Hi all,

I'm not too sure how to word my question so I'll try keep it simple. Basically, I'm trying to get the distance between two ellipses that share the same class. A single ellipse is created in the 'display' method, so any instance of the class will share the same x and y coordinates.  So at the moment I don't know what I should be plugging in for the x2 and y2 points of my distance formula because they are not defined. I could solve my problem by making another ellipse in the display method with different x,y variables but then I would have to implement my 'moveBall method etc to accommodate the new variables, which I don't want to do. So the way I have defined the class using a single ellipse I now don't know what I should be plugging in for the x2 and y2 coordinates of the distance formula located in the 'collision' method.

Hope that sort of make sense? I'm sure their is a simple logical solution I'm not seeing.

1. color c = color(255, 0, 0);
   color c2 = color(0, 255, 0);
   Ball ballOne = new Ball(50, 250);
   Ball ballTwo = new Ball(950, 250);
   
   void setup() {
     background(0);
     size(1000, 500);
     smooth();
     ellipseMode(CENTER);
     frameRate(60);
   }
   
   void draw()
   {
     background(0);
     ballOne.display(c);
     ballOne.moveBall(); 
     ballTwo.display(c);
     ballTwo.moveBall();
     if (ballOne.collide(ballTwo))
     {
       fill(c2);
     }
     else
     {
       fill(c);
     }
     if (frameCount % 60 == 0)
     {
       println(frameRate);
     }
   }
   
   class Ball {
     int dia;
     int x, y; 
     int speedX;
     int speedY;
     Ball(int x_, int y_)
     {
       x = x_;
       y = y_;
       dia = 100;
       speedX = 6;
       speedY = 1;
     }
     void display(color cAll)
     {
       noStroke();
       fill(cAll);
       ellipse(x, y, dia, dia);
     }
     void moveBall()
     {
       x = x + speedX;
       if (x > width - dia/2)
       {
         speedX = -abs(speedX);
       }
       if (x < 0 + dia/2)
       {
         speedX = abs(speedX);
       }
     }
     boolean collide(Ball b)
     {
       //How do i get the x2 and y2 coordinates for the second instance of Ball
       float distance = sqrt (pow(x - x2, 2) + pow(y - y2, 2));  // < --------- ?!?!
       println("This is distance: " + distance);
       if (distance < ((b.dia/2) + dia/2))
       {
         return true;
       }
       return false;
     }
   }
   
   

Sorry this could be in the wrong section but I'm wondering if anyone knows what the name is of the default font being used in the standard IDE for Processing. Asking because I have started using Eclipse IDE for Java and coming from the Processing language I would like to have the same font in Eclipse.

Thanks.

Hi.

I'm really nervous about taking my first exam tomorrow on Processing .
I struggle with questions that require output values to be written out. I am wondering if someone would be kind enough to explain what mental steps, procedures or questions one should take when faced with these sorts of questions. I thought I knew the process of loops but sometimes I just get confused with the more complicated ones.

Thanks.

1. //1.
   String[] myArray = split("shoes and ships and ceiling wax and cabbages and kings", ' ');
   String[][] myOtherArray = new String[3][3];
   int index = 1;
   for (int i = 0; i < 3; i++) {
     for (int j = 0; j < 3; j++) {
       myOtherArray[i][j] = myArray[index];
       index++;
     }
     println(myOtherArray[2][0]);
   }
   -------------------------------------
   //2.
   int x = 0;
   for (int i = 0; i < 10; i++)
   if (i % 2 == 0) {
   x += 5;
   println(x);
   }
   
   ------------------------------------
   //3.
   for (int i = 1; i <= 5; i++)
   for (int j = 10; j > i; j--)
   statement;
   
   ------------------------------------
   //4.
   String[] myArray = {"hello", "there", "folks", "this", "is", "a", "test"};
   String accum = "";
   for(int i = myArray.length -1; i > 0; i--) {
   accum = myArray[i] + accum;
   }
   println(accum); length
   
   -----------------------------------
2. //5
   int[] myArray = {1,2,3,4,5,6,7,8,9};
   for (int i = 5; i >=0; i--)  {
   myArray[i] += myArray[i + 1];
   println(myArray[i]);
   }
   
   

Hi, I'm simply trying to draw a few concentric circles with two colors but it's not working properly.
I can't see the problem. Any suggestions?

1. Heart loops;
   color col = color(255, 0, 0);
   color col2 = color(0, 0, 255);
   
   void setup() {
     size(800, 800);
     background(255);
     smooth();
     loops = new Heart(width/2, height/2, 800, 30);
   }
   
   void draw() {  
     loops.drawCircle();
   }
   
   class Heart {
     int x, y;
     int dia;
     int steps;
     Heart(int _x, int _y, int _dia, int _steps) {
       x = _x;
       y = _y;
       dia = _dia;
       steps = _steps;
     }
     void drawCircle() {
       for (int i = dia; i > 0; i-=steps) {
         if (i%(2 * steps) == 0) {       
           fill(col);
         }
         else
         {
           fill(col2);
         }
         ellipse(x, y, i, i);
       }
     }
   }
   
   

Hi.

I am trying to simply count all the letters for a user input string but don't want any 'spaces' to be included in the count, just the letters.

Is this possible using length() ?

Thanks for any help!

1. import javax.swing.JOptionPane;
   String s;
   
   void setup()  {
     size(1000,400);
     background(255);
     fill(0);
     smooth();
     textAlign(CENTER);
     textSize(18);
     s = JOptionPane.showInputDialog("Enter a word or sentence");
    
   }
   
   void draw()  {
     text("There are "+s.length()+ " letters in your word or sentence.", width/2, 80);  // length of string.
   }
   

Hi.

Just wondering if somebody could tell me why an 'unexpected char '\' error is being generated in this code?

Thanks

1. int[] xpos = new int[50];
   int[] ypos = new int[50];
   
   void setup() {
     size(200, 200);
     smooth();
   
     for (int i = 0; i < xPos.length; i++) {
       xpos[i] = 0;
       ypos[i] = 0;
     }
   }
   
   void draw() {
     background(255);
     for (int i = 0; i < xpos.length-1; i++) {
       xpos[i] = xpos[i + 1];
       ypos[i] = ypos[i + 1];
     }
     xpos[xpos.length–1] = mouseX;
     ypos[ypos.length–1] = mouseY;
     for (int i = 0; i < xpos.length; i++) {
       noStroke();
       fill(255-i*5);
       ellipse(xpos[i], ypos[i], i, i);
     }
   }
   
   

Hi.

Well I'm stuck again. All I'm trying to do is be able to click the mouse and drag the circle into any quadrant and have the ball 'snap' to the center of the quadrant upon a mouse release. When the mouse is released the color of the ball should change too - nothing occurs on a mouse press.
How can I drag and release the 'ball' at this point and also make it change color upon a release?

Thanks.

1. Ball all;
   
   void setup() {
     size(400, 400);
     smooth();
     all = new Ball();
   }
   
   void draw() {
     background(255);
     lines(); 
     all.mouseClicked();
     all.positions(); 
     all.display();
   }
   
   void lines() {
     line(width/2, 0, width/2, height);
     line(0, height/2, width, height/2);
   }
   
   class Ball { 
     int posX;
     int posY;
     final int dia;
     color col;
     Ball() {
       posX = mouseX;
       posY = mouseY;
       dia = 100;   
       col = color(random(0, 255), random(0, 255), random(0, 255));
     }
     void display() {
       fill(col);
       noStroke();
       ellipse(posX, posY, dia, dia);
       strokeWeight(3);
       stroke(0);
     }
     void positions() {     
       if (posX <= width/2 && posY <=height/2) {
         posX=width/4;
         posY=height/4;
       }
       if (posX >= width/2 && posY <=height/2) {
         posX = 3*width/4;
         posY = height/4;
       }
       if (posX <= width/2 && posY >= height/2) {
         posX = width/4;
         posY = 3*height/4;
       }
       if (posX >= width/2 && posY >= height/2) {
         posX = 3*width/4;
         posY = 3*height/4;
       }
     }
     void mouseClicked() {  
       posX = mouseX;
       posY = mouseY;
     }
   }
   
   

Hi all.

I am trying to write a program that will start with two random ellipses, at random diameters between 20,40 and at random positions and color with each start. The speed of the balls must be randomised between -5 and 5. If the two balls collide the program stops and if the balls hit any edges they are rebounded. I'm not sure how to go about adding collision detection to the balls or have them bounce off edges.
I have never used a 'class' before so I'm just not sure if I have implemented things correctly (constructor) along with the functions I have used and well probably many other things that are wrong.

Any help would be appreciated.

Thanks.

1. Ball myBall;
   
   void setup() {
     size(400, 400);
     myBall = new Ball();  //should this line be in the constructor for class ball?
     smooth();
     frameRate(200);
   }
   
   void draw() {
     background(255);
     myBall.display();
     myBall.movingBall();
     myBall.collision();
   }
   
   class Ball {
     int radius;
     int locX, locY;
     int speedX, speedY;
     color col;
     //CONSTRUCTOR
     Ball() {
       speedX=int(random(-5, 5));
       speedY=int(random(-5, 5));
       col = int(random(0, 255));  //??? Color
       radius = int(random(20, 40));
       locY = int(random(0, 400)); 
       locX = int(random(0, 400));
     } 
     void display() {
       ellipseMode(CENTER);
       noStroke();
       fill(col);
       smooth();
       ellipse(locX + speedX, locY + speedY, radius*2, radius*2);
     }
     void movingBall() {
       if (locX >= width || locX <=0) {
         speedX = -1;
       }
       if (locY >= height || locY <= 0) {
         speedY = -1;
       }
       if (locX <= width) {
         locX++;
       }
       if (locY <= height) {
         locY++;
       }
     }
     void collision() {   // ????
     }
   }