When the map border shroud must be rendered, but no cells at the border are visible, then we know that no shroud will be visible at all. We can bail from rendering early in this case.
Changes in the shroud are now tracked. If a cell changes it will mark itself and its neighbors as dirty. During the render phase all dirty cells will have their vertices calculated and cached. If a cell is not dirty, the pre-calculated vertices are retrieved from cache. Then the sprite renderer is provided the sprite and the pre-calculated vertices to draw.
This prevents constant recalculation of vertices for the shroud in the render phase, requiring instead only dirty cells in the visible area. The update phase is reduced to a practical noop, instead incurring the cost only of changed cells each frame, rather than checking the visible area.
To resolve the ambiguity introduced when the introduction of isometric maps meant that cell and map coordinates were no longer equivalent, a new type has been introduced so they can each be represented separately.
Automatically formatted all files via VS. This generally corrects indentation, removes trailing whitespace and corrects misplaced tabs or spaces. Manually tweaked a few files where required.
