precision highp float;
varying vec2 uv0;

uniform sampler2D inputImageTexture;
uniform sampler2D inputImageTexture2;
uniform int imageWidth;
uniform int imageHeight;
uniform float progress;
uniform float count; // = 10.0
uniform float smoothness; // = 0.5

vec4 getFromColor(vec2 p)
{
    return texture2D(inputImageTexture,p);
}

vec4 getToColor(vec2 p)
{
    return texture2D(inputImageTexture2,p);
}

vec4 transition (vec2 p) {
  float pr = smoothstep(-smoothness, 0.0, p.x - progress * (1.0 + smoothness));
  float s = step(pr, fract(count * p.x));
  return mix(getFromColor(p), getToColor(p), s);
}
    
void main(void)
{
    vec4 resultColor = transition(uv0);
    gl_FragColor=resultColor;
}