2014.10.24


enu: positive quadrant        - some room of positive values, etc abstraction
     in Cartesian 2-3d coords - values >= x0y0z0, often referred to as of 1st/positive quadrant
     in bitmap                - pixel coords with x0y0 at lower-left
     in cubes/volumes         - object in-out detection
     example                  - x
                                |
                                0--y
                               /
                              z


rus:                          -    ,  
       2-3d . -  >= x0y0z0, ..   1 . 
      bitmap                 -  pixel-   x0y0  - 
      /          -  
                        - x
                                |
                                0--y
                               /
                              z
