(ideal-blot (min blot (/ min-ext 2)))
(ideal-thickness (min thickness (/ min-ext 2)))
(outer (ly:round-filled-box
- (interval-widen xext ideal-thickness)
- (interval-widen yext ideal-thickness)
- ideal-blot))
- (inner (ly:make-stencil (list 'color (x11-color 'white) (ly:stencil-expr (ly:round-filled-box
- (cons (+ (car xext) ideal-thickness) (- (cdr xext) ideal-thickness))
- (cons (+ (car yext) ideal-thickness) (- (cdr yext) ideal-thickness))
- (- ideal-blot (* ideal-thickness 2))))))))
+ (interval-widen xext ideal-thickness)
+ (interval-widen yext ideal-thickness)
+ ideal-blot))
+ (inner (ly:make-stencil (list 'color (x11-color 'white)
+ (ly:stencil-expr (ly:round-filled-box
+ xext yext (- ideal-blot ideal-thickness)))))))
(set! stencil (ly:stencil-add outer inner))
stencil))