Move library tree where it belongs

2026-01-23 17:25:54 +01:00 · 2010-01-24 09:19:39 +00:00
parent e74978ba77
commit 58caf78a86
6020 changed files with 2790154 additions and 0 deletions
--- a/lib-src/libnyquist/nyquist/cmt/tempomap.c
+++ b/lib-src/libnyquist/nyquist/cmt/tempomap.c
@@ -0,0 +1,124 @@
+/* tempomap.c -- used by midifile reader to record and lookup time maps */
+/*
+ *  This module is designed to provide tempo change list insert and
+ *  lookup facilities.  The exact interpretation of beat and tempo are
+ *  defined in one function, elapsed_time, which takes a tempo and a
+ *  number of beats, and returns time.
+ */
+
+#include "cext.h"
+#include "midifns.h"
+#include "timebase.h"
+#include "moxc.h"
+#include "seq.h"
+#include "tempomap.h"
+
+static time_type elapsed_time();
+
+/* tempomap_create -- create a tempomap */
+/**/
+tempomap_type tempomap_create()
+{
+    tempochange_type tempochange = tempochange_alloc();
+    tempomap_type tempomap = tempomap_alloc();
+    tempomap->hint = tempomap->entries = tempochange;
+    tempochange->beat = 0L;
+    /* default tempo is 120 (= 50000microsec/beat) and 24 divisions/quarter */
+    /* this may be overridden by a tempomap_insert */
+    tempochange->tempo = 500000L / 24;
+    tempochange->rtime = 0L;
+    tempochange->next = NULL;
+    return tempomap;
+}
+
+
+/* tempomap_free -- deallocate storage for tempo map */
+/**/
+void tempomap_free(tm)
+  tempomap_type tm;
+{
+    while (tm->entries) {
+        tempochange_type tc = tm->entries;
+        tm->entries = tc->next;
+        tempochange_free(tc);
+    }
+    memfree(tm, sizeof(tempomap_node));
+}
+
+
+/* tempomap_insert -- insert a tempo change into the map */
+/**/
+void tempomap_insert(tempomap, beat, tempo)
+  tempomap_type tempomap;
+  long beat;    /* beat division number */
+  long tempo;   /* microseconds per beat division */
+{
+    tempochange_type tempochange = tempochange_alloc();
+    register tempochange_type prev;
+    register tempochange_type next;
+
+    tempochange->tempo = tempo;
+    tempochange->beat = beat;
+
+    if ((!(tempomap->hint->next)) ||
+          (tempomap->hint->beat > beat))
+        tempomap->hint = tempomap->entries;
+
+    /* find the insert point */
+    for (prev = tempomap->hint;
+         (next = prev->next) && (next->beat <= beat);
+         prev = next);
+
+     /* make the insert */
+    tempochange->next = next;
+    prev->next = tempochange;
+    tempomap->hint = prev;
+
+    /* update the real time of each change */
+    for (tempochange = prev;
+         tempochange->next;
+         tempochange = tempochange->next) {
+        tempochange->next->rtime =
+            tempochange->rtime +
+            elapsed_time(tempochange->tempo,
+                         tempochange->next->beat - tempochange->beat);
+    }
+}
+
+
+/* tempomap_lookup -- convert beat to 4us time */
+/*
+ * The returned time is real time in units of 4us.
+ */
+time_type tempomap_lookup(tempomap, beat)
+  tempomap_type tempomap;
+  long beat;
+{
+    register tempochange_type prev;
+    register tempochange_type next;
+
+    if ((!(tempomap->hint->next)) || 
+          (tempomap->hint->beat > beat))
+        tempomap->hint = tempomap->entries;
+
+    /* find the last inflection point */
+    for (prev = tempomap->hint;
+         (next = prev->next) && (next->beat <= beat);
+         prev = next);
+
+    /* interpolate */
+    return prev->rtime +
+           elapsed_time(prev->tempo, beat - prev->beat);
+}
+
+
+/* elapsed_time -- compute the real elapsed time at a given tempo */
+/*
+ * the time returned is in units of 4us.
+ */
+static time_type elapsed_time(tempo, beat)
+  long tempo;
+  long beat;
+{
+    return (time_type)((tempo * beat) >> 2);
+}