layout (location = 0) out vec4 oColour;
in float aAlpha;
uniform vec4 uColour;

#include "motion_vectors_fs.glsl"

void main(){
   compute_motion_vectors();

   vec2 ssuv = gl_FragCoord.xy;
   vec3 vDither = vec3( dot( vec2( 171.0, 231.0 ), ssuv) );
   float dither = fract( vDither.g / 71.0 ) - 0.5;

   if( aAlpha+dither<0.5 )
      discard;

   oColour = vec4( uColour.rgb, uColour.a * aAlpha );
}