On Thursday 16 November 2000 18:23, John Califf wrote:
> The situation is this.  Krayon does NOT use the normal QPixmap and
> QImage and QPainter classes for its drawing and image processing.
> Instead, it uses custom classes and routines, all written at a low
> level.  Essentially, it's binary reading and writing of scan lines in a
> format similar to, but not exactly like, QImage.  But these scan lines
> are broken up by a number of tiles, which are updated with a timer
> which runs continuously.  Sounds complicated, and it is. Another
> difference is that Krayon access binary data by channel, like RGBA.  On=
e
> for each color, basically. This is well encapsulated and you can access
> the data in terms of x,y coordinates and translate to QImage and QPixma=
p
> formats, regardless of the tiles, but writing TO the data using Qt is
> nearly impossible.  Each tile is like a piece of paper with writing on
> it, wrapping lines.  And there are hundreds of such tiles for a large
> image, like laying sheets of typewritten paper out on a desktop.  Scan
> lines are within each tile, and do not run continuously across the
> entire image as in almost every other image format.

Think of a 1MB JPG images that uses say 40MB uncompressed when in memory.=
 You=20
can't handle images of that size with QPainter drawing routines. You _nee=
d_=20
the tile system to keep only the tiles you currently work on in memory.

QImage also can't handle CYMK data. The abstract Krayon image class can (=
or=20
can be extended to support it).

There are a bazillion reasons why you want to keep the tile system.

Greetings,
Matthias

--
Matthias Elter
me@kde.org
me@caldera.de
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