start GPOS

main
Matthew Butterick 7 years ago
parent 53e1ab3334
commit ff8e2f867b

@ -0,0 +1,7 @@
#lang fontkit/racket
(require "font.rkt" "directory.rkt" "gpos.rkt")
(define f (openSync fira-path))
(define ds (send f _getTableStream 'GPOS))
(send GPOS decode ds)

@ -0,0 +1,195 @@
#lang fontkit/racket
(require restructure br/cond "opentype.rkt")
(provide (all-defined-out))
#|
approximates
https://github.com/mbutterick/fontkit/blob/master/src/tables/GPOS.js
|#
(define ValueFormat (+Bitfield uint16be '(xPlacement yPlacement xAdvance yAdvance xPlaDevice yPlaDevice xAdvDevice yAdvDevice)))
(define types
(mhash
'xPlacement int16be
'yPlacement int16be
'xAdvance int16be
'yAdvance int16be
'xPlaDevice uint16be ;; pointer
'yPlaDevice uint16be ;; pointer
'xAdvDevice uint16be ;; pointer
'yAdvDevice uint16be)) ;; pointer
(define-subclass RestructureBase (ValueRecord [key 'valueFormat])
(define/public (buildStruct parent)
(define struct parent)
(while (and (not (hash-ref struct (· this key))) (hash-ref struct parent))
(hash-set! struct (hash-ref struct parent)))
(cond
[(not (hash-ref struct (· this key))) (void)]
[else (define fields (mhash))
(hash-set! fields 'rel (λ () (hash-ref struct (error '_startOffset-not-available))))
(define format (hash-ref struct (· this key)))
(for ([key (in-list format)])
(when (hash-ref format key)
(hash-set! fields key (hash-ref types key))))
(+Struct fields)]))
(define/override (size val ctx)
(send (buildStruct ctx) size val ctx))
(define/override (decode stream parent)
(define res (send (buildStruct parent) decode stream parent))
(hash-remove! res 'rel)
res)
(define/override (encode . args)
(error 'GPOS-encode-not-implemented)))
(define PairValueRecord (+Struct
(dictify
'secondGlyph uint16be
'value1 (+ValueRecord 'valueFormat1)
'value2 (+ValueRecord 'valueFormat2))))
(define PairSet (+Array PairValueRecord uint16be))
(define Class2Record (+Struct
(dictify
'value1 (+ValueRecord 'valueFormat1)
'value2 (+ValueRecord 'valueFormat2))))
(define Anchor (+VersionedStruct uint16be
(dictify
;; Design units only
1 (dictify 'xCoordinate int16be
'yCoordinate int16be)
;; Design units plus contour point
2 (dictify 'xCoordinate int16be
'yCoordinate int16be
'anchorPoint uint16be)
;; Design units plus Device tables
3 (dictify 'xCoordinate int16be
'yCoordinate int16be
'xDeviceTable uint16be ; pointer
'yDeviceTable uint16be)))) ; pointer
(define EntryExitRecord (+Struct
(dictify 'entryAnchor uint16be ; pointer
'exitAnchor uint16be))) ; pointer
(define MarkRecord (+Struct
(dictify 'class uint16be
'markAnchor uint16be)))
(define MarkArray (+Array MarkRecord uint16be))
(define BaseRecord (+Array uint16be)) ; pointer
(define BaseArray (+Array BaseRecord uint16be))
(define ComponentRecord (+Array uint16be)) ; pointer
(define LigatureAttach (+Array ComponentRecord uint16be))
(define LigatureArray (+Array uint16be uint16be)) ; pointer
(define-subclass VersionedStruct (GPOSLookup-VersionedStruct))
(define GPOSLookup
(+GPOSLookup-VersionedStruct
(λ (parent) (· parent lookupType))
(dictify
;; Single Adjustment
1 (+VersionedStruct uint16be
(dictify
;; Single positioning value
1 (dictify
'coverage uint16be ; pointer
'valueFormat ValueFormat
'value (+ValueRecord))
2 (dictify
'coverage uint16be ; pointer
'valueFormat ValueFormat
'valueCount uint16be
'values (+LazyArray (+ValueRecord) 'valueCount))))
;; Pair Adjustment Positioning
2 (+VersionedStruct uint16be
(dictify
;; Adjustments for glyph pairs
1 (dictify
'coverage uint16be ; pointer
'valueFormat1 ValueFormat
'valueFormat2 ValueFormat
'pairSetCount uint16be
'pairSets (+LazyArray uint16be 'pairSetCount)) ; pointer
;; Class pair adjustment
2 (dictify
'coverage uint16be ; pointer
'valueFormat1 ValueFormat
'valueFormat2 ValueFormat
'classDef1 uint16be ; pointer
'classDef2 uint16be ; pointer
'class1Count uint16be
'class2Count uint16be
'classRecords (+LazyArray (+LazyArray Class2Record 'class2Count) 'class1Count))))
;; Cursive Attachment Positioning
3 (dictify
'format uint16be
'coverage uint16be ; pointer
'entryExitCount uint16be
'entryExitRecords (+Array EntryExitRecord 'entryExitCount))
;; MarkToBase Attachment Positioning
4 (dictify
'format uint16be
'markCoverage uint16be ; pointer
'baseCoverage uint16be ; pointer
'classCount uint16be
'markArray uint16be ; pointer
'baseArray uint16be) ; pointer
;; MarkToLigature Attachment Positioning
5 (dictify
'format uint16be
'markCoverage uint16be ; pointer
'ligatureCoverage uint16be ; pointer
'classCount uint16be
'markArray uint16be ; pointer
'ligatureArray uint16be)
;; MarkToMark Attachment Positioning
6 (dictify
'format uint16be
'mark1Coverage uint16be ; pointer
'mark2Coverage uint16be ; pointer
'classCount uint16be
'mark1Array uint16be ; pointer
'mark2Array uint16be) ; pointer
7 Context ;; Contextual positioning
8 ChainingContext ;; Chaining contextual positioning
;; Extension positioning
9 (dictify
'posFormat uint16be
'lookupType uint16be ;; cannot also be 9
'extension uint32be) ; pointer
)))
;; Fix circular reference
;; GPOSLookup.versions[9].extension.type = GPOSLookup;
(define gpos-common-dict (dictify 'scriptList uint16be ; pointer
'featureList uint16be ; pointer
'lookupList uint16be)) ; pointer
(define-subclass VersionedStruct (GPOS-VersionedStruct))
(define GPOS (+GPOS-VersionedStruct uint32be
(dictify
#x00010000 gpos-common-dict
#x00010001 (append gpos-common-dict (dictify 'featureVariations uint32be))))) ; pointer

@ -282,8 +282,9 @@ https://github.com/mbutterick/fontkit/blob/master/src/TTFFont.js
(define/contract (openSync filename [postscriptName #f])
((string?) ((option/c string?)) . ->* . TTFFont?)
(define/contract (openSync str-or-path [postscriptName #f])
(((or/c path? string?)) ((option/c string?)) . ->* . TTFFont?)
(define filename (if (path? str-or-path) (path->string str-or-path) str-or-path))
(define buffer (file->bytes filename))
(create buffer filename postscriptName))

@ -0,0 +1,62 @@
#lang fontkit/racket
(require restructure)
(provide (all-defined-out))
(define LookupRecord (+Struct
(dictify
'sequenceIndex uint16be
'lookupListIndex uint16be)))
(define Context
(+VersionedStruct
uint16be
(dictify
;; Simple context
1 (dictify
'coverage uint16be ; pointer
'ruleSetCount uint16be
'ruleSets (+Array uint16be 'ruleSetCount)) ; pointer
;; Class-based context
2 (dictify
'coverage uint16be ; pointer
'classDef uint16be ; pointer
'classSetCnt uint16be
'classSet (+Array uint16be 'classSetCnt)) ; pointer
3 (dictify
'glyphCount uint16be
'lookupCount uint16be
'coverages (+Array uint16be 'glyphCount) ; pointer
'lookupRecords (+Array LookupRecord 'lookupCount)))))
(define ChainingContext
(+VersionedStruct
uint16be
(dictify
;; Simple context glyph substitution
1 (dictify
'coverage uint16be ; pointer
'chainCount uint16be
'chainRuelSets (+Array uint16be 'chainCount)) ; pointer
;; Class-based chaining context
2 (dictify
'coverage uint16be ; pointer
'backtrackClassDef uint16be ; pointer
'inputClassDef uint16be ; pointer
'lookaheadClassDef uint16be ; pointer
'chainCount uint16be
'chainClassSet (+Array uint16be 'chainCount)) ; pointer
;; Coverage-based chaining context
3 (dictify
'backtrackGlyphCount uint16be
'backtrackCoverage (+Array uint16be 'backtrackGlyphCount) ; pointer
'inputGlyphCount uint16be
'inputCoverage (+Array uint16be 'inputGlyphCount) ; pointer
'lookaheadGlyphCount uint16be
'lookaheadCoverage (+Array uint16be 'lookaheadGlyphCount) ; pointer
'lookupCount uint16be
'lookupRecords (+Array LookupRecord 'lookupCount)))))

@ -0,0 +1,14 @@
#lang racket/base
(require racket/class)
(provide (all-defined-out))
(define RestructureBase
(class object%
(super-new)
(abstract decode)
(abstract encode)
(abstract size)
(define/public (process . args) (void))
(define/public (preEncode . args) (void))))
(define (RestructureBase? x) (is-a? x RestructureBase))

@ -1,17 +1,6 @@
#lang racket/base
(require (for-syntax racket/base br/syntax) racket/class br/define)
(provide (all-defined-out))
(define RestructureBase
(class object%
(super-new)
(abstract decode)
(abstract encode)
(abstract size)
(define/public (process . args) (void))
(define/public (preEncode . args) (void))))
(define (RestructureBase? x) (is-a? x RestructureBase))
(require (for-syntax racket/base br/syntax) racket/class br/define "base.rkt")
(provide (all-defined-out) (all-from-out "base.rkt"))
(define-macro (test-module . EXPRS)

@ -1,6 +1,7 @@
#lang restructure/racket
(r+p "number.rkt"
(r+p "base.rkt"
"number.rkt"
"struct.rkt"
"string.rkt"
"array.rkt"

@ -108,8 +108,8 @@ https://github.com/mbutterick/restructure/blob/master/src/VersionedStruct.coffee
(define-subclass Struct (VersionedStruct version-resolver [versions (dictify)])
(unless ((disjoin integer? procedure? RestructureBase?) version-resolver)
(raise-argument-error 'VersionedStruct "integer, function, or Restructure object" version-resolver))
(unless (and (dict? versions) (andmap dict? (map cdr versions)))
(raise-argument-error 'VersionedStruct "dict of dicts" versions))
(unless (and (dict? versions) (andmap (λ (val) (or (dict? val) (Struct? val))) (map cdr versions)))
(raise-argument-error 'VersionedStruct "dict of dicts or Structs" versions))
(inherit-field fields key-index)
(field [forced-version #f])

@ -1,5 +1,25 @@
#lang racket/base
(require racket/contract)
(require racket/contract racket/class)
(provide (all-defined-out))
(define (option/c x) (or/c #f x))
(define (option/c x) (or/c #f x))
(module+ main
(define-syntax-rule (define/public/contract (ID . ARGS) CONTRACT . BODY)
(define/public (ID . ARGS)
(define/contract (ID . ARGS)
CONTRACT . BODY)
(ID . ARGS)))
(define c% (class object%
(super-new)
(define/public/contract (add x y)
(integer? integer? . -> . integer?)
(+ x y))))
(define c (make-object c%))
(send c add 12 21))
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