#version 450 core
in vec2 vTexPos;
out vec4 fColor;
layout(binding = 0) uniform sampler2D wincol;
layout(binding = 1) uniform sampler2D winpos;
layout(binding = 2) uniform sampler2D cloudcol;
layout(binding = 3) uniform sampler2D cloudpos;
vec4 blend (vec4 src, vec4 dst) {
    return src + (1-src.a) * dst;
}
void main() { 
    //fColor = texture(t0, vTexPos) + texture(t2, vTexPos); 
    vec4 x = texture(wincol, vTexPos);
    float xz = texture(winpos, vTexPos).z;
    vec4 y = texture(cloudcol, vTexPos);
    float yz = texture(cloudpos, vTexPos).z;
    fColor = ( xz > yz ? blend(x,y) : blend(y,x)) ;
}