[comp.sys.amiga] The old Picture-in-the-Workbench trick, eh?

john13@garfield.UUCP (11/30/87)

--
In the process of cleaning out a dank and dusty subdirectory today, I found
a nifty program from way back, dualpf.c (from Jim Mackraz, demonstrating
dual playfield mode). When I first saw it I was on the flat side of the
learning curve, so it had never even been catted before (this was in my Unix
account, it's much lower on disk space than my bedroom bureau :-).

"Well", sez I, "this is a great way to put a picture in the background of my
Workbench!". And it's real easy, load it in, put in hooks to get rid of it
later, let you twiddle with the colours in a DPaint-like colour requestor,
and exit. It shouldn't interfere with anything except possibly Dropshadow.

EXCEPT... nowhere can I find an IFF reader that decides if a picture is
"suitable" for a given screen and rejects it if not, and otherwise loads it
into an _existing_ rastport. I had intended to use Leo Schwab's short viewer,
but that's deeply enmeshed in viewports and such; this program would be so
sweet and easy if I could just loadiff(rp, MAXPLANES, MAXX, MAXY, "filename")
that I almost hate to go through the hassle of Intuitionizing Leo's.

Is there in fact such a simple routine, ready to link? It seems like such a
useful general-purpose routine, yet everyone writes their own, and everyone's
code is closely tied to their own application. A happy exception is the colour
requestor example I have, a modification of one by -=RJ=-; it can just be linked
to anything else as a .o and it'll give you complete colour control of any
screen you like when you invoke it.

John

PS A big win to the dual-playfield approach, in my view, is that the picture
shows through _anywhere_ the background colour is, and you can use a multi-
colour picture with its own colourmap. No mucking about with the layers on the
Workbench screen.
-- 
"MEGA BRAIN 8K MEMORY"
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