From reedwhit@skips.dseg.ti.com Fri Oct 8 14:28:03 1993 Date: Fri, 8 Oct 93 16:26:58 CDT From: reedwhit@skips.dseg.ti.com (Reed Whittington) Message-Id: <9310082126.AA22246@skips.dseg.ti.com> To: info-performer@sgi.sgi.com Subject: Best HUD in Perfomer Status: OR I'm looking for the most efficient way to implement HUD symbology on top of a performer visual. I have tried drawing to the overlay plane in a post draw call back. This tends to task the graphics pipe more than would be expected. Even drawing every 10th frame creates a big spike. I have considered putting the symbology in its own pfChannel. Would this be recommended? What have others tried? It seems the Performer Channel Stats are efficiently implemented. How were the ChanStats done? --Reed From srf@rose Fri Oct 8 15:23:03 1993 From: srf@rose (Sharon Fischler) Message-Id: <9310081522.ZM19134@rose.asd.sgi.com> Date: Fri, 8 Oct 1993 15:22:50 -0700 References: <9310082126.AA22246@skips.dseg.ti.com> To: reedwhit@skips.dseg.ti.com (Reed Whittington), info-performer@sgi.sgi.com Subject: Re: Best HUD in Perfomer Status: OR +>---- On Oct 8, 4:26pm, Reed Whittington wrote: > Subject: Best HUD in Perfomer -> -> -> ->I'm looking for the most efficient way to implement HUD symbology on ->top of a performer visual. I have tried drawing to the overlay plane ->in a post draw call back. This tends to task the graphics pipe more ->than would be expected. Even drawing every 10th frame creates a big ->spike. I have considered putting the symbology in its own pfChannel. Draw your static info in the overlay planes and ONLY redraw it when the window receives a REDRAW event (moved, resized, etc.). Changing between drawing to the overlays and drawing to regular bitplanes takes a big hit. For things that need to be updated real-time, you can set zfunction(ZF_ALWAYS); zwritemask(0x0); draw stuff zfunction(ZF_LEQUAL); zwritemask(0xffffffff); If you have a whole lot of stuff to draw, then it might faster to just turn off zbuffer but I would think that most HUDs aren't that dense. you also want to disable fog BEFORE you change the projection matrix (ortho2). srf. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Sharon Rose Fischler - Silicon Graphics, Advanced Graphics Development srf@sgi.com (415) 390 - 1002 MS 7L-590 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ From wgerhard@afit.af.mil Sat Oct 9 11:08:11 1993 Date: Sat, 9 Oct 1993 14:08:00 -0400 From: William E Gerhard Message-Id: <199310091808.AA00347@stealth.afit.af.mil> To: info-performer@sgi.sgi.com Subject: HUD's in performer Status: OR I have been working on a distributed interactive flight simulator here at AFIT and I used GL calls in a draw call back. The call back is setup to be called after our aircraft model is drawn. All the vertices in the bgnline();...endline(); calls are defined in our aircraft model space. We use a Polhemeus Fastrack with this thing, so as an added bonus, the HUD changes perspective with the rest of the simulation if the pilot moves his head. The text on the HUD was a little more difficult, but I ended making a vector based font class which works well. There is not much of a performance hit with this scheme if as many of the vertices as possible are defined as static. Bill Gerhard wgerhard@afit.af.mil From guest Wed Mar 9 08:28:49 1994 From: Mark Coyle Subject: GL and Performer To: info-performer@sgi.sgi.com Message-Id: <9403091423.AA25661@dexter.psych.umn.edu> X-Mailer: ELM [version 2.4 PL6] Content-Type: text Content-Transfer-Encoding: 7BIT Content-Length: 435 Status: OR Hi, I know this is in the FAQ but I can't seem to get GL to draw into a Performer Window (i.e. a HUD). I'm sure it is just a wrong/missing/ function call. If anyone has a simple sample program that does this, i would appreciate getting a copy of the code. I have just signed onto this group, so I apologize if this questioned has been answered before. Mark Coyle Human Factors Lab Computer Science Department U of Minnesota From guest Wed Mar 9 09:50:24 1994 Date: Wed, 9 Mar 94 11:27:55 CST From: aaron@skips.dseg.ti.com (Aaron M. Hightower) Message-Id: <9403091727.AA17205@skips.dseg.ti.com> To: iris-performer@sgi.sgi.com Subject: Drawing HUD's Status: OR From the FAQ: (Sharon Fischler) ------------ Subject: -12- How do I overlay graphics on top of my Performer scene? Date: 06 Oct 93 00:00:01 EST Typically this is done to implement a heads-up display (HUD). In the draw function callback, the basic algorithm is: save state with pfPushState() disable textures, fog, & lighting with pfBasicState() save & clear projection matrix ortho2() save & clear modelling matrix draw() restore modelling matrix restore projection matrix restore state with pfPopState() Or, you can draw your static info in the overlay planes and only redraw it when the window receives a REDRAW event (moved, resized, etc.). Changing between drawing to the overlays and drawing to regular bitplanes takes a big hit. For things that need to be updated real-time, draw() would consist of: zfunction(ZF_ALWAYS); zwritemask(0x0); draw HUD stuff zfunction(ZF_LEQUAL); zwritemask(0xffffffff); ----------------------------------------------------------------------------- Example: (modification of PostDraw from Perfly) void drawHUD(pfChannel *chan) /* example function */ { pfPushState(); pfBasicState(); pfPushIdentMatrix(); zfunction(ZF_ALWAYS); zwritemask(0); /* Example of how to put into pixel coordinates. * Not necessary depending on requirements of GL calls * IE: You may want to use different coordintes instead */ pfGetChanSize(chan,&chanSizeX,&chanSizeY); ortho2(-.5f,chanSizeX-.5f,-.5f,chanSizeY-.5f); **** DRAW GL JUNK HERE **** zfunction(ZF_LEQUAL); zwritemask(0xffffffff); pfPopMatrix(); pfPopState(); } void PostDraw(pfChannel *chan, void *data) { drawHUD(chan); /*** Insert this line into PostDraw in perfly ***/ if (ViewState->stats) pfDrawChanStats(chan); if(chan == ViewState->masterChan) pfuCollectInput(); } From guest Tue Jun 14 09:09:37 1994 Date: Tue, 14 Jun 94 09:09:30 -0700 From: stimpy@niesten.arc.nasa.gov (William Briggs) Message-Id: <9406141609.AA05949@niesten.arc.nasa.gov> To: info-performer@sgi.sgi.com Subject: 2-D Overlay Status: OR I am using IRIX 4.0.5 and Performer 1.0 on a SkyWriter (no RE...yet :^) Is it possible to do a two-dimensional overlay in a channel? Up until now, I have drawn a crosshair with a draw callback. I transform to the viewpoint and then in front of it. However, roundoff error causes the crosshair lines to wiggle, forcing me to put them farther away. With them farther away, they interact with the terrain, dissapearing behind it when the viewpoint is too close. From aschaffe Tue Jun 14 13:30:37 1994 From: aschaffe (Allan Schaffer) Message-Id: <9406141330.ZM12638@holodeck.asd.sgi.com> Date: Tue, 14 Jun 1994 13:30:22 -0700 In-Reply-To: stimpy@niesten.arc.nasa.gov (William Briggs) "2-D Overlay" (Jun 14, 9:09am) References: <9406141609.AA05949@niesten.arc.nasa.gov> X-Mailer: Z-Mail (3.1.0 22feb94 MediaMail) To: stimpy@niesten.arc.nasa.gov (William Briggs) Subject: Re: 2-D Overlay Cc: info-performer@sgi.sgi.com Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 Status: O On Jun 14, 9:09am, William Briggs wrote: > I am using IRIX 4.0.5 and Performer 1.0 on a SkyWriter (no RE...yet :^) > > Is it possible to do a two-dimensional overlay in a channel? Up until > now, I have drawn a crosshair with a draw callback. I transform to the > viewpoint and then in front of it. However, roundoff error causes the > crosshair lines to wiggle, forcing me to put them farther away. With > them farther away, they interact with the terrain, dissapearing behind > it when the viewpoint is too close. You might try changing the Z buffer state right before and after you draw the crosshairs. This will force them to always be drawn "over" the scene. pfDraw(); ... zfunction(ZF_ALWAYS); zwritemask(0x0); draw crosshairs zfunction(ZF_LEQUAL); zwritemask(0xffffffff); Allan -- Allan Schaffer Silicon Graphics aschaffe@sgi.com