Assign random color to each circle

Processing Coding Questions
1

I am trying to complete a school project and this is what I have right now (see below). I want to assign a random color to each circle every time - but right now, I am stuck at where the same color is being assigned to all the circles (a random color each time)… Can anyone help me? I want each circle to have a different shade of brown :frowning:

Tribble[] tribble = new Tribble[50];
color aColor = color( random(255),random(255),random(255) );

void setup() {
  size(400, 400);
  background(255);
  frameRate(30);
  for (int i = 0; i < tribble.length; i++) {
    tribble[i] = new Tribble(random(0, 400), random(0, 400));
  }
}

void draw() {
  background(255);
  tribble[(int)random(tribble.length)].excited();
  for (int i=0; i<tribble.length; i++) {
    tribble[i].display();
  }
}


class Tribble {
  float xPos, yPos;
  int start;
  float time;
  int offset;
  boolean wakeup;


  Tribble(float x, float y) {
    xPos = x;
    yPos = y;
  }
  //Makes the tribble excited
 void excited() {
time = (frameCount/60) % 7;
if (time >= 4 && time < 6) xPos += random(-1, 1);
}

  //Draws the tribble.
  void display() {
    ellipseMode(CENTER);
    fill(aColor);
    ellipse(xPos, yPos, 50, 50);
  }
}
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2

Why don’t you make the variable aColor a field of your class Tribble as well? :roll_eyes:

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3

An online example sketch w/ colored balloons: :sunglasses:
http://Studio.ProcessingTogether.com/sp/pad/export/ro.9FqnMDLUZqQCV

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4

I’m a little confused because in my code I’m constructing 200 circles at once

5

color aColor can be an attribute in your Tribble class. In the constructor of your class, you can assign it by:

...
  color aColor;
  Tribble(float x, float y) {
    xPos = x;
    yPos = y;
    aColor = color(random(255),random(255),random(255))
  }
...

And now, when you’re calling fill(aColor) in your display function, you should be getting different colors. You can also experiment with different color spaces like colorMode(HSB) and have acolor=color(random(255),255,255) so that you specify a certain range of hue you like.

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6

You’ve only got 1 aColor variable:
color aColor = color( random(255),random(255),random(255) );

Instead, turn it into an additional field for your class Tribble, like all the other 6 fields already are:

class Tribble {
  float xPos, yPos, time;
  int start, offset;
  boolean wakeup;
  color aColor = (int) random(#000000);
}

This way, each instance of Tribble got its own aColor variable. :upside_down_face:

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7

How does the

(int) random(#000000);

work? Isn’t that saying pick a number between 0 and 0? or am I understanding that completely wrong? :thinking:

8

Try out: println(#000000); on Processing’s IDE (PDE): -16777216
https://Processing.org/reference/color_datatype.html

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