+
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Color
+
+(define-public color? list?)
+
+; predefined colors
+(define-public black '(0.0 0.0 0.0))
+(define-public white '(1.0 1.0 1.0))
+(define-public red '(1.0 0.0 0.0))
+(define-public green '(0.0 1.0 0.0))
+(define-public blue '(0.0 0.0 1.0))
+(define-public cyan '(1.0 1.0 0.0))
+(define-public magenta '(1.0 0.0 1.0))
+(define-public yellow '(0.0 1.0 1.0))
+
+(define-public grey '(0.5 0.5 0.5))
+(define-public darkred '(0.5 0.0 0.0))
+(define-public darkgreen '(0.0 0.5 0.0))
+(define-public darkblue '(0.0 0.0 0.5))
+(define-public darkcyan '(0.5 0.5 0.0))
+(define-public darkmagenta '(0.5 0.0 0.5))
+(define-public darkyellow '(0.0 0.5 0.5))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Pitch Trill Heads
+
+(define (parenthesize-elements grob)
+ (let*
+ ((elts (ly:grob-object grob 'elements))
+ (x-ext (ly:relative-group-extent elts grob X))
+ (font (ly:grob-default-font grob))
+ (lp (ly:font-get-glyph font "accidentals.leftparen"))
+ (rp (ly:font-get-glyph font "accidentals.rightparen"))
+ (padding 0.1))
+
+ (ly:stencil-add
+ (ly:stencil-translate-axis lp (- (car x-ext) padding) X)
+ (ly:stencil-translate-axis rp (+ (cdr x-ext) padding) X))
+ ))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;
+
+(define-public (chain-grob-member-functions grob value . funcs)
+ (for-each
+ (lambda (func)
+ (set! value (func grob value)))
+ funcs)
+
+ value)