knob: use double precision normal on dent.

Fixes -0dB vs +0dB rounding issue.

diff --git a/gtk2_ardour/ardour_knob.cc b/gtk2_ardour/ardour_knob.cc
index ee25eaee2441dbbf5b60ea37bab328b18d10f014..bfc3c88057ed5ab90e0f21a2d7ebc9b9d7bd7119 100644 (file)
--- a/gtk2_ardour/ardour_knob.cc
+++ b/gtk2_ardour/ardour_knob.cc
@@ -361,7 +361,7 @@ ArdourKnob::on_motion_notify_event (GdkEventMotion *ev)
                                delta = tozero + remain;
                                _dead_zone_delta = 0;
                        } else {
-                               c->set_interface(_normal);
+                               c->set_value (c->normal());
                                val = _normal;
                                _dead_zone_delta = remain / px_deadzone;
                                return true;
@@ -369,7 +369,7 @@ ArdourKnob::on_motion_notify_event (GdkEventMotion *ev)
                }
 
                if (fabsf (rintf((val - _normal) / scale) + _dead_zone_delta) < 1) {
-                       c->set_interface(_normal);
+                       c->set_value (c->normal());
                        _dead_zone_delta += delta / px_deadzone;
                        return true;
                }