Xref: utzoo comp.sys.amiga.tech:17973 comp.sys.amiga.graphics:931 comp.sys.amiga.programmer:2667
Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!jordan
From: jordan@unix.cis.pitt.edu (Kenneth D Jordan)
Newsgroups: comp.sys.amiga.tech,comp.sys.amiga.graphics,comp.sys.amiga.programmer
Subject: Question re. double buffering / Intuition
Keywords: Intuition, Amiga, double buffering, graphics
Message-ID: <115475@unix.cis.pitt.edu>
Date: 15 Apr 91 13:22:23 GMT
Organization: Univ. of Pittsburgh, Computing & Information Services
Lines: 32

In the course of writing various scientific applications I've often required
double buffering for my animations.  The problem is that I've never been able
to successfully attach gadgets to the active window nor have I been able to
open another window or requester.  In the past I simply avoided the problem
by restricting user interation to menu bars (which was consistent with those
applications).  Now, however, I want and need the other features of Intuition.

Briefly, my code allocates and initializes two RastPorts and BitMaps ala the
RKM, opens a custom screen with the CUSTOMBITMAP flag set, and opens a window
on that screen.  (The actual code is quite large, and extracting the relevant
portions into a small test case is rather painful.)  Maintaining a pointer to
the RastPort to be used for rendering is sufficient to make use of the various
graphics and Intuition system functions which require a pointer to a RastPort.
My problem arises when calling other functions such as OpenRequester,
OpenWindow, and AddGadget, which require something other than the RastPort.
These end up appearing anywhere: on the correct RastPort, on the alternate
RastPort, or (I think) somewhere else altogether.  When opening requesters
the border often ends up on the correct RastPort but the gadgets never appear.  Letting rp be a pointer to the rendering RastPort (which works for functions
which require a ptr to a RastPort) and win be a pointer to the window, I've
tried things like win->RPort = rp and win->BorderRPort = rp before opening a
requester, but there's no apparent effect.

Any suggestions (including pointers to PD code which exhibits gadgets or
requesters on double buffered screens) would be greatly appreciated.  Please
send mail to nystrom@a.psc.edu.  Thanks!

--------------------------------------------------------------------------------
Nick Nystrom
Chemistry Department
University of Pittsburgh
nystrom@a.psc.edu
--------------------------------------------------------------------------------