From: Marcus Sundberg <mackan@stacken.kth.se>
  To  : ggi-develop@eskimo.com
  Date: Fri, 26 Mar 1999 22:20:24 +0000

Re: Visuals 'n stuff

Nicolai Haehnle wrote:
> 
> Jim Kjellin wrote:
> 
> > I'm currently in the process of porting a game to ggi (mainly linux but
> > other OS's if there is demand).
> >
> > Since the game was develope under Windows/DX (not by me mind you :P) it uses
> > a big bunch surfaces
> > for visual-fx and sprites etc.
> 
> I'm also porting a DX game to GGI and I have this problem, too. I'm currently
> writing a GGI extension that does all the memory-visual stuff automatically.
> You don't have to cope with visuals any more when using it.
> 
> Every drawmap (=surface) is represented by a structure which looks like this:
> 
> typedef struct _ggidm_drawmap {
>         ggi_visual_t    vis;
>         struct dm_visual *parent;
> 
>         struct _ggidm_drawmap *prev;
>         struct _ggidm_drawmap *next;
> 
>         int             flags;
>         ggi_coord       pos;
>         ggi_coord       size;
> } *ggidm_drawmap;
> 
> The API is designed to make porting DX games as easy as possible (it's not
> complete yet):
> 
> int ggiDMSetMode(ggi_visual_t vis, int sizex, int sizey, int frames,
>                  ggi_graphtype type);
> 
> ggidm_drawmap ggiDMAddDrawmap(ggi_visual_t vis, int sizex, int sizey,
>                               int flags);
> ggidm_drawmap ggiDMGetVisibleDrawmap(ggi_visual_t vis, int frame);
> int ggiDMFlip(ggi_visual_t vis);
> 
> int ggiDMCloseDrawmap(ggidm_drawmap dm);
> int ggiDMAcquired(ggidm_drawmap dm);
> int ggiDMAcquire(ggidm_drawmap dm, int acquire);
> int ggiDMBlit(ggidm_drawmap dest, int destx, int desty,
>               ggidm_drawmap src, int srcx, int srcy, int dx, int dy,
>               int flags);
> int ggiDMBlitToVisual(ggi_visual_t dest, int destx, int desty,
>                       ggidm_drawmap src, int srcx, int srcy, int dx, int dy,
>                       int flags);
> int ggiDMBlitFromVisual(ggidm_drawmap dest, int destx, int desty,
>                         ggi_visual_t src, int srcx, int srcy, int dx, int dy,
>                         int flags);
> 
> Of course the library is far from being complete and I don't have a lot of time
> in the next two weeks.
> However, the main thing, i.e. drawmap allocation is already written (though not
> very efficient yet). It still needs lots of debugging, though...
> 
> BTW: GGI doesn't seem to support transparent blitting, right? This is badly
> needed...

LibGGI supports everything you want it to, it's just a matter of writing
the right extension.
The reason LibGGI itself doesn't support transparent blitting is to
keep the core library as small as possible.

//Marcus
-- 
-------------------------------+------------------------------------
        Marcus Sundberg        | http://www.stacken.kth.se/~mackan/
 Royal Institute of Technology |       Phone: +46 707 295404
       Stockholm, Sweden       |   E-Mail: mackan@stacken.kth.se