HI!
I'm quite new with processing, but althought my work doesn't seem that complex compared to other stuff i've seen (flight404 good example) it has serious problems with framerate. That's the code:

import processing.opengl.*;



class circle {
 float x,y;
 float speedX,speedY;
 float speedX1,speedY1;
 float SX1;
 float SY1;
 float mX,mY;



 void init(){
   x = random (0,width);
   y = random (0,height);
   speedX=0;
   speedY=0;

   speedX1=0;
   speedY1=0;
 }

 void update(){


   x+= (speedX-speedX1);
   y+= (speedY-speedY1);
 
    if (mousePressed == true) {
    x+=speedX-speedX1+mX;
    y+=speedY-speedY1+mY;

   }    
 }


 void render(){
  /* noStroke();
   fill(10,81,95);
   ellipse (x,y,10,10);
   */

  float k=10;
  stroke(0,92,90);
  strokeWeight(3);
  line (x-k,y,x+k,y);
  line (x,y-k,x,y+k);
 }
}

class attrattori{
 float x,y;

 void render (){
   fill(10,81,95,100);
   ellipse(x,y,10,10);
 }
}

int nCircle =70;
circle [] cerchi = new circle [nCircle];

int nAtt =64;
int spWidth=16;
int spHeight=12;
attrattori [] punto  = new attrattori [nAtt];

void setup (){
 colorMode(HSB,100);
 size (1400,700,OPENGL);

 for (int i=0;i<nCircle;i++){
   cerchi[i] = new circle();
 }
 for (int i=0;i<nCircle;i++){
   cerchi[i].init();
 }

 for (int i=0;i<nAtt;i++){
   punto[i] = new attrattori();
 }


 int i=0;
 for (int x=0;x<width;x+=width/spWidth){
   punto[i].x=x;
   punto[i].y=0;
   //println("A  i="+i+"  x="+x+" y="+0);
   if (i<nAtt-1){
     i++;
   }
 }
 for (int x=0;x<width;x+=width/spWidth){
   punto[i].x=x;
   punto[i].y=height;
   //println("A  i="+i+"  x="+x+" y="+height);
   if (i<nAtt-1){
     i++;
   }
 }

 for (int y=0;y<height;y+=height/spHeight){

   punto[i].y=y;
   punto[i].x=0;
   //println("B  i="+i+"  x="+0+" y="+y);
   if (i<nAtt-1){
     i++;
   }
 }
 for (int y=0;y<height;y+=height/spHeight){

   punto[i].y=y;
   punto[i].x=width;
   //println("B  i="+i+"  x="+width+" y="+y);
   if (i<nAtt-1){
     i++;
   }
 }
}

void draw (){
 noStroke();
 fill(23, 4, 90,90);
 rect(0,0,width,height);
 if (keyPressed){
   if (key=='c'){
     for (int i=0; i<nCircle;i++){
       cerchi[i].init();
     }
   }
 }
 for (int i=0; i<nCircle;i++){
   cerchi[i].update();
 }
 for (int i=0; i<nCircle;i++){
   cerchi[i].render();
 }

 for (int i=0; i<nAtt;i++){
  // punto[i].render();
 }

//cerchi e attrattori

 for (int i=0; i<nCircle;i++){
   for (int j=0; j<nAtt; j++){
     float dAttX = (cerchi[i].x-punto[j].x);
     float dAttY = (cerchi[i].y-punto[j].y);
     float dAtt  = dist (cerchi[i].x,cerchi[i].y,punto[j].x,punto[j].y);


   cerchi[i].speedX += ((100)/((dAtt*dAtt*dAttX)+0.0001))*100;
   cerchi[i].speedY += ((100)/((dAtt*dAtt*dAttY)+0.0001))*100;
     //println("i ="+i+", j ="+j);
   }
 }

//cerchi un con l'altro

 for (int i=0; i<nCircle;i++){
   for (int j=0; j<nCircle;j++){

     float dX = (cerchi[i].x-cerchi[j].x);
     float dY = (cerchi[i].y-cerchi[j].y);

     float dd  = dist (cerchi[i].x,cerchi[i].y,cerchi[j].x,cerchi[j].y);

  cerchi[i].speedX1 =dX*dd*dd*0.000000001;
  cerchi[i].speedY1 =dY*dd*dd*0.000000001;
     if (dd<400){
       stroke(0,0,0,dd);
       float sw=(1/(dd*dd))*5000;
       strokeWeight(sw);
       if (sw>100){
         strokeWeight(100);
         line (cerchi[i].x,cerchi[i].y,cerchi[j].x,cerchi[j].y);
         }
         else{
           line (cerchi[i].x,cerchi[i].y,cerchi[j].x,cerchi[j].y);
         }
   
       //println("i ="+i+", j ="+j);
     }
     if (dd<=410 && dd>=405){
       float rx =random(-2,2);
       float ry =random(-2,2);
       //noFill();
       float xRect=(cerchi[i].x+((cerchi[j].x-cerchi[i].x)/3));
       float yRect=(cerchi[i].y+((cerchi[j].y-cerchi[i].y)/3));
       
       stroke(0);
       
       int k=5;
       line (xRect-k,yRect,xRect+k,yRect);
       line (xRect,yRect-k,xRect,yRect+k);
       
       //rect(xRect+rx,yRect+ry,10,10);

     }
   }
 }

 //mouseinput
   for (int i=0; i<nCircle;i++){
 
float mmX = (mouseX-cerchi[i].x);
float mmY = (mouseY-cerchi[i].y);
float mm  = dist(mouseX,mouseY,cerchi[i].x,cerchi[i].y);
cerchi[i].mX= (mmX/(mm*mm))*1000;
cerchi[i].mY= (mmY/(mm*mm))*1000;


   }

 smooth();
}


I Know that if i get rid of the "smooth" and if i decrease the particles it gets already better but i wish i could get to a better performance.

Any suggestion?
thanks
lorenzo

i changed nCircles to 10 and printed out all the coords

(lineA is the line within the "dd<400" condition,
lineB is the other one. indexes are i and j)

Code:

LineA[0][0]: 158.08415,47.811424,158.08415,47.811424
LineA[1][1]: 220.40291,280.42963,220.40291,280.42963
LineA[2][2]: 380.9574,540.06433,380.9574,540.06433
LineA[3][3]: 1001.6303,420.28998,1001.6303,420.28998
LineA[4][4]: 506.69843,374.4198,506.69843,374.4198
LineA[5][5]: 206.04227,102.92694,206.04227,102.92694
LineA[6][6]: 324.68802,515.3001,324.68802,515.3001
LineA[7][7]: 372.7746,536.14685,372.7746,536.14685
LineA[8][8]: 669.50446,167.508,669.50446,167.508
LineA[9][9]: 987.21924,217.91843,987.21924,217.91843
 

the above don't need drawing at all

and all of these lines you are drawing twice but only need to be drawn once

Code:

LineA[0][1]: 158.08415,47.811424,220.40291,280.42963
LineA[1][0]: 220.40291,280.42963,158.08415,47.811424

LineA[1][2]: 220.40291,280.42963,380.9574,540.06433
LineA[2][1]: 380.9574,540.06433,220.40291,280.42963

LineA[1][4]: 220.40291,280.42963,506.69843,374.4198
LineA[4][1]: 506.69843,374.4198,220.40291,280.42963

LineA[2][4]: 380.9574,540.06433,506.69843,374.4198
LineA[4][2]: 506.69843,374.4198,380.9574,540.06433

LineA[0][5]: 158.08415,47.811424,206.04227,102.92694
LineA[5][0]: 206.04227,102.92694,158.08415,47.811424

LineA[1][5]: 220.40291,280.42963,206.04227,102.92694
LineA[5][1]: 206.04227,102.92694,220.40291,280.42963

LineA[1][6]: 220.40291,280.42963,324.68802,515.3001
LineA[6][1]: 324.68802,515.3001,220.40291,280.42963

LineA[1][7]: 220.40291,280.42963,372.7746,536.14685
LineA[7][1]: 372.7746,536.14685,220.40291,280.42963

LineA[2][6]: 380.9574,540.06433,324.68802,515.3001
LineA[6][2]: 324.68802,515.3001,380.9574,540.06433

LineA[2][7]: 380.9574,540.06433,372.7746,536.14685
LineA[7][2]: 372.7746,536.14685,380.9574,540.06433

LineA[3][9]: 1001.6303,420.28998,987.21924,217.91843
LineA[9][3]: 987.21924,217.91843,1001.6303,420.28998

LineA[4][6]: 506.69843,374.4198,324.68802,515.3001
LineA[6][4]: 324.68802,515.3001,506.69843,374.4198

LineA[4][7]: 506.69843,374.4198,372.7746,536.14685
LineA[7][4]: 372.7746,536.14685,506.69843,374.4198

LineA[4][8]: 506.69843,374.4198,669.50446,167.508
LineA[8][4]: 669.50446,167.508,506.69843,374.4198

LineA[6][7]: 324.68802,515.3001,372.7746,536.14685
LineA[7][6]: 372.7746,536.14685,324.68802,515.3001

LineA[8][9]: 669.50446,167.508,987.21924,217.91843
LineA[9][8]: 987.21924,217.91843,669.50446,167.508
 

and then there are these that you have to draw all of

Code:

LineB[4][5]: 401.4797,283.92218,411.4797,283.92218
LineB[5][4]: 301.261,193.42456,311.261,193.42456
LineB[5][4]: 306.261,188.42456,306.261,198.42456
LineB[4][5]: 406.4797,278.92218,406.4797,288.92218