op/paint: document ImageOp gotcha

Signed-off-by: Elias Naur <mail@eliasnaur.com>
theclapp · May 14, 2020 · 29c9b06 · 29c9b06
1 parent b7ba809
commit 29c9b06
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/op/paint/paint.go b/op/paint/paint.go
@@ -15,6 +15,9 @@ import (
 )
 
 // ImageOp sets the brush to an image.
+//
+// Note: the ImageOp may keep a reference to the backing image.
+// See NewImageOp for details.
 type ImageOp struct {
 	// Rect is the section if the backing image to use.
 	Rect image.Rectangle