Hi

I have been trying this for two days...

How to convert this "example code of make a cuve" into a PVector class and get the new location or velocity from the other PVector class, I think someone ask a bout two objects question, I don't know if it the same. 

1. float beginX = 20.0;  // Initial x-coordinate
   float beginY = 10.0;  // Initial y-coordinate
   float endX = 570.0;   // Final x-coordinate
   float endY = 320.0;   // Final y-coordinate
   float distX;          // X-axis distance to move
   float distY;          // Y-axis distance to move
   float exponent = 4;   // Determines the curve
   float x = 0.0;        // Current x-coordinate
   float y = 0.0;        // Current y-coordinate
   float step = 0.01;    // Size of each step along the path
   float pct = 0.0;      // Percentage traveled (0.0 to 1.0)
2. void setup()
   {
     size(640, 360);
     noStroke();
     smooth();
     distX = endX - beginX;
     distY = endY - beginY;
   }
3. void draw()
   {
     fill(0, 2);
     rect(0, 0, width, height);
     pct += step;
     if (pct < 1.0) {
       x = beginX + (pct * distX);
       y = beginY + (pow(pct, exponent) * distY);
     }
     fill(255);
     ellipse(x, y, 20, 20);
   }
4. void mousePressed() {
     pct = 0.0;
     beginX = x;
     beginY = y;
     endX = mouseX;
     endY = mouseY;
     distX = endX - beginX;
     distY = endY - beginY;
   }

 

I don't know what should be in constructor, and why? like this:

 Ball(PVector P) {
  
      velocity = new PVector();
    location =new PVector();

   PVector acceleration=PVector.sub(location,velocity) ;

}

or

Ball(float _x,float _y) {
   
    x = _x;
    y=_y;

   }

 

 

@ class is art @ (@_@)  this problem had bother me long enough ...> <

here is my bad code :

1. ///data from Rhino's grasshopper-  " X" coordinate, and "Y" coordinate
2. float lines1X[];
   float lines1Y[];
   float lines2X[];
   float lines2Y[];
   float lines3X[];
   float lines3Y[];
3. //there are more lines...
4. ArrayList stations1= new ArrayList();//does not work
5. 
   void setup() {
     size(800, 550);
    // PImage img = loadImage("2012 siteBase.jpg");
    // image (img, 0, 0);
     lines1X = float(loadStrings("xPosition.txt"));
     lines1Y = float(loadStrings("yPosition.txt"));
     lines2X = float(loadStrings("x2Pos.txt"));
     lines2Y = float(loadStrings("y2Pos.txt"));
     lines3X = float(loadStrings("x3Pos.txt"));
     lines3Y = float(loadStrings("y3Pos.txt"));
    
   }
   void draw() {
    
     for (int i =0; i<lines2X.length; i++) {
       float mapX = map(lines2X[i], 0, 800, 0, width);
       float mapY = map(lines2Y[i], 550, 0, 0, height);
       fill(255, 0, 0);
       ellipse(mapX, mapY, 10, 10);
     }
     //  -------------------------------------------------------
6.   for (int i =0; i<lines3X.length; i++) {
       float mapX = map(lines3X[i], 0, 800, 0, width);
       float mapY = map(lines3Y[i], 550, 0, 0, height);
       fill(255, 0, 0);
       ellipse(mapX, mapY, 10, 10);
     }
     //  -------------------------------------------------------
     for (int i =0; i<lines4X.length; i++) {
       float mapX = map(lines4X[i], 0, 800, 0, width);
       float mapY = map(lines4Y[i], 550, 0, 0, height);
       fill(255, 0, 0);
       ellipse(mapX, mapY, 10, 10);
     }
   }
7. //////////////////try to change above repeat loop to class, but doesn't work 
8. class stations {
    
     ArrayList stations;
     float  mapX;
     float  mapY;
     stations station;
9.   void addStation (float x, float y) {
       PVector station= new PVector(x, y);
       stations.add(station);
     }
10. 
      void display() {
     
        for (int i =0; i<stations.size(); i++) {
          PVector station= (PVector) stations.get(i);
          fill(255, 0, 0);
          ellipse(mapX, mapY, 10, 10);
        }
      }
    }
    
11. ///////////////I try to write some thing like this too,
12. class stations {
      PVector ball;
       PVector loc;
      float linesX[];
      float linesY[];
      float linesZ[];
13.   stations(float loadStrings("ttopY.txt"), float loadStrings("ttopZ.txt"),float loadStrings("ttopX.txt") ) {
        linesX[]= loadStrings("ttopZ.txt");
        linesY[]= loadStrings("ttopZ.txt");
        linesZ[]= loadStrings("ttopX.txt");
      }

....~'"~|||....#_#   never work .....

here is the simple example which is worked with only one line, and no class  

The idea is: I have a map, they have points in (x,y) creat I want to have a train or car drive on this route.  

1. ArrayList<PVector> Balls;
   PVector loc;
   PVector vel;
   PVector ball;
   float lines1X[];
   float lines1Y[];
   boolean goBack = false;
2. int t = 0;
   float exponent =4;
   float x=0.0;
   float y=0.0;
   float step = 0.05;
   float pct = 0.0;
3. void setup(){
   size(600, 600);
     Balls = new ArrayList();
     lines1X = float(loadStrings("xPosition.txt"));
     lines1Y = float(loadStrings("yPosition.txt"));
     for(int i =0; i<lines1X.length; i++){
        float mapX = map(lines1X[i],0,2500,0,width);
        float mapY = map(lines1Y[i],2500,0,0,height);
        PVector ball = new PVector(mapX,mapY);
        Balls.add(ball);
      
    
     }
4.   noStroke();
     smooth();
     loc=new PVector(Balls.get(0).x,Balls.get(0).y);
    
   }
   void draw(){
      fill(0, 155);
     rect(0, 0, width, height);
     //distX = endX - beginX;
     //distY = endY - beginY;
    
     //for(int i =0; i<Balls.size()-1; i++){
      
       PVector ball = Balls.get(t);
         if (pct < 1.0) {
           pct += step;
           loc.x = loc.x + (pct * (Balls.get(t+1).x-loc.x));
           loc.y = loc.y + (pow(pct,exponent) * (Balls.get(t+1).y-loc.y));
           //y = beginY + (pow(pct, exponent) * distY);
           println(pct);
           if(pct >= 1){
             if(t==Balls.size()-2){
               goBack = true;
             }else if(t==0){
               goBack = false;
             }
            
             if(goBack){
               t--;
             }else{
               t++;
             }
            
             pct =0;
           }
         }
    // }
    
5.   fill(255,0,0);
     ellipse(loc.x, loc.y, 10, 10);
    
    
    
     for(int i = 0; i<Balls.size(); i++){
       PVector bb = Balls.get(i);
       fill(0,255,0);
       ellipse(bb.x,bb.y,10,10);
       text(str(i),bb.x+5,bb.y-5);
     }
   }

xPosition.txt

{

1408.0
1317.391112
1394.302423
1509.650022
1475.176701
1440.958262
1350.16011
1273.364917
1304.509774
1274.0
}

yPosition.txt

{

950.0
1053.201979
1126.070458
1164.261628
1294.595287
1425.331547
1528.800457
1640.490372
1771.466451
1905.0

}

my Xmas tree was made by this long way without class

http://www.openprocessing.org/sketch/48335

sorry the question is so long...

Hope some one know how to make it. .

 

 

 

 

 

 

Hi

I want to rotate one class of balls

I saw this

http://bazaar.launchpad.net/~philho/+junk/Processing/view/head:/_QuickExperiments/Rotations/Rotations.pde

but still don't know how to deal with that if I have a class;

////////Here is my class code

class Station {
  int radius;
  int numberSt;
  int xx, yy;
  Station(int n, int centx, int centy, int rad) {
    xx = centx;
    yy = centy;
    numberSt = n;
    radius = rad;
    ellipseMode(CENTER);
  }
  void display() {
    float degreeInc = 2.0*( PI / numberSt);
    int count = -1;
    int[] pointsx = new int[ numberSt + 1];
    int[] pointsy = new int[ numberSt + 1];
    int smallRad = 10;
    for ( float deg = 0; deg < 2*PI; deg = deg + degreeInc)
    { 

      int dy = int(radius * sin(deg));
      int dx = int(radius * cos(deg));
      ellipse(xx+dx, yy+dy, smallRad, smallRad);
      count++;
      pointsx[count] = xx+dx;
      pointsy[count] = yy+dy;
    }
  }
}

 

/////main code is

int numberSt=3;
int numStations =4;
Station[] stations= new Station[numStations];

void setup() {
  size(600, 600);
  background(0);
  smooth();
  ellipseMode(CENTER);
  stations[0] = new Station(numberSt, 100, 100, 50);
  stations[1] = new Station(numberSt, 300, 100, 50);
  stations[2] = new Station(numberSt, 100, 300, 50);
  stations[3] = new Station(numberSt, 300, 300, 50);
}

void draw() {
  fill(0, 20);
  rect(0, 0, width, height);
  for (int i = 0; i <numStations; i++)
  {
   for (float c=0; c<2*PI; c+= 0.01){
     pushMatrix();
     translate(100,100);
     rotate(c);
      fill(255, 100);
      stations[0].display();
     popMatrix();
      }
      for (float c=0; c<2*PI; c+= 0.01){
     pushMatrix();
     translate(300,100);
     rotate(c);
      fill(255, 100);
      stations[1].display();
     popMatrix();
      }
        for (float c=0; c<2*PI; c+= 0.01){
     pushMatrix();
     translate(100,300);
     rotate(c);
      fill(255, 100);
      stations[2].display();
     popMatrix();
      }
        for (float c=0; c<2*PI; c+= 0.01){
     pushMatrix();
     translate(300,300);
     rotate(c);
      fill(255, 100);
      stations[3].display();
     popMatrix();
      }
  }
}

I try to put rotate(); inside the class, but didn't workout (-"-)

 

I am interested in following video,

http://www.guardian.co.uk/news/datablog/video/2012/jan/12/high-speed-2-hs2-rail-britain-mapped-animation?fb=native

I don't know how make the movement along the curve or some trajectory like "train", basicly, I tried to move point "like" curvy, but if I have specific line, I want the particles going alone this line, only I can get jumping behavior...not so smooth...I want the train.....

please (;-;)  someone tell me how can I do it?