polyvox/library/PolyVoxCore/include/SurfaceExtractor.h

210 lines
9.9 KiB
C++

/*******************************************************************************
Copyright (c) 2005-2009 David Williams
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source
distribution.
*******************************************************************************/
#ifndef __PolyVox_SurfaceExtractor_H__
#define __PolyVox_SurfaceExtractor_H__
#include "PolyVoxForwardDeclarations.h"
#include "LargeVolume.h"
#include "PolyVoxImpl/TypeDef.h"
namespace PolyVox
{
template< template<typename> class VolumeType, typename VoxelType>
class SurfaceExtractor
{
public:
SurfaceExtractor(VolumeType<VoxelType>* volData, Region region, SurfaceMesh<PositionMaterialNormal>* result);
void execute();
private:
//Compute the cell bitmask for a particular slice in z.
template<bool isPrevZAvail>
uint32_t computeBitmaskForSlice(const Array2DUint8& pPreviousBitmask, Array2DUint8& pCurrentBitmask);
//Compute the cell bitmask for a given cell.
template<bool isPrevXAvail, bool isPrevYAvail, bool isPrevZAvail>
void computeBitmaskForCell(const Array2DUint8& pPreviousBitmask, Array2DUint8& pCurrentBitmask);
//Use the cell bitmasks to generate all the vertices needed for that slice
void generateVerticesForSlice(const Array2DUint8& pCurrentBitmask,
Array2DInt32& m_pCurrentVertexIndicesX,
Array2DInt32& m_pCurrentVertexIndicesY,
Array2DInt32& m_pCurrentVertexIndicesZ);
////////////////////////////////////////////////////////////////////////////////
// NOTE: These two functions are in the .h file rather than the .inl due to an apparent bug in VC2010.
//See http://stackoverflow.com/questions/1484885/strange-vc-compile-error-c2244 for details.
////////////////////////////////////////////////////////////////////////////////
template< template<typename> class VolumeType, typename VoxelType>
Vector3DFloat computeCentralDifferenceGradient(const typename VolumeType<VoxelType>::Sampler& volIter)
{
uint8_t voxel1nx = volIter.peekVoxel1nx0py0pz().getDensity();
uint8_t voxel1px = volIter.peekVoxel1px0py0pz().getDensity();
uint8_t voxel1ny = volIter.peekVoxel0px1ny0pz().getDensity();
uint8_t voxel1py = volIter.peekVoxel0px1py0pz().getDensity();
uint8_t voxel1nz = volIter.peekVoxel0px0py1nz().getDensity();
uint8_t voxel1pz = volIter.peekVoxel0px0py1pz().getDensity();
return Vector3DFloat
(
static_cast<float>(voxel1nx) - static_cast<float>(voxel1px),
static_cast<float>(voxel1ny) - static_cast<float>(voxel1py),
static_cast<float>(voxel1nz) - static_cast<float>(voxel1pz)
);
}
template< template<typename> class VolumeType, typename VoxelType>
Vector3DFloat computeSobelGradient(const typename VolumeType<VoxelType>::Sampler& volIter)
{
static const int weights[3][3][3] = { { {2,3,2}, {3,6,3}, {2,3,2} }, {
{3,6,3}, {6,0,6}, {3,6,3} }, { {2,3,2}, {3,6,3}, {2,3,2} } };
const uint8_t pVoxel1nx1ny1nz = volIter.peekVoxel1nx1ny1nz().getDensity();
const uint8_t pVoxel1nx1ny0pz = volIter.peekVoxel1nx1ny0pz().getDensity();
const uint8_t pVoxel1nx1ny1pz = volIter.peekVoxel1nx1ny1pz().getDensity();
const uint8_t pVoxel1nx0py1nz = volIter.peekVoxel1nx0py1nz().getDensity();
const uint8_t pVoxel1nx0py0pz = volIter.peekVoxel1nx0py0pz().getDensity();
const uint8_t pVoxel1nx0py1pz = volIter.peekVoxel1nx0py1pz().getDensity();
const uint8_t pVoxel1nx1py1nz = volIter.peekVoxel1nx1py1nz().getDensity();
const uint8_t pVoxel1nx1py0pz = volIter.peekVoxel1nx1py0pz().getDensity();
const uint8_t pVoxel1nx1py1pz = volIter.peekVoxel1nx1py1pz().getDensity();
const uint8_t pVoxel0px1ny1nz = volIter.peekVoxel0px1ny1nz().getDensity();
const uint8_t pVoxel0px1ny0pz = volIter.peekVoxel0px1ny0pz().getDensity();
const uint8_t pVoxel0px1ny1pz = volIter.peekVoxel0px1ny1pz().getDensity();
const uint8_t pVoxel0px0py1nz = volIter.peekVoxel0px0py1nz().getDensity();
//const uint8_t pVoxel0px0py0pz = volIter.peekVoxel0px0py0pz().getDensity();
const uint8_t pVoxel0px0py1pz = volIter.peekVoxel0px0py1pz().getDensity();
const uint8_t pVoxel0px1py1nz = volIter.peekVoxel0px1py1nz().getDensity();
const uint8_t pVoxel0px1py0pz = volIter.peekVoxel0px1py0pz().getDensity();
const uint8_t pVoxel0px1py1pz = volIter.peekVoxel0px1py1pz().getDensity();
const uint8_t pVoxel1px1ny1nz = volIter.peekVoxel1px1ny1nz().getDensity();
const uint8_t pVoxel1px1ny0pz = volIter.peekVoxel1px1ny0pz().getDensity();
const uint8_t pVoxel1px1ny1pz = volIter.peekVoxel1px1ny1pz().getDensity();
const uint8_t pVoxel1px0py1nz = volIter.peekVoxel1px0py1nz().getDensity();
const uint8_t pVoxel1px0py0pz = volIter.peekVoxel1px0py0pz().getDensity();
const uint8_t pVoxel1px0py1pz = volIter.peekVoxel1px0py1pz().getDensity();
const uint8_t pVoxel1px1py1nz = volIter.peekVoxel1px1py1nz().getDensity();
const uint8_t pVoxel1px1py0pz = volIter.peekVoxel1px1py0pz().getDensity();
const uint8_t pVoxel1px1py1pz = volIter.peekVoxel1px1py1pz().getDensity();
const int xGrad(- weights[0][0][0] * pVoxel1nx1ny1nz -
weights[1][0][0] * pVoxel1nx1ny0pz - weights[2][0][0] *
pVoxel1nx1ny1pz - weights[0][1][0] * pVoxel1nx0py1nz -
weights[1][1][0] * pVoxel1nx0py0pz - weights[2][1][0] *
pVoxel1nx0py1pz - weights[0][2][0] * pVoxel1nx1py1nz -
weights[1][2][0] * pVoxel1nx1py0pz - weights[2][2][0] *
pVoxel1nx1py1pz + weights[0][0][2] * pVoxel1px1ny1nz +
weights[1][0][2] * pVoxel1px1ny0pz + weights[2][0][2] *
pVoxel1px1ny1pz + weights[0][1][2] * pVoxel1px0py1nz +
weights[1][1][2] * pVoxel1px0py0pz + weights[2][1][2] *
pVoxel1px0py1pz + weights[0][2][2] * pVoxel1px1py1nz +
weights[1][2][2] * pVoxel1px1py0pz + weights[2][2][2] *
pVoxel1px1py1pz);
const int yGrad(- weights[0][0][0] * pVoxel1nx1ny1nz -
weights[1][0][0] * pVoxel1nx1ny0pz - weights[2][0][0] *
pVoxel1nx1ny1pz + weights[0][2][0] * pVoxel1nx1py1nz +
weights[1][2][0] * pVoxel1nx1py0pz + weights[2][2][0] *
pVoxel1nx1py1pz - weights[0][0][1] * pVoxel0px1ny1nz -
weights[1][0][1] * pVoxel0px1ny0pz - weights[2][0][1] *
pVoxel0px1ny1pz + weights[0][2][1] * pVoxel0px1py1nz +
weights[1][2][1] * pVoxel0px1py0pz + weights[2][2][1] *
pVoxel0px1py1pz - weights[0][0][2] * pVoxel1px1ny1nz -
weights[1][0][2] * pVoxel1px1ny0pz - weights[2][0][2] *
pVoxel1px1ny1pz + weights[0][2][2] * pVoxel1px1py1nz +
weights[1][2][2] * pVoxel1px1py0pz + weights[2][2][2] *
pVoxel1px1py1pz);
const int zGrad(- weights[0][0][0] * pVoxel1nx1ny1nz +
weights[2][0][0] * pVoxel1nx1ny1pz - weights[0][1][0] *
pVoxel1nx0py1nz + weights[2][1][0] * pVoxel1nx0py1pz -
weights[0][2][0] * pVoxel1nx1py1nz + weights[2][2][0] *
pVoxel1nx1py1pz - weights[0][0][1] * pVoxel0px1ny1nz +
weights[2][0][1] * pVoxel0px1ny1pz - weights[0][1][1] *
pVoxel0px0py1nz + weights[2][1][1] * pVoxel0px0py1pz -
weights[0][2][1] * pVoxel0px1py1nz + weights[2][2][1] *
pVoxel0px1py1pz - weights[0][0][2] * pVoxel1px1ny1nz +
weights[2][0][2] * pVoxel1px1ny1pz - weights[0][1][2] *
pVoxel1px0py1nz + weights[2][1][2] * pVoxel1px0py1pz -
weights[0][2][2] * pVoxel1px1py1nz + weights[2][2][2] *
pVoxel1px1py1pz);
//Note: The above actually give gradients going from low density to high density.
//For our normals we want the the other way around, so we switch the components as we return them.
return Vector3DFloat(static_cast<float>(-xGrad),static_cast<float>(-yGrad),static_cast<float>(-zGrad));
}
////////////////////////////////////////////////////////////////////////////////
// End of compiler bug workaroumd.
////////////////////////////////////////////////////////////////////////////////
//Use the cell bitmasks to generate all the indices needed for that slice
void generateIndicesForSlice(const Array2DUint8& pPreviousBitmask,
const Array2DInt32& m_pPreviousVertexIndicesX,
const Array2DInt32& m_pPreviousVertexIndicesY,
const Array2DInt32& m_pPreviousVertexIndicesZ,
const Array2DInt32& m_pCurrentVertexIndicesX,
const Array2DInt32& m_pCurrentVertexIndicesY,
const Array2DInt32& m_pCurrentVertexIndicesZ);
//The volume data and a sampler to access it.
VolumeType<VoxelType>* m_volData;
typename VolumeType<VoxelType>::Sampler m_sampVolume;
//Holds a position in volume space.
int32_t iXVolSpace;
int32_t iYVolSpace;
int32_t iZVolSpace;
//Holds a position in region space.
uint32_t uXRegSpace;
uint32_t uYRegSpace;
uint32_t uZRegSpace;
//Used to return the number of cells in a slice which contain triangles.
uint32_t m_uNoOfOccupiedCells;
//The surface patch we are currently filling.
SurfaceMesh<PositionMaterialNormal>* m_meshCurrent;
//Information about the region we are currently processing
Region m_regSizeInVoxels;
Region m_regSizeInCells;
/*Region m_regSizeInVoxelsCropped;
Region m_regSizeInVoxelsUncropped;
Region m_regVolumeCropped;*/
Region m_regSlicePrevious;
Region m_regSliceCurrent;
};
}
#include "SurfaceExtractor.inl"
#endif