#version 130

uniform sampler2D texture;

in vec2 texCoord;
in vec4 color;

out vec4 final;
void main(void) 
{
    vec4 myColor = color;
    float P = 1.0 / 512.0;
    float treshold = 0.2;

    final = texture2D(texture, texCoord);
    if (final.a <= treshold)
        discard;

    vec4 px[8] = vec4[](
            texture2D(texture, texCoord+vec2(P, P)),
            texture2D(texture, texCoord+vec2(-P, P)),
            texture2D(texture, texCoord+vec2(-P, -P)),
            texture2D(texture, texCoord+vec2(P, -P)),

            texture2D(texture, texCoord+vec2(P, 0)),
            texture2D(texture, texCoord+vec2(0, P)),
            texture2D(texture, texCoord+vec2(-P, 0)),
            texture2D(texture, texCoord+vec2(0, -P))
            );

    for(int i = 0; i < 8; ++i)
    {
        if(px[i].a <= treshold)
            myColor = vec4(vec3(0.0), 1.0);
    }

    final = myColor;

}