Adding defines so that Boost can be used instead of C++0x when pathfinding.

library/PolyVoxCore/include/AStarPathfinder.h

@@ -32,8 +32,6 @@ freely, subject to the following restrictions:
 
 #include "PolyVoxImpl/TypeDef.h"
 
-#include <functional>
-
 namespace PolyVox
 {
 	const float sqrt_1 = 1.0f;
@@ -60,8 +58,8 @@ namespace PolyVox
 			float fHBias = 1.0,
 			uint32_t uMaxNoOfNodes = 10000,
 			Connectivity connectivity = TwentySixConnected,
-			std::function<bool (const Volume<VoxelType>*, const Vector3DInt16&)> funcIsVoxelValidForPath = &aStarDefaultVoxelValidator<VoxelType>,
+			polyvox_function<bool (const Volume<VoxelType>*, const Vector3DInt16&)> funcIsVoxelValidForPath = &aStarDefaultVoxelValidator<VoxelType>,
-			std::function<void (float)> funcProgressCallback = 0
+			polyvox_function<void (float)> funcProgressCallback = 0
 		)
 			:volume(volData)
 			,start(v3dStart)
@@ -94,10 +92,10 @@ namespace PolyVox
 		uint32_t maxNumberOfNodes;
 
 		//Used to determine whether a given voxel is valid.
-		std::function<bool (const Volume<VoxelType>*, const Vector3DInt16&)> isVoxelValidForPath;
+		polyvox_function<bool (const Volume<VoxelType>*, const Vector3DInt16&)> isVoxelValidForPath;
 
 		//Progress callback
-		std::function<void (float)> progressCallback;
+		polyvox_function<void (float)> progressCallback;
 	};
 
 	template <typename VoxelType>

library/PolyVoxCore/include/AStarPathfinder.inl

@@ -264,7 +264,10 @@ namespace PolyVox
 		array[0] = abs(a.getX() - b.getX());
 		array[1] = abs(a.getY() - b.getY());
 		array[2] = abs(a.getZ() - b.getZ());
-
+		
+		//Maybe this is better implemented directly
+		//using three compares and two swaps... but not
+		//until the profiler says so.
 		std::sort(&array[0], &array[3]);
 
 		uint16_t cornerSteps = array[0];
@@ -303,20 +306,22 @@ namespace PolyVox
 		//Apply the bias to the computed h value;
 		hVal *= m_params.hBias;
 
-		std::hash<uint32_t> uint32Hash;
+		//Having computed hVal, we now apply some random bias to break ties.
-
+		//This needs to be deterministic on the input position. This random
+		//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;
-
+		//Stop hashVal going over 65535, and divide by 1000000 to make sure it is small.
 		hashVal &= 0x0000FFFF;
-
 		float fHash = hashVal / 1000000.0f;
 
+		//Apply the hash and return
 		hVal += fHash;
-
 		return hVal;
 	}
 }

library/PolyVoxCore/include/PolyVoxImpl/TypeDef.h

@@ -45,6 +45,13 @@ freely, subject to the following restrictions:
 	#include <boost/smart_ptr.hpp>
 	#define polyvox_shared_ptr boost::shared_ptr
 
+	#include <boost/functional.hpp>
+	#define polyvox_function boost::function
+
+	#include <boost/functional/hash.hpp>
+	#define polyvox_hash boost::hash
+
+
 	//As long as we're requiring boost, we'll use it to compensate
 	//for the missing cstdint header too.
 	#include <boost/cstdint.hpp>
@@ -57,8 +64,11 @@ freely, subject to the following restrictions:
 #else
 	//We have a decent compiler - use real C++0x features
 	#include <cstdint>
+	#include <functional>
 	#include <memory>
 	#define polyvox_shared_ptr std::shared_ptr
+	#define polyvox_function std::function
+	#define polyvox_hash std::hash
 #endif
 
 #endif