#20 color conversion bug in blit()
In my latest Allegro project, i store all my gfx as 24
bit bitmaps in datafiles. I want to make the program
independent of the existing video hardware, i.e. it
should support all color depths from 8 to 32. For this
purpose, i load the datafiles with set_color_conversion
(COLORCONV_NONE) and then blit the loaded bitmaps onto
output-device specific bitmaps, letting blit to the
conversion. However, if the bitmaps contain pink
colors, they get sometimes transparent. And, if i use
COLORCONV_DITHER, at the borders between transparent
and non transparent areas of my bitmaps, i get a lot
of pink pixels.
I have this behaviour at least when converting to
16bit and 8bit - and looking at the source code in
blit.c shows that blit() doesn't care about
transparency, even in the opposite conversion from
8bit to 32bit.
very basic test case for the bug
added timing to the test