shaders/sky.frag


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#version 150
#extension GL_ARB_explicit_attrib_location : enable
#extension GL_ARB_explicit_uniform_location : enable

layout(location = 0) out vec4 frag_color ;
layout(location = 1) uniform vec4 globalAmbient ;

uniform vec4 lightpos ;

uniform sampler2D texture ;
uniform sampler2D night_tex ;

in vec2 texcoord;
in vec4 position ;

void main() {  
    // the sun
    
    vec3 lighttofrag = vec3(position*10000000 - lightpos) ;
    vec3 lighttocamera = vec3(lightpos) ;
    vec4 mul = vec4(vec3( sqrt(0.001 / (1 - dot(normalize(lighttocamera), normalize(lighttofrag))))), 1) ;
    mul *= vec4(1.0,0.95,0.8,1.0) ;
    frag_color = 
        mix(texture2D(night_tex,texcoord) * (1-globalAmbient.a),
            texture2D(texture,texcoord) * vec4(normalize(globalAmbient.xyz),1),
            (globalAmbient.a + 1) / 2) ;
    frag_color += mul ;

}