Re: Major API change for SDL 0.9.11

[Christian Reiniger <reiniger@rz.uni-wuerzburg.de>]

Sam Lantinga wrote:
> 
> I'm implementing "load-from-memory" for SDL_LoadWAV() and SDL_LoadBMP().
> The most flexible way to do this is to implement a general data source
> abstraction and allow you to define your own data sources.  This should
> help people writing PAK file compilers and so forth.
> Comments anybody?

[...]

>                 SDL_LoadBMP(SDL_RWFromFile("sample.bmp", "rb"), 1, ...);
>         The SDL_LoadBMP() function will close the opened file automatically.

How does SDL_RWFromFile () work? In particular - how do you determine
where to 
get the file? If I want e.g. open something contained in a PPlay
PakFile, how 
do I tell SDL_RWFromFile() and how does it contact the PPlay Fiel
mechanism?
(PPlay PakFiles have to be "mounted" with ppfMountPak
("somedir/mypak.pak") 
before use; Files are then opened via 
ppFILE myfile = ppfOpen ("pakfile://somedir/mypak/myfilename", "rb") or
ppFILE myfile = ppfOpen ("file://somedir/mypak/myfilename", "rb") or
just
ppFILE myfile = ppfOpen ("somedir/mypak/myfilename", "rb")
and accessed with ppfRead (myfile, ...) etc
(the last two ppfOpen () calls are synonyms, looking for the file both
in
the mounted pakfiles and the normal filesystem, the first one looks only
in
the pakfiles))

I currently see two solutions to this:
(1) you also use some URL scheme
(2) you define some "data source" objects (well, interfaces) and let the
user 
pass instances of those to SDL_RWFromXXX ()

Iīd favor the first one, as there should be little that cannot be
expressed in 
an URL. URLs are slightly slower, but thatīs only relevant for those 
"letīs use thousands of tiny files" games (and for those some speedup
system
like PFileīs open-by-number can be used (which is btw also beneficiary
(sp?)
if you just use normal filenames)).
And the URL thingy is certainly nicer to handle for the user.

Cu
	Christian
.