add hfs-seconds type

main
Matthew Butterick 5 years ago
parent d050669d3a
commit 4d6399fac5

@ -1,5 +1,6 @@
#lang racket/base
(require xenomorph)
#lang debug racket/base
(require xenomorph
racket/date)
(provide head)
#|
@ -7,53 +8,64 @@ approximates
https://github.com/mbutterick/fontkit/blob/master/src/tables/head.js
|#
; `name` table dates are seconds since 1/1/1904 (Mac file convention)
; whereas Racket / posix tracks since 1/1/1970
; so we adjust with the difference in seconds
(define mac-to-posix-delta 2082844800)
(define hfs-seconds (x:int #:size 8
#:signed #f
#:endian 'be
#:post-decode (λ (int) (seconds->date (- int mac-to-posix-delta)))
#:pre-encode (λ (dt) (+ (date->seconds dt) mac-to-posix-delta))))
(define head (x:struct
'version int32be ;; 0x00010000 (version 1.0)
'revision int32be ;; set by font manufacturer
'checkSumAdjustment uint32be
'magicNumber uint32be ;; set to 0x5F0F3CF5
'flags uint16be
'unitsPerEm uint16be ;; range from 64 to 16384
'created (x:array #:type int32be #:length 2)
'modified (x:array #:type int32be #:length 2)
'xMin int16be ;; for all glyph bounding boxes
'yMin int16be ;; for all glyph bounding boxes
'xMax int16be ;; for all glyph bounding boxes
'yMax int16be ;; for all glyph bounding boxes
'macStyle (x:bitfield #:type uint16be
#:flags '(bold italic underline outline shadow condensed extended))
'lowestRecPPEM uint16be ;; smallest readable size in pixels
'fontDirectionHint int16be
'indexToLocFormat int16be ;; 0 for short offsets 1 for long
'glyphDataFormat int16be ;; 0 for current format
))
'version int32be ;; 0x00010000 (version 1.0)
'revision int32be ;; set by font manufacturer
'checkSumAdjustment uint32be
'magicNumber uint32be ;; set to 0x5F0F3CF5
'flags uint16be
'unitsPerEm uint16be ;; range from 64 to 16384
'created hfs-seconds
'modified hfs-seconds
'xMin int16be ;; for all glyph bounding boxes
'yMin int16be ;; for all glyph bounding boxes
'xMax int16be ;; for all glyph bounding boxes
'yMax int16be ;; for all glyph bounding boxes
'macStyle (x:bitfield #:type uint16be
#:flags '(bold italic underline outline shadow condensed extended))
'lowestRecPPEM uint16be ;; smallest readable size in pixels
'fontDirectionHint int16be
'indexToLocFormat int16be ;; 0 for short offsets 1 for long
'glyphDataFormat int16be ;; 0 for current format
))
(module+ test
(require rackunit "../helper.rkt"
racket/serialize)
(define ip (open-input-file charter-italic-path))
(define dir (deserialize (read (open-input-file charter-italic-directory-path))))
(define offset (hash-ref (hash-ref (hash-ref dir 'tables) 'head) 'offset))
(define length (hash-ref (hash-ref (hash-ref dir 'tables) 'head) 'length))
(check-equal? offset 236)
(check-equal? length 54)
(define table-bytes #"\0\1\0\0\0\2\0\0.\252t<_\17<\365\0\t\3\350\0\0\0\0\316\3\301\261\0\0\0\0\316\3\304\364\377\36\377\24\4\226\3\324\0\2\0\t\0\2\0\0\0\0")
(file-position ip 0)
(check-equal? (peek-bytes length offset ip) table-bytes)
(define table-data (decode head table-bytes))
(check-equal? (hash-ref table-data 'unitsPerEm) 1000)
(check-equal? (hash-ref table-data 'yMin) -236)
(check-equal? (hash-ref table-data 'yMax) 980)
(check-equal? (hash-ref table-data 'xMax) 1174)
(check-equal? (hash-ref table-data 'xMin) -226)
(check-equal? (hash-ref table-data 'macStyle) (make-hash '((shadow . #f)
(extended . #f)
(condensed . #f)
(underline . #f)
(outline . #f)
(bold . #f)
(italic . #t))))
(check-equal? (hash-ref table-data 'magicNumber) #x5F0F3CF5)
(check-equal? (hash-ref table-data 'indexToLocFormat) 0) ; used in loca table
(check-equal? (encode head table-data #f) table-bytes))
(require rackunit "../helper.rkt"
racket/serialize)
(define ip (open-input-file charter-italic-path))
(define dir (deserialize (read (open-input-file charter-italic-directory-path))))
(define offset (hash-ref (hash-ref (hash-ref dir 'tables) 'head) 'offset))
(define length (hash-ref (hash-ref (hash-ref dir 'tables) 'head) 'length))
(check-equal? offset 236)
(check-equal? length 54)
(define table-bytes #"\0\1\0\0\0\2\0\0.\252t<_\17<\365\0\t\3\350\0\0\0\0\316\3\301\261\0\0\0\0\316\3\304\364\377\36\377\24\4\226\3\324\0\2\0\t\0\2\0\0\0\0")
(file-position ip 0)
(check-equal? (peek-bytes length offset ip) table-bytes)
(define table-data (decode head table-bytes))
(check-equal? (hash-ref table-data 'unitsPerEm) 1000)
(check-equal? (hash-ref table-data 'yMin) -236)
(check-equal? (hash-ref table-data 'yMax) 980)
(check-equal? (hash-ref table-data 'xMax) 1174)
(check-equal? (hash-ref table-data 'xMin) -226)
(check-equal? (hash-ref table-data 'macStyle) (make-hash '((shadow . #f)
(extended . #f)
(condensed . #f)
(underline . #f)
(outline . #f)
(bold . #f)
(italic . #t))))
(check-equal? (hash-ref table-data 'magicNumber) #x5F0F3CF5)
(check-equal? (hash-ref table-data 'indexToLocFormat) 0) ; used in loca table
(check-equal? (encode head table-data #f) table-bytes))
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