Author :
Sylvain Becker
Date :
2020-09-07 18:50:30
Hash :ebc12a2f Message :SDL_Surface refcount: destination surface keep track of surfaces
that are mapped to it and automatically invalidate them when it is freed
- refcount is kept so that an external application can still create a reference
to SDL_Surface.
- lock_data was un-used and is now renamed and used as a list keep track of the blitmap