#version 450

layout(local_size_x = 1, local_size_y = 1, local_size_z = 1) in;

layout(set = 0, binding = 0) buffer wData {
    int buf[];
} write_buffer;

layout(set = 0, binding = 1) buffer rData {
    int buf[];
} read_buffer;

layout(set = 0, binding = 2) buffer Settings {
    int settings[];
} settings;

ivec4 separate(int pix){
    ivec4 r = ivec4(
    (pix & 0x000000FF),
    (pix & 0x0000FF00) >> 8,
    (pix & 0x00FF0000) >> 16,
    (pix & 0xFF000000) >> 24
    );
    return r;
}

uint get_idx(int offset_x, int offset_y){

    uint x = min(settings.settings[0], max(0, gl_GlobalInvocationID.x + offset_x));
    uint y = min(settings.settings[1], max(0, gl_GlobalInvocationID.y + offset_y));
    return ((y * settings.settings[0]) + x);
}

void main() {

    uint idx = get_idx(0,0);

    ivec4 p  = separate(read_buffer.buf[get_idx(0 , 0)]);
    ivec4 p0 = separate(read_buffer.buf[get_idx(0 , 1)]);
    ivec4 p1 = separate(read_buffer.buf[get_idx(0 ,-1)]);
    ivec4 p2 = separate(read_buffer.buf[get_idx(1 , 1)]);
    ivec4 p3 = separate(read_buffer.buf[get_idx(-1,-1)]);
    ivec4 p4 = separate(read_buffer.buf[get_idx(1 , 0)]);
    ivec4 p5 = separate(read_buffer.buf[get_idx(-1, 0)]);
    ivec4 p6 = separate(read_buffer.buf[get_idx(1 ,-1)]);
    ivec4 p7 = separate(read_buffer.buf[get_idx(-1, 1)]);

    ivec3 d0 = abs(p0.xyz - p1.xyz);
    ivec3 d1 = abs(p2.xyz - p3.xyz);
    ivec3 d2 = abs(p4.xyz - p5.xyz);
    ivec3 d3 = abs(p6.xyz - p7.xyz);

    ivec3 m = max(max(max(d0, d1), d2), d3);

    if ((m.x + m.y + m.z) > 275){
        p.x = 0;
        p.y = 0;
        p.z = 255;
    }

   //p.z = max(p.z - (d0.x + d0.y + d0.z + d1.x + d1.y + d1.z)/5, 0);

   write_buffer.buf[idx] = (write_buffer.buf[idx] & (~0x000000FF) ) | (p.x);
   write_buffer.buf[idx] = (write_buffer.buf[idx] & (~0x0000FF00) ) | (p.y << 8);
   write_buffer.buf[idx] = (write_buffer.buf[idx] & (~0x00FF0000) ) | (p.z << 16);
   write_buffer.buf[idx] = (write_buffer.buf[idx] & (~0xFF000000) ) | (p.w << 24);

//  read_buffer.buf[idx] = (read_buffer.buf[idx] & (~0x000000FF) ) | (p.x);
//  read_buffer.buf[idx] = (read_buffer.buf[idx] & (~0x0000FF00) ) | (p.y << 8);
//  read_buffer.buf[idx] = (read_buffer.buf[idx] & (~0x00FF0000) ) | (p.z << 16);
//  read_buffer.buf[idx] = (read_buffer.buf[idx] & (~0xFF000000) ) | (p.w << 24);
}