From ccf8bf68ce13c1f8e48d49de4345f33161da4f3d Mon Sep 17 00:00:00 2001 From: David Kastrup Date: Thu, 2 May 2013 21:40:16 +0200 Subject: [PATCH] Issue 3573: Calculate wordwrapped/justified lines using the stencil stacking primitives In that manner, the spacing decisions are sure to be correct. --- scm/define-markup-commands.scm | 150 +++++++++++++++++++-------------- 1 file changed, 87 insertions(+), 63 deletions(-) diff --git a/scm/define-markup-commands.scm b/scm/define-markup-commands.scm index ca4fac36a9..6de7c9a8f4 100644 --- a/scm/define-markup-commands.scm +++ b/scm/define-markup-commands.scm @@ -1369,69 +1369,93 @@ equivalent to @code{\"fi\"}. "Perform simple wordwrap, return stencil of each line." (define space (if justify ;; justify only stretches lines. - (* 0.7 base-space) - base-space)) - (define (stencil-space stencil line-start) - (if (ly:stencil-empty? stencil X) - 0 - (cdr (ly:stencil-extent - (ly:stencil-stack (if line-start - empty-stencil - point-stencil) - X RIGHT stencil) - X)))) - (define (take-list width space stencils - accumulator accumulated-width) - "Return (head-list . tail) pair, with head-list fitting into width" - (if (null? stencils) - (cons accumulator stencils) - (let* ((first (car stencils)) - (first-wid (stencil-space first (null? accumulator))) - (newwid (+ (if (or (ly:stencil-empty? first Y) - (ly:stencil-empty? first X)) - 0 space) - first-wid accumulated-width))) - (if (or (null? accumulator) - (< newwid width)) - (take-list width space - (cdr stencils) - (cons first accumulator) - newwid) - (cons accumulator stencils))))) - (let loop ((lines '()) - (todo stencils)) - (let* ((line-break (take-list line-width space todo - '() 0.0)) - (line-stencils (car line-break)) - (space-left (- line-width - (stencil-space - (stack-stencil-line 0 line-stencils) - #t))) - (line-words (count (lambda (s) (not (or (ly:stencil-empty? s Y) - (ly:stencil-empty? s X)))) - line-stencils)) - (line-word-space (cond ((not justify) space) - ;; don't stretch last line of paragraph. - ;; hmmm . bug - will overstretch the last line in some case. - ((null? (cdr line-break)) - base-space) - ((< line-words 2) space) - (else (/ space-left (1- line-words))))) - (line (stack-stencil-line line-word-space - (if (= text-dir RIGHT) - (reverse line-stencils) - line-stencils)))) - (if (pair? (cdr line-break)) - (loop (cons line lines) - (cdr line-break)) - (begin - (if (= text-dir LEFT) - (set! line - (ly:stencil-translate-axis - line - (- line-width (interval-end (ly:stencil-extent line X))) - X))) - (reverse (cons line lines))))))) + (* 0.7 base-space) + base-space)) + (define (stencil-len s) + (interval-end (ly:stencil-extent s X))) + (define (maybe-shift line) + (if (= text-dir LEFT) + (ly:stencil-translate-axis + line + (- line-width (stencil-len line)) + X) + line)) + (if (null? stencils) + '() + (let loop ((lines '()) + (todo stencils)) + (let word-loop + ((line (first todo)) + (todo (cdr todo)) + (word-list (list (first todo)))) + (cond + ((pair? todo) + (let ((new (if (= text-dir LEFT) + (ly:stencil-stack (car todo) X RIGHT line space) + (ly:stencil-stack line X RIGHT (car todo) space)))) + (cond + ((<= (stencil-len new) line-width) + (word-loop new (cdr todo) + (cons (car todo) word-list))) + (justify + (let* ((word-list + ;; This depends on stencil stacking being + ;; associative so that stacking + ;; left-to-right and right-to-left leads to + ;; the same result + (if (= text-dir LEFT) + word-list + (reverse! word-list))) + (len (stencil-len line)) + (stretch (- line-width len)) + (spaces + (- (stencil-len + (stack-stencils X RIGHT (1+ space) word-list)) + len))) + (if (zero? spaces) + ;; Uh oh, nothing to fill. + (loop (cons (maybe-shift line) lines) todo) + (loop (cons + (stack-stencils X RIGHT + (+ space (/ stretch spaces)) + word-list) + lines) + todo)))) + (else ;; not justify + (loop (cons (maybe-shift line) lines) todo))))) + ;; todo is null + (justify + ;; Now we have the last line assembled with space + ;; which is compressed. We want to use the + ;; uncompressed version instead if it fits, and the + ;; justified version if it doesn't. + (let* ((word-list + ;; This depends on stencil stacking being + ;; associative so that stacking + ;; left-to-right and right-to-left leads to + ;; the same result + (if (= text-dir LEFT) + word-list + (reverse! word-list))) + (big-line (stack-stencils X RIGHT base-space word-list)) + (big-len (stencil-len big-line)) + (len (stencil-len line))) + (reverse! lines + (list + (if (> big-len line-width) + (stack-stencils X RIGHT + (/ + (+ + (* (- big-len line-width) + space) + (* (- line-width len) + base-space)) + (- big-len len)) + word-list) + (maybe-shift big-line)))))) + (else ;; not justify + (reverse! lines (list (maybe-shift line))))))))) + (define-markup-list-command (wordwrap-internal layout props justify args) (boolean? markup-list?) -- 2.39.2