uniform sampler2DMS src_color;

vec4 aa_apply(sampler2DMS tex, vec2 fragCoord, vec2 resolution) {
    ivec2 texel_coord = ivec2(fragCoord.x, fragCoord.y);

        vec4 sample1 = texelFetch(tex, texel_coord, 0);
        vec4 sample2 = texelFetch(tex, texel_coord, 1);
        vec4 sample3 = texelFetch(tex, texel_coord, 2);
        vec4 sample4 = texelFetch(tex, texel_coord, 3);
        vec4 sample5 = texelFetch(tex, texel_coord, 4);
        vec4 sample6 = texelFetch(tex, texel_coord, 5);
        vec4 sample7 = texelFetch(tex, texel_coord, 6);
        vec4 sample8 = texelFetch(tex, texel_coord, 7);
        vec4 sample9 = texelFetch(tex, texel_coord, 8);
        vec4 sample10 = texelFetch(tex, texel_coord, 9);
        vec4 sample11 = texelFetch(tex, texel_coord, 10);
        vec4 sample12 = texelFetch(tex, texel_coord, 11);
        vec4 sample13 = texelFetch(tex, texel_coord, 12);
        vec4 sample14 = texelFetch(tex, texel_coord, 13);
        vec4 sample15 = texelFetch(tex, texel_coord, 14);
        vec4 sample16 = texelFetch(tex, texel_coord, 15);

    // Average Samples
    vec4 msaa_color = (
        sample1 + sample2 + sample3 + sample4 + sample5 + sample6 + sample7 + sample8 + 
        sample9 + sample10 + sample11 + sample12 + sample13 + sample14 + sample15 + sample16
    ) / 16.0;

    return msaa_color;
}