mods

fontland/fontland/font.rkt

@@ -1,6 +1,6 @@
 #lang debug racket/base
 (require "racket.rkt")
-(require "freetype-ffi.rkt" (except-in ffi/unsafe -> array?) racket/runtime-path "subset.rkt" "glyph.rkt" "bbox.rkt" "glyphrun.rkt" "directory.rkt" xenomorph "tables.rkt" "ttfglyph.rkt")
+(require "freetype-ffi.rkt" "subset.rkt" "glyph.rkt" "bbox.rkt" "glyphrun.rkt" "directory.rkt" xenomorph "tables.rkt")
 (provide (all-defined-out))
 
 #|

fontland/fontland/glyph.rkt

@@ -1,7 +1,7 @@
 #lang racket/base
 (require "racket.rkt")
 
-(require "freetype-ffi.rkt")
+(require xenomorph "freetype-ffi.rkt")
 (provide (all-defined-out))
 (module+ test (require rackunit))
 
@@ -79,4 +79,179 @@ https://github.com/mbutterick/fontkit/blob/master/src/glyph/CFFGlyph.js
 
 
 
+#|
+approximates
+https://github.com/mbutterick/fontkit/blob/master/src/glyph/TTFGlyph.js
+|#
+
+;; The header for both simple and composite glyphs
+(define-subclass Struct (RGlyfHeader))
+(define GlyfHeader (+RGlyfHeader
+                    (dictify 'numberOfContours int16be ;; if negative, this is a composite glyph
+                             'xMin int16be
+                             'yMin int16be
+                             'xMax int16be
+                             'yMax int16be)))
+
+;; Flags for simple glyphs
+(define-macro (define-flag-series . IDS)
+  #`(match-define (list . IDS) (map (curry expt 2) (range #,(length (syntax->list #'IDS))))))
+
+;; Flags for simple glyphs
+(define-flag-series ON_CURVE
+  X_SHORT_VECTOR
+  Y_SHORT_VECTOR
+  REPEAT
+  SAME_X
+  SAME_Y)
+
+;; Flags for composite glyphs
+(define-flag-series ARG_1_AND_2_ARE_WORDS    
+  ARGS_ARE_XY_VALUES       
+  ROUND_XY_TO_GRID         
+  WE_HAVE_A_SCALE
+  __EMPTY-FLAG___
+  MORE_COMPONENTS          
+  WE_HAVE_AN_X_AND_Y_SCALE 
+  WE_HAVE_A_TWO_BY_TWO     
+  WE_HAVE_INSTRUCTIONS     
+  USE_MY_METRICS           
+  OVERLAP_COMPOUND         
+  SCALED_COMPONENT_OFFSET  
+  UNSCALED_COMPONENT_OFFSET)
+
+;; Represents a point in a simple glyph
+(define-subclass object% (Point onCurve endContour [x 0] [y 0])
+
+  (define/public (copy)
+    (+Point onCurve endContour x y)))
+
+;; Represents a component in a composite glyph
+(define-subclass object% (Component glyphID dx dy)
+  (field [pos 0]
+         [scaleX 1]
+         [scaleY 1]
+         [scale01 0]
+         [scale10 0]))
+
+;; Represents a TrueType glyph.
+(define-subclass Glyph (TTFGlyph)
+  (inherit-field _font id)
+
+  ;; Parses just the glyph header and returns the bounding box
+  (define/override (_getCBox internal)
+    (unfinished))
+
+  ;; Parses a single glyph coordinate
+  (define/public (_parseGlyphCoord port prev short same)
+    (unless (input-port? port)
+      (raise-argument-error '_parseGlyphCoord "input port" port))
+    (unless (number? prev)
+      (raise-argument-error '_parseGlyphCoord "number" prev))
+    (unless (and (boolean? short) (boolean? same))
+      (raise-argument-error '_parseGlyphCoord "booleans" (list short same)))
+    (+ prev (if short 
+                ((if (not same) - +) (decode uint8 port))
+                (if same 0 (decode int16be port)))))
+                 
+
+  ;; Decodes the glyph data into points for simple glyphs,
+  ;; or components for composite glyphs
+  (define/public (_decode)
+    (define offsets (· _font loca offsets))
+    (match-define (list glyfPos nextPos) (take (drop offsets id) 2))
+
+    ;; Nothing to do if there is no data for this glyph
+    (and (not (= glyfPos nextPos))
+         (let ()
+           (define port (send _font _getTableStream 'glyf))
+           (pos port (+ (pos port) glyfPos))
+           (define startPos (pos port))
+           (define glyph (decode GlyfHeader port))
+           (match (· glyph numberOfContours)
+             [(? positive?) (_decodeSimple glyph port)]
+             [(? negative?) (_decodeComposite glyph port startPos)])
+           glyph)))
+
+  (define/public (_decodeSimple glyph port)
+    (unless (dict? glyph)
+      (raise-argument-error 'TTFGlyph-_decodeSimple "decoded RGlyfHeader" glyph))
+
+    (unless (input-port? port)
+      (raise-argument-error 'TTFGlyph-_decodeSimple "input port" port))
+
+    ;; this is a simple glyph
+    (dict-set! glyph 'points empty)
+    (define endPtsOfContours (decode (+Array uint16be (· glyph numberOfContours)) port))
+    (dict-set! glyph 'instructions (decode (+Array uint8be uint16be) port))
+    (define numCoords (add1 (last endPtsOfContours)))
+
+    (define flags
+      (for*/lists (flags)
+                  ([i (in-naturals)]
+                   #:break (= (length flags) numCoords)
+                   [flag (in-value (decode uint8 port))]
+                   [count (in-range (add1 (if (not (zero? (bitwise-and flag REPEAT)))
+                                              (decode uint8 port)
+                                              0)))])
+                  flag))
+
+    (match-define-values
+     (points _ _)
+     (for/fold ([points empty] [px 0] [py 0])
+               ([(flag i) (in-indexed flags)])
+       (define point (+Point (zero? (bitwise-and flag ON_CURVE)) (and (index-of endPtsOfContours i) #t) 0 0))
+       (define next-px (_parseGlyphCoord port px (not (zero? (bitwise-and flag X_SHORT_VECTOR))) (not (zero? (bitwise-and flag SAME_X)))))
+       (define next-py (_parseGlyphCoord port py (not (zero? (bitwise-and flag Y_SHORT_VECTOR))) (not (zero? (bitwise-and flag SAME_Y)))))
+       (set-field! x point next-px)
+       (set-field! y point next-py)
+       (values (cons point points) next-px next-py)))
+    (dict-set! glyph 'points (reverse points)))
+
+  (define/public (_decodeComposite glyph port [offset 0])
+    ;; this is a composite glyph
+    (dict-set! glyph 'components empty)
+    (define haveInstructions #f)
+    (define flags MORE_COMPONENTS)
+
+    (dict-set! glyph 'components
+               (for/list ([i (in-naturals)]
+                          #:break (zero? (bitwise-and flags MORE_COMPONENTS)))
+                 (set! flags (send uint16be decode port))
+                 (define gPos (- (pos port) offset))
+                 (define glyphID (send uint16be decode port))
+                 (unless haveInstructions
+                   (set! haveInstructions (not (zero? (bitwise-and flags WE_HAVE_INSTRUCTIONS)))))
+
+                 (match-define
+                   (list dx dy)
+                   (let ([decoder (if (not (zero? (bitwise-and flags ARG_1_AND_2_ARE_WORDS))) int16be int8)])
+                     (list (send decoder decode port) (send decoder decode port))))
+
+                 (define component (+Component glyphID dx dy))
+                 (set-field! pos component gPos)
+
+                 (cond
+                   [(not (zero? (bitwise-and flags WE_HAVE_A_SCALE)))
+                    (define scale (read-fixed14 port))
+                    (set-field! scaleX component scale)
+                    (set-field! scaleY component scale)]
+                   [(not (zero? (bitwise-and flags WE_HAVE_AN_X_AND_Y_SCALE)))
+                    (set-field! scaleX component (read-fixed14 port))
+                    (set-field! scaleY component (read-fixed14 port))]
+                   [(not (zero? (bitwise-and flags WE_HAVE_A_TWO_BY_TWO)))
+                    (set-field! scaleX component (read-fixed14 port))
+                    (set-field! scale01 component (read-fixed14 port))
+                    (set-field! scale10 component (read-fixed14 port))
+                    (set-field! scaleY component (read-fixed14 port))])
+                 component))
+    haveInstructions))
+        
 
+(define (bytes->fixed14 b1 b2)
+  (/ (+ (* b1 (expt 2 8)) b2) (expt 2 14) 1.0))
+  
+(define (read-fixed14 stream)
+  (define b1 (send uint8 decode stream))
+  (define b2 (send uint8 decode stream))
+  (bytes->fixed14 b1 b2))

fontland/fontland/subset.rkt

@@ -1,6 +1,6 @@
 #lang debug racket/base
 (require "racket.rkt")
-(require racket/serialize "ttfglyphencoder.rkt" "table/loca.rkt" "directory.rkt" xenomorph)
+(require racket/serialize "table/loca.rkt" "directory.rkt" xenomorph)
 (provide Subset CFFSubset TTFSubset)
 
 #|
@@ -78,7 +78,6 @@ https://github.com/mbutterick/fontkit/blob/master/src/subset/TTFSubset.js
 |#
 
 (define-subclass Subset (TTFSubset)
-  (field [glyphEncoder (make-object TTFGlyphEncoder)])
   (field [glyf #f]
          [offset #f]
          [loca #f]

fontland/fontland/tables.rkt

@@ -18,12 +18,14 @@ https://github.com/mbutterick/fontkit/blob/master/src/tables/index.js
                     (test-module (require (submod TABLE-ID-STRING test) ...))
                     (define ID (make-hasheq (map cons (list 'TABLE-ID ...) (list TABLE-ID ...)))))))
 
-(define-table-codecs table-codecs
-  ;; required tables
-  #;cmap head hhea hmtx maxp #;name OS/2 post
-  ;; TrueType outlines
-  cvt_ fpgm loca prep glyf
-  ;; PostScript outlines
-  #;CFF_ #;CFF2 #;VORG
-  ;; Advanced OpenType Tables
-  #;BASE #;GDEF #;GPOS #;GSUB #;JSTF)
+(define-table-codecs table-codecs head hhea hmtx maxp OS/2 post cvt_ fpgm loca prep glyf)
+
+
+#|
+Tables not suppoted:
+cmap name
+PostScript outlines:
+CFF_ CFF2 VORG
+Advanced OpenType Tables
+BASE GDEF GPOS GSUB JSTF
+|#