#version 450 core
in vec2 vTexPos;
out vec4 fColor;

uniform vec2 winSize;
uniform sampler2D screenTexture;

const float horOff = 1.0 / winSize.x;
//const float verOff = 1.0 / 600.0;

//const float kernel[9] = float[](
//    0.025,0.05,0.1, 0.2, 0.25, 0.2,0.1, 0.05, 0.025
//   0.1,0.1,0.1,0.1,0.2,0.1,0.1,0.1,0.1
//    );
const float kernel[3] = float[](
    0.25,0.5, 0.25
    );

void main()
{
    vec4 sampleTex[3];
    for(int i=0; i<3; i++)
    {
        sampleTex[i] = vec4(texture(screenTexture, vTexPos + vec2((i-1)*horOff,0)));
    }
    vec4 col = vec4(0,0,0,0);
    for (int i = 0; i < 3; i++)
        col += sampleTex[i] * kernel[i];
    fColor = col;
}