Re: [programming in c] bitmap gramophone

Spiros Bousbouras wrote:

On Tue, 02 Apr 2024 14:29:17 +0200
fir <fir@grunge.pl> wrote:

fir wrote:

fir wrote:

>
than i run the playback just from teh screen data
so i can play bitmap data like sorta of bitmap
gramophone (hovever playing bitmaps genarally makes
mostly if not ony some buzzes not much interesting)

>
i mean normal graphical bitmaps sound like buzzes
whan those that are generated from loaded vaw - it is those
who are mess soound like music
>
so regular imeges give buzes but mess images give music

>
>
some things showed imo
>
1) the vaves seem to be 16 bit signed, so drawing it as a bitmap
not fully works cos -min and +max have nearly the same color on screen
   (0x8000 is lowest 0x7fff is max)where 0 sound and -1 sound have quite
different colors 0x0000 and 0xffff) - but at least it seems i generati
it right (?)
>
       unsigned short val=amplitude*127*256*sin(t);
>
i rewritten the code
>
void buffer_add_sinwave(int len, float amplitude, float hz)
   {
     for(int i=wave_pos; i<wave_pos+len; i++)
     {
             if(i>big_ofscreen_buffer_size_x*big_ofscreen_buffer_size_y)
continue;

>
Shouldn't this be  break ? When
i>big_ofscreen_buffer_size_x*big_ofscreen_buffer_size_y  , it will remain
true for all the other values of  i  in the loop.
>

>
             float cycle = 22050.0/hz;
             float t = 2*M_PI*fmod(i,cycle)/cycle;
             unsigned short val=amplitude*127*256*sin(t);
              big_ofscreen_buffer[i] =  val;
     }
     wave_pos+=len;
    return;
}

>
Are  big_ofscreen_buffer , big_ofscreen_buffer_size_x , big_ofscreen_buffer_size_y
global variables ?
>

yes, what people call it, (coz it is not global but module scope (exe/dll) in fact)
thsi name is bad should be offscreen buffer but when i code various experiments i dont care for names to much (than in normal 'design' code)