int noiseNum;
float noiseScale = 0.01;
int octaves = 4;
float falloff = 0.5;

void setup(){
  size(400,400);
  perlin_terrain();
}
void loop(){
}
void perlin_terrain(){
  noiseDetail(octaves,falloff);
  for(int j=0;j<height;j++){
    for(int i=0;i<width;i++){
      float col = noise((i+noiseNum)*noiseScale, (j+noiseNum)*noiseScale) * 2000;
      int col1 = int(col/50)*10;
      float col2 = col%50;
      stroke(0,255-col1,col2+100);
      point(i,j);
    }
  }
}
void mousePressed(){
  noiseNum += width;
  perlin_terrain();  
}