From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,548a224fd381d8f4 X-Google-Attributes: gid103376,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!postnews.google.com!s20g2000yqh.googlegroups.com!not-for-mail From: Ludovic Brenta Newsgroups: comp.lang.ada Subject: Re: Programming graphic systems Date: Thu, 23 Apr 2009 14:31:37 -0700 (PDT) Organization: http://groups.google.com Message-ID: <4287862f-b02a-4f43-85c4-f1d0cdd1b9ab@s20g2000yqh.googlegroups.com> References: <49f03485$0$2849$ba620e4c@news.skynet.be> NNTP-Posting-Host: 94.108.209.210 Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Trace: posting.google.com 1240522297 8075 127.0.0.1 (23 Apr 2009 21:31:37 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Thu, 23 Apr 2009 21:31:37 +0000 (UTC) Complaints-To: groups-abuse@google.com Injection-Info: s20g2000yqh.googlegroups.com; posting-host=94.108.209.210; posting-account=pcLQNgkAAAD9TrXkhkIgiY6-MDtJjIlC User-Agent: G2/1.0 X-HTTP-UserAgent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.0.7) Gecko/2009030810 Iceweasel/3.0.7 (Debian-3.0.7-1),gzip(gfe),gzip(gfe) Xref: g2news2.google.com comp.lang.ada:5529 Date: 2009-04-23T14:31:37-07:00 List-Id: Olivier Scalbert wrote on comp.lang.ada: > When playing with my GPS, I was thinking of the beautiful graphic > systems used in safety critical environment (medical, aircraft, ATC, ...). > I assume lots of them must be written in Ada. I was asking myself how > are they programmed mainly at the graphic level. Does the application > part use a graphic toolkit provided by the graphic board manufacturer or > do you have to program all the graphic primitives yourself in Ada (as > Bresenham line algorithm, ...) and written to the raster memory (which > must be very cool!) ? Until a couple of years ago, I used to work for Barco avionics [1,2] and indeed most of our devices were programmed in Ada. We wrote our own display drivers in Ada; they worked by writing into the graphics processor's registers over PCI and I2C. For bitmaps and video, we would write into a RAM buffer then point the graphics board to the buffer (i.e. write the address of the buffer in a register of the board). However, to draw the geometrical symbols for the flight instruments, we would of course use the hardware primitives rather than reimplement them in software. After writing a command and parameters in a set of registers, we would wait for a completion flag to become true in another register. [1] http://www.barco.com/aerospace [2] http://www.cs.kuleuven.ac.be/~dirk/ada-belgium/events/07/070612-abga.html For air (or rail, or seaport) traffic control, Barco also offers 2048x2048-pixel liquid crystal displays with an X server embedded in them. I didn't work in that division so I can't provide any more details. Nowadays I work in air traffic flow management [3] and we use an in- house binding to Motif for older screens and GtkAda for newer ones. ETFMS is a mission-critical, soft-real-time, distributed application. It is neither life-critical (i.e. nobody dies if it crashes) nor embedded (i.e. no DO-178B certification is needed) and the real-time requirements are in seconds, not micro- or nanoseconds, so we can use mainstream graphical subsystems (i.e. X11 on "normal" workstations and servers). [3] http://www.cfmu.eurocontrol.int/cfmu/public/standard_page/developments_etfms_index.html -- Ludovic Brenta.