[Bug 24278] Transparent PNG are shown inverted by applications compiled with Lazarus

http://bugs.winehq.org/show_bug.cgi?id=24278

--- Comment #10 from Marc Weustink  2010-09-09 14:00:56 CDT ---
32bpp bmp files with alpha channel suffer from the same problem.

The point is that alpha images in lazarus are not premultiplied, while the
AlphaBlend() function requires a premultiplied bitmap. So I need to premultiply
all pixels. Therefore I need the pixels of the bitmap.
I need the direction of the scanlines in order to get the sourcerectangle of
the image we want to alphablend