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adjust drawing calculation related to baselines and scale

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This commit is contained in:
Matthew Flatt 2010-09-17 11:17:20 -06:00
parent 6f390ac655
commit fa5cccfc2a
1 changed files with 41 additions and 32 deletions
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73
collects/racket/draw/dc.rkt
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@ -1133,10 +1133,10 @@
(let ([nw (if blank?
0.0
(integral (/ (PangoRectangle-width logical) (exact->inexact PANGO_SCALE))))]
[nh (integral (/ (PangoRectangle-height logical) (exact->inexact PANGO_SCALE)))]
[nd (integral (/ (- (PangoRectangle-height logical)
(pango_layout_get_baseline layout))
(exact->inexact PANGO_SCALE)))]
[nh (/ (PangoRectangle-height logical) (exact->inexact PANGO_SCALE))]
[nd (/ (- (PangoRectangle-height logical)
(pango_layout_get_baseline layout))
(exact->inexact PANGO_SCALE))]
[na 0.0])
(loop next-s (+ w nw) (max h nh) (max d nd) (max a na))))])))]))
;; This is character-by-character mode. It uses a cached per-character+font layout
@ -1236,8 +1236,7 @@
;; Move into position and draw the glyphs
(cairo_move_to cr
(align-x/delta x 0)
(+ (align-y/delta y 0)
(/ (vector-ref first-v 4) (->fl PANGO_SCALE))))
(align-y/delta (+ y (/ (vector-ref first-v 4) (->fl PANGO_SCALE))) 0))
(pango_cairo_show_glyph_string cr first-font glyph-string)
(free glyph-infos)
(free log-clusters)
@ -1247,32 +1246,42 @@
(for/fold ([w 0.0][h 0.0][d 0.0][a 0.0])
([ch (in-string s)])
(let ([layout (vector-ref (hash-ref layouts (char->integer ch)) 0)])
(when draw?
(cairo_move_to cr (align-x/delta (+ x w) 0) (align-y/delta y 0))
;; Here's the draw command, which uses most of the time in this mode:
(pango_cairo_show_layout cr layout))
(let ([v (and cache (hash-ref cache (char->integer ch) #f))])
(if v
;; Used cached size:
(values (if blank? 0.0 (+ w (vector-ref v 0)))
(max h (vector-ref v 1))
(max d (vector-ref v 2))
(max a (vector-ref v 3)))
;; Query and record size:
(begin
(pango_layout_get_extents layout #f logical)
(let ([baseline (pango_layout_get_baseline layout)]
[orig-h (PangoRectangle-height logical)])
(let ([lw (integral (/ (PangoRectangle-width logical) (exact->inexact PANGO_SCALE)))]
[lh (integral (/ orig-h (exact->inexact PANGO_SCALE)))]
[ld (integral (/ (- orig-h baseline) (exact->inexact PANGO_SCALE)))]
[la 0.0])
(when cache
(hash-set! cache (char->integer ch) (vector lw lh ld la baseline
;; rounded width in Pango units:
(inexact->exact
(floor (* lw (->fl PANGO_SCALE)))))))
(values (if blank? 0.0 (+ w lw)) (max h lh) (max d ld) (max a la)))))))))))
(let-values ([(lw lh ld la)
(let ([v (and cache (hash-ref cache (char->integer ch) #f))])
(if v
;; Used cached size:
(values (vector-ref v 0)
(vector-ref v 1)
(vector-ref v 2)
(vector-ref v 3))
;; Query and record size:
(begin
(pango_layout_get_extents layout #f logical)
(let ([baseline (pango_layout_get_baseline layout)]
[orig-h (PangoRectangle-height logical)])
;; We keep an integer width to pixel-align each individual character,
;; but we keep non-integral lh & ld to pixel-align the baseline.
(let ([lw (integral (/ (PangoRectangle-width logical)
(exact->inexact PANGO_SCALE)))]
[lh (/ orig-h (exact->inexact PANGO_SCALE))]
[ld (/ (- orig-h baseline) (exact->inexact PANGO_SCALE))]
[la 0.0])
(when cache
(hash-set! cache (char->integer ch)
(vector lw lh ld la baseline
;; rounded width in Pango units:
(inexact->exact
(floor (* lw (->fl PANGO_SCALE)))))))
(values lw lh ld la))))))])
(when draw?
(cairo_move_to cr
(align-x/delta (+ x w) 0)
(let ([bl (- lh ld)])
(- (align-y/delta (+ y bl) 0)
(align-y/delta bl 0))))
;; Here's the draw command, which uses most of the time in this mode:
(pango_cairo_show_layout cr layout))
(values (if blank? 0.0 (+ w lw)) (max h lh) (max d ld) (max a la)))))))
(when rotate? (cairo_restore cr))))))))
(define/private (extract-only-run layout vec)