[linux-audio-dev] Which sequencer framework for a simple MIDI drum looper ?

Stephen Cameron smcameron at yahoo.com
Wed Aug 16 15:06:54 UTC 2006

--- _ langagemachine <langagemachine at gmail.com> wrote:

> Thanks for suggesting Gneutronica :-) It provides useful answers to
> some of my needs.
> If I had to make one main adjustment to my personal preferences, it
> would be in the way that the pattern is visually rendered : while your
> way of indicating note velocity (according to its vertical position on
> a grid) makes it efficient and precise to set, I find it is not easy
> to visualize the whole rhythm pattern at a glance. Not so easy as
> colouring the block in a progressive shade of black&white would make
> it, IMHO.

Hm, that's an idea I hadn't thought of.  More difficult to program...
Also, though it's mostly a step sequencer, if you uncheck the "snap to grid"
box, then the timing is freeform, and the gridlines become just 
visual guides, so there really is no "block" to color, but maybe the
background color of each row could be graded along the x-axis
according to the velocity of notes in the vicinity... sounds a 
little processor intensive to accomplish though.  Or maybe just
pre-generated bitmaps could be pasted, or single pixel high
gradient lines duplicated vertically...  Exactly how to do that
in gnome is not something I know off the top of my head.

Well, lately my music programming has been to do with a voice
editor for my yamaha motif rack (kind of a pain to program
that thing) but even that has been put on the back burner for
awhile, so I doubt I'll be tweaking the graphics on gneutronica
anytime soon.

If you (or anyone) wanted to experiment, the code that draws 
each row in that grid is in gneutronica.c, in the function
called canvas_event().  The for loop towards the bottom is
where it draws each note.  I'm thinking it wouldn't be too 
hard to add a section that draws a series of vertical lines
of diminishing intensity in say, red, or some other color,
beginning at the note's initial X position that fades out as 
you move to the right, then superimpose my existing note 
outline in a contrasting color over that.  Or whatever else
you want to try out.

> Well, maybe one gets used to it after working on the editor ... I will
> install Gneutronica and make a more insightful feedback :-)

Thanks.  It's not anything like a perfect program, so don't 
get your expectations too high.

-- steve

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