uniform sampler2D uTexGarbage;

in vec4 aColour;
in vec2 aUv;
in vec3 aNorm;
in vec3 aCo;
in vec3 aWorldCo;

#include "common_world.glsl"
#include "motion_vectors_fs.glsl"
#include "light_clearskies.glsl"

void main()
{
   compute_motion_vectors();

   world_info world;
   scene_state( g_time, world );

   vec3 rd = normalize(aNorm);

   float fmove = g_time * 0.004;
   vec2 cloudplane = (rd.xz / (rd.y*sign(rd.y))) * 0.025;
   vec4 clouds1 = texture( uTexGarbage, cloudplane + vec2(0.1,0.4)*fmove*2.0 );
   vec4 clouds2 = texture( uTexGarbage, cloudplane*2.0 + vec2(0.3,0.1)*fmove );

   float cloud_d = max(clouds1.b*clouds2.r -0.2 - clouds2.g*0.4,0.0);
   float cloud_e = pow(cloud_d,1.5)*pow(abs(rd.y),0.3)*2.0;

   oColour = vec4( scene_sky( -rd, world ) ,1.0);

   vec3 cloud_colour    = mix( mix(NIGHTSKY_COLOUR,vec3(1.0),world.day_phase), 
                                    SUNSET_COLOUR, world.sunset_phase );
   oColour.rgb = mix( oColour.rgb, cloud_colour, cloud_e );
}