Cutting down and simplifying Marching Cubes code (also now slower...).

This commit is contained in:
David Williams 2015-05-10 19:43:09 +02:00
parent 3937dc3c61
commit 5ce0d9c3e0
2 changed files with 33 additions and 234 deletions

View File

@ -325,7 +325,7 @@ namespace PolyVox
//
// 1. It leaves the user in control of memory allocation and would allow them to implement e.g. a mesh pooling system.
// 2. The user-provided mesh could have a different index type (e.g. 16-bit indices) to reduce memory usage.
// 3. The user could provide a custom mesh class, e.g a thin wrapper around an openGL VBO to allow direct writing into this structure.
// 3. The user could provide a custom mesh class, e.g a thin wrapper around an OpenGL VBO to allow direct writing into this structure.
//
// We don't provide a default MeshType here. If the user doesn't want to provide a MeshType then it probably makes
// more sense to use the other variant of this function where the mesh is a return value rather than a parameter.

View File

@ -145,232 +145,30 @@ namespace PolyVox
uint32_t uXRegSpace = iXVolSpace - m_regSizeInVoxels.getLowerX();
uint32_t uYRegSpace = iYVolSpace - m_regSizeInVoxels.getLowerY();
m_sampVolume.setPosition(iXVolSpace,iYVolSpace,iZVolSpace);
computeBitmaskForCell<false, false, isPrevZAvail>(pPreviousBitmask, pCurrentBitmask, uXRegSpace, uYRegSpace);
//Process the edge where x is minimal.
iXVolSpace = m_regSliceCurrent.getLowerX();
m_sampVolume.setPosition(iXVolSpace, m_regSliceCurrent.getLowerY(), iZVolSpace);
for(iYVolSpace = m_regSliceCurrent.getLowerY() + 1; iYVolSpace <= iMaxYVolSpace; iYVolSpace++)
{
uXRegSpace = iXVolSpace - m_regSizeInVoxels.getLowerX();
uYRegSpace = iYVolSpace - m_regSizeInVoxels.getLowerY();
m_sampVolume.movePositiveY();
computeBitmaskForCell<false, true, isPrevZAvail>(pPreviousBitmask, pCurrentBitmask, uXRegSpace, uYRegSpace);
}
//Process the edge where y is minimal.
iYVolSpace = m_regSliceCurrent.getLowerY();
m_sampVolume.setPosition(m_regSliceCurrent.getLowerX(), iYVolSpace, iZVolSpace);
for(iXVolSpace = m_regSliceCurrent.getLowerX() + 1; iXVolSpace <= iMaxXVolSpace; iXVolSpace++)
{
uXRegSpace = iXVolSpace - m_regSizeInVoxels.getLowerX();
uYRegSpace = iYVolSpace - m_regSizeInVoxels.getLowerY();
m_sampVolume.movePositiveX();
computeBitmaskForCell<true, false, isPrevZAvail>(pPreviousBitmask, pCurrentBitmask, uXRegSpace, uYRegSpace);
}
//Process all remaining elemnents of the slice. In this case, previous x and y values are always available
for(iYVolSpace = m_regSliceCurrent.getLowerY() + 1; iYVolSpace <= iMaxYVolSpace; iYVolSpace++)
for(iYVolSpace = m_regSliceCurrent.getLowerY(); iYVolSpace <= iMaxYVolSpace; iYVolSpace++)
{
m_sampVolume.setPosition(m_regSliceCurrent.getLowerX(), iYVolSpace, iZVolSpace);
for(iXVolSpace = m_regSliceCurrent.getLowerX() + 1; iXVolSpace <= iMaxXVolSpace; iXVolSpace++)
for(iXVolSpace = m_regSliceCurrent.getLowerX(); iXVolSpace <= iMaxXVolSpace; iXVolSpace++)
{
uXRegSpace = iXVolSpace - m_regSizeInVoxels.getLowerX();
uYRegSpace = iYVolSpace - m_regSizeInVoxels.getLowerY();
m_sampVolume.movePositiveX();
computeBitmaskForCell<true, true, isPrevZAvail>(pPreviousBitmask, pCurrentBitmask, uXRegSpace, uYRegSpace);
}
}
m_sampVolume.setPosition(iXVolSpace, iYVolSpace, iZVolSpace);
return m_uNoOfOccupiedCells;
}
template<typename VolumeType, typename MeshType, typename ControllerType>
template<bool isPrevXAvail, bool isPrevYAvail, bool isPrevZAvail>
void MarchingCubesSurfaceExtractor<VolumeType, MeshType, ControllerType>::computeBitmaskForCell(const Array2DUint8& pPreviousBitmask, Array2DUint8& pCurrentBitmask, uint32_t uXRegSpace, uint32_t uYRegSpace)
{
uint8_t iCubeIndex = 0;
typename VolumeType::VoxelType v000;
typename VolumeType::VoxelType v100;
typename VolumeType::VoxelType v010;
typename VolumeType::VoxelType v110;
typename VolumeType::VoxelType v001;
typename VolumeType::VoxelType v101;
typename VolumeType::VoxelType v011;
typename VolumeType::VoxelType v111;
typename VolumeType::VoxelType v000 = m_sampVolume.getVoxel();
typename VolumeType::VoxelType v100 = m_sampVolume.peekVoxel1px0py0pz();
typename VolumeType::VoxelType v010 = m_sampVolume.peekVoxel0px1py0pz();
typename VolumeType::VoxelType v110 = m_sampVolume.peekVoxel1px1py0pz();
if(isPrevZAvail)
{
if(isPrevYAvail)
{
if(isPrevXAvail)
{
v111 = m_sampVolume.peekVoxel1px1py1pz();
//z
uint8_t iPreviousCubeIndexZ = pPreviousBitmask(uXRegSpace, uYRegSpace);
iPreviousCubeIndexZ >>= 4;
//y
uint8_t iPreviousCubeIndexY = pCurrentBitmask(uXRegSpace, uYRegSpace - 1);
iPreviousCubeIndexY &= 192; //192 = 128 + 64
iPreviousCubeIndexY >>= 2;
//x
uint8_t iPreviousCubeIndexX = pCurrentBitmask(uXRegSpace - 1, uYRegSpace);
iPreviousCubeIndexX &= 128;
iPreviousCubeIndexX >>= 1;
iCubeIndex = iPreviousCubeIndexX | iPreviousCubeIndexY | iPreviousCubeIndexZ;
if (m_controller.convertToDensity(v111) < m_tThreshold) iCubeIndex |= 128;
}
else //previous X not available
{
v011 = m_sampVolume.peekVoxel0px1py1pz();
v111 = m_sampVolume.peekVoxel1px1py1pz();
//z
uint8_t iPreviousCubeIndexZ = pPreviousBitmask(uXRegSpace, uYRegSpace);
iPreviousCubeIndexZ >>= 4;
//y
uint8_t iPreviousCubeIndexY = pCurrentBitmask(uXRegSpace, uYRegSpace - 1);
iPreviousCubeIndexY &= 192; //192 = 128 + 64
iPreviousCubeIndexY >>= 2;
iCubeIndex = iPreviousCubeIndexY | iPreviousCubeIndexZ;
if (m_controller.convertToDensity(v011) < m_tThreshold) iCubeIndex |= 64;
if (m_controller.convertToDensity(v111) < m_tThreshold) iCubeIndex |= 128;
}
}
else //previous Y not available
{
if(isPrevXAvail)
{
v101 = m_sampVolume.peekVoxel1px0py1pz();
v111 = m_sampVolume.peekVoxel1px1py1pz();
//z
uint8_t iPreviousCubeIndexZ = pPreviousBitmask(uXRegSpace, uYRegSpace);
iPreviousCubeIndexZ >>= 4;
//x
uint8_t iPreviousCubeIndexX = pCurrentBitmask(uXRegSpace - 1, uYRegSpace);
iPreviousCubeIndexX &= 160; //160 = 128+32
iPreviousCubeIndexX >>= 1;
iCubeIndex = iPreviousCubeIndexX | iPreviousCubeIndexZ;
if (m_controller.convertToDensity(v101) < m_tThreshold) iCubeIndex |= 32;
if (m_controller.convertToDensity(v111) < m_tThreshold) iCubeIndex |= 128;
}
else //previous X not available
{
v001 = m_sampVolume.peekVoxel0px0py1pz();
v101 = m_sampVolume.peekVoxel1px0py1pz();
v011 = m_sampVolume.peekVoxel0px1py1pz();
v111 = m_sampVolume.peekVoxel1px1py1pz();
//z
uint8_t iPreviousCubeIndexZ = pPreviousBitmask(uXRegSpace, uYRegSpace);
iCubeIndex = iPreviousCubeIndexZ >> 4;
if (m_controller.convertToDensity(v001) < m_tThreshold) iCubeIndex |= 16;
if (m_controller.convertToDensity(v101) < m_tThreshold) iCubeIndex |= 32;
if (m_controller.convertToDensity(v011) < m_tThreshold) iCubeIndex |= 64;
if (m_controller.convertToDensity(v111) < m_tThreshold) iCubeIndex |= 128;
}
}
}
else //previous Z not available
{
if(isPrevYAvail)
{
if(isPrevXAvail)
{
v110 = m_sampVolume.peekVoxel1px1py0pz();
v111 = m_sampVolume.peekVoxel1px1py1pz();
//y
uint8_t iPreviousCubeIndexY = pCurrentBitmask(uXRegSpace, uYRegSpace - 1);
iPreviousCubeIndexY &= 204; //204 = 128+64+8+4
iPreviousCubeIndexY >>= 2;
//x
uint8_t iPreviousCubeIndexX = pCurrentBitmask(uXRegSpace - 1, uYRegSpace);
iPreviousCubeIndexX &= 170; //170 = 128+32+8+2
iPreviousCubeIndexX >>= 1;
iCubeIndex = iPreviousCubeIndexX | iPreviousCubeIndexY;
if (m_controller.convertToDensity(v110) < m_tThreshold) iCubeIndex |= 8;
if (m_controller.convertToDensity(v111) < m_tThreshold) iCubeIndex |= 128;
}
else //previous X not available
{
v010 = m_sampVolume.peekVoxel0px1py0pz();
v110 = m_sampVolume.peekVoxel1px1py0pz();
v011 = m_sampVolume.peekVoxel0px1py1pz();
v111 = m_sampVolume.peekVoxel1px1py1pz();
//y
uint8_t iPreviousCubeIndexY = pCurrentBitmask(uXRegSpace, uYRegSpace - 1);
iPreviousCubeIndexY &= 204; //204 = 128+64+8+4
iPreviousCubeIndexY >>= 2;
iCubeIndex = iPreviousCubeIndexY;
if (m_controller.convertToDensity(v010) < m_tThreshold) iCubeIndex |= 4;
if (m_controller.convertToDensity(v110) < m_tThreshold) iCubeIndex |= 8;
if (m_controller.convertToDensity(v011) < m_tThreshold) iCubeIndex |= 64;
if (m_controller.convertToDensity(v111) < m_tThreshold) iCubeIndex |= 128;
}
}
else //previous Y not available
{
if(isPrevXAvail)
{
v100 = m_sampVolume.peekVoxel1px0py0pz();
v110 = m_sampVolume.peekVoxel1px1py0pz();
v101 = m_sampVolume.peekVoxel1px0py1pz();
v111 = m_sampVolume.peekVoxel1px1py1pz();
//x
uint8_t iPreviousCubeIndexX = pCurrentBitmask(uXRegSpace - 1, uYRegSpace);
iPreviousCubeIndexX &= 170; //170 = 128+32+8+2
iPreviousCubeIndexX >>= 1;
iCubeIndex = iPreviousCubeIndexX;
if (m_controller.convertToDensity(v100) < m_tThreshold) iCubeIndex |= 2;
if (m_controller.convertToDensity(v110) < m_tThreshold) iCubeIndex |= 8;
if (m_controller.convertToDensity(v101) < m_tThreshold) iCubeIndex |= 32;
if (m_controller.convertToDensity(v111) < m_tThreshold) iCubeIndex |= 128;
}
else //previous X not available
{
v000 = m_sampVolume.getVoxel();
v100 = m_sampVolume.peekVoxel1px0py0pz();
v010 = m_sampVolume.peekVoxel0px1py0pz();
v110 = m_sampVolume.peekVoxel1px1py0pz();
v001 = m_sampVolume.peekVoxel0px0py1pz();
v101 = m_sampVolume.peekVoxel1px0py1pz();
v011 = m_sampVolume.peekVoxel0px1py1pz();
v111 = m_sampVolume.peekVoxel1px1py1pz();
typename VolumeType::VoxelType v001 = m_sampVolume.peekVoxel0px0py1pz();
typename VolumeType::VoxelType v101 = m_sampVolume.peekVoxel1px0py1pz();
typename VolumeType::VoxelType v011 = m_sampVolume.peekVoxel0px1py1pz();
typename VolumeType::VoxelType v111 = m_sampVolume.peekVoxel1px1py1pz();
if (m_controller.convertToDensity(v000) < m_tThreshold) iCubeIndex |= 1;
if (m_controller.convertToDensity(v100) < m_tThreshold) iCubeIndex |= 2;
@ -380,18 +178,19 @@ namespace PolyVox
if (m_controller.convertToDensity(v101) < m_tThreshold) iCubeIndex |= 32;
if (m_controller.convertToDensity(v011) < m_tThreshold) iCubeIndex |= 64;
if (m_controller.convertToDensity(v111) < m_tThreshold) iCubeIndex |= 128;
}
}
}
//Save the bitmask
pCurrentBitmask(uXRegSpace, uYRegSpace) = iCubeIndex;
if(edgeTable[iCubeIndex] != 0)
if (edgeTable[iCubeIndex] != 0)
{
++m_uNoOfOccupiedCells;
}
}
}
return m_uNoOfOccupiedCells;
}
template<typename VolumeType, typename MeshType, typename ControllerType>
void MarchingCubesSurfaceExtractor<VolumeType, MeshType, ControllerType>::generateVerticesForSlice(const Array2DUint8& pCurrentBitmask,