The offset values were incorrect, and have been fixed.
The default constructor for WorldData was setting the position values of Chunks incorrectly, and this has been fixed.
Added a tunable ZOOM parameter to change the world zoom.
Made two functions for creating square and circular sprites of a given colour respectively.
Made three sprites: surface tile, dirt tile and player. The player sprite doesn't work correctly yet.
Fixed a bug where only four chunks were drawn, instead of nine, due to a problem with the for-loops.