[Libdlo] Basic PNG and SVG display

[Florian Echtler]

Hello Phil,

> If my MIMO has 16 MB of RAM (as "most devices" do), it has space for 10 
> framebuffers (or maybe 20 - does anyone know how many bits per pixel it 
> stores?).  
the in-device memory stores one 16-bit-per-pixel (RGB565) framebuffer
and optional a second 8-bit-per-pixel (RGB323) framebuffer in 24-bit
mode.

> Presumably a video player or similar could use 
> double-buffering (is there a standard ioctl on the framebuffer device 
> for that?).  That still leaves 8 to find a use for.  Here's my 
> suggestion: save old screen content as it is overwritten, and if that 
> content "comes back" (e.g. you maximise a window that obscures your 
> wallpaper, and then minimise it again) you restore it from the data 
> stored on the device.  
Doesn't X do exactly that with offscreen pixmaps? I am admittedly
absolutely no expert on X and/or framebuffers, but I thought that the
Xserver itself already has suitable heuristics for making use of a
framebuffer that is larger than the screen itself.

> I think this sort of technique could make a big 
> performance difference especially while we don't have any compression.  
There's the RLE "compression" which might actually work quite well for
large same-color areas as they usually occur in desktop interfaces.. 

Yours, Florian
-- 
0666 - Filemode of the Beast