// Dartmouth CS 2, Winter 2009, Chris Bailey-Kellogg
// Notes 9 | Sketch 4

size(300,300);

// Create lines from points; try varying the spacing (R&F 6-05)
for (int x=0; x<100; x+=10) {
  point(x, 5);
}
for (int x=100; x<200; x+=5) {
  point(x, 5);
}
for (int x=200; x<300; x++) {
  point(x, 5);
}

// Spacing can be geometric
for (float x=1; x<300; x*=1.2) {
  point(x, 20);
}

// Add some noise (Greenberg 6-07)
for (int x=0; x<100; x++) {
  point(x, 50+random(-5,5));
}
// Spreading (Greenberg 6-08)
float h=0, dh=0.2;
for (int x=0; x<100; x++) {
  point(150+x, 50+random(-h,h));
  h += dh;
}

// Gradient -- change color with position (R&F 6-04)
for (int x=0; x<256; x+=2) {
  stroke(x);
  line(x, 100, x, 150);
}

// Random-colored bullseye (based on R&F 6-03)
stroke(0);
smooth();
for (int d=100; d > 0; d -= 20) {
  fill(random(255),random(255),random(255));
  ellipse(150, 230, d, d);
}