gc-linux-devel

[Gc-linux-devel] RGB Framebuffer ideas

[Malcolm <mal...@gm...>]

1) Write directly to EFB, use GX to copy to XFB
+ No CPU overhead
- Max yres of 528
- Max xres of 640
- No ypan or ywrap

2) Write to RAM, use CPU to copy to XFB
- Large CPU overhead
+ Max yres of 574
+ Max xres of 720
+ ypan or ywrap

3) Write to RAM, use CPU copy to EFB, use GX to copy to XFB
- small CPU overhead
- Max yres of 528
- Max xres of 640
+ ypan or ywrap

4) Write to RAM, use CPU to create texture, use GX to draw texture to
EFB and copy to XFB
- some CPU overhead
- Max yres of 528
- Max xres of 640
+ ypan or ywrap



CPU overhead could be reduced for mostly static images using deferred IO.
http://lwn.net/Articles/259210/

-- 
Malcolm Parsons

Re: [Gc-linux-devel] RGB Framebuffer ideas

[Groepaz <gr...@gm...>]

On Samstag 12 Juli 2008, Malcolm wrote:
> 1) Write directly to EFB, use GX to copy to XFB
> + No CPU overhead
> - Max yres of 528
> - Max xres of 640
> - No ypan or ywrap
>
> 2) Write to RAM, use CPU to copy to XFB
> - Large CPU overhead
> + Max yres of 574
> + Max xres of 720
> + ypan or ywrap
>
> 3) Write to RAM, use CPU copy to EFB, use GX to copy to XFB
> - small CPU overhead
> - Max yres of 528
> - Max xres of 640
> + ypan or ywrap
>
> 4) Write to RAM, use CPU to create texture, use GX to draw texture to
> EFB and copy to XFB
> - some CPU overhead
> - Max yres of 528
> - Max xres of 640
> + ypan or ywrap

you forgot one important thing ... all ways except the first require an 
additional video buffer in main ram, and thus waste memory.

-- 

http://www.hitmen-console.org
http://www.pokefinder.org
http://ftp.pokefinder.org

The Scene always wins.