#version 450 core
#ifdef GL_ES
precision mediump float;
#endif

uniform vec2 resolution;
uniform float ticks;
uniform int program;

uniform sampler2D images[4];
layout (binding = 0,rgba32f) uniform image2D backbuffer;
uniform float ratios[4];
uniform float params[32];

out vec4 fragColor;

float random (in float x) {
  return fract(sin(x)*43758.5453123)-0.5;
}

vec4 img(int i) {
	vec2 st = gl_FragCoord.xy/resolution.xy;
  st.x *= ratios[i];
  st.x += (1-ratios[i])*0.5;
  st.x += 0.5;
  return texture2D(images[i],st);
}

void main (void) {
    vec4 image = img(0);
  if (program == 0) {
    image = img(2);
    image.rg = image.gr;
    image = 1.5*image;
    }
  /*
  else {
    ivec2 P = ivec2(gl_FragCoord.xy);
    vec4 buf = imageLoad(backbuffer,P);
    vec4 img1 = mix(img(0),img(1),sin(ticks));
    vec4 img2 = mix(img(2),img(3),cos(ticks));
    buf.bg = buf.gr;
    //buf.b = 0.0;
    vec4 i = mix(img1,img2,0.5);
    //P = ivec2(gl_FragCoord.xy);
    imageStore(backbuffer,P,i);
    image = mix(i,buf,0.8);
    }
    */
  fragColor = image;
}