typesetting/pitfall/fontkit/fpgm.rkt

#lang fontkit/racket
(require restructure)
(provide (all-defined-out))
#|
approximates
https://github.com/mbutterick/fontkit/blob/master/src/tables/fpgm.js
|#

;; A list of instructions that are executed once when a font is first used.
;; These instructions are known as the font program. The main use of this table
;; is for the definition of functions that are used in many different glyph programs.


(define-subclass Struct (fpgm%))

(define fpgm (make-object fpgm%
               (dictify
                'instructions (make-object Array uint8))))


(test-module
 (require racket/serialize)
 (define ip (open-input-file charter-path))
 (define dir (deserialize (read (open-input-file charter-directory-path))))
 (define offset (· dir tables fpgm offset))
 (define len (· dir tables fpgm length))
 (check-equal? offset 4140)
 (check-equal? len 371)
 (set-port-position! ip 0)
 (define ds (+DecodeStream (peek-bytes len offset ip)))
 (check-equal? (hash-ref (send fpgm decode ds) 'instructions) '(184
                                                                0
                                                                0
                                                                44
                                                                75
                                                                184
                                                                0
                                                                9
                                                                80
                                                                88
                                                                177
                                                                1
                                                                1
                                                                142
                                                                89
                                                                184
                                                                1
                                                                255
                                                                133
                                                                184
                                                                0
                                                                68
                                                                29
                                                                185
                                                                0
                                                                9
                                                                0
                                                                3
                                                                95
                                                                94
                                                                45
                                                                184
                                                                0
                                                                1
                                                                44
                                                                32
                                                                32
                                                                69
                                                                105
                                                                68
                                                                176
                                                                1
                                                                96
                                                                45
                                                                184
                                                                0
                                                                2
                                                                44
                                                                184
                                                                0
                                                                1
                                                                42
                                                                33
                                                                45
                                                                184
                                                                0
                                                                3
                                                                44
                                                                32
                                                                70
                                                                176
                                                                3
                                                                37
                                                                70
                                                                82
                                                                88
                                                                35
                                                                89
                                                                32
                                                                138
                                                                32
                                                                138
                                                                73
                                                                100
                                                                138
                                                                32
                                                                70
                                                                32
                                                                104
                                                                97
                                                                100
                                                                176
                                                                4
                                                                37
                                                                70
                                                                32
                                                                104
                                                                97
                                                                100
                                                                82
                                                                88
                                                                35
                                                                101
                                                                138
                                                                89
                                                                47
                                                                32
                                                                176
                                                                0
                                                                83
                                                                88
                                                                105
                                                                32
                                                                176
                                                                0
                                                                84
                                                                88
                                                                33
                                                                176
                                                                64
                                                                89
                                                                27
                                                                105
                                                                32
                                                                176
                                                                0
                                                                84
                                                                88
                                                                33
                                                                176
                                                                64
                                                                101
                                                                89
                                                                89
                                                                58
                                                                45
                                                                184
                                                                0
                                                                4
                                                                44
                                                                32
                                                                70
                                                                176
                                                                4
                                                                37
                                                                70
                                                                82
                                                                88
                                                                35
                                                                138
                                                                89
                                                                32
                                                                70
                                                                32
                                                                106
                                                                97
                                                                100
                                                                176
                                                                4
                                                                37
                                                                70
                                                                32
                                                                106
                                                                97
                                                                100
                                                                82
                                                                88
                                                                35
                                                                138
                                                                89
                                                                47
                                                                253
                                                                45
                                                                184
                                                                0
                                                                5
                                                                44
                                                                75
                                                                32
                                                                176
                                                                3
                                                                38
                                                                80
                                                                88
                                                                81
                                                                88
                                                                176
                                                                128
                                                                68
                                                                27
                                                                176
                                                                64
                                                                68
                                                                89
                                                                27
                                                                33
                                                                33
                                                                32
                                                                69
                                                                176
                                                                192
                                                                80
                                                                88
                                                                176
                                                                192
                                                                68
                                                                27
                                                                33
                                                                89
                                                                89
                                                                45
                                                                184
                                                                0
                                                                6
                                                                44
                                                                32
                                                                32
                                                                69
                                                                105
                                                                68
                                                                176
                                                                1
                                                                96
                                                                32
                                                                32
                                                                69
                                                                125
                                                                105
                                                                24
                                                                68
                                                                176
                                                                1
                                                                96
                                                                45
                                                                184
                                                                0
                                                                7
                                                                44
                                                                184
                                                                0
                                                                6
                                                                42
                                                                45
                                                                184
                                                                0
                                                                8
                                                                44
                                                                75
                                                                32
                                                                176
                                                                3
                                                                38
                                                                83
                                                                88
                                                                176
                                                                64
                                                                27
                                                                176
                                                                0
                                                                89
                                                                138
                                                                138
                                                                32
                                                                176
                                                                3
                                                                38
                                                                83
                                                                88
                                                                35
                                                                33
                                                                176
                                                                128
                                                                138
                                                                138
                                                                27
                                                                138
                                                                35
                                                                89
                                                                32
                                                                176
                                                                3
                                                                38
                                                                83
                                                                88
                                                                35
                                                                33
                                                                184
                                                                0
                                                                192
                                                                138
                                                                138
                                                                27
                                                                138
                                                                35
                                                                89
                                                                32
                                                                176
                                                                3
                                                                38
                                                                83
                                                                88
                                                                35
                                                                33
                                                                184
                                                                1
                                                                0
                                                                138
                                                                138
                                                                27
                                                                138
                                                                35
                                                                89
                                                                32
                                                                176
                                                                3
                                                                38
                                                                83
                                                                88
                                                                35
                                                                33
                                                                184
                                                                1
                                                                64
                                                                138
                                                                138
                                                                27
                                                                138
                                                                35
                                                                89
                                                                32
                                                                184
                                                                0
                                                                3
                                                                38
                                                                83
                                                                88
                                                                176
                                                                3
                                                                37
                                                                69
                                                                184
                                                                1
                                                                128
                                                                80
                                                                88
                                                                35
                                                                33
                                                                184
                                                                1
                                                                128
                                                                35
                                                                33
                                                                27
                                                                176
                                                                3
                                                                37
                                                                69
                                                                35
                                                                33
                                                                35
                                                                33
                                                                89
                                                                27
                                                                33
                                                                89
                                                                68
                                                                45
                                                                184
                                                                0
                                                                9
                                                                44
                                                                75
                                                                83
                                                                88
                                                                69
                                                                68
                                                                27
                                                                33
                                                                33
                                                                89
                                                                45)))