From f41ebce14762d7022ace414513af3f446ebc7d41 Mon Sep 17 00:00:00 2001
From: fred <fred>
Date: Wed, 27 Mar 2002 02:06:30 +0000
Subject: [PATCH] lilypond-1.5.39

---
 Documentation/regression-test.tely |  2 +
 input/regression/beam-concave.ly   | 88 ++++++++++++++++++++++++++++++
 lily/include/beam.hh               |  2 +-
 3 files changed, 91 insertions(+), 1 deletion(-)
 create mode 100644 input/regression/beam-concave.ly

diff --git a/Documentation/regression-test.tely b/Documentation/regression-test.tely
index 36cacbfb90..a2e6e9ce38 100644
--- a/Documentation/regression-test.tely
+++ b/Documentation/regression-test.tely
@@ -124,6 +124,8 @@ Grace note do weird things with timing. Fragile.
 
 @lilypondfile[printfilename]{beaming.ly}
 
+@lilypondfile[printfilename]{beam-concave.ly}
+
 @lilypondfile[printfilename]{beam-extreme.ly}
 
 @lilypondfile[printfilename]{beam-position.ly}
diff --git a/input/regression/beam-concave.ly b/input/regression/beam-concave.ly
new file mode 100644
index 0000000000..1cf0fa5420
--- /dev/null
+++ b/input/regression/beam-concave.ly
@@ -0,0 +1,88 @@
+\header{
+  texidoc = "Concave beams should be horizontal.  However, what exactly
+it is that makes a beam concave is still unclear.
+
+Beams 1 and 3 should be sloped, 2 and 4 should be horizontal.  Two
+sane attempts of calculating concaveness of a beam fail to distinguish
+beams this way."
+
+}
+
+\score{
+  \notes\relative c'{
+    \property Voice.Beam \set #'debug-concave = ##t
+
+%%%  \property Voice.Beam \set #'concaveness = #0.8
+%%%  \property Voice.Beam \set #'concaveness-no-slope = ##f
+%%%  \property Voice.Beam \set #'concaveness-square = ##f
+
+    
+    
+    \property Voice.Beam \set #'concaveness-no-slope = ##t
+    %%\property Voice.Beam \set #'concaveness = #0.25
+    
+    %% this gives what baerenreiter does, but it's too kludgy
+    %% to make much sense
+    \property Voice.Beam \set #'concaveness-square = ##t
+    \property Voice.Beam \set #'concaveness = #0.08
+    
+%% This case seems easy: second beam should be horizontal.
+    
+    %% SCS-I Menuet I, m15
+    %% sloped
+    %% slope = -0.5ss
+    %% concaveness: 0.50
+    %% concaveness-no-slope: 0.25
+    %% concaveness-no-slope^2: 0.06
+    \clef bass
+    \time 3/4
+    \key g\major
+    a8 g fis e b dis
+    
+    %% SCS-I Menuet II, m20
+    %% horizontal
+    %% slope = 0
+    %% concaveness: 1.12
+    %% concaveness-no-slope: 0.38
+    %% concaveness-no-slope^2: 0.09
+    \key f\major
+    fis,^"horiz." a c es d c
+
+%%% Sarabande: the first beam, obviously more concave, is not horizontal,
+%%% but is matched with the next beam in the piece: context.
+    
+    %% Sarabande: m24
+    %% sloped
+    %% concaveness: 0.75
+    %% concaveness-no-slope: 0.00
+    %% concaveness-no-slope^2: 0.00
+    \stemUp
+    [d,16 a' b cis]
+
+    %% Sarabande: m25
+    %% horizontal
+    %% concaveness: 0.50
+    %% concaveness-no-slope: 0.25
+    %% concaveness-no-slope^2: 0.12
+    [a'16^"horiz." b c b]
+    
+% Hmm.  Concaveness of both: 1.75
+%     %% SCS-VI Prelude, m81
+%     %% slope = 0.0
+%     \stemBoth
+%     \key d\major
+%     [e,8 cis a']
+    
+%     %% SCS-VI Prelude, m82
+%     %% slope = 0.1ss (possibly b.o. context?)
+%     [g, e' cis]
+    
+  }
+  \paper{
+    linewidth = -1.0
+  }
+}
+
+%% Local variables:
+%% LilyPond-indent-level:2
+%% End:
diff --git a/lily/include/beam.hh b/lily/include/beam.hh
index eba0901fbe..35dfbeb8aa 100644
--- a/lily/include/beam.hh
+++ b/lily/include/beam.hh
@@ -33,7 +33,7 @@ public:
     y-dy callbacks
    */
   DECLARE_SCHEME_CALLBACK (least_squares, (SCM));
-  DECLARE_SCHEME_CALLBACK (cancel_suspect_slope, (SCM));
+  DECLARE_SCHEME_CALLBACK (check_concave, (SCM));
   DECLARE_SCHEME_CALLBACK (slope_damping, (SCM));
   DECLARE_SCHEME_CALLBACK (quantise_dy, (SCM));
   DECLARE_SCHEME_CALLBACK (user_override, (SCM));
-- 
2.39.5