[Gambas-devel] Flaw in GTK+ 2 / 3
gambas at ...1...
Wed Jan 2 17:21:18 CET 2013
Since a few revision, all drawings are done in gb.gtk with cairo ; as
requested by GTK+, which has deprecated the old drawing API.
Fine. But there is a problem with images.
Images in GTK+ are managed by the GdkPixbuf class, which stores the
image data in memory with the RGBA format. (As x86 is little endian, in
memory you have actually R-G-B-A, and if you read it as a 32 bits
integer, R is in the lowest bits and A in the highest).
But Cairo only handles images in the pre-multiplied BGRP format (like Qt4).
So each time you call Draw.Image() or Paint.DrawImage(), a costly
conversion is needed.
I'm currently searching for some sort of workaround for this design flaw
That flaw has not been fixed in GTK+ 3 apparently. Why didn't they
change GdkPixbuf so that it uses the same format as Cairo, or why didn't
they deprecated GdkPixbuf for a new image class using that format? That
is the question...
Any suggestion is welcome!
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