// cannabisleaf — generated from https://github.com/gl-transitions/gl-transitions/blob/master/transitions/cannabisleaf.glsl
// Author: @Flexi23
// License: MIT
// Description: A cannabis-leaf shape grows from the center to reveal the incoming image

uniform shader _from;
uniform shader _to;
uniform float2 _resolution;
uniform float progress;
uniform float ratio;

vec4 getFromColor(vec2 uv) { return vec4(unpremul(_from.eval(vec2(uv.x, 1.0 - uv.y) * _resolution))); }
vec4 getToColor(vec2 uv) { return vec4(unpremul(_to.eval(vec2(uv.x, 1.0 - uv.y) * _resolution))); }

vec4 transition (vec2 uv) {
  if(progress == 0.0){
    return getFromColor(uv);
  }
  vec2 leaf_uv = (uv - vec2(0.5))/10./pow(progress,3.5);
	leaf_uv.y += 0.35;
	float r = 0.18;
	float o = atan(leaf_uv.y, leaf_uv.x);
  return mix(getFromColor(uv), getToColor(uv), 1.-step(1. - length(leaf_uv)+r*(1.+sin(o))*(1.+0.9 * cos(8.*o))*(1.+0.1*cos(24.*o))*(0.9+0.05*cos(200.*o)), 1.));
}

half4 main(float2 _coord) {
  vec2 _uv = _coord / _resolution;
  vec4 _c = clamp(transition(vec2(_uv.x, 1.0 - _uv.y)), 0.0, 1.0);
  return half4(_c.rgb * _c.a, _c.a);
}