2 ;;;; beam.scm -- Beam scheme stuff
4 ;;;; source file of the GNU LilyPond music typesetter
6 ;;;; (c) 2000--2001 Jan Nieuwenhuizen <janneke@gnu.org>
10 ;; width in staff space.
12 (define (default-beam-flag-width-function type)
15 ((eq? type 1) 1.65) ;; FIXME: check what this should be and why
18 ;; There are several ways to calculate the direction of a beam
20 ;; * majority: number count of up or down notes
21 ;; * mean : mean centre distance of all notes
22 ;; * median : mean centre distance weighted per note
24 ;; [Ross] states that the majority of the notes dictates the
25 ;; direction (and not the mean of "center distance")
27 ;; But is that because it really looks better, or because he wants
28 ;; to provide some real simple hands-on rules?
30 ;; We have our doubts, so we simply provide all sensible alternatives.
32 (define (dir-compare up down)
35 ;; arguments are in the form (up . down)
36 (define (beam-dir-majority count total)
37 (dir-compare (car count) (cdr count)))
39 (beam-dir-majority '(0 . 0) '(0 . 0))
41 (define (beam-dir-mean count total)
42 (dir-compare (car total) (cdr total)))
44 (define (beam-dir-median count total)
45 (if (and (> (car count) 0)
47 (dir-compare (/ (car total) (car count)) (/ (cdr total) (cdr count)))
48 (dir-compare (car count) (cdr count))))