[LAD] Real-time plotting of audio/ oscilloscope.

[Robin Gareus]

On 06/18/2010 02:05 AM, Jeremy wrote:
[..]
> Anyway, is there any library that provides me with an array to write to, and
> it handles refreshing the screen?  That way I would essentially just be
> writing to an array, which should be really fast inside the realtime loop.
>  I thought that is what SDL does, but I guess not.
> 
> Jeremy

Not sure where this is going. You started by saying you only needed a
simple debug tool.. but of course it's fun to tinker with SDL. :)

For drawing array-data on screen, pure-data would be a good choice.
Should not take more than 1 min: just open the Pd help for "tabwrite~"
and replace the "phasor~" with "adc~" to feed it with real-time audio-data.

If you want to stick with SDL, use a jack-ringbuffer (which is basically
an array); the jack-process callback writes into it
and in the main SDL thread: you read from the ring-buffer, plot it,
sleep for 40ms, repeat.

http://das.nasophon.de/jack_oscrolloscope/ is using SDL.

UTSL,
robin