ardour/livetrax
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improve scroll and drag behaviour of volume-controller knob

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This commit is contained in:
Robin Gareus 2013-09-01 03:19:13 +02:00
parent dd0a1cd846
commit 66292718a1
2 changed files with 54 additions and 4 deletions
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54
gtk2_ardour/volume_controller.cc
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@ -142,7 +142,6 @@ VolumeController::adjust (double control_delta)
double v;
if (!_linear) {
/* we map back into the linear/fractional slider position,
* because this kind of control goes all the way down
* to -inf dB, and we want this occur in a reasonable way in
@ -150,7 +149,7 @@ VolumeController::adjust (double control_delta)
* gain coefficient domain (or dB domain), the lower end of the
* control range (getting close to -inf dB) takes forever.
*/
#if 0
/* convert to linear/fractional slider position domain */
v = gain_to_slider_position_with_max (_controllable->get_value (), _controllable->upper());
/* increment in this domain */
@ -171,6 +170,57 @@ VolumeController::adjust (double control_delta)
}
/* and return it */
return dB_to_coefficient (v);
#else
/* ^^ Above algorithm is not symmetric. Scroll up to steps, scoll down two steps, -> different gain.
*
* see ./libs/gtkmm2ext/gtkmm2ext/motionfeedback.h and gtk2_ardour/monitor_section.cc:
* min-delta (corr) = MIN(0.01 * page inc, 1 * size_inc) // (gain_control uses size_inc=0.01, page_inc=0.1)
* range corr: 0..2 -> -inf..+6dB
* step sizes [0.01, 0.10, 0.20] * page_inc, [1,2,10,100] * step_inc. [1,2,10,100] * page_inc
*
* 0.001, 0.01, 0.02, 0.1, .2, 1, 10
* -> 1k steps between -inf..0dB
* -> 1k steps between 0..+dB
*
* IOW:
* the range is from *0 (-inf dB) to *2.0 ( +6dB)
* the knob is configured to to go in steps of 0.001 - that's 2000 steps between 0 and 2.
* or 1000 steps between 0 and 1.
*
* we cannot round to .01dB steps because
* There are only 600 possible values between +0db and +6dB when going in steps of .01dB
* 1000/600 = 1.66666...
*
******
* idea: make the 'controllable use a fixed range of dB.
* do a 1:1 mapping between values. :et's stick with the range of 0..2 in 0.001 steps
*
* "-80" becomes 0 and "+6" becomes 2000. (NB +6dB is actually 1995, but we clamp that to the top)
*
* This approach is better (more consistet) but not good. At least the dial does not annoy me as much
* anymore as it did before.
*
* const double stretchfactor = rint((_controllable->upper() - _controllable->lower()) / 0.001); // 2000;
* const double logfactor = stretchfactor / ((20.0 * log10( _controllable->upper())) + 80.0); // = 23.250244732
*/
v = _controllable->get_value ();
/* assume everything below -60dB is silent (.001 ^= -60dB)
* but map range -80db..+6dB to a scale of 0..2000
* 80db was motivated because 2000/((20.0 * log(1)) + 80.0) is an integer value. "0dB" is included on the scale.
* but this leaves a dead area at the bottom of the meter..
*/
double arange = (v >= 0.001) ? ( ((20.0 * log10(v)) + 80.0) * 23.250244732 ) : ( 0 );
/* add the delta */
v = rint(arange) + rint(control_delta * 1000.0); // (min steps is 1.0/0.001 == 1000.0)
/* catch bottom -80..-60 db in one step */
if (v < 466) v = (control_delta > 0) ? 0.001 : 0;
/* reverse operation (pow(10, .05 * ((v / 23.250244732) - 80.0)))
* can be simplified to :*/
else v = pow(10, (v * 0.00215051499) - 4.0);
/* clamp value in coefficient domain */
v = std::max (_controllable->lower(), std::min (_controllable->upper(), v));
return v;
#endif
} else {
double mult;

4
libs/gtkmm2ext/motionfeedback.cc
View File

@ -389,10 +389,10 @@ MotionFeedback::pixwin_scroll_event (GdkEventScroll* ev)
if (ev->state & Keyboard::GainExtraFineScaleModifier) {
scale = 0.01;
} else {
scale = 0.05;
scale = 0.10;
}
} else {
scale = 0.25;
scale = 0.20;
}
switch (ev->direction) {