Performance::remap_grace_durations(): robust way of handling grace

[lilypond.git] / lily / performance.cc

diff --git a/lily/performance.cc b/lily/performance.cc
index 0bfe37ee826581ccab7815b50afd71930725740f..78070a064a39f8b57c640faca06fc8b0234c7a00 100644 (file)
--- a/lily/performance.cc
+++ b/lily/performance.cc
@@ -3,7 +3,7 @@
 
   source file of the GNU LilyPond music typesetter
 
-  (c) 1997--2006 Jan Nieuwenhuizen <janneke@gnu.org>
+  (c) 1997--2007 Jan Nieuwenhuizen <janneke@gnu.org>
 */
 
 #include "performance.hh"
@@ -34,7 +34,7 @@ Performance::~Performance ()
 }
 
 void
-Performance::output (Midi_stream &midi_stream)
+Performance::output (Midi_stream &midi_stream) const
 {
   int tracks_ = audio_staffs_.size ();
 
@@ -43,6 +43,7 @@ Performance::output (Midi_stream &midi_stream)
 
   midi_stream << Midi_header (1, tracks_, clocks_per_4);
   message (_ ("Track...") + " ");
+  
   int channel = 0;
   for (vsize i = 0; i < audio_staffs_.size (); i++)
     {
@@ -50,30 +51,37 @@ Performance::output (Midi_stream &midi_stream)
       if (be_verbose_global)
        progress_indication ("[" + to_string (i));
 
-      /*
-       MIDI players tend to ignore instrument settings on
-       channel 10, the percussion channel by default.
-      */
-      if (channel % 16 == 9)
-       channel++;
+      int midi_channel =  s->channel_;
+
+      if (midi_channel < 0)
+       {
+         midi_channel = channel;
+         channel ++;
+         /*
+           MIDI players tend to ignore instrument settings on
+           channel 10, the percussion channel.
+         */
+         if (channel % 16 == 9)
+           channel ++;
+       }
 
       /*
        Huh? Why does each staff also have a separate channel? We
        should map channels to voices, not staves. --hwn.
       */
-      if (channel > 15)
+      if (midi_channel > 15)
        {
          warning (_ ("MIDI channel wrapped around"));
          warning (_ ("remapping modulo 16"));
+
+         midi_channel = midi_channel % 16; 
        }
 
-      s->output (midi_stream, channel);
-      channel ++;
+      s->output (midi_stream, midi_channel);
       if (be_verbose_global)
        progress_indication ("]");
     }
 }
-
 void
 Performance::add_element (Audio_element *p)
 {
@@ -81,7 +89,7 @@ Performance::add_element (Audio_element *p)
 }
 
 void
-Performance::write_output (string out)
+Performance::write_output (string out) const
 {
   if (out == "-")
     out = "lelie.midi";
@@ -99,3 +107,21 @@ Performance::write_output (string out)
 }
 
 
+void
+Performance::remap_grace_durations ()
+{
+  for (vsize i = 0; i < audio_elements_.size (); i++)
+    {
+      if (Audio_column * col = dynamic_cast<Audio_column*> (audio_elements_[i]))
+       {
+         col->when_.main_part_ = col->when_.main_part_ + Rational (1,4) * col->when_.grace_part_;
+         col->when_.grace_part_ = Rational (0);
+       }
+    }
+}
+
+void
+Performance::process ()
+{
+  remap_grace_durations ();
+}