use const static member instead of a magic number

[ardour.git] / libs / ardour / amp.cc

diff --git a/libs/ardour/amp.cc b/libs/ardour/amp.cc
index 1579b5dcea7b2f0e64b2283cfc7f1c01f1b4d9e3..f60240fd57c128dc6ca97a74364eecbb90b56912 100644 (file)
--- a/libs/ardour/amp.cc
+++ b/libs/ardour/amp.cc
@@ -33,16 +33,20 @@
 
 using namespace ARDOUR;
 using namespace PBD;
+using std::min;
+
+/* gain range of -inf to +6dB, default 0dB */
+const float Amp::max_gain_coefficient = 1.99526231f;
 
 Amp::Amp (Session& s)
        : Processor(s, "Amp")
        , _apply_gain(true)
        , _apply_gain_automation(false)
        , _current_gain(1.0)
+       , _gain_automation_buffer(0)
 {
        Evoral::Parameter p (GainAutomation);
-       /* gain range of -inf to +6dB, default 0dB */
-       p.set_range (0, 1.99526231f, 1, false);
+       p.set_range (0, max_gain_coefficient, 1, false);
        boost::shared_ptr<AutomationList> gl (new AutomationList (p));
        _gain_control = boost::shared_ptr<GainControl> (new GainControl (X_("gaincontrol"), s, this, p, gl));
        _gain_control->set_flags (Controllable::GainLike);
@@ -84,7 +88,8 @@ Amp::run (BufferSet& bufs, framepos_t /*start_frame*/, framepos_t /*end_frame*/,
 
                if (_apply_gain_automation) {
 
-                       gain_t* gab = _session.gain_automation_buffer ();
+                       gain_t* gab = _gain_automation_buffer;
+                       assert (gab);
 
                        for (BufferSet::audio_iterator i = bufs.audio_begin(); i != bufs.audio_end(); ++i) {
                                Sample* const sp = i->data();
@@ -112,7 +117,7 @@ Amp::run (BufferSet& bufs, framepos_t /*start_frame*/, framepos_t /*end_frame*/,
                                for (BufferSet::midi_iterator i = bufs.midi_begin(); i != bufs.midi_end(); ++i) {
 
                                        MidiBuffer& mb (*i);
-
+                                       
                                        for (MidiBuffer::iterator m = mb.begin(); m != mb.end(); ++m) {
                                                Evoral::MIDIEvent<MidiBuffer::TimeType> ev = *m;
                                                if (ev.is_note_on()) {
@@ -170,7 +175,7 @@ Amp::apply_gain (BufferSet& bufs, framecnt_t nframes, gain_t initial, gain_t tar
                        Evoral::MIDIEvent<MidiBuffer::TimeType> ev = *m;
 
                        if (ev.is_note_on()) {
-                               gain_t scale = delta * (ev.time()/(double) nframes);
+                               const gain_t scale = delta * (ev.time()/(double) nframes);
                                ev.scale_velocity (initial+scale);
                        }
                }
@@ -369,10 +374,7 @@ Amp::inc_gain (gain_t factor, void *src)
 void
 Amp::set_gain (gain_t val, void *src)
 {
-       // max gain at about +6dB (10.0 ^ ( 6 dB * 0.05))
-       if (val > 1.99526231f) {
-               val = 1.99526231f;
-       }
+       val = min (val, max_gain_coefficient);
 
        if (src != _gain_control.get()) {
                _gain_control->set_value (val);
@@ -381,7 +383,7 @@ Amp::set_gain (gain_t val, void *src)
                return;
        }
 
-       _gain_control->set_double(val, false);
+       _gain_control->set_double (val);
        _session.set_dirty();
 }
 
@@ -412,9 +414,8 @@ Amp::set_state (const XMLNode& node, int version)
 void
 Amp::GainControl::set_value (double val)
 {
-       // max gain at about +6dB (10.0 ^ ( 6 dB * 0.05))
-       if (val > 1.99526231) {
-               val = 1.99526231;
+       if (val > max_gain_coefficient) {
+               val = max_gain_coefficient;
        }
 
        _amp->set_gain (val, this);
@@ -440,14 +441,19 @@ Amp::GainControl::internal_to_user (double v) const
        return accurate_coefficient_to_dB (v);
 }
 
+/** Write gain automation for this cycle into the buffer previously passed in to
+ *  set_gain_automation_buffer (if we are in automation playback mode and the
+ *  transport is rolling).
+ */
 void
 Amp::setup_gain_automation (framepos_t start_frame, framepos_t end_frame, framecnt_t nframes)
 {
-       Glib::Mutex::Lock am (control_lock(), Glib::TRY_LOCK);
+       Glib::Threads::Mutex::Lock am (control_lock(), Glib::Threads::TRY_LOCK);
 
        if (am.locked() && _session.transport_rolling() && _gain_control->automation_playback()) {
+               assert (_gain_automation_buffer);
                _apply_gain_automation = _gain_control->list()->curve().rt_safe_get_vector (
-                       start_frame, end_frame, _session.gain_automation_buffer(), nframes);
+                       start_frame, end_frame, _gain_automation_buffer, nframes);
        } else {
                _apply_gain_automation = false;
        }
@@ -470,4 +476,14 @@ Amp::value_as_string (boost::shared_ptr<AutomationControl> ac) const
 
        return Automatable::value_as_string (ac);
 }
-       
+
+/** Sets up the buffer that setup_gain_automation and ::run will use for
+ *  gain automationc curves.  Must be called before setup_gain_automation,
+ *  and must be called with process lock held.
+ */
+
+void
+Amp::set_gain_automation_buffer (gain_t* g)
+{
+       _gain_automation_buffer = g;
+}