sph_common.h

游戏编程精粹６第中关于粒子的实时流体仿真系统,对入门的游戏开发者很有帮助．

#ifndef _SPH_COMMON_H_
#define _SPH_COMMON_H_

#include "glg.h"


#define SPH_MALLOC(x) malloc((x))

//	#define PRINT_N_INTERACTIONS
//#define PRINT_DIST
#define INITIAL_GRID_CAPACITY 60
//#define WATER_DENSITY 1000.0f /* kg/m^3 */

//typedef short particle_index;
typedef int particle_index;


typedef struct
{
	void* prealloc;
	int used_size;
	int capacity;
} sph_mem_pool;

typedef struct
{
	int index;
	float distsq;
} sph_neighbour;

typedef struct
{
	int* sizes;
	sph_neighbour** p; /** **/
	void* pool;
	int used_by_rigid; // Neighbour list memory used by rigid body particles
	int n_poolused; // Used size of memory pool
} sph_neighbour_list;


typedef struct
{
//	int** particles; /** particles indexed by grid **/
	particle_index** particles; /** particles indexed by grid **/
	int* sizes;      /** number of particles grid has **/
//	particle_index* sizes;      /** number of particles grid has **/
	int* caps;       /** capacity of each grid **/
	int capacity;
	int width;
	int height;
	int depth;
	float grid_len;  /** length of grid edge */

	float minx;
	float miny;
	float minz;

	sph_mem_pool mempool;
	//int* particle_to_grid; /** particle index to grid index map **/
} sph_grid;

typedef struct
{
	int gx;
	int gy;
	int gz;
} grid_vector3i;



void sph_mem_pool_create(sph_mem_pool* pool, int size);
void* sph_mem_pool_alloc(sph_mem_pool* pool, int size);
void sph_mem_pool_free(sph_mem_pool* pool);
void sph_mem_pool_destroy(sph_mem_pool* pool);


vector3* alloc_vec3array(int size);
void free_vec3array(vector3* a);

void sph_neighbour_list_create(sph_neighbour_list* l, int n_particles);
void sph_neighbour_list_create_gpu(sph_neighbour_list* l, int n_particles);

void sph_grid_create(sph_grid* g, int n_particles, float grid_len);

void sph_grid_clear(sph_grid* g, const vector3* pos, int start, int end);
void sph_grid_alloc(sph_grid* g, const vector3* pos, int start, int end);

void sph_grid_get_neighbours(sph_grid* g, const vector3* pos, int start, int end,
							 sph_neighbour_list* n_list, float search_radius);
#endif