double Line::GetDistance(const Line& line, const Vector2D& point) {
return std::sqrt(GetDistanceSquared(line, point));
}
double Line::GetDistanceSquared(const Vector2D& point) const {
return GetDistanceSquared(*this, point);
}
int
main( int argc, char *argv[ ] )
{
#ifndef _OPENMP
fprintf( stderr, "OpenMP is not available\n" );
return 1;
#endif
omp_set_num_threads( NUMT );
int numProcessors = omp_get_num_procs( );
fprintf( stderr, "Have %d processors.\n", numProcessors );
for ( int i = 0; i < NUMBODIES; i++ )
{
Bodies[i].mass = EARTH_MASS * Ranf( 0.5f, 10.f );
Bodies[i].x = EARTH_DIAMETER * Ranf( -100.f, 100.f );
Bodies[i].y = EARTH_DIAMETER * Ranf( -100.f, 100.f );
Bodies[i].z = EARTH_DIAMETER * Ranf( -100.f, 100.f );
Bodies[i].vx = Ranf( -100.f, 100.f );;
Bodies[i].vy = Ranf( -100.f, 100.f );;
Bodies[i].vz = Ranf( -100.f, 100.f );;
};
double time0 = omp_get_wtime( );
for ( int t = 0; t < NUMSTEPS; t++ )
{
// #pragma omp parallel for schedule(dynamic)
for ( int i = 0; i < NUMBODIES; i++ )
{
float fx = 0.;
float fy = 0.;
float fz = 0.;
Body *bi = &Bodies[i];
#pragma omp parallel for reduction(+:fx,fy,fz) schedule(dynamic)
for ( int j = 0; j < NUMBODIES; j++ )
{
if ( j == i ) continue;
Body *bj = &Bodies[j];
float rsqd = GetDistanceSquared( bi, bj );
if ( rsqd > 0. )
{
float f = G * bi->mass * bj->mass / rsqd;
float ux, uy, uz;
GetUnitVector( bi, bj, &ux, &uy, &uz );
fx += f * ux;
fy += f * uy;
fz += f * uz;
}
}
float ax = fx / Bodies[i].mass;
float ay = fy / Bodies[i].mass;
float az = fz / Bodies[i].mass;
Bodies[i].xnew = Bodies[i].x + Bodies[i].vx * TIMESTEP + 0.5 * ax * TIMESTEP * TIMESTEP;
Bodies[i].ynew = Bodies[i].y + Bodies[i].vy * TIMESTEP + 0.5 * ay * TIMESTEP * TIMESTEP;
Bodies[i].znew = Bodies[i].z + Bodies[i].vz * TIMESTEP + 0.5 * az * TIMESTEP * TIMESTEP;
Bodies[i].vxnew = Bodies[i].vx + ax * TIMESTEP;
Bodies[i].vynew = Bodies[i].vy + ay * TIMESTEP;
Bodies[i].vznew = Bodies[i].vz + az * TIMESTEP;
}
// setup the state for the next animation step:
for ( int i = 0; i < NUMBODIES; i++ )
{
Bodies[i].x = Bodies[i].xnew;
Bodies[i].y = Bodies[i].ynew;
Bodies[i].z = Bodies[i].znew;
Bodies[i].vx = Bodies[i].vxnew;
Bodies[i].vy = Bodies[i].vynew;
Bodies[i].vz = Bodies[i].vznew;
}
} // t
double time1 = omp_get_wtime( );
// print performance here:::
double mbodies = (float)(NUMBODIES * NUMBODIES * NUMSTEPS) / (time1 - time0) / 1000000.;
printf("Performance = %8.2lf MegaBodies/Sec\n", mbodies);
printf("Time = %8.2lf MegaSecs\n", (time1 - time0) * 1000000.);
return 0;
}
double Line::GetDistance(const Vector2D& point) const {
return std::sqrt(GetDistanceSquared(*this, point));
}
double GetDistance(const Vector2D& p, const Vector2D& one, const Vector2D& two) {
return std::sqrt(GetDistanceSquared(p, one, two));
}
