PVector[] p ;
float shift ;
float fade;
float fillCol ;
float rot ;
float spin ;
float deg  ;
int   bval ;

void setup() 
{
  size(400, 400);
  frameRate(7) ;
}

void draw()
{
  p = new PVector[3];
  p[0] = new PVector(-width/2, height/2);
  p[1] = new PVector(width/2, height/2);
  p[2] = new PVector(0, -height/2);
  shift = 1.0;
  fade = 255.0 / (width/2.0/shift);
  spin = 360.0 / (width/2.0/shift);
  fillCol = 0;
  rot = 0;
  translate(width/2, height/2);
  background(0);
  smooth();
  noStroke();
  deg = deg + 0.075 ;
  bval = 1 ;
  triBlur();
}

void triBlur() {
  bval++ ;
  fill( color(fillCol,fillCol,128) );
  fillCol += fade;
  rotate(spin+radians(deg));
  // another interesting variation: uncomment the line below 
  // rotate(rot+=radians(spin));
  triangle(p[0].x += shift, p[0].y -= shift/2, 
           p[1].x -= shift, p[1].y -= shift/2, 
           p[2].x, p[2].y += shift); 
  if (p[0].x < 0) {
    // recursive call
    triBlur();
  }
}