#version 330 core
in vec2 vUV;
out float FragColor;

uniform sampler2D ssaoInput;
uniform vec2 texelSize; 
uniform int horizontal; 


const float w0 = 0.2270270270;
const float w1 = 0.1945945946;
const float w2 = 0.1216216216;
const float w3 = 0.0540540541;
const float w4 = 0.0162162162;

void main()
{
    float result = 0.0;
    if (horizontal == 1)
    {
        result += texture(ssaoInput, vUV).r * w0;
        result += texture(ssaoInput, vUV + vec2(texelSize.x, 0.0)).r * w1;
        result += texture(ssaoInput, vUV - vec2(texelSize.x, 0.0)).r * w1;
        result += texture(ssaoInput, vUV + vec2(2.0 * texelSize.x, 0.0)).r * w2;
        result += texture(ssaoInput, vUV - vec2(2.0 * texelSize.x, 0.0)).r * w2;
        result += texture(ssaoInput, vUV + vec2(3.0 * texelSize.x, 0.0)).r * w3;
        result += texture(ssaoInput, vUV - vec2(3.0 * texelSize.x, 0.0)).r * w3;
        result += texture(ssaoInput, vUV + vec2(4.0 * texelSize.x, 0.0)).r * w4;
        result += texture(ssaoInput, vUV - vec2(4.0 * texelSize.x, 0.0)).r * w4;
    }
    else
    {
        result += texture(ssaoInput, vUV).r * w0;
        result += texture(ssaoInput, vUV + vec2(0.0, texelSize.y)).r * w1;
        result += texture(ssaoInput, vUV - vec2(0.0, texelSize.y)).r * w1;
        result += texture(ssaoInput, vUV + vec2(0.0, 2.0 * texelSize.y)).r * w2;
        result += texture(ssaoInput, vUV - vec2(0.0, 2.0 * texelSize.y)).r * w2;
        result += texture(ssaoInput, vUV + vec2(0.0, 3.0 * texelSize.y)).r * w3;
        result += texture(ssaoInput, vUV - vec2(0.0, 3.0 * texelSize.y)).r * w3;
        result += texture(ssaoInput, vUV + vec2(0.0, 4.0 * texelSize.y)).r * w4;
        result += texture(ssaoInput, vUV - vec2(0.0, 4.0 * texelSize.y)).r * w4;
    }

    FragColor = result;
}