;;;;
;;;; source file of the GNU LilyPOnd music typesetter
;;;;
+;;;; This file implements different flag styles in Scheme / GUILE, most
+;;;; notably the old-straight-flag and the modern-straight-flag styles.
+;;;;
+
(define-public (no-flag stem-grob)
"No flag: Simply return empty stencil"
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;; ;; TODO
-;; (define-public (add-stroke-straight stencil dir stroke-style)
-;; stencil
-;; )
-;;
-;; ;; Create a stencil for a straight flag
-;; ;; flag-thickness, -spacing are given in staff spaces
-;; ;; *flag-length are given in black notehead widths
-;; ;; TODO
-;; (define-public (straight-flag flag-thickness flag-spacing
-;; upflag-angle upflag-length
-;; downflag-angle downflag-length)
-;; (lambda (stem-grob)
-;; (let* ((log (ly:grob-property stem-grob 'duration-log))
-;; (staff-space 1) ; TODO
-;; (black-notehead-width 1) ; TODO
-;; (stem-thickness 1) ; TODO: get rid of
-;; (half-stem-thickness (/ stem-thickness 2))
-;; (staff-space 1) ; TODO
-;; (up-length (+ (* upflag-length black-notehead-width) half-stem-thickness))
-;; (down-length (+ (* downflag-length black-notehead-width) half-stem-thickness))
-;; (thickness (* flag-thickness staff-space))
-;; (spacing (* flag-spacing staff-space)))
-;; empty-stencil
-;; )
-;; )
-;; )
-;;
-;; ;; Modern straight flags: angles are not so large as with the old style
-;; (define-public (modern-straight-flag stem-grob)
-;; ((straight-flag 0.55 0.9 -18 0.95 22 1.0) stem-grob))
-;;
-;; ;; Old-straight flags (Bach, etc.): quite large flag angles
-;; (define-public (old-straight-flag stem-grob)
-;; ((straight-flag 0.55 0.9 -45 0.95 45 1.0) stem-grob))
+(define-public (add-stroke-straight stencil stem-grob dir log stroke-style offset length thickness stroke-thickness)
+ "Add the stroke for acciaccatura to the given flag stencil.
+ The stroke starts for up-flags at upper-end-of-flag+(0,length/2) and
+ ends at (0, vertical-center-of-flag-end) - (flag-x-width/2, flag-x-width + flag-thickness).
+ Here length is the whole length, while flag-x-width is just the
+ x-extent and thus depends on the angle! Other combinations don't look as
+ good... For down-stems the y-coordinates are simply mirrored."
+ (let* ((start (offset-add offset (cons 0 (* (/ length 2) dir))))
+ (end (offset-add (cons 0 (cdr offset))
+ (cons (- (/ (car offset) 2)) (* (- (+ thickness (car offset))) dir))))
+ (stroke (make-line-stencil stroke-thickness (car start) (cdr start) (car end) (cdr end))))
+ (ly:stencil-add stencil stroke)))
+
+(define PI-OVER-180 (/ (atan 1 1) 45))
+(define (degrees->radians angle-degrees)
+ "Convert the given angle from degrees to radians"
+ (* angle-degrees PI-OVER-180))
+
+(define (polar->rectangular radius angle-in-degrees)
+ "Convert polar coordinate @code{radius} and @code{angle-in-degrees}
+ to (x-length . y-length)"
+ (let* ((complex (make-polar
+ radius
+ (degrees->radians angle-in-degrees))))
+ (cons
+ (real-part complex)
+ (imag-part complex))))
+
+(define (buildflag flag-stencil remain curr-stencil spacing)
+ "Internal function to recursively create a stencil with @code{remain} flags
+ from the single-flag stencil curr-stencil, which is already translated to
+ the position of the previous flag position."
+ (if (> remain 0)
+ (let* ((translated-stencil (ly:stencil-translate-axis curr-stencil spacing Y))
+ (new-stencil (ly:stencil-add flag-stencil translated-stencil)))
+ (buildflag new-stencil (- remain 1) translated-stencil spacing))
+ flag-stencil))
+
+(define-public (straight-flag flag-thickness flag-spacing
+ upflag-angle upflag-length
+ downflag-angle downflag-length)
+ "Create a stencil for a straight flag.
+ flag-thickness, -spacing are given in staff spaces,
+ *flag-angle is given in degree, *flag-length is given in staff spaces.
+ All lengths will be scaled according to the font size of the note."
+ (lambda (stem-grob)
+ (let* ((log (ly:grob-property stem-grob 'duration-log))
+ (dir (ly:grob-property stem-grob 'direction))
+ (stem-up (eqv? dir UP))
+ (layout (ly:grob-layout stem-grob))
+ ; scale with the note size (e.g. for grace notes)
+ (factor (magstep (ly:grob-property stem-grob 'font-size 0)))
+ (grob-stem-thickness (ly:grob-property stem-grob 'thickness))
+ (line-thickness (ly:output-def-lookup layout 'line-thickness))
+ (half-stem-thickness (/ (* grob-stem-thickness line-thickness) 2))
+ (raw-length (if stem-up upflag-length downflag-length))
+ (angle (if stem-up upflag-angle downflag-angle))
+ (flag-length (+ (* raw-length factor) half-stem-thickness))
+ (flag-end (polar->rectangular flag-length angle))
+ (thickness (* flag-thickness factor))
+ (thickness-offset (cons 0 (* -1 thickness dir)))
+ (spacing (* -1 flag-spacing factor dir ))
+ (start (cons (- half-stem-thickness) (* half-stem-thickness dir)))
+ ; The points of a round-filled-polygon need to be given in clockwise
+ ; order, otherwise the polygon will be enlarged by blot-size*2!
+ (points (if stem-up (list start flag-end
+ (offset-add flag-end thickness-offset)
+ (offset-add start thickness-offset))
+ (list start
+ (offset-add start thickness-offset)
+ (offset-add flag-end thickness-offset)
+ flag-end)))
+ (stencil (ly:round-filled-polygon points half-stem-thickness))
+ ; Log for 1/8 is 3, so we need to subtract 3
+ (flag-stencil (buildflag stencil (- log 3) stencil spacing))
+ (stroke-style (ly:grob-property stem-grob 'stroke-style)))
+ (if (equal? stroke-style "grace")
+ (add-stroke-straight flag-stencil stem-grob
+ dir log
+ stroke-style
+ flag-end flag-length
+ thickness
+ (* half-stem-thickness 2))
+ flag-stencil))))
+
+(define-public (modern-straight-flag stem-grob)
+ "Modern straight flag style (for composers like Stockhausen, Boulez, etc.).
+ The angles are 18 and 22 degrees and thus smaller than for the ancient style
+ of Bach etc."
+ ((straight-flag 0.55 1 -18 1.1 22 1.2) stem-grob))
+
+(define-public (old-straight-flag stem-grob)
+ "Old straight flag style (for composers like Bach). The angles of the flags
+ are both 45 degrees."
+ ((straight-flag 0.55 1 -45 1.2 45 1.4) stem-grob))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
tmpstencil)))
(if (ly:stencil-empty? stroke-stencil)
(begin
- (ly:warning (_ "flag stroke `~a' or `~a'not found") font-char alt-font-char)
+ (ly:warning (_ "flag stroke `~a' or `~a' not found") font-char alt-font-char)
stencil)
(ly:stencil-add stencil stroke-stencil)))))
projects / lilypond.git / blobdiff