[GSOC] Tiled Rendering, ahunt, Weekly Report 12 / WK32

[Andrzej Hunt]

Hi All,

This week was primarily work on the Calc Tiled Rendering:

* Realised on Friday that my current approach was probably a huge waste
   of time.
** Using logic mapping makes cell sizes etc. correct, but breaks
    lots of assumptions meaning that the usual Calc UI is quite broken
    (problems/corruption with repainting when scrolling etc.)
** Requires lots of debugging/digging to adjust those parts (the code
    is quite complex...).
** Instead we can keep pixel mapping, but use the
    LogicToPixel/PixelToLogic( Object, MapMode) methods to do our own
    conversion directly before painting in the appropriate places
    (allowing use of pixel-based adjustments as needed), and meaning
    that most code (around scrolling/repainting) can stay with pixel
    coordinates as before.

* But fortunately a large portion of the commits are vaguely reusable
   (with some adjustment) for the new approach, i.e. they indicate most
   of the relevant places in the code that still need adjusting.
** Started this work on a new branch:
    feature/calctiledrendering_simpler.

Cheers,
	Andrzej