physics.cpp

/**\brief  Implementation of functions defined in physics.h
 * \author Henry J Schmale
 * \date   March 11, 2015
 * \file   physics.cpp
 */

#include "physics.h"
#include <glog/logging.h>
#include "config.h"
#include "constants.h"

using namespace std;

void calcElectroForceVecs(){
    int i = 0;
    double Et = 0;
    for(double x = XMIN; x <= XMAX; x += DXY_RES){
        for(double y = YMIN; y <= YMAX; y += DXY_RES){
            if(i >= VECCOUNT){
                continue;
            }
            Et = 0;
            for(int n = 0; n < NUMSRCS; n++){
                Et = (abs(ELECTRIC_FORCE * CHARGE_PROTON * 
                          charges[n].m_charge) /
                      pow(calcDistance(&charges[n], x, y), 2));
                double angle = atan2((y - charges[n].m_yPos),
                                     (x - charges[n].m_xPos));
                if(charges[n].m_charge > 0){
                    vectors[i].m_xC -= cos(angle) * Et;
                    vectors[i].m_yC -= sin(angle) * Et; 
                }else{
                    vectors[i].m_xC += cos(angle) * Et;
                    vectors[i].m_yC += sin(angle) * Et;
                }
            }
            i++;
        }
    }
}

void calcUpdatedBallState(pithBall *b, double dT){
    double F;
    CHECK_NOTNULL(b);
    CHECK(dT > 0);
    b->px = b->cx; // Mv Current x&y to prevs
    b->py = b->cy;
    for(int n = 0; n < NUMSRCS; n++){
        F = (abs(ELECTRIC_FORCE * b->charge * charges[n].m_charge) /
              pow(calcDistance(&charges[n], b->cx, b->cy), 2));
        double angle = atan2((b->cx - charges[n].m_yPos),
                             (b->cy - charges[n].m_xPos));
        if(charges[n].m_charge > 0){
            b->fx -= cos(angle) * F;
            b->fy -= sin(angle) * F; 
        }else{
            b->fx += cos(angle) * F;
            b->fy += sin(angle) * F;
        }
    }
    
}