Added initial Smoothed Particle Hydrodynamics implementation (SPH), for CPU and CUDA.

This software is contributed under the ZLib license by Rama Hoetzlein, http://www.rchoetzlein.com
We plan to integrate the SPH into the core Bullet library, including interaction with rigid bodies and soft bodies.

Extras/sph/common/point_set.h

@@ -0,0 +1,165 @@
+/*
+  FLUIDS v.1 - SPH Fluid Simulator for CPU and GPU
+  Copyright (C) 2008. Rama Hoetzlein, http://www.rchoetzlein.com
+
+  ZLib license
+  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 DEF_POINT_SET
+	#define DEF_POINT_SET
+
+	#include <iostream>
+	#include <vector>
+	#include <stdio.h>
+	#include <stdlib.h>
+	#include <math.h>
+	
+	#include "common_defs.h"
+	#include "geomx.h"
+	#include "vector.h"	
+
+	typedef signed int		xref;
+	
+	#define MAX_NEIGHBOR		80
+	
+	#define MAX_PARAM			21
+
+	// Scalar params
+	#define PNT_DRAWMODE		0
+		#define PNT_SPHERE			0
+		#define PNT_POINT			1
+	#define PNT_DRAWSIZE		1		
+	#define POINT_GRAV			2
+	#define PLANE_GRAV			3
+
+	// Vector params
+	#define EMIT_POS			0
+	#define EMIT_ANG			1
+	#define EMIT_DANG			2
+	#define EMIT_SPREAD			3
+	#define EMIT_RATE			4
+	#define POINT_GRAV_POS		5	
+	#define PLANE_GRAV_DIR		6	
+
+
+	#define BPOINT				0
+	#define BPARTICLE			1
+
+	struct Point {
+		Vector3DF		pos;
+		DWORD			clr;
+		int				next;
+	};
+	
+	struct Particle {	
+		Vector3DF		pos;
+		DWORD			clr;
+		int				next;
+		Vector3DF		vel;			
+		Vector3DF		vel_eval;		
+		unsigned short	age;
+	};
+
+	class PointSet : public GeomX {
+	public:
+		PointSet ();
+
+		// Point Sets
+		
+		virtual void Initialize ( int mode, int max );
+		virtual void Draw ( float* view_mat, float rad );		
+		virtual void Reset ();		
+		virtual int AddPoint ();		
+		virtual int AddPointReuse ();
+		Point* GetPoint ( int n )		{ return (Point*) GetElem(0, n); }		
+		int	NumPoints ()				{ return NumElem(0); }		
+
+		// Metablobs
+		virtual float GetValue ( float x, float y, float z );
+		virtual Vector3DF GetGradient ( float x, float y, float z );
+	//	virtual float GetValue ( float x, float y, float z, Vector3DF& dir );
+		virtual DWORD GetColor ( float x, float y, float z );
+		
+		// Particle system		
+		virtual void Run ();
+		virtual void Advance ();		
+		virtual void Emit ( float spacing );			
+
+		// Misc
+		virtual void AddVolume ( Vector3DF min, Vector3DF max, float spacing );
+
+		// Parameters			
+		void SetParam (int p, float v )		{ m_Param[p] = v; }
+		void SetParam (int p, int v )		{ m_Param[p] = (float) v; }
+		float GetParam ( int p )			{ return (float) m_Param[p]; }
+		Vector3DF GetVec ( int p )			{ return m_Vec[p]; }
+		void SetVec ( int p, Vector3DF v )	{ m_Vec[p] = v; }
+		void Toggle ( int p )				{ m_Toggle[p] = !m_Toggle[p]; }		
+		bool GetToggle ( int p )			{ return m_Toggle[p]; }
+
+		float GetDT()						{ return (float) m_DT; }
+
+		// Spatial Subdivision
+		void Grid_Setup ( Vector3DF min, Vector3DF max, float sim_scale, float cell_size, float border );		
+		void Grid_Create ();
+		void Grid_InsertParticles ();	
+		void Grid_Draw ( float* view_mat );		
+		void Grid_FindCells ( Vector3DF p, float radius );
+		int Grid_FindCell ( Vector3DF p );
+		Vector3DF GetGridRes ()		{ return m_GridRes; }
+		Vector3DF GetGridMin ()		{ return m_GridMin; }
+		Vector3DF GetGridMax ()		{ return m_GridMax; }
+		Vector3DF GetGridDelta ()	{ return m_GridDelta; }
+		int GetGridCell ( int x, int y, int z );
+		Point* firstGridParticle ( int gc, int& p );
+		Point* nextGridParticle ( int& p );
+		unsigned short* getNeighborTable ( int n, int& cnt );
+
+	protected:
+		int							m_Frame;		
+
+		// Parameters
+		double						m_Param [ MAX_PARAM ];			// see defines above
+		Vector3DF					m_Vec [ MAX_PARAM ];
+		bool						m_Toggle [ MAX_PARAM ];
+		
+		// Particle System
+		double						m_DT;
+		double						m_Time;
+
+		// Spatial Grid
+		std::vector< int >			m_Grid;
+		std::vector< int >			m_GridCnt;
+		int							m_GridTotal;			// total # cells
+		Vector3DF					m_GridMin;				// volume of grid (may not match domain volume exactly)
+		Vector3DF					m_GridMax;
+		Vector3DF					m_GridRes;				// resolution in each axis
+		Vector3DF					m_GridSize;				// physical size in each axis
+		Vector3DF					m_GridDelta;
+		float						m_GridCellsize;
+		int							m_GridCell[27];
+
+		// Neighbor Table
+		unsigned short				m_NC[65536];			// neighbor table (600k)
+		unsigned short				m_Neighbor[65536][MAX_NEIGHBOR];	
+		float						m_NDist[65536][MAX_NEIGHBOR];
+
+		static int m_pcurr;
+	};
+
+#endif