Bounce.fs

Code

uniform sampler2D startImage;
uniform sampler2D endImage;
uniform float progress;
uniform float bounces;
uniform float shadow_height;
uniform vec4 shadow_colour;
precision mediump float;
/*{
    "CATEGORIES": [
        "Wipe"
    ],
    "CREDIT": "Automatically converted from https://www.github.com/gl-transitions/gl-transitions/tree/master/Bounce.glsl",
    "DESCRIPTION": "",
    "INPUTS": [
        {
            "NAME": "startImage",
            "TYPE": "image"
        },
        {
            "NAME": "endImage",
            "TYPE": "image"
        },
        {
            "DEFAULT": 0,
            "MAX": 1,
            "MIN": 0,
            "NAME": "progress",
            "TYPE": "float"
        },
        {
            "DEFAULT": 2,
            "MAX": 10,
            "MIN": 0,
            "NAME": "bounces",
            "TYPE": "float"
        },
        {
            "DEFAULT": 0.1,
            "MAX": 1,
            "MIN": 0,
            "NAME": "shadow_height",
            "TYPE": "float"
        },
        {
            "DEFAULT": [
                0,
                0,
                0,
                1
            ],
            "NAME": "shadow_colour",
            "TYPE": "color"
        }
    ],
    "ISFVSN": "2",
    "VSN": ""
}
*/



vec4 getFromColor(vec2 inUV)	{
	return texture2D(startImage, inUV);
}
vec4 getToColor(vec2 inUV)	{
	return texture2D(endImage, inUV);
}



// Author: Adrian Purser
// License: MIT


const float PI = 3.14159265358;

vec4 transition (vec2 uv) {
  float time = progress;
  float stime = sin(time * PI / 2.);
  float phase = time * PI * bounces;
  float y = (abs(cos(phase))) * (1.0 - stime);
  float d = uv.y - y;
  return mix(
    mix(
      getToColor(uv),
      shadow_colour,
      step(d, shadow_height) * (1. - mix(
        ((d / shadow_height) * shadow_colour.a) + (1.0 - shadow_colour.a),
        1.0,
        smoothstep(0.95, 1., progress) // fade-out the shadow at the end
      ))
    ),
    getFromColor(vec2(uv.x, uv.y + (1.0 - y))),
    step(d, 0.0)
  );
}



void main()	{
	gl_FragColor = transition((gl_FragCoord.xy / u_resolution.xy).xy);
}