On 08/10/14 13:36, Raine M. Ekman
wrote:
Phil CM <philcm@gnu.org> wrote:
Now the only think that is left is a
portamento function, to go from
one note to another (/exactly/ like so-404
<http://d00m.org/%7Esomeone/so404/>
does).
Quoting Philipp Überbacher <murks@tuxfamily.org>:
I have never done this but I suggest to
look at the calf monosynth
code. AFAIR it has a couple of different ways to handle
successive/overlapping notes.
Another synth that comes to mind and has portamento is phasex.
Well, if it has to be exactly the same, I'd suggest digging in the
so-404 code and not in those other synths. Looks like it adjusts
frequency at samplerate/100, calculating:
freq = ((portamento/127.0)*0.9)*freq +
(1.0-((portamento/127.0)*0.9))*tfreq;
I guess tfreq is the target frequency of the note being
portamented towards.
OK, so I found how to control the envelope with a new control, and
how to output values in console while jalv runs, like this :
printf("Key: %d, Period: %d, Vel: %d, Envelope: %f\n", key,
m_period, velocity, m_envelope);
And it prints this :
Key: 77, Period: 276, Vel: 81, Envelope: 0.632812
Key: 79, Period: 246, Vel: 75, Envelope: 0.585938
Key: 64, Period: 584, Vel: 43, Envelope: 0.335938
Key: 76, Period: 292, Vel: 54, Envelope: 0.421875
Key: 65, Period: 551, Vel: 54, Envelope: 0.421875
Key: 64, Period: 584, Vel: 64, Envelope: 0.500000
Key: 77, Period: 276, Vel: 55, Envelope: 0.429688
Key: 76, Period: 292, Vel: 44, Envelope: 0.343750
Key: 76, Period: 292, Vel: 63, Envelope: 0.492188
Key: 67, Period: 491, Vel: 78, Envelope: 0.609375
So apparently the period is the note. (I looked in the lib
for the formula).
Now how do I introduce those freq and portamento variables, are they
variables (or parameters or functions or keywords) that exists for
me to use it, or do I have to declare them and if so, how do I
connect them to render()? Maybe I don't even need them, most of the
logic seems to be already here:
See, look how it goes :
void render(uint32_t from, uint32_t to) {
if (m_key == LV2::INVALID_KEY)
return;
for (uint32_t i = from; i < to; ++i) {
m_envelope = *p(p_enve);
float pwm = *p(p_pwm) + (1 - *p(p_pwm)) * m_envelope;
float s = -0.25 + 0.5 * (m_counter > m_period * (1
+ pwm) / 2);
// float s = -0.25 + 0.5 * (m_counter > m_period /
2);
m_counter = (m_counter + 1) % m_period;
p(p_left)[i] += s;
p(p_right)[i] += s;
if (m_envelope > 0)
m_envelope -= 0.5 / m_rate;
}
}
And from and to are already there. This for loop
determines the duration of the note, right? I have to use some of
that time to go from from to to in a fraction of
that time.
How do I do that?
--
Phil