/*Drew Cogbill
 ex40.14
 [computation08]*/

// Convert pixel values into a circle's diameter 
PImage trista; 
int index; 
float x = 0.0;
float y = 0.0;

void setup() { 
  smooth(); 
  fill(0); 
  trista = loadImage("trista.jpg");
  trista.loadPixels();
  size(400, 400);
  background(204);
} 

void draw() { 
  color c = trista.pixels[index];
  float r = red(c);
  stroke(c*2);
  float mappedr = map(r, 0, 255, 4, 15);
  if (x > 400) {
    x = mappedr;
  }
  if (y > 400) {
    y = mappedr;
  }
  line(x, y, mappedr, y+mappedr);
  index++; 
  x += mappedr;
  y += mappedr;
  if (index == width*height) { 
    index = 0;  // Return to the first pixel 
  } 
}