 KiB
C++
#pragma region License
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/******************************************************************************
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This file is part of the PolyVox library
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Copyright (C) 2006 David Williams
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program 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
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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******************************************************************************/
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#pragma endregion
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#include "PolyVoxCore/PolyVoxImpl/ReferenceSurfaceExtractor.h"
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#include "PolyVoxCore/BlockVolume.h"
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#include "PolyVoxCore/BlockVolumeIterator.h"
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#include "PolyVoxCore/IndexedSurfacePatch.h"
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#include "PolyVoxCore/MarchingCubesTables.h"
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#include "PolyVoxCore/Region.h"
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#include "PolyVoxCore/SurfaceVertex.h"
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#include "PolyVoxCore/Vector.h"
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namespace PolyVox
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{
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void extractReferenceSurfaceImpl(BlockVolume<uint8>* volumeData, Region region, IndexedSurfacePatch* singleMaterialPatch)
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{
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static int32 vertexIndicesX[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
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static int32 vertexIndicesY[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
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static int32 vertexIndicesZ[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1];
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memset(vertexIndicesX,0xFF,sizeof(vertexIndicesX)); //0xFF is -1 as two's complement - this may not be portable...
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memset(vertexIndicesY,0xFF,sizeof(vertexIndicesY));
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memset(vertexIndicesZ,0xFF,sizeof(vertexIndicesZ));
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//When generating the mesh for a region we actually look one voxel outside it in the
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// back, bottom, right direction. Protect against access violations by cropping region here
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Region regVolume = volumeData->getEnclosingRegion();
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//regVolume.setUpperCorner(regVolume.getUpperCorner() - Vector3DInt32(1,1,1));
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region.cropTo(regVolume);
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region.setUpperCorner(region.getUpperCorner() - Vector3DInt32(1,1,1));
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//Offset from lower block corner
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const Vector3DFloat offset = static_cast<Vector3DFloat>(region.getLowerCorner());
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Vector3DFloat vertlist[12];
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Vector3DFloat normlist[12];
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uint8 vertMaterials[12];
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BlockVolumeIterator<uint8> volIter(*volumeData);
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volIter.setValidRegion(region);
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//////////////////////////////////////////////////////////////////////////
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//Get mesh data
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//////////////////////////////////////////////////////////////////////////
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//Iterate over each cell in the region
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volIter.setPosition(region.getLowerCorner().getX(),region.getLowerCorner().getY(), region.getLowerCorner().getZ());
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while(volIter.moveForwardInRegionXYZ())
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{
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//Current position
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const uint16 x = volIter.getPosX();
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const uint16 y = volIter.getPosY();
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const uint16 z = volIter.getPosZ();
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//Voxels values
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const uint8 v000 = volIter.getVoxel();
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const uint8 v100 = volIter.peekVoxel1px0py0pz();
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const uint8 v010 = volIter.peekVoxel0px1py0pz();
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const uint8 v110 = volIter.peekVoxel1px1py0pz();
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const uint8 v001 = volIter.peekVoxel0px0py1pz();
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const uint8 v101 = volIter.peekVoxel1px0py1pz();
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const uint8 v011 = volIter.peekVoxel0px1py1pz();
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const uint8 v111 = volIter.peekVoxel1px1py1pz();
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//Determine the index into the edge table which tells us which vertices are inside of the surface
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uint8 iCubeIndex = 0;
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if (v000 == 0) iCubeIndex |= 1;
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if (v100 == 0) iCubeIndex |= 2;
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if (v110 == 0) iCubeIndex |= 4;
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if (v010 == 0) iCubeIndex |= 8;
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if (v001 == 0) iCubeIndex |= 16;
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if (v101 == 0) iCubeIndex |= 32;
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if (v111 == 0) iCubeIndex |= 64;
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if (v011 == 0) iCubeIndex |= 128;
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/* Cube is entirely in/out of the surface */
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if (edgeTable[iCubeIndex] == 0)
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{
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continue;
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}
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/* Find the vertices where the surface intersects the cube */
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if (edgeTable[iCubeIndex] & 1)
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{
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vertlist[0].setX(x + 0.5f);
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vertlist[0].setY(y);
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vertlist[0].setZ(z);
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normlist[0].setX(v000 > v100 ? 1.0f : -1.0f);
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normlist[0].setY(0.0f);
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normlist[0].setZ(0.0f);
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vertMaterials[0] = v000 | v100; //Because one of these is 0, the or operation takes the max.
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}
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if (edgeTable[iCubeIndex] & 2)
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{
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vertlist[1].setX(x + 1.0f);
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vertlist[1].setY(y + 0.5f);
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vertlist[1].setZ(z);
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normlist[1].setX(0.0f);
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normlist[1].setY(v100 > v110 ? 1.0f : -1.0f);
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normlist[1].setZ(0.0f);
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vertMaterials[1] = v100 | v110;
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}
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if (edgeTable[iCubeIndex] & 4)
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{
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vertlist[2].setX(x + 0.5f);
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vertlist[2].setY(y + 1.0f);
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vertlist[2].setZ(z);
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normlist[2].setX(v010 > v110 ? 1.0f : -1.0f);
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normlist[2].setY(0.0f);
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normlist[2].setZ(0.0f);
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vertMaterials[2] = v010 | v110;
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}
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if (edgeTable[iCubeIndex] & 8)
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{
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vertlist[3].setX(x);
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vertlist[3].setY(y + 0.5f);
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vertlist[3].setZ(z);
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normlist[3].setX(0.0f);
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normlist[3].setY(v000 > v010 ? 1.0f : -1.0f);
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normlist[3].setZ(0.0f);
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vertMaterials[3] = v000 | v010;
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}
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if (edgeTable[iCubeIndex] & 16)
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{
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vertlist[4].setX(x + 0.5f);
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vertlist[4].setY(y);
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vertlist[4].setZ(z + 1.0f);
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normlist[4].setX(v001 > v101 ? 1.0f : -1.0f);
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normlist[4].setY(0.0f);
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normlist[4].setZ(0.0f);
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vertMaterials[4] = v001 | v101;
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}
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if (edgeTable[iCubeIndex] & 32)
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{
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vertlist[5].setX(x + 1.0f);
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vertlist[5].setY(y + 0.5f);
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vertlist[5].setZ(z + 1.0f);
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normlist[5].setX(0.0f);
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normlist[5].setY(v101 > v111 ? 1.0f : -1.0f);
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normlist[5].setZ(0.0f);
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vertMaterials[5] = v101 | v111;
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}
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if (edgeTable[iCubeIndex] & 64)
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{
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vertlist[6].setX(x + 0.5f);
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vertlist[6].setY(y + 1.0f);
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vertlist[6].setZ(z + 1.0f);
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normlist[6].setX(v011 > v111 ? 1.0f : -1.0f);
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normlist[6].setY(0.0f);
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normlist[6].setZ(0.0f);
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vertMaterials[6] = v011 | v111;
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}
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if (edgeTable[iCubeIndex] & 128)
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{
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vertlist[7].setX(x);
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vertlist[7].setY(y + 0.5f);
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vertlist[7].setZ(z + 1.0f);
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normlist[7].setX(0.0f);
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normlist[7].setY(v001 > v011 ? 1.0f : -1.0f);
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normlist[7].setZ(0.0f);
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vertMaterials[7] = v001 | v011;
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}
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if (edgeTable[iCubeIndex] & 256)
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{
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vertlist[8].setX(x);
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vertlist[8].setY(y);
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vertlist[8].setZ(z + 0.5f);
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normlist[8].setX(0.0f);
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normlist[8].setY(0.0f);
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normlist[8].setZ(v000 > v001 ? 1.0f : -1.0f);
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vertMaterials[8] = v000 | v001;
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}
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if (edgeTable[iCubeIndex] & 512)
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{
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vertlist[9].setX(x + 1.0f);
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vertlist[9].setY(y);
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vertlist[9].setZ(z + 0.5f);
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normlist[9].setX(0.0f);
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normlist[9].setY(0.0f);
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normlist[9].setZ(v100 > v101 ? 1.0f : -1.0f);
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vertMaterials[9] = v100 | v101;
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}
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if (edgeTable[iCubeIndex] & 1024)
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{
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vertlist[10].setX(x + 1.0f);
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vertlist[10].setY(y + 1.0f);
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vertlist[10].setZ(z + 0.5f);
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normlist[10].setX(0.0f);
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normlist[10].setY(0.0f);
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normlist[10].setZ(v110 > v111 ? 1.0f : -1.0f);
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vertMaterials[10] = v110 | v111;
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}
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if (edgeTable[iCubeIndex] & 2048)
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{
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vertlist[11].setX(x);
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vertlist[11].setY(y + 1.0f);
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vertlist[11].setZ(z + 0.5f);
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normlist[11].setX(0.0f);
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normlist[11].setY(0.0f);
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normlist[11].setZ(v010 > v011 ? 1.0f : -1.0f);
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vertMaterials[11] = v010 | v011;
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}
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for (int i=0;triTable[iCubeIndex][i]!=-1;i+=3)
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{
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//The three vertices forming a triangle
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const Vector3DFloat vertex0 = vertlist[triTable[iCubeIndex][i ]] - offset;
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const Vector3DFloat vertex1 = vertlist[triTable[iCubeIndex][i+1]] - offset;
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const Vector3DFloat vertex2 = vertlist[triTable[iCubeIndex][i+2]] - offset;
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const Vector3DFloat normal0 = normlist[triTable[iCubeIndex][i ]];
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const Vector3DFloat normal1 = normlist[triTable[iCubeIndex][i+1]];
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const Vector3DFloat normal2 = normlist[triTable[iCubeIndex][i+2]];
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//Cast to floats and divide by two.
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//const Vector3DFloat vertex0AsFloat = (static_cast<Vector3DFloat>(vertex0) / 2.0f) - offset;
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//const Vector3DFloat vertex1AsFloat = (static_cast<Vector3DFloat>(vertex1) / 2.0f) - offset;
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//const Vector3DFloat vertex2AsFloat = (static_cast<Vector3DFloat>(vertex2) / 2.0f) - offset;
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const uint8 material0 = vertMaterials[triTable[iCubeIndex][i ]];
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const uint8 material1 = vertMaterials[triTable[iCubeIndex][i+1]];
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const uint8 material2 = vertMaterials[triTable[iCubeIndex][i+2]];
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//If all the materials are the same, we just need one triangle for that material with all the alphas set high.
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SurfaceVertex v0(vertex0, normal0, material0 + 0.1f);
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SurfaceVertex v1(vertex1, normal1, material1 + 0.1f);
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SurfaceVertex v2(vertex2, normal2, material2 + 0.1f);
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//singleMaterialPatch->addTriangle(surfaceVertex0Alpha1, surfaceVertex1Alpha1, surfaceVertex2Alpha1);
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int32 index = getIndexFor(v0.getPosition(), vertexIndicesX, vertexIndicesY, vertexIndicesZ);
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if(index == -1)
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{
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singleMaterialPatch->m_vecVertices.push_back(v0);
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singleMaterialPatch->m_vecTriangleIndices.push_back(singleMaterialPatch->m_vecVertices.size()-1);
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setIndexFor(v0.getPosition(), singleMaterialPatch->m_vecVertices.size()-1, vertexIndicesX, vertexIndicesY, vertexIndicesZ);
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}
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else
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{
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singleMaterialPatch->m_vecTriangleIndices.push_back(index);
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}
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index = getIndexFor(v1.getPosition(), vertexIndicesX, vertexIndicesY, vertexIndicesZ);
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if(index == -1)
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{
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singleMaterialPatch->m_vecVertices.push_back(v1);
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singleMaterialPatch->m_vecTriangleIndices.push_back(singleMaterialPatch->m_vecVertices.size()-1);
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setIndexFor(v1.getPosition(), singleMaterialPatch->m_vecVertices.size()-1, vertexIndicesX, vertexIndicesY, vertexIndicesZ);
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}
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else
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{
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singleMaterialPatch->m_vecTriangleIndices.push_back(index);
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}
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index = getIndexFor(v2.getPosition(), vertexIndicesX, vertexIndicesY, vertexIndicesZ);
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if(index == -1)
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{
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singleMaterialPatch->m_vecVertices.push_back(v2);
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singleMaterialPatch->m_vecTriangleIndices.push_back(singleMaterialPatch->m_vecVertices.size()-1);
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setIndexFor(v2.getPosition(), singleMaterialPatch->m_vecVertices.size()-1, vertexIndicesX, vertexIndicesY, vertexIndicesZ);
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}
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else
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{
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singleMaterialPatch->m_vecTriangleIndices.push_back(index);
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}
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}//For each triangle
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}//For each cell
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}
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int32 getIndexFor(const Vector3DFloat& pos, int32 vertexIndicesX[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1], int32 vertexIndicesY[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1], int32 vertexIndicesZ[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1])
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{
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assert(pos.getX() >= 0.0f);
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assert(pos.getY() >= 0.0f);
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assert(pos.getZ() >= 0.0f);
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assert(pos.getX() <= POLYVOX_REGION_SIDE_LENGTH);
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assert(pos.getY() <= POLYVOX_REGION_SIDE_LENGTH);
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assert(pos.getZ() <= POLYVOX_REGION_SIDE_LENGTH);
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float xIntPart;
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float xFracPart = std::modf(pos.getX(), &xIntPart);
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float yIntPart;
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float yFracPart = std::modf(pos.getY(), &yIntPart);
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float zIntPart;
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float zFracPart = std::modf(pos.getZ(), &zIntPart);
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//Of all the fractional parts, two should be zero and one should have a value.
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if(xFracPart > 0.000001f)
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{
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return vertexIndicesX[static_cast<uint16>(xIntPart)][static_cast<uint16>(yIntPart)][static_cast<uint16>(zIntPart)];
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}
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if(yFracPart > 0.000001f)
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{
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return vertexIndicesY[static_cast<uint16>(xIntPart)][static_cast<uint16>(yIntPart)][static_cast<uint16>(zIntPart)];
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}
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if(zFracPart > 0.000001f)
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{
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return vertexIndicesZ[static_cast<uint16>(xIntPart)][static_cast<uint16>(yIntPart)][static_cast<uint16>(zIntPart)];
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}
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while(true);
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}
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void setIndexFor(const Vector3DFloat& pos, int32 newIndex, int32 vertexIndicesX[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1], int32 vertexIndicesY[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1], int32 vertexIndicesZ[POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1][POLYVOX_REGION_SIDE_LENGTH+1])
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{
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assert(pos.getX() >= 0.0f);
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assert(pos.getY() >= 0.0f);
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assert(pos.getZ() >= 0.0f);
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assert(pos.getX() <= POLYVOX_REGION_SIDE_LENGTH);
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assert(pos.getY() <= POLYVOX_REGION_SIDE_LENGTH);
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assert(pos.getZ() <= POLYVOX_REGION_SIDE_LENGTH);
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assert(newIndex < 10000);
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float xIntPart;
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float xFracPart = std::modf(pos.getX(), &xIntPart);
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float yIntPart;
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float yFracPart = std::modf(pos.getY(), &yIntPart);
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float zIntPart;
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float zFracPart = std::modf(pos.getZ(), &zIntPart);
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//Of all the fractional parts, two should be zero and one should have a value.
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if(xFracPart > 0.000001f)
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{
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vertexIndicesX[static_cast<uint16>(xIntPart)][static_cast<uint16>(yIntPart)][static_cast<uint16>(zIntPart)] = newIndex;
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}
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if(yFracPart > 0.000001f)
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{
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vertexIndicesY[static_cast<uint16>(xIntPart)][static_cast<uint16>(yIntPart)][static_cast<uint16>(zIntPart)] = newIndex;
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}
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if(zFracPart > 0.000001f)
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{
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vertexIndicesZ[static_cast<uint16>(xIntPart)][static_cast<uint16>(yIntPart)][static_cast<uint16>(zIntPart)] = newIndex;
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}
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}
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} |