Initial check in of RaycastWithCallback

library/PolyVoxCore/CMakeLists.txt

@@ -40,6 +40,8 @@ SET(CORE_INC_FILES
 	include/PolyVoxForwardDeclarations.h
 	include/Raycast.h
 	include/Raycast.inl
+	include/RaycastWithCallback.h
+	include/RaycastWithCallback.inl
 	include/Region.h
 	include/SurfaceExtractor.h
 	include/SurfaceExtractor.inl

library/PolyVoxCore/include/RaycastWithCallback.h

@@ -0,0 +1,60 @@
+/*******************************************************************************
+Copyright (c) 2005-2009 David Williams
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+    claim that you wrote the original software. If you use this software
+    in a product, an acknowledgment in the product documentation would be
+    appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must not be
+    misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source
+    distribution.
+*******************************************************************************/
+
+#ifndef __PolyVox_RaycastWithCallback_H__
+#define __PolyVox_RaycastWithCallback_H__
+
+namespace PolyVox
+{
+	template <typename VoxelType>
+	class RaycastWithCallback
+	{
+	public:
+		///Constructor
+		RaycastWithCallback(Volume<VoxelType>* volData, const Vector3DFloat& v3dStart, const Vector3DFloat& v3dDirection, polyvox_function<bool(const Vector3DInt32& position)> funcCallback);
+
+		///Sets the start position for the ray.
+		void setStart(const Vector3DFloat& v3dStart);
+		///Set the direction for the ray.
+		void setDirection(const Vector3DFloat& v3dDirection);
+
+		///Performs the raycast.
+		void execute();
+
+	private:
+		polyvox_function<bool(const Vector3DInt32& position)> m_funcCallback;
+
+		void doRaycast(float x1, float y1, float z1, float x2, float y2, float z2);
+
+		Volume<VoxelType>* m_volData;
+		VolumeSampler<VoxelType> m_sampVolume;
+
+		Vector3DFloat m_v3dStart;
+		Vector3DFloat m_v3dDirection;
+		float m_fMaxDistance;
+	};
+}
+
+#include "RaycastWithCallback.inl"
+
+#endif //__PolyVox_RaycastWithCallback_H__

library/PolyVoxCore/include/RaycastWithCallback.inl

@@ -0,0 +1,154 @@
+/*******************************************************************************
+Copyright (c) 2005-2009 David Williams
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must not
+    claim that you wrote the original software. If you use this software
+    in a product, an acknowledgment in the product documentation would be
+    appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must not be
+    misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source
+    distribution. 	
+*******************************************************************************/
+namespace PolyVox
+{
+	template <typename VoxelType>
+	RaycastWithCallback<VoxelType>::RaycastWithCallback(Volume<VoxelType>* volData, const Vector3DFloat& v3dStart, const Vector3DFloat& v3dDirection, polyvox_function<bool(const Vector3DInt32& position)> funcCallback)
+		:m_volData(volData)
+		,m_sampVolume(volData)
+		,m_v3dStart(v3dStart)
+		,m_v3dDirection(v3dDirection)
+		,m_funcCallback(funcCallback)
+	{
+		//Check the user provided a callback, because it
+		//is used to determine when to finish the raycast.
+		assert(m_funcCallback);
+	}
+
+	template <typename VoxelType>
+	void RaycastWithCallback<VoxelType>::setStart(const Vector3DFloat& v3dStart)
+	{
+		m_v3dStart = v3dStart;
+	}
+
+	template <typename VoxelType>
+	void RaycastWithCallback<VoxelType>::setDirection(const Vector3DFloat& v3dDirection)
+	{
+		m_v3dDirection = v3dDirection;
+	}
+
+	template <typename VoxelType>
+	void RaycastWithCallback<VoxelType>::execute(void)
+	{
+		//The doRaycast function is assuming that it is iterating over the areas defined between
+		//voxels. We actually want to define the areas as being centered on voxels (as this is
+		//what the CubicSurfaceExtractor generates). We add (0.5,0.5,0.5) here to adjust for this.
+		Vector3DFloat v3dStart = m_v3dStart + Vector3DFloat(0.5f, 0.5f, 0.5f);
+
+		//Compute the end point
+		Vector3DFloat v3dEnd = v3dStart + m_v3dDirection;
+
+		//Do the raycast
+		doRaycast(v3dStart.getX(), v3dStart.getY(), v3dStart.getZ(), v3dEnd.getX(), v3dEnd.getY(), v3dEnd.getZ());
+	}
+
+	// This function is based on Christer Ericson's code and description of the 'Uniform Grid Intersection Test' in
+	// 'Real Time Collision Detection'. The following information from the errata on the book website is also relevent:
+	//
+	//	pages 326-327. In the function VisitCellsOverlapped() the two lines calculating tx and ty are incorrect.
+	//  The less-than sign in each line should be a greater-than sign. That is, the two lines should read:
+	//
+	//	float tx = ((x1 > x2) ? (x1 - minx) : (maxx - x1)) / Abs(x2 - x1);
+	//	float ty = ((y1 > y2) ? (y1 - miny) : (maxy - y1)) / Abs(y2 - y1);
+	//
+	//	Thanks to Jetro Lauha of Fathammer in Helsinki, Finland for reporting this error.
+	//
+	//	Jetro also points out that the computations of i, j, iend, and jend are incorrectly rounded if the line
+	//  coordinates are allowed to go negative. While that was not really the intent of the code — that is, I
+	//  assumed grids to be numbered from (0, 0) to (m, n) — I'm at fault for not making my assumption clear.
+	//  Where it is important to handle negative line coordinates the computation of these variables should be
+	//  changed to something like this:
+	//
+	//	// Determine start grid cell coordinates (i, j)
+	//	int i = (int)floorf(x1 / CELL_SIDE);
+	//	int j = (int)floorf(y1 / CELL_SIDE);
+	//
+	//	// Determine end grid cell coordinates (iend, jend)
+	//	int iend = (int)floorf(x2 / CELL_SIDE);
+	//	int jend = (int)floorf(y2 / CELL_SIDE);
+	//
+	//	page 328. The if-statement that reads "if (ty <= tx && ty <= tz)" has a superfluous condition.
+	//  It should simply read "if (ty <= tz)".
+	//
+	//	This error was reported by Joey Hammer (PixelActive). 
+	template <typename VoxelType>
+	void RaycastWithCallback<VoxelType>::doRaycast(float x1, float y1, float z1, float x2, float y2, float z2)
+	{
+		int i = (int)floorf(x1);
+		int j = (int)floorf(y1);
+		int k = (int)floorf(z1);
+
+		int iend = (int)floorf(x2);
+		int jend = (int)floorf(y2);
+		int kend = (int)floorf(z2);
+
+		int di = ((x1 < x2) ? 1 : ((x1 > x2) ? -1 : 0));
+		int dj = ((y1 < y2) ? 1 : ((y1 > y2) ? -1 : 0));
+		int dk = ((z1 < z2) ? 1 : ((z1 > z2) ? -1 : 0));
+
+		float minx = floorf(x1), maxx = minx + 1.0f;
+		float tx = ((x1 > x2) ? (x1 - minx) : (maxx - x1)) / abs(x2 - x1);
+		float miny = floorf(y1), maxy = miny + 1.0f;
+		float ty = ((y1 > y2) ? (y1 - miny) : (maxy - y1)) / abs(y2 - y1);
+		float minz = floorf(z1), maxz = minz + 1.0f;
+		float tz = ((z1 > z2) ? (z1 - minz) : (maxz - z1)) / abs(z2 - z1);
+
+		float deltatx = 1.0f / abs(x2 - x1);
+		float deltaty = 1.0f / abs(y2 - y1);
+		float deltatz = 1.0f / abs(z2 - z1);
+
+		m_sampVolume.setPosition(i,j,k);
+
+		for(;;)
+		{
+			//Call the callback. If it returns false then finish the loop.
+			if(!m_funcCallback(Vector3DInt32(i,j,k)))
+			{
+				break;
+			}
+
+			if(tx <= ty && tx <= tz)
+			{
+				tx += deltatx;
+				i += di;
+
+				if(di == 1) m_sampVolume.movePositiveX();
+				if(di == -1) m_sampVolume.moveNegativeX();
+			} else if (ty <= tz)
+			{
+				ty += deltaty;
+				j += dj;
+
+				if(dj == 1) m_sampVolume.movePositiveY();
+				if(dj == -1) m_sampVolume.moveNegativeY();
+			} else 
+			{
+				tz += deltatz;
+				k += dk;
+
+				if(dk == 1) m_sampVolume.movePositiveZ();
+				if(dk == -1) m_sampVolume.moveNegativeZ();
+			}
+		}
+	}
+}