Mountain Landscape Generator

/* based on the 'simple mountain' code of Nellie Robinson (narobins)  */

​

float[] pts;

int n;

int len;

float roughness;

int num_layers = 7;

​

void setup() {

  size(1200, 700);

  n = 7;

  len = int(pow(2, n));

  noLoop();

  noStroke();

}

​

float calcError(float n) {

 return random(-roughness, roughness) * n; 

}

​

void draw() {

  background(255);

  roughness = 0.02;

  pts = new float[len + 1];

  for (int i = num_layers; i > 0; i--) {

    pts[0] = (height - 100)/pow(2, i) + 25;

    pts[len] = (height - 100)/pow(2, i) + 25;

    fill(40 * i);

    fillarray();

    display();

    roughness *= 2.5;

  }

}

​

void fillarray() {

  for (int i = 0; i < n; i++) {

    int inc = len / int(pow(2, i));

    int start = 0;

    int next = start + inc;

    while(next <= len) {

      pts[(start + next) / 2] = calcError(inc) + (pts[start] + pts[next]) / 2;

      start = next;

      next += inc;

    }

  }

}

​

//draws layers back to front

void display() {

  float inc = width/float(len);

  beginShape();

  vertex(0, pts[0]);

  for (int i = 0; i < len + 1; i++) {

    curveVertex(i*inc, pts[i]);

  } 

  vertex(width, pts[len]);

  vertex(width, height);

  vertex(0, height);

  endShape(CLOSE);

}

​

void mousePressed() {

  redraw();

}