main
Matthew Butterick 6 years ago
parent ed3a32e395
commit 88e32db398

@ -221,7 +221,7 @@ https://github.com/mbutterick/fontkit/blob/master/src/TTFFont.js
#;(make-object (if (· this has-cff-table?)
CFFSubset
TTFSubset) this)
(+TTFSubset this))
(+ttf-subset this))
(define/contract (has-table? this tag)

@ -14,27 +14,20 @@
fontland/ttf-glyph
xenomorph)
(provide Subset +Subset TTFSubset +TTFSubset includeGlyph encode-to-port)
(provide subset +subset ttf-subset +ttf-subset subset-include-glyph encode-to-port)
#|
approximates
https://github.com/devongovett/fontkit/blob/master/src/subset/Subset.js
|#
#;(define-subclass object% (Subset font)
(field [glyphs empty] ; list of glyph ids in the subset
[mapping (mhash)]) ; mapping of glyph ids to indexes in `glyphs`
(send this includeGlyph 0) ; always include the missing glyph in subset
(as-methods
includeGlyph))
; glyphs = list of glyph ids in the subset
; mapping = of glyph ids to indexes in `glyphs`
(struct Subset (font glyphs mapping) #:transparent #:mutable)
(struct subset (font glyphs mapping) #:transparent #:mutable)
(define (+Subset font [glyphs empty] [mapping (mhash)])
(define ss (Subset font glyphs mapping))
(includeGlyph ss 0)
(define (+subset font [glyphs empty] [mapping (mhash)])
(define ss (subset font glyphs mapping))
(subset-include-glyph ss 0)
ss)
(define (encode-to-port ss)
@ -42,17 +35,17 @@ https://github.com/devongovett/fontkit/blob/master/src/subset/Subset.js
(encode ss p)
p)
(define (includeGlyph ss glyph-or-gid)
(define (subset-include-glyph ss glyph-or-gid)
#;((or/c object? index?) . ->m . index?)
(define glyph (if (object? glyph-or-gid)
(· glyph-or-gid id)
glyph-or-gid))
(hash-ref! (Subset-mapping ss) glyph
(hash-ref! (subset-mapping ss) glyph
(λ ()
;; put the new glyph at the end of `glyphs`,
;; and put its index in the mapping
(set-Subset-glyphs! ss (append (Subset-glyphs ss) (list glyph)))
(sub1 (length (Subset-glyphs ss))))))
(set-subset-glyphs! ss (append (subset-glyphs ss) (list glyph)))
(sub1 (length (subset-glyphs ss))))))
#|
approximates
@ -99,31 +92,21 @@ approximates
https://github.com/mbutterick/fontkit/blob/master/src/subset/TTFSubset.js
|#
#;(define-subclass Subset (TTFSubset)
(field [glyf #f]
[offset #f]
[loca #f]
[hmtx #f])
(as-methods
_addGlyph
encode))
(struct TTFSubset Subset (glyf offset loca hmtx) #:transparent #:mutable)
(struct ttf-subset subset (glyf offset loca hmtx) #:transparent #:mutable)
(define (+TTFSubset font [glyphs empty] [mapping (mhash)]
(define (+ttf-subset font [glyphs empty] [mapping (mhash)]
[glyf #f]
[offset #f]
[loca #f]
[hmtx #f])
(define ss (TTFSubset font glyphs mapping glyf offset loca hmtx))
(includeGlyph ss 0)
(define ss (ttf-subset font glyphs mapping glyf offset loca hmtx))
(subset-include-glyph ss 0)
ss)
(define (_addGlyph ss gid)
(define (ttf-subset-add-glyph ss gid)
#;(index? . ->m . index?)
(define glyph (send (Subset-font ss) getGlyph gid))
(define glyph (send (subset-font ss) getGlyph gid))
;; glyph-decode unpacks the `glyf` table data corresponding to a certin gid.
;; here, it's not necessary for non-composite glyphs
;; because they just get copied entirely into the subset.
@ -132,9 +115,9 @@ https://github.com/mbutterick/fontkit/blob/master/src/subset/TTFSubset.js
(define ttf-glyf-data (glyph-decode glyph))
;; get the offset to the glyph from the loca table
(match-define (list curOffset nextOffset) (take (drop (· (Subset-font ss) loca offsets) gid) 2))
(match-define (list curOffset nextOffset) (take (drop (· (subset-font ss) loca offsets) gid) 2))
(define port (send (Subset-font ss) _getTableStream 'glyf))
(define port (send (subset-font ss) _getTableStream 'glyf))
(pos port (+ (pos port) curOffset))
(define buffer (read-bytes (- nextOffset curOffset) port))
@ -142,58 +125,58 @@ https://github.com/mbutterick/fontkit/blob/master/src/subset/TTFSubset.js
;; if it is a compound glyph, include its components
(when (and ttf-glyf-data (negative? (· ttf-glyf-data numberOfContours)))
(for ([ttf-glyph-component (in-list (· ttf-glyf-data components))])
(define gid (includeGlyph ss (ttf-glyph-component-glyph-id ttf-glyph-component)))
(define gid (subset-include-glyph ss (ttf-glyph-component-glyph-id ttf-glyph-component)))
;; note: this (ttf-glyph-component-pos component) is correct. It's a field of a Component object, not a port
(bytes-copy! buffer (ttf-glyph-component-pos ttf-glyph-component) (send uint16be encode #f gid))))
;; skip variation shit
(set-TTFSubset-glyf! ss (append (TTFSubset-glyf ss) (list buffer)))
(hash-update! (TTFSubset-loca ss) 'offsets (λ (os)
(append os (list (TTFSubset-offset ss)))))
(set-ttf-subset-glyf! ss (append (ttf-subset-glyf ss) (list buffer)))
(hash-update! (ttf-subset-loca ss) 'offsets (λ (os)
(append os (list (ttf-subset-offset ss)))))
(hash-update! (TTFSubset-hmtx ss) 'metrics (λ (ms) (append ms
(hash-update! (ttf-subset-hmtx ss) 'metrics (λ (ms) (append ms
(list (mhash 'advance (glyph-advance-width glyph)
'bearing (· (get-glyph-metrics glyph) leftBearing))))))
(set-TTFSubset-offset! ss (+ (TTFSubset-offset ss) (bytes-length buffer)))
(sub1 (length (TTFSubset-glyf ss))))
(set-ttf-subset-offset! ss (+ (ttf-subset-offset ss) (bytes-length buffer)))
(sub1 (length (ttf-subset-glyf ss))))
;; tables required by PDF spec:
;; head, hhea, loca, maxp, cvt, prep, glyf, hmtx, fpgm
;; additional tables required for standalone fonts:
;; name, cmap, OS/2, post
(define (cloneDeep val) (deserialize (serialize val)))
(define (clone-deep val) (deserialize (serialize val)))
(define (encode ss port)
#;(output-port? . ->m . void?)
(set-TTFSubset-glyf! ss empty)
(set-TTFSubset-offset! ss 0)
(set-TTFSubset-loca! ss (mhash 'offsets empty))
(set-TTFSubset-hmtx! ss (mhash 'metrics empty 'bearings empty))
(set-ttf-subset-glyf! ss empty)
(set-ttf-subset-offset! ss 0)
(set-ttf-subset-loca! ss (mhash 'offsets empty))
(set-ttf-subset-hmtx! ss (mhash 'metrics empty 'bearings empty))
;; include all the glyphs used in the document
;; not using `in-list` because we need to support adding more
;; glyphs to the array as component glyphs are discovered & enqueued
(for ([idx (in-naturals)]
#:break (= idx (length (Subset-glyphs ss))))
(define gid (list-ref (Subset-glyphs ss) idx))
(_addGlyph ss gid))
#:break (= idx (length (subset-glyphs ss))))
(define gid (list-ref (subset-glyphs ss) idx))
(ttf-subset-add-glyph ss gid))
(define maxp (cloneDeep (· (Subset-font ss) maxp to-hash)))
(dict-set! maxp 'numGlyphs (length (TTFSubset-glyf ss)))
(define maxp (clone-deep (· (subset-font ss) maxp to-hash)))
(dict-set! maxp 'numGlyphs (length (ttf-subset-glyf ss)))
;; populate the new loca table
(dict-update! (TTFSubset-loca ss) 'offsets (λ (vals) (append vals (list (TTFSubset-offset ss)))))
(loca-pre-encode (TTFSubset-loca ss))
(dict-update! (ttf-subset-loca ss) 'offsets (λ (vals) (append vals (list (ttf-subset-offset ss)))))
(loca-pre-encode (ttf-subset-loca ss))
(define head (cloneDeep (· (Subset-font ss) head to-hash)))
(dict-set! head 'indexToLocFormat (· (TTFSubset-loca ss) version))
(define head (clone-deep (· (subset-font ss) head to-hash)))
(dict-set! head 'indexToLocFormat (· (ttf-subset-loca ss) version))
(define hhea (cloneDeep (· (Subset-font ss) hhea to-hash)))
(dict-set! hhea 'numberOfMetrics (length (· (TTFSubset-hmtx ss) metrics)))
(define hhea (clone-deep (· (subset-font ss) hhea to-hash)))
(dict-set! hhea 'numberOfMetrics (length (· (ttf-subset-hmtx ss) metrics)))
(send Directory encode port
@ -201,13 +184,13 @@ https://github.com/mbutterick/fontkit/blob/master/src/subset/TTFSubset.js
(mhash
'head head
'hhea hhea
'loca (TTFSubset-loca ss)
'loca (ttf-subset-loca ss)
'maxp maxp
'cvt_ (· (Subset-font ss) cvt_)
'prep (· (Subset-font ss) prep)
'glyf (TTFSubset-glyf ss)
'hmtx (TTFSubset-hmtx ss)
'fpgm (· (Subset-font ss) fpgm))))
'cvt_ (· (subset-font ss) cvt_)
'prep (· (subset-font ss) prep)
'glyf (ttf-subset-glyf ss)
'hmtx (ttf-subset-hmtx ss)
'fpgm (· (subset-font ss) fpgm))))
#;(report* (bytes-length (send stream dump)) (send stream dump))
#;(report* (bytes-length (file->bytes "out.bin")) (file->bytes "out.bin"))

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