Revert "finish structifying font"

This reverts commit 9e6c9c57f3.
main
Matthew Butterick 5 years ago
parent 9e6c9c57f3
commit 5b08f07136

@ -3,14 +3,15 @@
(for-syntax racket/base)
"core.rkt"
"reference.rkt"
racket/class
racket/match
racket/string
racket/format
racket/list
racket/dict
sugar/unstable/dict
"font.rkt"
fontland)
(provide make-embedded-font)
#|
approximates
@ -30,149 +31,142 @@ https://github.com/mbutterick/pdfkit/blob/master/lib/font/embedded.coffee
(for/list ([code (in-list codePoints)])
(~r code #:base 16 #:min-width 4 #:pad-string "0"))))
(struct $embedded-font $font (font subset unicode widths scale) #:mutable)
(define (make-embedded-font font id)
[define subset (create-subset font)]
;; we make `unicode` and `width` fields integer-keyed hashes not lists
;; because they offer better random access and growability
[define unicode (mhasheqv 0 '(0))] ; always include the missing glyph (gid = 0)
[define widths (mhasheqv 0 (glyph-advance-width (get-glyph font 0)))]
;; always include the width of the missing glyph (gid = 0)
[define name (font-postscript-name font)]
[define scale (/ 1000 (font-units-per-em font))]
[define ascender (* (font-ascent font) scale)]
[define descender (* (font-descent font) scale)]
[define bbox (font-bbox font)]
[define line-gap (* (font-linegap font) scale)]
(define new-font
($embedded-font name id ascender descender line-gap bbox
#f ; no dictionary
#f ; not embedded
'embfont-embed-placeholder 'embfont-encode-placeholder 'embfont-string-width-placeholder
font subset unicode widths scale))
(define (embed-proc) (embfont-embed new-font))
(set-$font-embed-proc! new-font embed-proc)
(define (encode-proc str [options #f]) (embfont-encode new-font str options))
(set-$font-encode-proc! new-font encode-proc)
(define (string-width-proc str size [options #f]) (embfont-string-width new-font str size options))
(set-$font-string-width-proc! new-font string-width-proc)
new-font)
(define (embfont-embed font)
;; no CFF support
(define isCFF #false) #;(is-a? subset CFFSubset)
(define font-file (make-ref))
(when isCFF
(dict-set! font-file 'Subtype 'CIDFontType0C))
(ref-write font-file (get-output-bytes (encode-to-port ($embedded-font-subset font))))
(ref-end font-file)
(define family-class (if (has-table? ($embedded-font-font font) 'OS/2)
(floor (/ (hash-ref (get-OS/2-table ($embedded-font-font font)) 'sFamilyClass) 256)) ; >> 8
0))
;; font descriptor flags
(match-define (list FIXED_PITCH SERIF SYMBOLIC SCRIPT _UNUSED NONSYMBOLIC ITALIC)
(map (λ (x) (expt 2 x)) (range 7)))
(define flags (sum-flags
[(not (zero? (hash-ref (get-post-table ($embedded-font-font font)) 'isFixedPitch))) FIXED_PITCH]
[(<= 1 family-class 7) SERIF]
[#t SYMBOLIC] ; assume the font uses non-latin characters
[(= family-class 10) SCRIPT]
[(hash-ref (hash-ref (get-head-table ($embedded-font-font font)) 'macStyle) 'italic) ITALIC]))
;; generate a random tag (6 uppercase letters. 65 is the char code for 'A')
(when (test-mode) (random-seed 0))
(define tag (list->string (for/list ([i (in-range 6)])
(integer->char (random 65 (+ 65 26))))))
(define name (string->symbol (string-append tag "+" (font-postscript-name ($embedded-font-font font)))))
(define bbox (font-bbox ($embedded-font-font font)))
(define descriptor (make-ref
(mhash
'Type 'FontDescriptor
'FontName name
'Flags flags
'FontBBox (map (λ (x) (* ($embedded-font-scale font) x))
(bbox->list bbox))
'ItalicAngle (font-italic-angle ($embedded-font-font font))
'Ascent ($font-ascender font)
'Descent ($font-descender font)
'CapHeight (* (or (font-cap-height ($embedded-font-font font)) (font-ascent ($embedded-font-font font))) ($embedded-font-scale font))
'XHeight (* (or (font-x-height ($embedded-font-font font)) 0) ($embedded-font-scale font))
'StemV 0)))
(dict-set! descriptor (if isCFF 'FontFile3 'FontFile2) font-file)
(ref-end descriptor)
(define descendant-font (make-ref
(mhash
'Type 'Font
'Subtype (string->symbol (string-append "CIDFontType" (if isCFF "0" "2")))
'BaseFont name
'CIDSystemInfo
(mhash
'Registry "Adobe"
'Ordering "Identity"
'Supplement 0)
'FontDescriptor descriptor
'W (list 0 (for/list ([idx (in-range (length (hash-keys ($embedded-font-widths font))))])
(hash-ref ($embedded-font-widths font) idx (λ () (error 'embed (format "hash key ~a not found" idx)))))))))
(ref-end descendant-font)
#;(define EmbeddedFont
(class PDFFont
(init-field font id)
(field [subset (create-subset font)]
;; we make `unicode` and `width` fields integer-keyed hashes not lists
;; because they offer better random access and growability
[unicode (mhash 0 '(0))] ; always include the missing glyph (gid = 0)
[widths (mhash 0 (glyph-advance-width (get-glyph font 0)))]
;; always include the width of the missing glyph (gid = 0)
[name (font-postscript-name font)]
[scale (/ 1000 (font-units-per-em font))])
(super-new [ascender (* (font-ascent font) scale)]
[descender (* (font-descent font) scale)]
[bbox (font-bbox font)]
[line-gap (* (font-linegap font) scale)])
(inherit-field [@ascender ascender]
[@descender descender]
[@dictionary dictionary])
(define/override (string-width string size [features #f])
; #f disables features ; null enables default features ; list adds features
(hash-ref! width-cache
(list string size (and features (sort features symbol<?)))
(λ ()
(define run (layout font string features))
(define width (glyphrun-advance-width run))
(define scale (/ size (+ (font-units-per-em font) 0.0)))
(* width scale))))
;; called from text.rkt
(define/override (encode text [features #f])
(define glyphRun (layout font text features))
(define glyphs (glyphrun-glyphs glyphRun))
(define positions (glyphrun-positions glyphRun))
(define-values (subset-idxs new-positions)
(for/lists (idxs posns)
([(g i) (in-indexed glyphs)]
[posn (in-list positions)])
(define gid (subset-add-glyph! subset (glyph-id g)))
(define subset-idx (to-hex gid))
(set-glyph-position-advance-width! posn (glyph-advance-width g))
(hash-ref! widths gid (λ () (glyph-position-advance-width posn)))
(hash-ref! unicode gid (λ () (glyph-codepoints g)))
(scale-glyph-position! posn scale)
(values subset-idx posn)))
(list subset-idxs new-positions))
(define/override (embed)
;; no CFF support
(define isCFF #false) #;(is-a? subset CFFSubset)
(define font-file (make-ref))
(when isCFF
(dict-set! font-file 'Subtype 'CIDFontType0C))
(ref-write font-file (get-output-bytes (encode-to-port subset)))
(ref-end font-file)
(define family-class (if (has-table? font 'OS/2)
(floor (/ (hash-ref (get-OS/2-table font) 'sFamilyClass) 256)) ; >> 8
0))
;; font descriptor flags
(match-define (list FIXED_PITCH SERIF SYMBOLIC SCRIPT _UNUSED NONSYMBOLIC ITALIC)
(map (λ (x) (expt 2 x)) (range 7)))
(define flags (sum-flags
[(not (zero? (hash-ref (get-post-table font) 'isFixedPitch))) FIXED_PITCH]
[(<= 1 family-class 7) SERIF]
[#t SYMBOLIC] ; assume the font uses non-latin characters
[(= family-class 10) SCRIPT]
[(hash-ref (hash-ref (get-head-table font) 'macStyle) 'italic) ITALIC]))
;; generate a random tag (6 uppercase letters. 65 is the char code for 'A')
(when (test-mode) (random-seed 0))
(define tag (list->string (for/list ([i (in-range 6)])
(integer->char (random 65 (+ 65 26))))))
(define name (string->symbol (string-append tag "+" (font-postscript-name font))))
(define bbox (font-bbox font))
(define descriptor (make-ref
(mhash
'Type 'FontDescriptor
'FontName name
'Flags flags
'FontBBox (map (λ (x) (* scale x))
(bbox->list bbox))
'ItalicAngle (font-italic-angle font)
'Ascent @ascender
'Descent @descender
'CapHeight (* (or (font-cap-height font) (font-ascent font)) scale)
'XHeight (* (or (font-x-height font) 0) scale)
'StemV 0)))
(dict-set! descriptor (if isCFF 'FontFile3 'FontFile2) font-file)
(ref-end descriptor)
(define descendant-font (make-ref
(mhash
'Type 'Font
'Subtype (string->symbol (string-append "CIDFontType" (if isCFF "0" "2")))
'BaseFont name
'CIDSystemInfo
(mhash
'Registry "Adobe"
'Ordering "Identity"
'Supplement 0)
'FontDescriptor descriptor
'W (list 0 (for/list ([idx (in-range (length (hash-keys widths)))])
(hash-ref widths idx (λ () (error 'embed (format "hash key ~a not found" idx)))))))))
(ref-end descendant-font)
[dict-set! ($font-dictionary font) 'Type 'Font]
[dict-set! ($font-dictionary font) 'Subtype 'Type0]
[dict-set! ($font-dictionary font) 'BaseFont name]
[dict-set! ($font-dictionary font) 'Encoding 'Identity-H]
[dict-set! ($font-dictionary font) 'DescendantFonts (list descendant-font)]
[dict-set! ($font-dictionary font) 'ToUnicode (to-unicode-cmap font)]
(ref-end ($font-dictionary font)))
(define (embfont-encode font text [features #f])
(define glyphRun (layout ($embedded-font-font font) text features))
(define glyphs (glyphrun-glyphs glyphRun))
(define positions (glyphrun-positions glyphRun))
(define-values (subset-idxs new-positions)
(for/lists (idxs posns)
([(g i) (in-indexed glyphs)]
[posn (in-list positions)])
(define gid (subset-add-glyph! ($embedded-font-subset font) (glyph-id g)))
(define subset-idx (to-hex gid))
(set-glyph-position-advance-width! posn (glyph-advance-width g))
(hash-ref! ($embedded-font-widths font) gid (λ () (glyph-position-advance-width posn)))
(hash-ref! ($embedded-font-unicode font) gid (λ () (glyph-codepoints g)))
(scale-glyph-position! posn ($embedded-font-scale font))
(values subset-idx posn)))
(list subset-idxs new-positions))
(define (embfont-string-width font string size [features #f])
; #f disables features ; null enables default features ; list adds features
(hash-ref! width-cache
(list string size (and features (sort features symbol<?)))
(λ ()
(define run (layout ($embedded-font-font font) string features))
(define width (glyphrun-advance-width run))
(define scale (/ size (+ (font-units-per-em ($embedded-font-font font)) 0.0)))
(* width scale))))
(define (to-unicode-cmap font)
(define cmap (make-ref))
(define entries
(for/list ([idx (in-range (length (hash-keys ($embedded-font-unicode font))))])
(define codepoints (hash-ref ($embedded-font-unicode font) idx))
(define encoded ; encode codePoints to utf16
;; todo: full utf16 support. for now just utf8
(for/list ([value (in-list codepoints)])
(to-hex value)))
(format "<~a>" (string-join encoded " "))))
(define unicode-cmap-str #<<HERE
[dict-set! @dictionary 'Type 'Font]
[dict-set! @dictionary 'Subtype 'Type0]
[dict-set! @dictionary 'BaseFont name]
[dict-set! @dictionary 'Encoding 'Identity-H]
[dict-set! @dictionary 'DescendantFonts (list descendant-font)]
[dict-set! @dictionary 'ToUnicode (toUnicodeCmap)]
(ref-end @dictionary))
(define/public (toUnicodeCmap)
(define cmap (make-ref))
(define entries
(for/list ([idx (in-range (length (hash-keys unicode)))])
(define codepoints (hash-ref unicode idx))
(define encoded ; encode codePoints to utf16
;; todo: full utf16 support. for now just utf8
(for/list ([value (in-list codepoints)])
(to-hex value)))
(format "<~a>" (string-join encoded " "))))
(define unicode-cmap-str #<<HERE
/CIDInit /ProcSet findresource begin
12 dict begin
begincmap
@ -194,21 +188,21 @@ CMapName currentdict /CMap defineresource pop
end
end
HERE
)
)
(ref-write cmap (format unicode-cmap-str (to-hex (sub1 (length entries))) (string-join entries " ")))
(ref-end cmap)
cmap)
(ref-write cmap (format unicode-cmap-str (to-hex (sub1 (length entries))) (string-join entries " ")))
(ref-end cmap)
cmap)))
#;(module+ test
(require rackunit fontland sugar/unstable/js)
(define f (open-font "../ptest/assets/charter.ttf"))
(define ef (make-object EmbeddedFont #f f #f))
(check-equal? (send ef string-width "f" 1000) 321.0)
(check-equal? (· ef ascender) 980)
(check-equal? (· ef descender) -238)
(check-equal? (· ef line-gap) 0)
(check-equal? (bbox->list (· ef bbox)) '(-161 -236 1193 963))
(define H-gid 41)
(check-equal? (· ef widths) (mhash 0 278))
(check-equal? (glyph-advance-width (get-glyph (· ef font) H-gid)) 738))
(require rackunit fontland sugar/unstable/js)
(define f (open-font "../ptest/assets/charter.ttf"))
(define ef (make-object EmbeddedFont #f f #f))
(check-equal? (send ef string-width "f" 1000) 321.0)
(check-equal? (· ef ascender) 980)
(check-equal? (· ef descender) -238)
(check-equal? (· ef line-gap) 0)
(check-equal? (bbox->list (· ef bbox)) '(-161 -236 1193 963))
(define H-gid 41)
(check-equal? (· ef widths) (mhash 0 278))
(check-equal? (glyph-advance-width (get-glyph (· ef font) H-gid)) 738))

@ -4,12 +4,15 @@
"reference.rkt"
racket/match
sugar/unstable/dict
racket/class
"standard-font.rkt"
"font.rkt"
fontland
"embedded-font.rkt")
(provide (all-defined-out))
(define (make-font-ref font)
(unless ($font-dictionary font)
(set-$font-dictionary! font (make-ref)))
@ -27,14 +30,14 @@
(define (PDFFont-open src family id)
(cond
[(and (string? src) (standard-font? src)) (make-standard-font src id)]
[else
#;[else
(define font
(cond
[(string? src) (open-font src)]
[(path? src) (open-font (path->string src))]
;; todo: other font-loading cases
[else (raise-argument-error 'PDFFont-open "loadable font thingy" src)]))
(make-embedded-font font id)]))
(make-object EmbeddedFont font id)]))
(define (current-line-height doc [include-gap #f])

@ -1,8 +1,10 @@
#lang racket/base
(require
racket/class
racket/string
racket/match
sugar/unstable/dict
"font.rkt"
"core.rkt"
"reference.rkt"
fontland

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