op/clip: move Rect to shapes.go

It's a specialized shape like the others.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

op/clip/clip.go

@@ -387,19 +387,3 @@ func (o Outline) Op() Op {
 		outline: true,
 	}
 }
-
-// Rect represents the clip area of a pixel-aligned rectangle.
-type Rect image.Rectangle
-
-// Op returns the op for the rectangle.
-func (r Rect) Op() Op {
-	return Op{
-		bounds:  image.Rectangle(r),
-		outline: true,
-	}
-}
-
-// Add the clip operation.
-func (r Rect) Add(ops *op.Ops) {
-	r.Op().Add(ops)
-}