A)

void setup() {
  size(200,200);
  smooth();
}

void draw() {
  background(255);
  stroke(0);
  fill(175);
  ellipse(50,50,50,50);
  ellipse(150,50,50,50);
  ellipse(50,150,50,50);
  ellipse(150,150,50,50);
}

B)

void setup() {
  size(200,200);
  smooth();
}

void draw() {
  background(255);
  stroke(0);
  line(100,0,100,100);
  line(100,100,0,200);
  line(100,100,200,200);
}

C)

void setup() {
  size(200,200);
  smooth();
}

void draw() {
  background(255);
  stroke(0);
  rectMode(CENTER);
  fill(175);
  rect(100,100,175,175);
  fill(255);
  ellipse(100,100,75,75);
}

Example Step 3 Answer:

float centerX = 100;
float centerY = 100;

void setup() {
  size(200,200);
  smooth();
}

void draw() {
  background(255);
  stroke(0);
  line(width/2,0,centerX,centerY);
  line(centerX,centerY,0,height);
  line(centerX,centerY,width,height);

  centerX += random(-1,1);
  centerY += random(-1,1);

  centerX = constrain(centerX,0,width);
  centerY = constrain(centerY,0,height);
}
  • Dolsign

    Hi I’ve attempted adding variable to A) with the intention of making it track from left to right but nothing is happening. What am I doing wrong?

    int circleX = 50;
    int circleY = 50;
    int circleSize = 50;
    int circleFill = 0;
    int speed = 1;

    // basic setup
    void setup() {
    size(200,200);
    background(255);
    smooth();
    }

    void draw() {
    stroke(0);
    fill(0);
    // circle top left
    ellipse(circleX,circleY,circleSize,circleSize);
    // circle top right
    ellipse(150,50,50,50);
    // circle bottom left
    ellipse(50,150,50,50);
    // circle bottom right
    ellipse(150,150,50,50);
    }

    void move() {
    circleX = circleX + speed;
    if (circleX > width) {
    circleX = 10;
    }
    }

    void display() {
    fill(circleFill);
    ellipse(circleX,circleY,circleSize,circleSize);
    }

    also do you know how I would create the > symbol on a mac because at the moment I can only copy and paste it. I’ve tried alt + every key available but still no joy

    Thank you

  • http://www.learningprocessing.com Daniel Shiffman

    You created the move() and display() functions, but never call them anywhere. Only draw() is called automatically by Processing so you’ll need to explicitly call your user-defined functions, i.e.

    void draw() {
  move();
  // etc.
}

    ‘>’ is SHIFT-PERIOD on my mac.