;;;; stencil.scm -- 
;;;;
;;;;  source file of the GNU LilyPond music typesetter
;;;; 
;;;; (c) 2003--2005 Han-Wen Nienhuys <hanwen@cs.uu.nl>

(define-public (stack-stencils axis dir padding stils)
  "Stack stencils STILS in direction AXIS, DIR, using PADDING."
  (cond
   ((null? stils) empty-stencil)
   ((null? (cdr stils)) (car stils))
   (else (ly:stencil-combine-at-edge
	  (car stils) axis dir (stack-stencils axis dir padding (cdr stils))
	  padding))))

(define-public (stack-stencils-padding-list axis dir padding stils)
  "Stack stencils STILS in direction AXIS, DIR, using a list of PADDING."
  (cond
   ((null? stils) empty-stencil)
   ((null? (cdr stils)) (car stils))
   (else (ly:stencil-combine-at-edge
	  (car stils) axis dir (stack-stencils-padding-list axis dir (cdr padding) (cdr stils))
	  (car padding)))))

(define-public (centered-stencil stencil)
  "Center stencil @var{stencil} in both the X and Y directions"
  (ly:stencil-aligned-to (ly:stencil-aligned-to stencil X CENTER) Y CENTER))

(define-public (stack-lines dir padding baseline stils)
  "Stack vertically with a baseline-skip."
  (if (null? stils)
      empty-stencil
      (if (null? (cdr stils))
	  (car stils)
	  (ly:stencil-combine-at-edge
	   (car stils) Y dir 
	   (stack-lines dir padding baseline (cdr stils))
	   padding baseline))))

(define-public (bracketify-stencil stil axis thick protusion padding)
  "Add brackets around STIL, producing a new stencil."

  (let* ((ext (ly:stencil-extent stil axis))
	 (lb (ly:bracket axis ext thick (- protusion)))
	 (rb (ly:bracket axis ext thick protusion)))
    (set! stil
	  (ly:stencil-combine-at-edge stil (other-axis axis) 1 lb padding))
    (set! stil
	  (ly:stencil-combine-at-edge stil (other-axis axis) -1 rb padding))
    stil))

(define-public (make-filled-box-stencil xext yext)
  "Make a filled box."
  
  (ly:make-stencil
      (list 'filledbox (- (car xext)) (cdr xext)
                       (- (car yext)) (cdr yext))
      xext yext))

(define-public (make-circle-stencil radius thickness fill)
  "Make a circle of radius @var{radius} and thickness @var{thickness}"
  (ly:make-stencil
   (list 'circle radius thickness fill) 
   (cons (- radius) radius)
   (cons (- radius) radius)))

(define-public (box-grob-stencil grob)
  "Make a box of exactly the extents of the grob.  The box precisely
encloses the contents.
"
  (let* ((xext (ly:grob-extent grob grob 0))
	 (yext (ly:grob-extent grob grob 1))
	 (thick 0.1))
    
    (ly:stencil-add
     (make-filled-box-stencil xext (cons (- (car yext) thick) (car yext)))
     (make-filled-box-stencil xext (cons (cdr yext) (+ (cdr yext) thick)))
     (make-filled-box-stencil (cons (cdr xext) (+ (cdr xext) thick)) yext)
     (make-filled-box-stencil (cons (- (car xext) thick) (car xext)) yext))))

;; TODO merge this and prev function. 
(define-public (box-stencil stencil thickness padding)
  "Add a box around STENCIL, producing a new stencil."
  (let* ((x-ext (interval-widen (ly:stencil-extent stencil 0) padding))
	 (y-ext (interval-widen (ly:stencil-extent stencil 1) padding))
	 (y-rule (make-filled-box-stencil (cons 0 thickness) y-ext))
	 (x-rule (make-filled-box-stencil
		  (interval-widen x-ext thickness) (cons 0 thickness))))
    (set! stencil (ly:stencil-combine-at-edge stencil X 1 y-rule padding))
    (set! stencil (ly:stencil-combine-at-edge stencil X -1 y-rule padding))
    (set! stencil (ly:stencil-combine-at-edge stencil Y 1 x-rule 0.0))  
    (set! stencil (ly:stencil-combine-at-edge stencil Y -1 x-rule 0.0))
    stencil))

(define-public (circle-stencil stencil thickness padding)
  "Add a circle around STENCIL, producing a new stencil."
  (let* ((x-ext (ly:stencil-extent stencil 0))
	 (y-ext (ly:stencil-extent stencil 1))
	 (diameter (max (- (cdr x-ext) (car x-ext))
			(- (cdr y-ext) (car y-ext))))
	 (radius (+ (/ diameter 2) padding thickness)))
    (ly:stencil-add
     (centered-stencil stencil) (make-circle-stencil radius thickness #f))))

(define-public (fontify-text font-metric text)
  "Set TEXT with font FONT-METRIC, returning a stencil."
  (let* ((b (ly:text-dimension font-metric text)))
    (ly:make-stencil
     `(text ,font-metric ,text) (car b) (cdr b))))
     
(define-public (fontify-text-white scale font-metric text)
  "Set TEXT with scale factor s"
  (let* ((b (ly:text-dimension font-metric text))
	 ;;urg -- workaround for using ps font
         (c `(white-text ,(* 2 scale) ,text)))
    ;;urg -- extent is not from ps font, but we hope it's close
    (ly:make-stencil c (car b) (cdr b))))