Giles Whitaker

PROCESSING PROGRAM:

int numparticles =10000;
particle[] particles;

void setup()
{
  size(500, 500);
  background(255);
  noStroke();
  //smooth();
  particles = new particle[numparticles];
  for(int i=0; i<numparticles; i++)
  {
    particles[i] = new particle(random(450, width-20), random(450, height-20), 10, 10, 5, 0.9,
                             color(0, 0, 0, 255));
  }
}

void draw()
{
  background(255);
  for(int i=0; i<numparticles; i++)
  {
    particles[i].collide();
    particles[i].move();
    particles[i].render();

    particles[i].xspeed*=particles[i].dampfactor;
    particles[i].yspeed*=particles[i].dampfactor;
   }
   if (frameCount%30==0) println(frameRate);
}

class particle
{
  float xpos, ypos;
  float xspeed, yspeed;
  int ewidth;
  int eheight;
  float speedfactor;
  float dampfactor;
  color col;

  particle(float x, float y,int ew, int eh, float sf, float df,color c)
  {
    xpos=x;
    ypos=y;
    xspeed=0;
    yspeed=0;
    ewidth=ew;
    eheight=eh;
    speedfactor=sf;
    dampfactor=df;
    col=c;
  }

  void collide()
  {
  int leftcols = (int)random(0, eheight+1);
  int rightcols=(int)random(0, eheight+1);
  int topcols= (int)random(0, ewidth+1);
  int botcols= (int)random(0, ewidth+1);

  xspeed+= (leftcols-rightcols)/speedfactor;
  yspeed+= (topcols-botcols)/speedfactor;
 }

 void move()
 {
   xpos+=xspeed;
   ypos+=yspeed;
   if (xpos+ewidth> width || xpos-ewidth<0) xspeed*=-1;
   if (ypos+eheight> height || ypos-eheight<0) yspeed*=-1;
 }

 void render()
 {
   fill(col);
   ellipse(xpos, ypos, ewidth, eheight);
 }

}
//---------------------------------------------------------------------------------------------------------


OPENFRAMEWORKS PROGRAM


main.cpp:

#include "ofMain.h"
#include "brownian.h"
//#include "ofAppGlutWindow.h"

//========================================================================
int main()
{

    //ofAppGlutWindow window;
	ofSetupOpenGL(500,500, OF_WINDOW);			// <-------- setup the GL context

	// this kicks off the running of my app
	// can be OF_WINDOW or OF_FULLSCREEN
	// pass in width and height too:
	ofRunApp(new brownian());
}

brownian.h:

#ifndef _BROWNIAN
#define _BROWNIAN


#include "ofMain.h"
#include "particle.h"

#define numparticles 10000


class brownian : public ofBaseApp
{
	public:
        brownian() {};
		void setup();
		void update();
		void draw();
        particle particles[numparticles];
};

#endif

brownian.cpp:

#include "ofMain.h"
#include "brownian.h"
#include <iostream>


//--------------------------------------------------------------
void brownian::setup()
{
   ofBackground(255,255,255);
   ofEnableSmoothing();
   int i;
   for(i=0; i<numparticles; i++)
  {
    particles[i] = particle(ofRandom(450, ofGetWidth()-20), ofRandom(450, ofGetHeight()-20), 10, 10, 5, 0.9);

  }

}
//------------------------------------------------------------
void brownian::update()
{
  int i;
  for(i=0; i<numparticles; i++)
  {
    particles[i].collide();
    particles[i].move();
    particles[i].xspeed*=particles[i].dampfactor;
    particles[i].yspeed*=particles[i].dampfactor;
  }
  if (ofGetFrameNum()%30 ==0) {std::cout << (ofToString(ofGetFrameRate())) <<"  ";}

}
//--------------------------------------------------------------
void brownian::draw()
{
    int i;
    for(i=0; i<numparticles; i++)
  {
     particles[i].render();
  }
}
//--------------------------------------------------------------

particle.h:

#ifndef _PARTICLE
#define _PARTICLE



class particle
{

	public:
		float xpos, ypos;
        float xspeed, yspeed;
        float ewidth;
        float eheight;
        float speedfactor;
        float dampfactor;
        particle() {};
        particle(float x, float y,int ew, int eh, float sf, float df);
        void collide();
        void move();
        void render();

};

#endif


particle.cpp:

#include "particle.h"
#include "ofMain.h"

particle::particle(float x, float y,int ew, int eh, float sf, float df)
{
    xpos=x;
    ypos=y;
    xspeed=0;
    yspeed=0;
    ewidth=ew;
    eheight=eh;
    speedfactor=sf;
    dampfactor=df;
}

void particle::collide()
{
    float leftcols = ofRandom(0, eheight+1);
    float rightcols= ofRandom(0, eheight+1);
    float topcols= ofRandom(0, ewidth+1);
    float botcols= ofRandom(0, ewidth+1);

  xspeed+= (leftcols-rightcols)/speedfactor;
  yspeed+= (topcols-botcols)/speedfactor;
}

void particle::move()
{
   xpos+=xspeed;
   ypos+=yspeed;
   if (xpos+ewidth> ofGetWidth() || xpos-ewidth<0) xspeed*=-1;
   if (ypos+eheight> ofGetHeight() || ypos-eheight<0) yspeed*=-1;
}

void particle::render()
{
   ofFill();
   ofSetColor(0,0,0);
   ofEllipse(xpos, ypos, ewidth, eheight);
}