FOR_SKETCHPUNKLABS_002

/** ************************************************ ***

Hello SketchpunkLabs guy.

Forgive me if I am mentioning stuff you already know,
but I am excited to see someone else is working on
the same kind of stuff I am working on, so I thought
I would share some of my notes.

You can check out my working demo by taking code from
pastebin and cutting and pasting it into shadertoy.

    www.tinyurl.com/SDF-009
    OR
    https://pastebin.com/yYSKzCHx

    ShaderToy: www.shadertoy.com

*** ************************************************ **/

const WID = 8; //:width  of tilemap in tiles.
const HIG = 4; //:height of tilemap in tiles.

//: To access the data in this, we need to be
//: able to convert an XY coordinate int a
//: 1-dimensional index.
//: Lets say we want to get tile [ 2,3 ]
//:
//:     var tcX = 2;
//:     var tcY = 3;
//:     var tcI = TileCoordXY_To_TileCoordIndex(
//:                                     tcX,tcY );;
//:     var tile_value = my_2d_tilemap[ tcI ];

const X = 1;
const _ = 0;
var my_2d_tilemap=[
    _,_,_,_,X,_,_,_
,   _,X,_,_,_,_,_,_
,   _,_,X,_,_,_,X,_
,   _,_,_,_,_,_,_,X
];;

function TileCoordIndex_To_TileCoordXY( tcI ){

    var tcX =  tcI % WID        ;
    var tcY = (tcI - tcX ) / WID;

    return([ tcX , tcY ]);

};;

function TileCoordXY_To_TileCoordIndex( tcX , tcY ){

    var tcI = tcX + ( WID * tcY);
    return( tcI );

};;


//:For A 3-Dimensional array of tiles, we can think
//:of it as a whole bunch of 2D tilemaps layered
//:on top of each other:
/** ************************************************ ***

    I haven't done the math for  1D index to
    voxel X,Y,Z coordinate yet. But here is my
    math for voxel X,Y,Z coord to index.

    D2D is the index math for a 2D tilemap.
    D3D is the final index for a 3D tilemap.

    T_X == tile coordinate X
    T_Y == tile coordinate Y
    NTX == number of tiles X ( tile map size x axis )
    NTY == number of tiles Y ( tile map size y axis )
    NTZ == number of tiles Z ( tile map size z axis )

        //: Index2D -and- Index3D
        int D2D = T_X + ( NTX    *    T_Y );
        int D3D = D2D + ( NTX * NTY * T_Z );

*** ************************************************ **/