// Horseys I (single horsey, footprint mode)
// Jo Wilson, May 2010
// http://www.pixelbrain.me.uk
// written in Processing 1.1

int dim = 400;    // screen dimensions (square)
int x, y;

void setup() {
  size(dim,dim,P3D);
  background(0);
  frameRate(1000);
  //choose starting point
  x = int(random(0.25*dim,0.75*dim));
  y = int(random(0.25*dim,0.75*dim));
}

void draw() {
  moveHorsey();
  // choose colour based on position (produces nice gradient)
  color c = color(200*(dim-x)/dim, 50*(dim-y)/dim, 200*x/dim);
  set(x, y, c);
}

// If horsey is inside the drawing area, choose which knight's move it will make.
void moveHorsey() {
  if ((x > 0) && (x < dim) && (y > 0) && (y < dim)) {
    float r = random(0,200);
    if (r < 25) {
      x = x + 1;
      y = y + 2;
    }
    else if (r < 50) {
      x = x + 1;
      y = y - 2;
    }
    else if (r < 75) {
      x = x + 2;
      y = y + 1;
    }
    else if (r < 100) {
      x = x + 2;
      y = y - 1;
    }
    else if (r < 125) {
      x = x - 1;
      y = y + 2;
    }
    else if (r < 150) {
      x = x - 1;
      y = y - 2;
    }
    else if (r < 175) {
      x = x - 2;
      y = y + 1;
    }
    else if (r < 200) {
      x = x - 2;
      y = y - 1;
    }
  }
  // If horsey has escaped, save picture and exit.
  //else {
    //save("Horseys1_"+dim+".png");
    //exit();
  //}
}

void mouseClicked() {
  reset();
}

// clear drawing canvas and re-initialise x and y
void reset() {
  background(0);
  x = int(random(0.25*dim,0.75*dim));
  y = int(random(0.25*dim,0.75*dim));
}