font/sfnt: support post table version 1.0
Currently, the library produces a parsing error when the font
contains a PostScript table of version 1.0.
CL adds this version to the validation code and implements a glyph
name lookup for it.
Change-Id: Id4999d8b252e5c2d8e897f637ba31270336cfe9a
Reviewed-on: https://go-review.googlesource.com/c/146080
Reviewed-by: Nigel Tao <nigeltao@golang.org>
diff --git a/font/sfnt/sfnt.go b/font/sfnt/sfnt.go
index 7a8effd..3109815 100644
--- a/font/sfnt/sfnt.go
+++ b/font/sfnt/sfnt.go
@@ -1165,6 +1165,8 @@
return nil, 0, err
}
switch u {
+ case 0x10000:
+ // No-op.
case 0x20000:
if f.post.length < headerSize+2+2*uint32(numGlyphs) {
return nil, 0, errInvalidPostTable
@@ -1299,30 +1301,20 @@
return b.segments, nil
}
-// GlyphName returns the name of the x'th glyph.
-//
-// Not every font contains glyph names. If not present, GlyphName will return
-// ("", nil).
-//
-// If present, the glyph name, provided by the font, is assumed to follow the
-// Adobe Glyph List Specification:
-// https://github.com/adobe-type-tools/agl-specification/blob/master/README.md
-//
-// This is also known as the "Adobe Glyph Naming convention", the "Adobe
-// document [for] Unicode and Glyph Names" or "PostScript glyph names".
-//
-// It returns ErrNotFound if the glyph index is out of range.
-func (f *Font) GlyphName(b *Buffer, x GlyphIndex) (string, error) {
- if int(x) >= f.NumGlyphs() {
+func (f *Font) glyphNameFormat10(x GlyphIndex) (string, error) {
+ if x >= numBuiltInPostNames {
return "", ErrNotFound
}
- if f.cached.postTableVersion != 0x20000 {
- return "", nil
- }
+ // https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6post.html
+ i := builtInPostNamesOffsets[x+0]
+ j := builtInPostNamesOffsets[x+1]
+ return builtInPostNamesData[i:j], nil
+}
+
+func (f *Font) glyphNameFormat20(b *Buffer, x GlyphIndex) (string, error) {
if b == nil {
b = &Buffer{}
}
-
// The wire format for a Version 2 post table is documented at:
// https://www.microsoft.com/typography/otspec/post.htm
const glyphNameIndexOffset = 34
@@ -1371,6 +1363,33 @@
}
}
+// GlyphName returns the name of the x'th glyph.
+//
+// Not every font contains glyph names. If not present, GlyphName will return
+// ("", nil).
+//
+// If present, the glyph name, provided by the font, is assumed to follow the
+// Adobe Glyph List Specification:
+// https://github.com/adobe-type-tools/agl-specification/blob/master/README.md
+//
+// This is also known as the "Adobe Glyph Naming convention", the "Adobe
+// document [for] Unicode and Glyph Names" or "PostScript glyph names".
+//
+// It returns ErrNotFound if the glyph index is out of range.
+func (f *Font) GlyphName(b *Buffer, x GlyphIndex) (string, error) {
+ if int(x) >= f.NumGlyphs() {
+ return "", ErrNotFound
+ }
+ switch f.cached.postTableVersion {
+ case 0x10000:
+ return f.glyphNameFormat10(x)
+ case 0x20000:
+ return f.glyphNameFormat20(b, x)
+ default:
+ return "", nil
+ }
+}
+
// GlyphAdvance returns the advance width for the x'th glyph. ppem is the
// number of pixels in 1 em.
//
