On October 22, 2015 10:40:56 AM Max Savenkov wrote:
I think I found another bug in Android implementation. For some reason,
in 'android_acknowledge_drawing_halt(ALLEGRO_DISPLAY *dpy)' Allegro does
not delete resources of bitmap if it has ALLEGRO_NO_PRESERVE_TEXTURE
flag set. Since in reality FBOs and textures for those bitmaps are
deleted when OpenGL context is deleted during suspension, this leads to
corruption after the game is resumed. I'm not very clear on details, but
somehow OTHER bitmaps may end up corrupted because of this.
I tried commenting out this flag and it seems to make everything better
:) So unless there is some remembered reason for it being there, I
propose to strike out this check.
I'll check this tomorrow.
Also, I'd like to question the whole approach Allegro takes to
suspension/resuming on Android. Why doesn't it uses the same method as
SDL, which preserves the whole OpenGL context, instead of re-uploading
bitmaps after resuming? This would eliminate the difference between
NO_PRESERVE_TEXTRURE and other bitmaps (as it should be with OpenGL) and
also preserve shaders (which presently has to be re-created as well
during resuming). This would allow Allegro (or its user at least) to
save memory by setting NO_PRESERVE_TEXTURE for all bitmaps and not store
in-memory copy of data. Is there any reason not to do so, or is it just
a historical decision?
If it's possible to preserve the context then NO_PRESERVE_TEXTURE should be a
no-op on Android like on PC. If you wish to create a patch for this then I'll
be happy to take a look at it.
Thanks.