common.h

#ifndef __CS267_COMMON_H__
#define __CS267_COMMON_H__

inline int min( int a, int b ) { return a < b ? a : b; }
inline int max( int a, int b ) { return a > b ? a : b; }

//
//  saving parameters
//
const int NSTEPS = 1000;
const int SAVEFREQ = 10;

//
// particle data structure
//
typedef struct 
{
  double x;
  double y;
  double vx;
  double vy;
  double ax;
  double ay;
} particle_t;

//
// QuadTree data structure
//
class QuadTreeNode
{
  public:
    QuadTreeNode(QuadTreeNode* parent, double x, double y, 
                 double width, double height, float theta);
    ~QuadTreeNode();
    void insert(particle_t* p);
    void computeCOM();
    void computeF(particle_t* p, double* dmin, double* davg, int* navg);
    void init_particles(particle_t* p, int n);
  private:
    particle_t* p;
    double m;
    double com_x;
    double com_y;
    double width;
    double height;
    float theta;
    double x;
    double y;
    double wn;
    double hn;
    double xmid;
    double ymid;
    bool external;
    QuadTreeNode* NW;
    QuadTreeNode* NE;
    QuadTreeNode* SW;
    QuadTreeNode* SE;
    QuadTreeNode* parent;
};

//
//  timing routines
//
double read_timer( );

//
//  simulation routines
//
double set_size( int n );
void init_particles( int n, particle_t *p );
void apply_force( particle_t &particle, particle_t &neighbor,
                  double *dmin, double *davg, int *navg);
void move( particle_t &p );


//
//  I/O routines
//
FILE *open_save( char *filename, int n );
void save( FILE *f, int n, particle_t *p );

//
//  argument processing routines
//
int find_option( int argc, char **argv, const char *option );
int read_int( int argc, char **argv, const char *option, int default_value );
char *read_string( int argc, char **argv, const char *option, 
                   char *default_value );

#endif