Mandelbrot shader

gistfile1.txt

precision mediump float;

varying vec2 position;

void main() {
  vec2 c = position;
  vec2 z = c;
  
  float escape = 0.;
  const float iter = 50.;
  for(float i = 0.; i<iter; i++) {
    escape = i;
    float x = (z.x * z.x - z.y * z.y) + c.x;
    float y = (z.y * z.x + z.x * z.y) + c.y;
    
    if ((x * x + y * y) > 800.0) break;
    z.x = x;
    z.y = y;
  }
  
  float b = escape/iter;
  
  vec3 col = vec3(0.5,0.8,1.0);
  
  gl_FragColor = vec4(col*b,1.);
}