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Initial support for run-length encoding of volumes when they are serialised to disk.

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This commit is contained in:
David Williams 2009-02-22 12:25:51 +00:00
parent bc008f3606
commit 3c4411952a
2 changed files with 111 additions and 0 deletions
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3
library/include/PolyVoxUtil/Serialization.h
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@ -33,6 +33,9 @@ namespace PolyVox
{
POLYVOX_API BlockVolume<uint8>* loadVolumeRaw(std::istream& stream);
POLYVOX_API void saveVolumeRaw(std::ostream& stream, BlockVolume<uint8>& volume);
POLYVOX_API BlockVolume<uint8>* loadVolumeRle(std::istream& stream);
POLYVOX_API void saveVolumeRle(std::ostream& stream, BlockVolume<uint8>& volume);
}
#endif

108
library/source/PolyVoxUtil/Serialization.cpp
View File

@ -77,4 +77,112 @@ namespace PolyVox
}
}
}
//Note: we don't do much error handling in here - exceptions will simply be propergated up to the caller.
//FIXME - think about pointer ownership issues. Or could return volume by value if the copy constructor is shallow
BlockVolume<uint8>* loadVolumeRle(istream& stream)
{
//Read volume dimensions
uint8 volumeWidthPower = 0;
uint8 volumeHeightPower = 0;
uint8 volumeDepthPower = 0;
stream.read(reinterpret_cast<char*>(&volumeWidthPower), sizeof(volumeWidthPower));
stream.read(reinterpret_cast<char*>(&volumeHeightPower), sizeof(volumeHeightPower));
stream.read(reinterpret_cast<char*>(&volumeDepthPower), sizeof(volumeDepthPower));
//FIXME - need to support non cubic volumes
BlockVolume<uint8>* volume = new BlockVolume<uint8>(volumeWidthPower);
uint16 volumeWidth = 0x0001 << volumeWidthPower;
uint16 volumeHeight = 0x0001 << volumeHeightPower;
uint16 volumeDepth = 0x0001 << volumeDepthPower;
//Read data
BlockVolumeIterator<uint8> volIter(*volume);
bool firstTime = true;
uint32 runLength = 0;
uint8 value = 0;
stream.read(reinterpret_cast<char*>(&value), sizeof(value));
stream.read(reinterpret_cast<char*>(&runLength), sizeof(runLength));
for(uint16 z = 0; z < volumeDepth; ++z)
{
for(uint16 y = 0; y < volumeHeight; ++y)
{
for(uint16 x = 0; x < volumeWidth; ++x)
{
volIter.setPosition(x,y,z);
if(runLength != 0)
{
volIter.setVoxel(value);
runLength--;
}
else
{
stream.read(reinterpret_cast<char*>(&value), sizeof(value));
stream.read(reinterpret_cast<char*>(&runLength), sizeof(runLength));
volIter.setVoxel(value);
runLength--;
}
}
}
}
return volume;
}
void saveVolumeRle(std::ostream& stream, BlockVolume<uint8>& volume)
{
//Write volume dimensions
uint16 volumeWidth = volume.getSideLength();
uint16 volumeHeight = volume.getSideLength();
uint16 volumeDepth = volume.getSideLength();
uint8 volumeWidthPower = logBase2(volumeWidth);
uint8 volumeHeightPower = logBase2(volumeHeight);
uint8 volumeDepthPower = logBase2(volumeDepth);
stream.write(reinterpret_cast<char*>(&volumeWidthPower), sizeof(volumeWidthPower));
stream.write(reinterpret_cast<char*>(&volumeHeightPower), sizeof(volumeHeightPower));
stream.write(reinterpret_cast<char*>(&volumeDepthPower), sizeof(volumeDepthPower));
//Write data
BlockVolumeIterator<uint8> volIter(volume);
uint8 current = 0;
uint32 runLength = 0;
bool firstTime = true;
for(uint16 z = 0; z < volumeDepth; ++z)
{
for(uint16 y = 0; y < volumeHeight; ++y)
{
for(uint16 x = 0; x < volumeWidth; ++x)
{
volIter.setPosition(x,y,z);
uint8 value = volIter.getVoxel();
if(firstTime)
{
current = value;
runLength = 1;
firstTime = false;
}
else
{
if(value == current)
{
runLength++;
}
else
{
stream.write(reinterpret_cast<char*>(&current), sizeof(current));
stream.write(reinterpret_cast<char*>(&runLength), sizeof(runLength));
current = value;
runLength = 1;
}
}
}
}
}
stream.write(reinterpret_cast<char*>(&current), sizeof(current));
stream.write(reinterpret_cast<char*>(&runLength), sizeof(runLength));
}
}