font/sfnt: use charmap EncodeRune API.
Change-Id: I91d850d1816b43748580f6f8a8f19151472750d0
Reviewed-on: https://go-review.googlesource.com/39070
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>
Run-TryBot: Nigel Tao <nigeltao@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/font/sfnt/cmap.go b/font/sfnt/cmap.go
index 42338f1..797e9d1 100644
--- a/font/sfnt/cmap.go
+++ b/font/sfnt/cmap.go
@@ -5,8 +5,6 @@
package sfnt
import (
- "unicode/utf8"
-
"golang.org/x/text/encoding/charmap"
)
@@ -112,20 +110,12 @@
var table [256]byte
copy(table[:], buf[6:])
return buf, func(f *Font, b *Buffer, r rune) (GlyphIndex, error) {
- // TODO: for this closure to be goroutine-safe, the
- // golang.org/x/text/encoding/charmap API needs to allocate a new
- // Encoder and new []byte buffers, for every call to this closure, even
- // though all we want to do is to encode one rune as one byte. We could
- // possibly add some fields in the Buffer struct to re-use these
- // allocations, but a better solution is to improve the charmap API.
- var dst, src [utf8.UTFMax]byte
- n := utf8.EncodeRune(src[:], r)
- _, _, err = charmap.Macintosh.NewEncoder().Transform(dst[:], src[:n], true)
- if err != nil {
+ x, ok := charmap.Macintosh.EncodeRune(r)
+ if !ok {
// The source rune r is not representable in the Macintosh-Roman encoding.
return 0, nil
}
- return GlyphIndex(table[dst[0]]), nil
+ return GlyphIndex(table[x]), nil
}, nil
}
