perlin.pde

float bg = 20;
float s = 255;

float xoff = 0;
float yoff = 1000;

float u(float n) {
  return width/100 * n;
}

void setup() {
  size(1000,1000);
  background(bg);
  strokeWeight(1);
  stroke(s);
  smooth();
}

void draw() {
  background(bg);
  for(float y = height*0.1; y < height*0.9; y += u(1.5)) {
    pushMatrix();
    translate(0, y);
    noFill();
    beginShape();
    for(float x = width*0.1; x < width*0.9; x++) {
      float ypos = map(noise(x/100 + xoff, y/100 + yoff), 0, 1, -100, 100);
      float magnitude = x < width*0.5 ? map(x, width*0.1, width*0.5, 0, 1) : map(x, width*0.5, width*1, 1, 0) ;
      ypos *= magnitude * 2 - 1;
      if(ypos > 0) ypos = 0;
      vertex(x, ypos);
    }
    endShape();
    popMatrix();
  }
  
  xoff += 0.02;
  yoff += -0.02;
}

void mousePressed() {
  String name = "yoel" + ".png";
  saveFrame(name);
}