image: fix build

accidentally deleted one method
TBR=rsc

R=rsc
CC=golang-dev
https://golang.org/cl/4438090

diff --git a/src/pkg/image/image.go b/src/pkg/image/image.go
index 9f205c1701c71b2df117819faf227f69df3ba1ac..222d21adefde3caeeb82744c7122b0f0cfc805a1 100644 (file)
--- a/src/pkg/image/image.go
+++ b/src/pkg/image/image.go
@@ -280,6 +280,13 @@ func (p *Alpha) At(x, y int) Color {
        return p.Pix[y*p.Stride+x]
 }
 
+func (p *Alpha) Set(x, y int, c AlphaColor) {
+       if !p.Rect.Contains(Point{x, y}) {
+               return
+       }
+       p.Pix[y*p.Stride+x] = toAlphaColor(c).(AlphaColor)
+}
+
 func (p *Alpha) SetAlpha(x, y int, c AlphaColor) {
        if !p.Rect.Contains(Point{x, y}) {
                return