draw: disable the image.Rectangle DstMask fast path until Go 1.5 is
released.
Change-Id: Ie5d6766d53952d3a81dfbd19a9f4022aaad6af5a
Reviewed-on: https://go-review.googlesource.com/9463
Reviewed-by: Rob Pike <r@golang.org>
diff --git a/draw/scale.go b/draw/scale.go
index 07cd20b..4d77764 100644
--- a/draw/scale.go
+++ b/draw/scale.go
@@ -410,9 +410,11 @@
if dstMask == nil {
return adr, nil
}
- if r, ok := dstMask.(image.Rectangle); ok {
- return adr.Intersect(r.Sub(dstMaskP)), nil
- }
+ // TODO: enable this fast path once Go 1.5 is released, where an
+ // image.Rectangle implements image.Image.
+ // if r, ok := dstMask.(image.Rectangle); ok {
+ // return adr.Intersect(r.Sub(dstMaskP)), nil
+ // }
// TODO: clip to dstMask.Bounds() if the color model implies that out-of-bounds means 0 alpha?
return adr, dstMask
}
diff --git a/draw/scale_test.go b/draw/scale_test.go
index d9265a1..cfa38a7 100644
--- a/draw/scale_test.go
+++ b/draw/scale_test.go
@@ -433,7 +433,9 @@
for _, dstMaskP := range dstMaskPs {
dstInside := mk(q, nil, image.Point{})
for _, wrap := range []bool{false, true} {
- dstMask := image.Image(rect)
+ // TODO: replace "rectImage(rect)" with "rect" once Go 1.5 is
+ // released, where an image.Rectangle implements image.Image.
+ dstMask := image.Image(rectImage(rect))
if wrap {
dstMask = srcWrapper{dstMask}
}
@@ -463,6 +465,19 @@
}
}
+// TODO: delete this wrapper type once Go 1.5 is released, where an
+// image.Rectangle implements image.Image.
+type rectImage image.Rectangle
+
+func (r rectImage) ColorModel() color.Model { return color.Alpha16Model }
+func (r rectImage) Bounds() image.Rectangle { return image.Rectangle(r) }
+func (r rectImage) At(x, y int) color.Color {
+ if (image.Point{x, y}).In(image.Rectangle(r)) {
+ return color.Opaque
+ }
+ return color.Transparent
+}
+
// The fooWrapper types wrap the dst or src image to avoid triggering the
// type-specific fast path implementations.
type (
