shader_pucker.txt

// ZA WARUDO

// helper function, please ignore
number _hue(number s, number t, number h)
{
	h = mod(h, 1.);
	number six_h = 6.0 * h;
	if (six_h < 1.) return (t-s) * six_h + s;
	if (six_h < 3.) return t;
	if (six_h < 4.) return (t-s) * (4.-six_h) + s;
	return s;
}

// input: vec4(h,s,l,a), with h,s,l,a = 0..1
// output: vec4(r,g,b,a), with r,g,b,a = 0..1
vec4 hsl_to_rgb(vec4 c)
{
	if (c.y == 0)
		return vec4(vec3(c.z), c.a);

	number t = (c.z < .5) ? c.y*c.z + c.z : -c.y*c.z + (c.y+c.z);
	number s = 2.0 * c.z - t;
	return vec4(_hue(s,t,c.x + 1./3.), _hue(s,t,c.x), _hue(s,t,c.x - 1./3.), c.w);
}

// input: vec4(r,g,b,a), with r,g,b,a = 0..1
// output: vec4(h,s,l,a), with h,s,l,a = 0..1
vec4 rgb_to_hsl(vec4 c)
{
	number low = min(c.r, min(c.g, c.b));
	number high = max(c.r, max(c.g, c.b));
	number delta = high - low;
	number sum = high+low;

	vec4 hsl = vec4(.0, .0, .5 * sum, c.a);
	if (delta == .0)
		return hsl;

	hsl.y = (hsl.z < .5) ? delta / sum : delta / (2.0 - sum);

	if (high == c.r)
		hsl.x = (c.g - c.b) / delta;
	else if (high == c.g)
		hsl.x = (c.b - c.r) / delta + 2.0;
	else
		hsl.x = (c.r - c.g) / delta + 4.0;

	hsl.x = mod(hsl.x / 6., 1.);
	return hsl;
}

uniform number time;
number pi = atan(1.0)*4.0;
vec4 effect(vec4 color, Image texture, vec2 texture_coords, vec2 scoord) {
  //distort part
  vec2 npos = texture_coords;
  number cx = texture_coords.x-0.5;
  number cy = texture_coords.y-0.5;
  number dist = sqrt(cx*cx + cy*cy);
  cx = cx/dist;
  cy = cy/dist;
  number circle = sin(min(time/130,pi))*1.2;
  npos.x = npos.x + (cx/6 * sin((dist-0.7)*17)/2) * circle;
  npos.y = npos.y + (cy/6 * sin((dist-0.7)*17)/2) * circle;
  vec4 texturecolor = Texel(texture, npos);
  texturecolor = texturecolor * color;
  //color part
  if(dist < circle) {
    texturecolor.r = 1 - texturecolor.r;
    texturecolor.g = 1 - texturecolor.g;
    texturecolor.b = 1 - texturecolor.b;
    vec4 chromcolo = rgb_to_hsl(texturecolor);
    chromcolo.x = 0.666 + time/400;
    if(mod(circle - dist, 0.4/3) < 0.06 && circle - dist < 0.4) {
    chromcolo.z = 1;
    chromcolo.a = 1;
  }
    texturecolor = hsl_to_rgb(chromcolo);
  }
  return vec4(texturecolor.r, texturecolor.g, texturecolor.b, texturecolor.a);
}