out vec4 FragColor;

uniform float uTime;
uniform vec3 uCam;
uniform vec4 uColour;

in vec3 aNorm;
in vec2 aUv;
in vec3 aCo;

#include "motion_vectors_fs.glsl"

const int NOISE_LOOP = 3;
vec3 digital_noise( uvec3 iuv ){
   iuv *=uvec3(8,2524,7552);
   for( int i=0; i<NOISE_LOOP; i++ )
      iuv += (iuv.yzx<<2) ^ (iuv.yxz)+iuv.z;
   return vec3(iuv)*(1.0/float(0xffffffffU));
}

vec2 rand_hash22( vec2 p ){
   vec3 p3 = fract(vec3(p.xyx) * 213.8976123);
   p3 += dot(p3, p3.yzx+19.19);
   return fract(vec2((p3.x + p3.y)*p3.z, (p3.x+p3.z)*p3.y));
}

void main(){
   compute_motion_vectors();

   vec2 ssuv = gl_FragCoord.xy;
   float grad = 1.0-aUv.y*0.1;
   float opacity = rand_hash22( vec2(floor(aUv.y*100.0),floor(aCo.z*10.0+uTime*40.0)) ).r*grad;
   
   vec3 vDither = vec3( dot( vec2( 171.0, 231.0 ), ssuv) );
   float dither = fract( vDither.g / 71.0 ) - 0.5;

   if( opacity<0.9 )
      discard;

   FragColor = vec4(0.7,0.5,0.5,1.0);
}