Sun May 9 16:23:47 BST 1999 Adam D. Moss <adam@gimp.org>
* app/tile.c
* app/tile.h
* app/tile_manager.c
* app/tile_pvt.h
* app/paint_funcs.c:
Added Tile Row Hinting to the GIMP tile structure. Tiles
now have cheap per-row hints indicating whether each row is
all-transparent, all-opaque, a mixture, or other properties.
These hints are automatically invalidated when the tile is checked
in as dirty, and are re-evaluated on demand.
Currently only the layer compositing routines take advantage
of these hints, though there is opportunity to use them to
advantage in numerous other places.
The whole layer compositing process is typically 2x-4x faster
now, especially on subsequent renders of data which has already
had its hints calculated.
See tile.h for the explicit TileRowHint query/set interface.
The procedure to re-evaluate tile hints currently resides in
paint_funcs.c but may be exposed to other parts of the core
if necessary.
This is experimental. Please report mis-rendering problems.
Modified tile swapping to preswap dirty tiles, using a thread if
threads are enabled in configure or a gtk_timeout if they're not. The
code appears stable but could use improvement. Be careful when
working in here; there are four sets of semaphores and getting the
locking wrong will cause deadlocks or tile corruption. I'll try to
write up a document describing what's going on in here sometime soon.
--sg
BST 1999 Adam D. Moss