X-Git-Url: https://git.donarmstrong.com/?a=blobdiff_plain;f=scm%2Fbeam.scm;h=d20458eb5364b5b6bd1b5a82268490b2e764ab37;hb=5b42a287848b7889e2ef2418e7d992d23594e31d;hp=b0feb6008fbec2b73ff54486fa0aea6f73f05ed5;hpb=af9078fd6d63dea5141e87a1b4d7cb5b0bcba84a;p=lilypond.git

diff --git a/scm/beam.scm b/scm/beam.scm
index b0feb6008f..d20458eb53 100644
--- a/scm/beam.scm
+++ b/scm/beam.scm
@@ -1,126 +1,61 @@
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;                  BEAMS
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;;
+;;;; beam.scm -- Beam scheme stuff
+;;;;
+;;;; source file of the GNU LilyPond music typesetter
+;;;; 
+;;;; (c)  2000--2004 Jan Nieuwenhuizen <janneke@gnu.org>
+;;;;
 
-(define (default-beam-space-function multiplicity)
-  (if (<= multiplicity 3) 0.816 0.844)
-  )
-
-;
-; width in staff space.
-;
-(define (default-beam-flag-width-function type)
+;;
+;; width in staff space.
+;;
+(define (beam-flag-width-function type)
   (cond
    ((eq? type 1) 1.98) 
    ((eq? type 1) 1.65) ;; FIXME: check what this should be and why
-   (else 1.32)
-   ))
-
-
-; This is a mess : global namespace pollution. We should wait
-;  till guile has proper toplevel environment support.
-
-
-;; Beams should be prevented to conflict with the stafflines, 
-;; especially at small slopes
-;;    ----------------------------------------------------------
-;;                                                   ########
-;;                                        ########
-;;                             ########
-;;    --------------########------------------------------------
-;;       ########
-;;
-;;       hang       straddle   sit        inter      hang
-
-;; inter seems to be a modern quirk, we don't use that
-
-  
-;; Note: quanting period is take as quants.top () - quants[0], 
-;; which should be 1 (== 1 interline)
-(define (mean a b) (* 0.5 (+ a  b)))
-(define (default-beam-dy-quants beam stafflinethick)
-  (let ((thick (ly-get-grob-property beam 'thickness))
-	)
-    
-    (list 0 (mean thick stafflinethick) (+ thick stafflinethick) 1)
-    ))
-
-;; two popular veritcal beam quantings
-;; see params.ly: #'beam-vertical-quants
-
-; (todo: merge these 2 funcs ? )
-
-(define (default-beam-y-quants beam multiplicity dy staff-line)
-  (let* ((beam-straddle 0)
-	 (thick (ly-get-grob-property beam 'thickness))
-	 (beam-sit (/ (+ thick staff-line) 2))
-	 (beam-hang (- 1 (/ (- thick staff-line) 2)))
-	 (quants (list beam-hang))
-	 )
-    
-    (if (or (<= multiplicity 1) (>= (abs dy) (/ staff-line 2)))
-	(set! quants (cons beam-sit quants)))
-    (if (or (<= multiplicity 2) (>= (abs dy) (/ staff-line 2)))
-	(set! quants (cons beam-straddle quants)))
-    ;; period: 1 (interline)
-    (append quants (list (+ 1 (car quants))))))
-
-(define (beam-traditional-y-quants beam multiplicity dy staff-line)
-  (let* ((beam-straddle 0)
-	(thick (ly-get-grob-property beam 'thickness))
-	(beam-sit (/ (+ thick staff-line) 2))
-	(beam-hang (- 1 (/ (- thick staff-line) 2)))
-	(quants '())
-	)
-    (if (>= dy (/ staff-line -2))
-	(set! quants (cons beam-hang quants)))
-    (if (and (<= multiplicity 1) (<= dy (/ staff-line 2)))
-	(set! quants (cons beam-sit quants)))
-    (if (or (<= multiplicity 2) (>= (abs dy) (/ staff-line 2)))
-	(set! quants (cons beam-straddle quants)))
-    ;; period: 1 (interline)
-    (append quants (list (+ 1 (car quants))))))
-
+   (else 1.32)))
 
 ;; There are several ways to calculate the direction of a beam
 ;;
 ;; * majority: number count of up or down notes
 ;; * mean    : mean centre distance of all notes
 ;; * median  : mean centre distance weighted per note
+;;
+;; [Ross] states that the majority of the notes dictates the
+;; direction (and not the mean of "center distance")
+;;
+;; But is that because it really looks better, or because he wants
+;; to provide some real simple hands-on rules?
+;;     
+;; We have our doubts, so we simply provide all sensible alternatives.
+
+
+;;
+;
+; DOCME: what goes into this func, what comes out.
 
 (define (dir-compare up down)
   (sign (- up down)))
 
 ;; arguments are in the form (up . down)
-(define (beam-dir-majority count total)
+(define-public (beam-dir-majority count total)
   (dir-compare (car count) (cdr count)))
 
-(beam-dir-majority '(0 . 0) '(0 . 0))
+(define-public (beam-dir-majority-median count total)
+  "First try majority. If that doesn't work, try median."
+  (let ((maj (dir-compare (car count) (cdr count))))
+    (if (not (= maj 0))
+	maj
+	(beam-dir-median count total))
+    ))
+
 
-(define (beam-dir-mean count total)
+(define-public (beam-dir-mean count total)
   (dir-compare (car total) (cdr total)))
 
-(define (beam-dir-median count total)
+(define-public (beam-dir-median count total)
   (if (and (> (car count) 0)
 	   (> (cdr count) 0))
       (dir-compare (/ (car total) (car count)) (/ (cdr total) (cdr count)))
       (dir-compare (car count) (cdr count))))
 	    
-
-
-;; [Ross] states that the majority of the notes dictates the
-;; direction (and not the mean of "center distance")
-;;
-;; But is that because it really looks better, or because he wants
-;; to provide some real simple hands-on rules?
-;;     
-;; We have our doubts, so we simply provide all sensible alternatives.
-
-;; array index multiplicity, last if index>size
-;; beamed stems
-
-
-;; TODO
-;;  - take #forced stems into account (now done in C++)?
-;;  - take staff-position of chord or beam into account
-