AnotherFoxGuy/polyvox
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Hopefully fixed difference in A* between windows.Linux.

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unknown
2012-11-02 11:36:28 +01:00
parent 38f34faaac
commit 1e81403e62
3 changed files with 48 additions and 27 deletions
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3
library/PolyVoxCore/include/PolyVoxCore/AStarPathfinder.h
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@ -174,7 +174,8 @@ namespace PolyVox
float SixConnectedCost(const Vector3DInt32& a, const Vector3DInt32& b);
float EighteenConnectedCost(const Vector3DInt32& a, const Vector3DInt32& b);
float TwentySixConnectedCost(const Vector3DInt32& a, const Vector3DInt32& b);
float computeH(const Vector3DInt32& a, const Vector3DInt32& b);
float computeH(const Vector3DInt32& a, const Vector3DInt32& b);
uint32_t hash(uint32_t a);
//Node containers
AllNodesContainer allNodes;

30
library/PolyVoxCore/include/PolyVoxCore/AStarPathfinder.inl
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@ -313,11 +313,17 @@ namespace PolyVox
//bias means it is much les likely that two paths are exactly the same
//length, and so far fewer nodes must be expanded to find the shortest path.
//See http://theory.stanford.edu/~amitp/GameProgramming/Heuristics.html#S12
polyvox_hash<uint32_t> uint32Hash;
uint32_t hashValX = uint32Hash(a.getX());
uint32_t hashValY = uint32Hash(a.getY());
uint32_t hashValZ = uint32Hash(a.getZ());
uint32_t hashVal = hashValX ^ hashValY ^ hashValZ;
//Note that if the hash is zero we can have differences between the Linux vs. Windows
//(or perhaps GCC vs. VS) versions of the code. This is probably because of the way
//sorting inside the std::set works (i.e. one system swaps values which are identical
//while the other one doesn't - both approaches are valid). For the same reason we want
//to make sure that position (x,y,z) has a differnt hash from e.g. position (x,z,y).
uint32_t aX = (a.getX() << 16) & 0x00FF0000;
uint32_t aY = (a.getY() << 8) & 0x0000FF00;
uint32_t aZ = (a.getZ() ) & 0x000000FF;
uint32_t hashVal = hash(aX | aY | aZ);
//Stop hashVal going over 65535, and divide by 1000000 to make sure it is small.
hashVal &= 0x0000FFFF;
float fHash = hashVal / 1000000.0f;
@ -326,4 +332,18 @@ namespace PolyVox
hVal += fHash;
return hVal;
}
// Robert Jenkins' 32 bit integer hash function
// http://www.concentric.net/~ttwang/tech/inthash.htm
template<typename VolumeType>
uint32_t AStarPathfinder<VolumeType>::hash( uint32_t a)
{
a = (a+0x7ed55d16) + (a<<12);
a = (a^0xc761c23c) ^ (a>>19);
a = (a+0x165667b1) + (a<<5);
a = (a+0xd3a2646c) ^ (a<<9);
a = (a+0xfd7046c5) + (a<<3);
a = (a^0xb55a4f09) ^ (a>>16);
return a;
}
}