// Brownian motion 
// by REAS <http://reas.com> 

int num = 2000; 
int range = 4; 
 
float[] ax = new float[num]; 
float[] ay = new float[num]; 
 
 
void setup() 
{ 
  size(200, 200); 
  for(int i=0; i<num; i++) { 
    ax[i] = 50; 
    ay[i] = height/2; 
  } 
  framerate(30); 
} 
 
void draw() 
{ 
  background(51); 
  
  // Shift all elements 1 place to the left 
  for(int i=1; i<num; i++) { 
    ax[i-1] = ax[i]; 
    ay[i-1] = ay[i]; 
  } 
 
  // Put a new value at the end of the array 
  ax[num-1] += random(-range, range); 
  ay[num-1] += random(-range, range); 
 
  // Constrain all points to the screen 
  ax[num-1] = constrain(ax[num-1], 0, width); 
  ay[num-1] = constrain(ay[num-1], 0, height); 
  
  // Draw a line connecting the points 
  for(int i=1; i<num; i++) {    
    float val = float(i)/num * 204.0 + 51; 
    stroke(val); 
    line(ax[i-1], ay[i-1], ax[i], ay[i]); 
  } 
}