#version 330 core

uniform sampler2D diffuseMap;
uniform sampler2D occlusionMap;
uniform vec2 textureTiling;

in vec2 fragTexCoord;
in vec3 fragNormal;
in vec2 fragTileTexCoord;

flat in uvec4 occlusionSides;
flat in int topLeftObscured;
flat in int topRightObscured;
flat in int bottomLeftObscured;
flat in int bottomRightObscured;
flat in int quadHeight;
flat in int quadWidth;

out vec4 outColor;

int calculate_ao_square()
{
    ivec2 tileCoord = ivec2(fragTileTexCoord);
    int ao_square = 0;

    if(tileCoord.x == quadWidth - 1 && ((occlusionSides.x & uint(1 << tileCoord.y)) > uint(0))) ao_square |= 1 << 0;

    if(tileCoord.x == quadWidth - 1 && tileCoord.y == quadHeight - 1 && bottomRightObscured > 0) ao_square |= 1 << 1;
    if(tileCoord.x == quadWidth - 1 && tileCoord.y != quadHeight - 1 && ((occlusionSides.x & uint(1 << (tileCoord.y+1))) > uint(0))) ao_square |= 1 << 1;
    if(tileCoord.x != quadWidth - 1 && tileCoord.y == quadHeight - 1 && ((occlusionSides.w & uint(1 << (tileCoord.x+1))) > uint(0))) ao_square |= 1 << 1;

    if(tileCoord.y == quadHeight - 1 && ((occlusionSides.w & uint(1 << tileCoord.x)) > uint(0))) ao_square |= 1 << 2;

    if(tileCoord.x == 0 && tileCoord.y == quadHeight - 1 && bottomLeftObscured > 0) ao_square |= 1 << 3;
    if(tileCoord.x == 0 && tileCoord.y != quadHeight - 1 && ((occlusionSides.y & uint(1 << (tileCoord.y+1))) > uint(0))) ao_square |= 1 << 3;
    if(tileCoord.x != 0 && tileCoord.y == quadHeight - 1 && ((occlusionSides.w & uint(1 << (tileCoord.x-1))) > uint(0))) ao_square |= 1 << 3;

    if(tileCoord.x == 0 && ((occlusionSides.y & uint(1 << tileCoord.y)) > uint(0))) ao_square |= 1 << 4;

    if(tileCoord.x == 0 && tileCoord.y == 0 && topRightObscured > 0) ao_square |= 1 << 5;
    if(tileCoord.x == 0 && tileCoord.y != 0 && ((occlusionSides.y & uint(1 << (tileCoord.y-1))) > uint(0))) ao_square |= 1 << 5;
    if(tileCoord.x != 0 && tileCoord.y == 0 && ((occlusionSides.z & uint(1 << (tileCoord.x-1))) > uint(0))) ao_square |= 1 << 5;

    if(tileCoord.y == 0 && ((occlusionSides.z & uint(1 << tileCoord.x)) > uint(0))) ao_square |= 1 << 6;

    if(tileCoord.x == quadWidth - 1 && tileCoord.y == 0 && topLeftObscured > 0) ao_square |= 1 << 7;
    if(tileCoord.x == quadWidth - 1 && tileCoord.y != 0 && ((occlusionSides.x & uint(1 << (tileCoord.y-1))) > uint(0))) ao_square |= 1 << 7;
    if(tileCoord.x != quadWidth - 1 && tileCoord.y == 0 && ((occlusionSides.z & uint(1 << (tileCoord.x+1))) > uint(0))) ao_square |= 1 << 7;

    return ao_square;
}

void main()
{
    vec2 texCoord = (floor(fragTexCoord*textureTiling) + fract(fragTileTexCoord)) / textureTiling;

    int ao_square = calculate_ao_square();

    outColor = texture(diffuseMap, texCoord);
    outColor *= texture(occlusionMap, (vec2(ao_square, 0)+fract(fragTileTexCoord))/vec2(256, 1));

    outColor.a = 1;

    //uint bit = uint(fragTileTexCoord * 32);
    //outColor.g = (((uint(quadWidth) >> bit) & uint(1)) == uint(1)) ? 
    //              ((bit % uint(2) == uint(0)) ? 1.0 : 0.8): 
    //              ((bit % uint(2) == uint(0)) ? 0.0 : 0.2);
}