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Re: terminal graphics using braille characters

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Eli the Bearded <*@eli.users.panix.com> wrote:
> In comp.lang.c, JohnF  <John@F.com> wrote:
>> luser droog <luser.droog@gmail.com> wrote:
>> > https://codereview.stackexchange.com/questions/248021/
>> >         text-based-rendering-animation-engine-for-the-terminal
>> 
>> Very cute. But I give up... where does "766F6964" come from?
>> And here's a 31-line terminal animation of stored functions...
> 
> I reworked it as a dots program:
> 
> // replaces asciigraph()
> void braille_graph( grid *g, double *f, int n )
> {
>     int    row=0,nrows=24, col=0,ncols=78;
>     double bigf=0.0,yval;
> 
>     grid_clear(g);
> 
>     for ( col=0; col<n; col++ )
>        if ( fabs(f[col]) > bigf ) bigf = fabs(f[col]);
> 
>     for ( row=0; row<nrows; row++ ) {
>         yval = bigf*((double)(nrows/2-row))/((double)(nrows/2));
> 
>         for ( col=0; col<ncols; col++ )
>            if (yval*f[(col*(n-1))/(ncols-1)]>=yval*yval)  
>                grid_set_pixel(g, col, row);
>     }
> 
>     renderer_update(g);
> }
> 
> // replaces main()
> void johnforkosh_function()
> {
>     int width = 80;
>     int height = 48;
> 
>     double f[999], pi=3.14159;
>     double t=0.0, dt=0.05, w1=16.,w2=3.;  int Nt=50;
>     int    i=0, N=511;                    /* f[] index */
> 
>     grid *g = grid_new(width, height);
>     renderer_new(g);
>     renderer_update(g);
> 
>     while ( --Nt > 0 ) {
>         for ( i=0; i<N; i++ ) {
>             double x = 2.0*pi*((double)i)/((double)(N-1));
>             f[i] = .75*sin(2.*x+pi/3.+w1*t) + 1.*sin(1.*x+pi/2.+w2*t);
>         }
> 
>         braille_graph(g, f, N);
>         t += dt;
>     }
>     renderer_free();
>     grid_free(g);
> }
> 
> I stuck those in examples.c and called it from main() in main.c. Ending
> frame:
> 
> ??????????????????????????????                     ????????????????????????
> ??????????????????????????????????????????            ???????????????????????????????????????
> ?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
> ?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
> ?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????
> ??????????????????????????????????????????????????????????????????
> 
> Also, to test it some more, I tried this out:
> 
> void try_them_all()
> {
>     int width = 64;
>     int height = 64;
> 
>     grid *g = grid_new(width, height);
>     renderer_new(g);
> 
>     renderer_update(g);
> 
>     for (int s = 0; s < 256; s ++) {
> 
>         for (int b = 0; b < 8; b ++) {
>             int i = 2 * (s % 32) + (b / 4);
>             int j = 4 * (s / 32) + (b % 4);
>             if ( s & (1 << b) ) {
>                 grid_set_pixel(g, i, j);
>             }
>         }
>         renderer_update(g);
>     }
>     renderer_free();
>     grid_free(g);
> }
> 
> Exercising the full character set:
> 
>  ?????????????????????????????????????????????????????????????????????????????????????????????
> ????????????????????????????????????????????????????????????????????????????????????????????????
> ????????????????????????????????????????????????????????????????????????????????????????????????
> ????????????????????????????????????????????????????????????????????????????????????????????????
> ????????????????????????????????????????????????????????????????????????????????????????????????
> ????????????????????????????????????????????????????????????????????????????????????????????????
> ????????????????????????????????????????????????????????????????????????????????????????????????
> ????????????????????????????????????????????????????????????????????????????????????????????????
> 
> Elijah
> ------
> had not previously been aware of ncursesw

Interesting; thanks, Eli. I actually wrote asciigraph() just
as a simple debugging tool for math functions (one in particular
that prompted me to write it), where printing a few specific x,f(x)'s
wasn't showing everything I needed. Never actually had any use for
the dynamic/animation part. Just put that omega*t and sleep;clear
in the test driver for "decorative" purposes. It's trivial enough
to cut-and-paste asciigraph()'s 10 lines (was originally almost 50
until I stumbled onto that f[]*yval>=yval*yval idea which
semi-magically accomplishes all necessary logic at one fell swoop)
into any module where it's useful to display a function's
general behavior. All this additional stuff is cute, but way
too elaborate for asciigraph()'s intended "low-profile" debugging
purpose.
--
John Forkosh  ( mailto:  j@f.com  where j=john and f=forkosh )

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Thread

terminal graphics using braille characters luser droog <luser.droog@gmail.com> - 2020-08-22 17:41 -0700
  Re: terminal graphics using braille characters JohnF <John@F.com> - 2020-08-23 03:32 +0000
    Re: terminal graphics using braille characters Eli the Bearded <*@eli.users.panix.com> - 2020-08-23 06:52 +0000
      Re: terminal graphics using braille characters "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2020-08-23 01:58 -0700
      Re: terminal graphics using braille characters John Forkosh <forkosh@panix.com> - 2020-08-24 06:10 +0000
    Re: terminal graphics using braille characters luser droog <luser.droog@gmail.com> - 2020-08-23 00:07 -0700
      Re: terminal graphics using braille characters Öö Tiib <ootiib@hot.ee> - 2020-08-23 01:35 -0700
      Re: terminal graphics using braille characters John Forkosh <forkosh@panix.com> - 2020-08-24 06:26 +0000
        Re: terminal graphics using braille characters luser droog <luser.droog@gmail.com> - 2020-08-23 23:59 -0700
          Re: terminal graphics using braille characters John Forkosh <forkosh@panix.com> - 2020-08-24 09:58 +0000

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