out vec4 FragColor;

uniform vec4 uColour;
uniform sampler2D uTexGarbage;
uniform float uTime;

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

void main()
{
   float fintensity = 1.0-(abs(aNorm.y)*0.7);
   float fblend = pow(fintensity,6.0);
   vec3 horizon = vec3( 0.61, 0.71, 0.86 )*1.5;
   vec3 skycolour = vec3( 0.31, 0.56, 0.91 );
   vec3 diffuse = mix( skycolour, horizon, fblend );

   float fmove = uTime * 0.004;
   vec2 cloudplane = (aCo.xz / (aCo.y*sign(aNorm.y))) * 0.03;
   vec4 clouds1 = texture( uTexGarbage, cloudplane + vec2(0.1,0.4)*fmove*2.0 );
   vec4 clouds2 = texture( uTexGarbage, cloudplane + 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(aNorm.y),0.3)*2.0;

   vec3 colour_ocean = vec3( 0.61, 0.84, 0.9 );
   float fhorizon = step( aNorm.y * 0.5 + 0.5, 0.5 );

   vec3 skycomp = mix(diffuse, vec3(1.0,1.0,1.0), cloud_e);
   skycomp = mix(mix(pow(colour_ocean,vec3(6.0))*0.6,skycomp, 0.7),skycomp,fhorizon);

   FragColor = vec4(skycomp, 0.0);
}