Sharon Clay (src++at++rose.engr.sgi.com)
Sun, 20 Dec 1998 15:03:35 -0800 (PST)
There's nothing like timing :-)
->
->David Gray wrote:
->>
->> Hello,
->>
->> I have a question regarding the interaction between the application
->> process (App) and a forked intersection process (Isect).
->>
->> I would like to know when scene graph changes made by the App (e.g.
->> changing DCS matrices) are seen by Isect.
->>
->> Given that processing in the Isect callback may span multiple frames, I
->> believe that there are three possibilities. The App changes may be
->> visible by Isect:
->>
->> 1. immediately,
->>
->> 2. at the next call to pfFrame in the App, or
In the call to pfFrame, downstream processes are updated and kicked off.
The Isect and Cull are both updated with scene graph changes and then
the internal Performer loop running these processes is released.
The updates happen in the address space of the downstream process so
that they can all happen in parallel.
When the downstream processes are kicked off, the user call backs, such
as the Isect callback or the channel Cull callback, are then called.
Special Cases: DBASE and Draw
DBASE: the dbase process does NOT keep full copy of the scene graph.
Rather, it updates UPSTREAM.
Draw: the draw is updated by the cull. Non-scene graph objects are
updated by the cull to the draw: pfPipe, pfPipeWin, pfChannel, VideoChannel,
and fluxes. Do not assume a full copy of the scene graph in the draw.
src.
--
-----{-----{---++at++ -----{----{---++at++ -----{----{---++at++ -----{----{---++at++
Sharon Rose Clay - Silicon Graphics, Advanced Systems Dev.
src++at++sgi.com (650) 933 - 1002 FAX: (650) 933 - 0858 MS 8U-590
-----{-----{---++at++ -----{----{---++at++ -----{----{---++at++ -----{----{---++at++
This archive was generated by hypermail 2.0b2 on Sun Dec 20 1998 - 15:03:50 PST