Removed block sharing ready for compression.

This commit is contained in:
David Williams 2011-02-05 17:56:59 +00:00
parent 5770d2bf04
commit 754690e251
8 changed files with 41 additions and 170 deletions

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@ -421,7 +421,7 @@ int main(int argc, char *argv[])
openGLWidget.show(); openGLWidget.show();
//Create an empty volume and then place a sphere in it //Create an empty volume and then place a sphere in it
Volume<MaterialDensityPair44> volData(256, 256, 256); Volume<MaterialDensityPair44> volData(128, 128, 128);
//createSphereInVolume(volData, 30); //createSphereInVolume(volData, 30);
createPerlinVolume(volData); createPerlinVolume(volData);

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@ -104,10 +104,6 @@ int main(int argc, char *argv[])
smoothRegion<MaterialDensityPair44>(volData, PolyVox::Region(Vector3DInt16(62, 62, 62), Vector3DInt16(130, 130, 130))); smoothRegion<MaterialDensityPair44>(volData, PolyVox::Region(Vector3DInt16(62, 62, 62), Vector3DInt16(130, 130, 130)));
smoothRegion<MaterialDensityPair44>(volData, PolyVox::Region(Vector3DInt16(62, 62, 62), Vector3DInt16(130, 130, 130))); smoothRegion<MaterialDensityPair44>(volData, PolyVox::Region(Vector3DInt16(62, 62, 62), Vector3DInt16(130, 130, 130)));
cout << "Tidying memory...";
volData.tidyUpMemory(0);
cout << "done." << endl;
QApplication app(argc, argv); QApplication app(argc, argv);
OpenGLWidget openGLWidget(0); OpenGLWidget openGLWidget(0);

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@ -34,7 +34,7 @@ namespace PolyVox
//Make VolumeSampler a friend //Make VolumeSampler a friend
friend class VolumeSampler<VoxelType>; friend class VolumeSampler<VoxelType>;
public: public:
Block(uint16_t uSideLength); Block(uint16_t uSideLength = 0);
Block(const Block& rhs); Block(const Block& rhs);
~Block(); ~Block();
@ -48,7 +48,7 @@ namespace PolyVox
void setVoxelAt(const Vector3DUint16& v3dPos, VoxelType tValue); void setVoxelAt(const Vector3DUint16& v3dPos, VoxelType tValue);
void fill(VoxelType tValue); void fill(VoxelType tValue);
bool isHomogeneous(void); void resize(uint16_t uSideLength);
uint32_t sizeInChars(void); uint32_t sizeInChars(void);
private: private:

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@ -33,24 +33,14 @@ namespace PolyVox
{ {
template <typename VoxelType> template <typename VoxelType>
Block<VoxelType>::Block(uint16_t uSideLength) Block<VoxelType>::Block(uint16_t uSideLength)
:m_tData(0) :m_uSideLength(0)
,m_uSideLengthPower(0)
,m_tData(0)
{ {
//Debug mode validation if(uSideLength != 0)
assert(isPowerOf2(uSideLength));
//Release mode validation
if(!isPowerOf2(uSideLength))
{ {
throw std::invalid_argument("Block side length must be a power of two."); resize(uSideLength);
} }
//Compute the side length
m_uSideLength = uSideLength;
m_uSideLengthPower = logBase2(uSideLength);
//If this fails an exception will be thrown. Memory is not
//allocated and there is nothing else in this class to clean up
m_tData = new VoxelType[m_uSideLength * m_uSideLength * m_uSideLength];
} }
template <typename VoxelType> template <typename VoxelType>
@ -146,19 +136,28 @@ namespace PolyVox
} }
template <typename VoxelType> template <typename VoxelType>
bool Block<VoxelType>::isHomogeneous(void) void Block<VoxelType>::resize(uint16_t uSideLength)
{ {
const VoxelType tFirstVoxel = m_tData[0]; //Debug mode validation
const uint32_t uNoOfVoxels = m_uSideLength * m_uSideLength * m_uSideLength; assert(isPowerOf2(uSideLength));
for(uint32_t ct = 1; ct < uNoOfVoxels; ++ct) //Release mode validation
if(!isPowerOf2(uSideLength))
{ {
if(m_tData[ct] != tFirstVoxel) throw std::invalid_argument("Block side length must be a power of two.");
{
return false;
}
} }
return true;
//Compute the side length
m_uSideLength = uSideLength;
m_uSideLengthPower = logBase2(uSideLength);
//Delete the old data
delete[] m_tData;
m_tData = 0;
//If this fails an exception will be thrown. Memory is not
//allocated and there is nothing else in this class to clean up
m_tData = new VoxelType[m_uSideLength * m_uSideLength * m_uSideLength];
} }
template <typename VoxelType> template <typename VoxelType>

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@ -153,21 +153,10 @@ namespace PolyVox
///Resises the volume to the specified dimensions ///Resises the volume to the specified dimensions
void resize(uint16_t uWidth, uint16_t uHeight, uint16_t uDepth, uint16_t uBlockSideLength = 32); void resize(uint16_t uWidth, uint16_t uHeight, uint16_t uDepth, uint16_t uBlockSideLength = 32);
void tidyUpMemory(uint32_t uNoOfBlocksToProcess = 1000000);
private: private:
polyvox_shared_ptr< Block<VoxelType> > getHomogenousBlock(VoxelType tHomogenousValue); Block<VoxelType> m_pBorderBlock;
std::vector< Block<VoxelType> > m_pBlocks;
polyvox_shared_ptr< Block<VoxelType> > m_pBorderBlock;
std::vector< polyvox_shared_ptr< Block<VoxelType> > > m_pBlocks;
std::vector<bool> m_vecBlockIsPotentiallyHomogenous;
//Note: We were once storing weak_ptr's in this map, so that the blocks would be deleted once they
//were not being referenced by anyone else. However, this made it difficult to know when a block was
//shared. A call to shared_ptr::unique() from within setVoxel was not sufficient as weak_ptr's did
//not contribute to the reference count. Instead we store shared_ptr's here, and check if they
//are used by anyone else (i.e are non-unique) when we tidy the volume.
std::map<VoxelType, polyvox_shared_ptr< Block<VoxelType> > > m_pHomogenousBlock;
uint32_t m_uNoOfBlocksInVolume; uint32_t m_uNoOfBlocksInVolume;
@ -185,8 +174,6 @@ namespace PolyVox
uint16_t m_uLongestSideLength; uint16_t m_uLongestSideLength;
uint16_t m_uShortestSideLength; uint16_t m_uShortestSideLength;
float m_fDiagonalLength; float m_fDiagonalLength;
uint32_t m_uCurrentBlockForTidying;
}; };
//Some handy typedefs //Some handy typedefs

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@ -53,9 +53,7 @@ namespace PolyVox
resize(uWidth, uHeight, uDepth, uBlockSideLength); resize(uWidth, uHeight, uDepth, uBlockSideLength);
//Create the border block //Create the border block
polyvox_shared_ptr< Block<VoxelType> > pTempBlock(new Block<VoxelType>(m_uBlockSideLength)); m_pBorderBlock.fill(VoxelType());
pTempBlock->fill(VoxelType());
m_pBorderBlock = pTempBlock;
} }
//////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////////
@ -74,7 +72,7 @@ namespace PolyVox
template <typename VoxelType> template <typename VoxelType>
VoxelType Volume<VoxelType>::getBorderValue(void) const VoxelType Volume<VoxelType>::getBorderValue(void) const
{ {
return m_pBorderBlock->getVoxelAt(0,0,0); return m_pBorderBlock.getVoxelAt(0,0,0);
} }
//////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////////
@ -174,14 +172,14 @@ namespace PolyVox
const uint16_t yOffset = uYPos - (blockY << m_uBlockSideLengthPower); const uint16_t yOffset = uYPos - (blockY << m_uBlockSideLengthPower);
const uint16_t zOffset = uZPos - (blockZ << m_uBlockSideLengthPower); const uint16_t zOffset = uZPos - (blockZ << m_uBlockSideLengthPower);
const polyvox_shared_ptr< Block< VoxelType > >& block = m_pBlocks const Block<VoxelType>& block = m_pBlocks
[ [
blockX + blockX +
blockY * m_uWidthInBlocks + blockY * m_uWidthInBlocks +
blockZ * m_uWidthInBlocks * m_uHeightInBlocks blockZ * m_uWidthInBlocks * m_uHeightInBlocks
]; ];
return block->getVoxelAt(xOffset,yOffset,zOffset); return block.getVoxelAt(xOffset,yOffset,zOffset);
} }
else else
{ {
@ -205,7 +203,7 @@ namespace PolyVox
template <typename VoxelType> template <typename VoxelType>
void Volume<VoxelType>::setBorderValue(const VoxelType& tBorder) void Volume<VoxelType>::setBorderValue(const VoxelType& tBorder)
{ {
return m_pBorderBlock->fill(tBorder); return m_pBorderBlock.fill(tBorder);
} }
//////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////////
@ -235,28 +233,10 @@ namespace PolyVox
blockY * m_uWidthInBlocks + blockY * m_uWidthInBlocks +
blockZ * m_uWidthInBlocks * m_uHeightInBlocks; blockZ * m_uWidthInBlocks * m_uHeightInBlocks;
polyvox_shared_ptr< Block<VoxelType> >& block = m_pBlocks[uBlockIndex]; Block<VoxelType>& block = m_pBlocks[uBlockIndex];
block.setVoxelAt(xOffset,yOffset,zOffset, tValue);
//It's quite possible that the user might attempt to set a voxel to it's current value.
//We test for this case firstly because it could help performance, but more importantly
//because it lets us avoid unsharing blocks unnecessarily.
if(block->getVoxelAt(xOffset, yOffset, zOffset) != tValue)
{
if(block.unique())
{
block->setVoxelAt(xOffset,yOffset,zOffset, tValue);
//There is a chance that setting this voxel makes the block homogenous and therefore shareable.
//But checking this will take some time, so for now just set a flag.
m_vecBlockIsPotentiallyHomogenous[uBlockIndex] = true;
}
else
{
polyvox_shared_ptr< Block<VoxelType> > pNewBlock(new Block<VoxelType>(*(block)));
block = pNewBlock;
m_vecBlockIsPotentiallyHomogenous[uBlockIndex] = false;
block->setVoxelAt(xOffset,yOffset,zOffset, tValue);
}
}
//Return true to indicate that we modified a voxel. //Return true to indicate that we modified a voxel.
return true; return true;
} }
@ -324,8 +304,6 @@ namespace PolyVox
//Clear the previous data //Clear the previous data
m_pBlocks.clear(); m_pBlocks.clear();
m_vecBlockIsPotentiallyHomogenous.clear();
m_pHomogenousBlock.clear();
//Compute the volume side lengths //Compute the volume side lengths
m_uWidth = uWidth; m_uWidth = uWidth;
@ -346,101 +324,14 @@ namespace PolyVox
//Create the blocks //Create the blocks
m_pBlocks.resize(m_uNoOfBlocksInVolume); m_pBlocks.resize(m_uNoOfBlocksInVolume);
m_vecBlockIsPotentiallyHomogenous.resize(m_uNoOfBlocksInVolume);
for(uint32_t i = 0; i < m_uNoOfBlocksInVolume; ++i) for(uint32_t i = 0; i < m_uNoOfBlocksInVolume; ++i)
{ {
m_pBlocks[i] = getHomogenousBlock(VoxelType()); m_pBlocks[i].resize(m_uBlockSideLength);
m_vecBlockIsPotentiallyHomogenous[i] = false; }
}
//Other properties we might find useful later //Other properties we might find useful later
m_uLongestSideLength = (std::max)((std::max)(m_uWidth,m_uHeight),m_uDepth); m_uLongestSideLength = (std::max)((std::max)(m_uWidth,m_uHeight),m_uDepth);
m_uShortestSideLength = (std::min)((std::min)(m_uWidth,m_uHeight),m_uDepth); m_uShortestSideLength = (std::min)((std::min)(m_uWidth,m_uHeight),m_uDepth);
m_fDiagonalLength = sqrtf(static_cast<float>(m_uWidth * m_uWidth + m_uHeight * m_uHeight + m_uDepth * m_uDepth)); m_fDiagonalLength = sqrtf(static_cast<float>(m_uWidth * m_uWidth + m_uHeight * m_uHeight + m_uDepth * m_uDepth));
//Reset the counter for tidying
m_uCurrentBlockForTidying = 0;
}
////////////////////////////////////////////////////////////////////////////////
/// Clean up the memory usage of the volume. Checks for any blocks which are
/// homogeneous and flags them as such for faster processing and reduced memory
/// usage.
/// \param uNoOfBlocksToProcess the number of blocks to process
////////////////////////////////////////////////////////////////////////////////
template <typename VoxelType>
void Volume<VoxelType>::tidyUpMemory(uint32_t uNoOfBlocksToProcess)
{
//Track the number of blocks we have processed.
uint32_t m_uNoOfProcessedBlocks = 0;
//We will loop around, and finish if we get back to our start position
uint32_t uFinishBlock = m_uCurrentBlockForTidying;
//Increment the current block, looping around if necessary
++m_uCurrentBlockForTidying;
m_uCurrentBlockForTidying %= m_uNoOfBlocksInVolume;
//While we have not reached the user specified limit and there are more blocks to process...
while((m_uNoOfProcessedBlocks < uNoOfBlocksToProcess) && (m_uCurrentBlockForTidying != uFinishBlock))
{
//We only do any work if the block is flagged as potentially homogeneous.
if(m_vecBlockIsPotentiallyHomogenous[m_uCurrentBlockForTidying])
{
//Check if it's really homogeneous (this can be slow).
if(m_pBlocks[m_uCurrentBlockForTidying]->isHomogeneous())
{
//If so, replace is with a block from out homogeneous collection.
VoxelType homogeneousValue = m_pBlocks[m_uCurrentBlockForTidying]->getVoxelAt(0,0,0);
m_pBlocks[m_uCurrentBlockForTidying] = getHomogenousBlock(homogeneousValue);
}
//Either way, we have now determined whether the block was sharable. So it's not *potentially* sharable.
m_vecBlockIsPotentiallyHomogenous[m_uCurrentBlockForTidying] = false;
//We've processed a block. This is inside the 'if' because the path outside the 'if' is trivially fast.
++m_uNoOfProcessedBlocks;
}
//Increment the current block, looping around if necessary
++m_uCurrentBlockForTidying;
m_uCurrentBlockForTidying %= m_uNoOfBlocksInVolume;
}
//Identify and remove any homogeneous blocks which are not actually in use.
typename std::map<VoxelType, polyvox_shared_ptr< Block<VoxelType> > >::iterator iter = m_pHomogenousBlock.begin();
while(iter != m_pHomogenousBlock.end())
{
if(iter->second.unique())
{
m_pHomogenousBlock.erase(iter++); //Increments the iterator and returns the previous position to be erased.
}
else
{
++iter; //Just increments the iterator.
}
}
}
template <typename VoxelType>
polyvox_shared_ptr< Block<VoxelType> > Volume<VoxelType>::getHomogenousBlock(VoxelType tHomogenousValue)
{
typename std::map<VoxelType, polyvox_shared_ptr< Block<VoxelType> > >::iterator iterResult = m_pHomogenousBlock.find(tHomogenousValue);
if(iterResult == m_pHomogenousBlock.end())
{
//Block<VoxelType> block;
polyvox_shared_ptr< Block<VoxelType> > pHomogeneousBlock(new Block<VoxelType>(m_uBlockSideLength));
//block.m_pBlock = temp;
//block.m_uReferenceCount++;
pHomogeneousBlock->fill(tHomogenousValue);
m_pHomogenousBlock.insert(std::make_pair(tHomogenousValue, pHomogeneousBlock));
return pHomogeneousBlock;
}
else
{
//iterResult->second.m_uReferenceCount++;
//polyvox_shared_ptr< Block<VoxelType> > result(iterResult->second);
return iterResult->second;
}
} }
} }

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@ -153,13 +153,13 @@ namespace PolyVox
const uint32_t uBlockIndexInVolume = uXBlock + const uint32_t uBlockIndexInVolume = uXBlock +
uYBlock * mVolume->m_uWidthInBlocks + uYBlock * mVolume->m_uWidthInBlocks +
uZBlock * mVolume->m_uWidthInBlocks * mVolume->m_uHeightInBlocks; uZBlock * mVolume->m_uWidthInBlocks * mVolume->m_uHeightInBlocks;
const polyvox_shared_ptr< Block<VoxelType> >& currentBlock = mVolume->m_pBlocks[uBlockIndexInVolume]; const Block<VoxelType>& currentBlock = mVolume->m_pBlocks[uBlockIndexInVolume];
mCurrentVoxel = currentBlock->m_tData + uVoxelIndexInBlock; mCurrentVoxel = currentBlock.m_tData + uVoxelIndexInBlock;
} }
else else
{ {
mCurrentVoxel = mVolume->m_pBorderBlock->m_tData + uVoxelIndexInBlock; mCurrentVoxel = mVolume->m_pBorderBlock.m_tData + uVoxelIndexInBlock;
} }
} }

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@ -46,8 +46,6 @@ void TestVolume::testSize()
} }
} }
volData.tidyUpMemory(0);
QCOMPARE(volData.getWidth(), g_uVolumeSideLength); QCOMPARE(volData.getWidth(), g_uVolumeSideLength);
QCOMPARE(volData.getHeight(), g_uVolumeSideLength); QCOMPARE(volData.getHeight(), g_uVolumeSideLength);
QCOMPARE(volData.getDepth(), g_uVolumeSideLength); QCOMPARE(volData.getDepth(), g_uVolumeSideLength);