From 5dcb49f7127f3c3b793492e1de5257174da0c930 Mon Sep 17 00:00:00 2001
From: Jim Hague <jim.hague@acm.org>
Date: Tue, 13 Aug 2013 00:51:43 +0100
Subject: [PATCH] Try to be cleverer when transposing for cello.

Jane says: Am most comfortable between the bottom G (the bottom line of the bass clef) and top D (the note above middle C), but can play from bottom C upwards (the C string is a bit growly) and at a push can get as high as the A above middle C.

Implement the following rule:

1. If range is G to d', transpose down 2 octaves.
2. If lowest note is < C, transpose down 1 octave.
3. Otherwise calculate the distance above d for the highest note on a one
   octave transposition, and the distance below G on a two octave
   transposition. Find the smallest, and use the corresponding
   transposition.
---
 makeCello.sh | 31 +++++++++++++++++++++++++------
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/makeCello.sh b/makeCello.sh
index 5cf1d40..7f7e4f2 100755
--- a/makeCello.sh
+++ b/makeCello.sh
@@ -13,10 +13,30 @@ if [ $# != 1 ]; then
     exit 1
 fi
 
-# Transpose down (return 0) if bottom note was < C.
+# Return 0 if we should transpose down 2 octaves, 1 if just one
+# octave. $2 is highest note, $3 is lowest note.
+#
+# If range is G to d', transpose down 2 octaves.
+# If lowest note is < C, transpose down 1 octave.
+# Otherwise calculate the distance above d for the highest note on a one
+# octave transposition, and the distance below G on a two octave
+# transposition. Find the smallest, and use the corresponding
+# transposition.
 transposedowntwo()
 {
-    return $(($3 >= 100))
+    if (($3 >= 104 && $2 <= 115)); then
+        return 0;
+    fi
+    if (($3 < 100)); then
+        return 1;
+    fi
+    over=$(($2 - 108))
+    under=$((104 - $3))
+    if (($over <= $under)); then
+        return 1;
+    fi
+
+    return 0;
 }
 
 dir=`pwd`
@@ -38,11 +58,10 @@ find $booke -name "*.abc" | sort |
         range=`./abcrange.py $filename`
 
         # Move down either one octave or two, depending on the range
-        # of the tune. If there are any notes below middle C, transpose
-        # down one octave. The default is to transpose down two octaves.
-        middle="d"
+        # of the tune.
+        middle="D"
         if transposedowntwo $range; then
-            middle="D"
+            middle="d"
         fi
 
         sed -e "/^ *K:/s/$/ clef=bass middle=$middle/" $filename > $outdir/$name.abc