export const Kernel = 
{
    Corners:
    [
        [ 1,  1, -1],
        [ 1, -1, -1],
        [-1,  1, -1],
        [-1, -1, -1],
        [ 1,  1,  1],
        [ 1, -1,  1],
        [-1,  1,  1],
        [-1, -1,  1]
    ],
    Cardinal:
    [
        [ 1,  0,  0],
        [ 0,  1,  0],
        [-1,  0,  0],
        [ 0, -1,  0],
        [ 0,  0,  1],
        [ 0,  0, -1]
    ],
    Loop(inList, inVector, inHandler)
    {
        for(let i=0; i<inList.length; i++)
        {
            let delta = inList[i];
            if(inHandler(inVector[0]+delta[0], inVector[1]+delta[1], inVector[2]+delta[2]))
            {
                return;
            }
        }
    }
};
export const Region = 
{
    Create()
    {
        return {voxels:[]};
    },
    I(inX, inY, inZ)
    {
        return inX + inY*32 + inZ*1024;
    },
    XYZ(inI)
    {
        let zWhole = Math.floor(inI / 1024);
        let zPart = inI % 1024;
        let yWhole = Math.floor(zPart / 32);
        let yPart = zPart % 32;
        return [yPart, yWhole, zWhole];
    },
    Surface(inRegion)
    {
        let surface = [];
        inRegion.voxels.forEach((inValue, inIndex) =>
        {
            if(inValue)
            {
                let coords = Region.XYZ(inIndex);
                Kernel.Loop(Kernel.Corners, coords, (inX, inY, inZ)=>
                {
                    let kernel = Region.I(inX, inY, inZ);
                    if(!inRegion.voxels[kernel])
                    {
                        console.log(coords, "surface");
                        surface.push(inIndex);
                        return true;
                    }
                });
            }
        });
        return surface;
    }
};