Animated Vector Graphics on an Oscilloscope

February 27, 2011 | My Projects | By: Mark VandeWettering

I lost the original edit to this post. Recreated.

So, while watching the Oscars, I decided to hack together a simple little graphics program that would allow me to generate more sophisticated graphics for the oscilloscope. I ended up with 263 lines of code that implemented a simple matrix-based set of graphics commands. Eventually, I’ll add some line clipping and some other graphics primitives, but for now, it seems to be working just fine.

YouTube – Animated Vector Graphics on an Oscilloscope

To give you a taste of what the library lets you do, here is the set of commands that I used to generate the animated dial you see in the film.

Dial(double seconds)
    int i ;
    TransformPush() ;
        fprintf(stderr, "... angle %lf\n", seconds*6.) ;
        Rotate(seconds*6.) ;
        Line(0.0, 1., -0.05, -0.05) ;
        Line(-0.05, -0.05, 0.05, -0.05) ;
        Line(0.05, -0.05, 0., 1.0) ;
    TransformPop() ;

    for (i=0; i<360; i+= 6) {
        TransformPush() ;
        Rotate((double) i) ;
        if ((i % 30) == 0)
            Line(1.0, 0., 0.90, 0.) ;
            Line(1.0, 0., 0.95, 0.) ;
        TransformPop() ;

Addendum: Congrats to Lee and all the Toy Story 3 crew, and to Randy for winning his second Oscar (with twenty nominations, incredible). He definitely has had the best speech of the night so far.


Comment from Alan Yates
Time 2/28/2011 at 2:17 pm

Very cool Mark!

Looks like your drawing commands are vaguely PostScript like, should be easy to use this for lots of fun thing! Asteroids on a atmega? Scope tetris?

Comment from Mark
Time 2/28/2011 at 4:45 pm

Actually Alan, both of those have been done. (admittedly not vector)

Comment from Isaac
Time 7/5/2012 at 5:22 pm

Sorry I am a beginner what language is this code?

Comment from Lee
Time 7/6/2012 at 8:54 pm

This reminds me of a trick I saw on Letterman in the mid 80’s. As the show went to commercial the shot was in the control room on a vector scope that was spinning unlocked. A hand reaches in and pushes the sync button. The scope locks revealing the written phrase on the screen “Late Night with David Letterman”. I was impressed. I was also probabbly on my 3rd margarita.

Comment from Henk
Time 3/21/2013 at 4:27 pm

Wow! Very clean vector animation. I thought that smooth CRT vector animation wasn’t possible using a sound car. I grew up playing on Vectrex consoles. CRT vector graphics are special.
I’m very interested in the code! Is that something you would share?

Comment from Vincent
Time 6/25/2013 at 5:45 pm

Hey Mark, did you ever release this code? I’d be very, very keen to have a play with it!

Comment from Mark VandeWettering
Time 6/26/2013 at 11:25 am

Sorry Vincent, it was sadly on a laptop that was stolen in a robbery at my house last year. I haven’t located a proper backup, but still have a couple of old drives that might contain it, but my confidence is fading.

Comment from Vincent
Time 7/12/2013 at 5:18 pm

Ah, that’s such a shame. I’m working on a project that requires exactly this right now. I’m pulling my hair out trying to figure out how to do something like this. I’m not a coder or anything…

If you manage to locate it in the next couple of weeks please let me know. I’d try to recompense in any way I can and give you credit when the project goes out!

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