From 2fc8afff9346df4d84b28245eb71fbedfc38cde5 Mon Sep 17 00:00:00 2001 From: Matthew Butterick Date: Thu, 15 Jun 2017 22:29:44 -0700 Subject: [PATCH] resume in ttfglyph:decodeSimple --- pitfall/fontkit/font.rkt | 2 +- pitfall/fontkit/glyph.rkt | 15 +++-- pitfall/fontkit/subset.rkt | 12 +++- pitfall/fontkit/ttfglyph.rkt | 124 +++++++++++++++++++++++++++++++++++ pitfall/sugar/case.rkt | 4 +- 5 files changed, 147 insertions(+), 10 deletions(-) create mode 100644 pitfall/fontkit/ttfglyph.rkt diff --git a/pitfall/fontkit/font.rkt b/pitfall/fontkit/font.rkt index 244079e8..354901af 100644 --- a/pitfall/fontkit/font.rkt +++ b/pitfall/fontkit/font.rkt @@ -1,5 +1,5 @@ #lang fontkit/racket -(require "freetype-ffi.rkt" ffi/unsafe racket/runtime-path "subset.rkt" "glyph.rkt" "layout-engine.rkt" "bbox.rkt" "glyphrun.rkt" "cmap-processor.rkt" "directory.rkt" restructure "tables.rkt") +(require "freetype-ffi.rkt" ffi/unsafe racket/runtime-path "subset.rkt" "glyph.rkt" "layout-engine.rkt" "bbox.rkt" "glyphrun.rkt" "cmap-processor.rkt" "directory.rkt" restructure "tables.rkt" "ttfglyph.rkt") (provide (all-defined-out)) (define-runtime-path charter-path "../pitfall/test/assets/charter.ttf") diff --git a/pitfall/fontkit/glyph.rkt b/pitfall/fontkit/glyph.rkt index 5ec34582..8397da37 100644 --- a/pitfall/fontkit/glyph.rkt +++ b/pitfall/fontkit/glyph.rkt @@ -1,6 +1,6 @@ #lang fontkit/racket (require "freetype-ffi.rkt") -(provide Glyph CFFGlyph TTFGlyph) +(provide Glyph CFFGlyph) (module+ test (require rackunit)) #| @@ -33,9 +33,17 @@ [_metrics #f]) (as-methods + _getPath + _getCBox + _getBBox + _getTableMetrics advanceWidth _getMetrics)) +(define-stub-stop _getPath) +(define-stub-stop _getCBox) +(define-stub-stop _getBBox) +(define-stub-stop _getTableMetrics) (define/contract (advanceWidth this) (->m number?) @@ -58,8 +66,3 @@ (define-subclass Glyph (CFFGlyph) (error 'cff-glyph-unimplemented)) - - -(define-subclass Glyph (TTFGlyph) - - ) \ No newline at end of file diff --git a/pitfall/fontkit/subset.rkt b/pitfall/fontkit/subset.rkt index d748a88f..6ee5c717 100644 --- a/pitfall/fontkit/subset.rkt +++ b/pitfall/fontkit/subset.rkt @@ -51,8 +51,16 @@ https://github.com/mbutterick/fontkit/blob/master/src/subset/TTFSubset.js ) -(define (_addGlyph . xs) - (void)) +(define/contract (_addGlyph this gid) + (index? . ->m . void?) + + (define glyph (send (· this font) getGlyph gid)) + (report glyph) + (define glyf (send glyph _decode)) + + ;; get the offset to the glyph from the loca table + (define curOffset (list-ref (hash-ref (send (· this font) _getTable 'loca) 'offsets) gid)) + (unfinished)) ;; tables required by PDF spec: ;; head, hhea, loca, maxp, cvt, prep, glyf, hmtx, fpgm diff --git a/pitfall/fontkit/ttfglyph.rkt b/pitfall/fontkit/ttfglyph.rkt new file mode 100644 index 00000000..fbd0e050 --- /dev/null +++ b/pitfall/fontkit/ttfglyph.rkt @@ -0,0 +1,124 @@ +#lang fontkit/racket +(require "glyph.rkt" restructure) +(provide (all-defined-out)) + +;; 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 ON_CURVE (expt 2 0)) +(define X_SHORT_VECTOR (expt 2 1)) +(define Y_SHORT_VECTOR (expt 2 2)) +(define REPEAT (expt 2 3)) +(define SAME_X (expt 2 4)) +(define SAME_Y (expt 2 5)) + +;; Flags for composite glyphs +(define ARG_1_AND_2_ARE_WORDS (expt 2 0)) +(define ARGS_ARE_XY_VALUES (expt 2 1)) +(define ROUND_XY_TO_GRID (expt 2 2)) +(define WE_HAVE_A_SCALE (expt 2 3)) +(define MORE_COMPONENTS (expt 2 5)) +(define WE_HAVE_AN_X_AND_Y_SCALE (expt 2 6)) +(define WE_HAVE_A_TWO_BY_TWO (expt 2 7)) +(define WE_HAVE_INSTRUCTIONS (expt 2 8)) +(define USE_MY_METRICS (expt 2 9)) +(define OVERLAP_COMPOUND (expt 2 10)) +(define SCALED_COMPONENT_OFFSET (expt 2 11)) +(define UNSCALED_COMPONENT_OFFSET (expt 2 12)) + +;; 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 steam prev short same) + (unfinished)) + + ;; Decodes the glyph data into points for simple glyphs, + ;; or components for composite glyphs + (define/public (_decode) + (define offsets (hash-ref (send _font _getTable 'loca) 'offsets)) + (define glyfPos (list-ref offsets id)) + (define nextPos (list-ref offsets (add1 id))) + + ;; Nothing to do if there is no data for this glyph + (unless (= glyfPos nextPos) + (define stream (send _font _getTableStream 'glyf)) + (increment-field! pos stream glyfPos) + (define startPos (· stream pos)) + + (define glyph (send GlyfHeader decode stream)) + + (let ([contour-count (· glyph numberOfContours)]) + (cond + [(positive? contour-count) + (_decodeSimple glyph stream)] + [(negative? contour-count) + (_decodeComposite glyph stream startPos)])) + + glyph)) + + (define/public (_decodeSimple glyph stream) + (unless (RGlyfHeader? glyph) + (raise-argument-error 'TTFGlyph-_decodeSimple "glyph" glyph)) + + (unless (DecodeStream? stream) + (raise-argument-error 'TTFGlyph-_decodeSimple "stream" stream)) + + ;; this is a simple glyph + (hash-set! glyph 'points empty) + + (define endPtsOfContours (send (+Array uint16be (· glyph numberOfContours)) decode stream)) + (hash-set! glyph 'instructions (send (+Array uint8be uint16be) decode stream)) + + (define numCoords (add1 (list-ref endPtsOfContours (sub1 (length endPtsOfContours))))) + + (define flags + (reverse + (for/fold ([flags empty]) + ([i (in-naturals)] + #:when (< (length flags) numCoords)) + (define flag (send stream readUInt8)) + + ;; check for repeat flag + (define repeated-flags + (cond + [(not (zero? (bitwise-and flag REPEAT))) + (define count (send stream readUInt8)) + (make-list count flag)] + [else empty])) + + (append repeated-flags (cons flag flags))))) + + (unfinished)) + + (define/public (_decodeComposite glyph stream [offset 0]) + (unfinished))) + + diff --git a/pitfall/sugar/case.rkt b/pitfall/sugar/case.rkt index 752f0a92..44151e53 100644 --- a/pitfall/sugar/case.rkt +++ b/pitfall/sugar/case.rkt @@ -14,4 +14,6 @@ [else (error 'ID (format "no match for ~a" TEST-VAL))])])) ;; like case but strictly uses `eq?` comparison (as opposed to `equal?`) -(define-case-macro caseq memq) \ No newline at end of file +(define-case-macro caseq memq) +(define-case-macro casev memv) +