Transparent raster images

[Martin Schulze]

Moin,

Thuban.UI.renderer contains draw_raster_data() which seems to support
an alpha channel and is supposed to support some sort of transparency.

How is this supposed to work?  In the WMS extension I can order the
server to create a GIF or PNG image with a transparent background.
I'd like to pass this information to the renderer, but don't know
how.  Any hint or links to explanations would be appreciated.

Regards,

	Joey

-- 
If nothing changes, everything will remain the same.  -- Barne's Law