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.
BST 1999 Adam D. Moss