image/font: make a zero Weight mean a normal weight.
Change-Id: I2000bdf1c49174b9eaefe1c680138392e3434ace
Reviewed-on: https://go-review.googlesource.com/21440
Reviewed-by: David Crawshaw <crawshaw@golang.org>
diff --git a/font/font.go b/font/font.go
index c3041d9..31e48c9 100644
--- a/font/font.go
+++ b/font/font.go
@@ -205,16 +205,21 @@
// Weight selects a normal, light or bold face.
//
// Not all fonts support weights.
+//
+// The named Weight constants (e.g. WeightBold) correspond to CSS' common
+// weight names (e.g. "Bold"), but the numerical values differ, so that in Go,
+// the zero value means to use a normal weight. For the CSS names and values,
+// see https://developer.mozilla.org/en/docs/Web/CSS/font-weight
type Weight int
const (
- WeightThin Weight = 100
- WeightExtraLight Weight = 200
- WeightLight Weight = 300
- WeightNormal Weight = 400
- WeightMedium Weight = 500
- WeightSemiBold Weight = 600
- WeightBold Weight = 700
- WeightExtraBold Weight = 800
- WeightBlack Weight = 900
+ WeightThin Weight = -3 // CSS font-weight value 100.
+ WeightExtraLight Weight = -2 // CSS font-weight value 200.
+ WeightLight Weight = -1 // CSS font-weight value 300.
+ WeightNormal Weight = +0 // CSS font-weight value 400.
+ WeightMedium Weight = +1 // CSS font-weight value 500.
+ WeightSemiBold Weight = +2 // CSS font-weight value 600.
+ WeightBold Weight = +3 // CSS font-weight value 700.
+ WeightExtraBold Weight = +4 // CSS font-weight value 800.
+ WeightBlack Weight = +5 // CSS font-weight value 900.
)
