got first two parts of gpos

pitfall/fontkit/GPOS-test.rkt

@@ -5,14 +5,24 @@
 (define f (openSync fira-path))
 (define ds (send f _getTableStream 'GPOS))
 
+#|
 (file-position (· ds _port))
-(peek-bytes 4 0 (· ds _port)) ; version
-(peek-bytes 2 4 (· ds _port)) ; scriptList pointer
-(peek-bytes 2 10 (· ds _port)) ; number of Scriptrecords
-
-(send uint16be decode #"\0\n")
-
-(define h (send GPOS decode ds))
+(send uint32be decode (peek-bytes 4 0 (· ds _port))) ; version
+(define ptr (send uint16be decode (peek-bytes 2 4 (· ds _port))))
+ptr ; scriptList pointer
+(send uint16be decode (peek-bytes 2 ptr (· ds _port))) ; number of Scriptrecords
+
+(file-position (· ds _port) 0)
+(define offset 692)
+(send uint32be decode (peek-bytes 4 offset (· ds _port))) ; version
+(define ptr2 (send uint16be decode (peek-bytes 2 (+ 4 offset) (· ds _port))))
+ptr2 ; scriptList pointer
+(send uint16be decode (peek-bytes 2 (+ ptr2 offset) (· ds _port))) ; number of Scriptrecords
+|#
+
+(report 'start-decode)
+(define h (send GPOS decode (send f _getTableStream 'GPOS)))
+h
 
 
 

pitfall/fontkit/GPOS.rkt

@@ -42,7 +42,7 @@ https://github.com/mbutterick/fontkit/blob/master/src/tables/GPOS.js
     (send (buildStruct ctx) size val ctx))
 
   
-  (define/override (decode stream parent)
+  (define/augride (decode stream parent)
     (define res (send (buildStruct parent) decode stream parent))
     (hash-remove! res 'rel)
     res)
@@ -185,8 +185,8 @@ https://github.com/mbutterick/fontkit/blob/master/src/tables/GPOS.js
 ;; GPOSLookup.versions[9].extension.type = GPOSLookup;
 
 (define gpos-common-dict (dictify 'scriptList (+Pointer uint16be ScriptList) ; pointer
-                                  ;'featureList (+Pointer uint16be FeatureList) ; pointer
-                                  ;'lookupList (+Pointer uint16be (+LookupList GPOSLookup))
+                                  'featureList (+Pointer uint16be FeatureList) ; pointer
+                                  ;'lookupList (+Pointer uint16be (LookupList GPOSLookup))
                                   )) ; pointer
 
 (define-subclass VersionedStruct (GPOS-VersionedStruct))

pitfall/fontkit/opentype.rkt

@@ -14,7 +14,7 @@
 
 (define LangSysRecord (+Struct
                        (dictify 'tag (+String 4)
-                                'langSys (+Pointer uint16be LangSysTable (mhash 'type 'parent)))))
+                                'langSys (+Pointer uint16be LangSysTable 'parent))))
 
 (define Script (+Struct
                 (dictify 'defaultLangSys (+Pointer uint16be LangSysTable)
@@ -24,13 +24,42 @@
 (define-subclass Struct (ScriptRecord-Struct))
 (define ScriptRecord (+ScriptRecord-Struct
                       (dictify 'tag (+String 4)
-                               'script uint16be #;(+Pointer uint16be Script (mhash 'type 'parent)))))
-(define-subclass Array (ScriptRecordArray)
-  (define/override (decode stream ctx)
-    (define val (super decode stream ctx))
-    (report (· this _len))
-    val))
-(define ScriptList (+ScriptRecordArray ScriptRecord uint16be))
+                               'script (+Pointer uint16be Script 'parent))))
+
+(define ScriptList (+Array ScriptRecord uint16be))
+
+;;#######################
+;; Features and Lookups #
+;;#######################
+
+
+(define Feature (+Struct (dictify
+                                'featureParams uint16be ; pointer
+                                'lookupCount uint16be
+                                'lookupListIndexes (+Array uint16be 'lookupCount))))
+
+(define FeatureRecord (+Struct (dictify
+                                'tag (+String 4)
+                                'feature (+Pointer uint16be Feature 'parent))))
+
+(define FeatureList (+Array FeatureRecord uint16be))
+
+(define LookupFlags (+Bitfield uint16be '(rightToLeft ignoreBaseGlyphs ignoreLigatures ignoreMarks useMarkFilteringSet #f markAttachmentType)))
+
+(define (LookupList SubTable)
+  (define Lookup (+Struct
+                  (dictify
+                   'lookupType uint16be
+                   'flags LookupFlags
+                   'subTableCount uint16be
+                   'subTables (+Array (+Pointer uint16be SubTable) 'subTableCount)
+                   'markFilteringSet uint16be))) ; TODO: only present when flags says so ...
+  (+LazyArray (+Pointer uint16be Lookup) uint16be))
+
+;;#############################################
+;; Contextual Substitution/Positioning Tables #
+;;#############################################
+
 
 (define LookupRecord (+Struct
                       (dictify
@@ -61,6 +90,10 @@
        'lookupRecords (+Array LookupRecord 'lookupCount)))))
 
 
+;;######################################################
+;; Chaining Contextual Substitution/Positioning Tables #
+;;######################################################
+
 (define ChainingContext
   (+VersionedStruct
    uint16be

pitfall/fontkit/post.rkt

@@ -45,7 +45,7 @@ https://github.com/mbutterick/fontkit/blob/master/src/tables/post.js
  (check-equal? offset 41520)
  (check-equal? len 514)
  (define ds (+DecodeStream (peek-bytes len offset ip)))
- (define version (send fixed32be decode ds))
+ (define version (send fixed32be decode ds)) ; version = 2
  (send post force-version! version)
  (define table-data (send post decode ds))
  (check-equal? (· table-data underlineThickness) 58)

pitfall/restructure/array.rkt

@@ -8,7 +8,6 @@ https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
 |#
 
 (define-subclass Streamcoder (Array type [_length #f] [lengthType 'count])
-  (field [_len #f])
           
   (define/augride (decode stream [parent #f])
     (let ([len (cond
@@ -20,7 +19,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Array.coffee
                   (unless (andmap (λ (x) (and x (number? x))) (list num denom))
                     (raise-argument-error 'Array:decode "valid length and size" (list num denom)))
                   (floor (/ (send stream length) (send type size)))])])
-    (set! _len len)
+    
       (caseq lengthType
              [(count) (for/list ([i (in-range len)])
                         (send type decode stream this))])))

pitfall/restructure/base.rkt

@@ -1,11 +1,17 @@
 #lang racket/base
-(require racket/class)
+(require racket/class sugar/debug)
 (provide (all-defined-out))
 
 (define RestructureBase
   (class object%
     (super-new)    
-    (abstract decode)
+    (field [starting-offset #f]
+           [parent #f])
+    (define/pubment (decode stream . args)
+      (set! starting-offset (and (object? stream) (send stream pos)))
+      (set! parent (and (pair? args) (is-a? (car args) RestructureBase) (car args)))
+      #;(report* starting-offset parent (and parent (get-field starting-offset parent)))
+      (inner (void) decode stream . args))
     (abstract encode)
     (abstract size)
     (define/public (process . args) (void))

pitfall/restructure/buffer.rkt

@@ -8,7 +8,7 @@ https://github.com/mbutterick/restructure/blob/master/src/Buffer.coffee
 |#
 
 (define-subclass RestructureBase (Buffer [_length #xffff])
-  (define/override (decode stream [parent #f])
+  (define/augride (decode stream [parent #f])
     (define len (resolveLength _length stream parent))
     (send stream readBuffer len))
 

pitfall/restructure/pointer.rkt

@@ -6,19 +6,23 @@ approximates
 https://github.com/mbutterick/restructure/blob/master/src/Pointer.coffee
 |#
 
-(define-subclass RestructureBase (Pointer offsetType type [options (mhash)])
+(define-subclass RestructureBase (Pointer offsetType type [scope 'local])
+  (and (symbol? scope) (caseq scope
+                              [(local parent) 'yay]
+                              [else (raise-argument-error 'Pointer "local or parent" scope)]))
 
-  (define/override (decode stream ctx)
-    (report (file-position (· stream _port)))
+  (define/augride (decode stream ctx)
+    #;(report* (· this starting-offset) (· this parent starting-offset))
     (define offset (send offsetType decode stream ctx))
-    (define ptr offset)
-    (report* offset ptr)
+    (define ptr (+ offset (caseq scope
+                                 [(local) (· this parent starting-offset)]
+                                 [(parent) (· this parent parent starting-offset)])))
+    #;(report* offset ptr)
     (cond
       [type (define orig-pos (send stream pos))
             (send stream pos ptr)
             (define val (send type decode stream ctx))
             (send stream pos orig-pos)
-            (report* options)
             val]
       [else ptr]))
             
@@ -26,8 +30,10 @@ https://github.com/mbutterick/restructure/blob/master/src/Pointer.coffee
   (define/override (encode stream val)
     (error 'Pointer-encode-not-done))
 
-  (define/override (size val)
-    (error 'Pointer-size-not-done))
+  (define/override (size [val #f] [ctx #f])
+    
+    (report* this offsetType type)
+    (report (send type size)))
 
   
 

pitfall/restructure/stream.rkt

@@ -113,8 +113,7 @@ https://github.com/mbutterick/restructure/blob/master/src/DecodeStream.coffee
 ;; Streamcoder is a helper class that checks / converts stream arguments before decode / encode
 ;; not a subclass of DecodeStream or EncodeStream, however.
 (define-subclass RestructureBase (Streamcoder)
-  
-  (define/overment (decode x . args)
+  (define/augment (decode x . args)
     (define stream (if (bytes? x) (+DecodeStream x) x))
     (unless (DecodeStream? stream)
       (raise-argument-error 'Streamcoder:decode "bytes or DecodeStream" x))
@@ -132,7 +131,7 @@ https://github.com/mbutterick/restructure/blob/master/src/DecodeStream.coffee
 
 (test-module
  (define-subclass Streamcoder (Dummy)
-   (define/augment (decode stream) "foo")
+   (define/augment (decode stream . args) "foo")
    (define/augment (encode stream val) "bar")
    (define/override (size) 42))
 

pitfall/restructure/struct.rkt

@@ -8,6 +8,8 @@ https://github.com/mbutterick/restructure/blob/master/src/Struct.coffee
 |#
 
 (define-subclass Streamcoder (Struct [assocs (dictify)])
+  (field [res #f])
+  
   (unless (assocs? assocs)
     (raise-argument-error 'Struct "assocs" assocs))
   (field [key-index #f] ; store the original key order
@@ -30,9 +32,8 @@ https://github.com/mbutterick/restructure/blob/master/src/Struct.coffee
   (update-fields! assocs)
   
   (define/augride (decode stream [parent #f] [length 0])
-    (define res (_setup stream parent length))
-    (_parseFields stream res fields)
-    #;(hash-set! (hash-ref res '_props) '_currentOffset (· stream pos))
+    (set! res (_setup stream parent length))
+    (_parseFields stream fields)
     (send this process res stream)
     res)
 
@@ -54,23 +55,15 @@ https://github.com/mbutterick/restructure/blob/master/src/Struct.coffee
           (send struct-type encode stream value-to-encode)))
 
   (define/public-final (_setup stream parent length)
-    (define res (mhasheq))
-
-    ;; define hidden properties
-    #;(hash-set! res '_props
-                 (mhasheq 'parent (mhasheq 'value parent)
-                          '_startOffset (mhasheq 'value (· stream pos))
-                          '_currentOffset (mhasheq 'value 0 'writable #t)
-                          '_length (mhasheq 'value length)))
-    res)
+    (mhasheq))
 
-  (define/public-final (_parseFields stream res fields)
+  (define/public-final (_parseFields stream fields)
     (for ([key (in-list key-index)])         
          (define dictvalue (dict-ref fields key))
          (define val
            (if (procedure? dictvalue)
                (dictvalue res)
-               (send dictvalue decode stream res)))
+               (send dictvalue decode stream this)))
          (hash-set! res key val)))
 
   (define/override (size [val (mhash)] [parent #f] [includePointers #t])
@@ -106,6 +99,7 @@ https://github.com/mbutterick/restructure/blob/master/src/VersionedStruct.coffee
 |#
 
 (define-subclass Struct (VersionedStruct version-resolver [versions (dictify)])
+  (inherit-field res)
   (unless ((disjoin integer? procedure? RestructureBase?) version-resolver)
     (raise-argument-error 'VersionedStruct "integer, function, or Restructure object" version-resolver))
   (unless (and (dict? versions) (andmap (λ (val) (or (dict? val) (Struct? val))) (map cdr versions)))
@@ -117,7 +111,7 @@ https://github.com/mbutterick/restructure/blob/master/src/VersionedStruct.coffee
     (set! forced-version version))
   
   (define/override (decode stream [parent #f] [length 0])
-    (define res (send this _setup stream parent length))
+    (set! res (send this _setup stream parent length))
     (define version (cond
                       [forced-version] ; for testing purposes: pass an explicit version
                       [(integer? version-resolver) version-resolver] 
@@ -130,7 +124,7 @@ https://github.com/mbutterick/restructure/blob/master/src/VersionedStruct.coffee
     (cond
       [(VersionedStruct? fields) (send fields decode stream parent)]
       [else
-       (send this _parseFields stream res fields)
+       (send this _parseFields stream fields)
        (send this process res stream)
        res]))
 
@@ -157,3 +151,4 @@ https://github.com/mbutterick/restructure/blob/master/src/VersionedStruct.coffee
       (define bs (apply bytes (for/list ([i (in-range struct-size)])
                                         (random 256))))
       (check-equal? (send vs encode #f (send vs decode bs)) bs)))
+

pitfall/restructure/utils.rkt

@@ -6,6 +6,6 @@
   (cond
     [(number? len) len]
     [(procedure? len) (len parent)]
-    [(and parent (symbol? len) (hash-ref parent len))] ; treat as key into RStruct parent
+    [(and parent (symbol? len) (hash-ref (· parent res) len))] ; treat as key into RStruct parent
     [(and stream (Number? len) (send len decode stream))]
     [else (raise-argument-error 'resolveLength "not a fixed size" len)]))