Clicca sul link qui sotto e metti le mani davanti alla webcam :
https://www.shadertoy.com/view/WtjGDz
// This is a rework of https://www.shadertoy.com/view/lssGDj,
// created by movAX13h, with sound, by Radical Ed
float character(int n, vec2 p)
{
p = floor(p*vec2(4.0, -4.0) + 2.5);