[AD] moving al_load_bitmap to core

[Peter Wang <novalazy@xxxxxxxxxx>]

Hi,

The discussion in Matthew's acodec proposal thread got me thinking. I
think there is a strong case to be made for moving the al_load_bitmap
registration framework to the core, and analogously leaving
al_load_sample (et al.) in allegro_audio.

1. Ogre3d pulls in FreeImage. Unfortunately, FreeImage stupidly
bundles its own copies of libpng and libjpeg, which may be different
and incompatible with the versions already on the system. Right now an
Allegro program cannot use both Ogre3d and al_load_bitmap.  If
al_load_bitmap was in the core then the user can simply write a loader
implementation that uses FreeImage, and avoid linking with
allegro_image.

2. Perhaps more seriously, not being able to use al_load_bitmap
automatically means you can't use *either* of the Allegro font addons
-- even if you just wanted to render TTF fonts. If al_load_bitmap was
in the core then the link between allegro_font and allegro_image would
be broken.

3. The user might well want to use some mega codec libraries with
Allegro, e.g. ImageMagick for images, audiofile for samples. Then they
really have no need for the default image/audio codec implementations.

I can't see any real downsides.

Peter