[Bug][Shapes] RoundRectangleGeometry clipping error

[davidbritch]

Description

The RoundRectangleGeometry class has been added to Forms 5.0. However, its not producing the result I'd expect when using it for image clipping:

            <Label Text="Clipped image with RectangleGeometry" />
            <Image Source="monkeyface.png">
                <Image.Clip>
                    <RectangleGeometry Rect="40,100,300,150" />
                </Image.Clip>
            </Image>
            <Label Text="Clipped image with RoundRectangleGeometry" />
            <Image Source="monkeyface.png">
                <Image.Clip>
                    <RoundRectangleGeometry CornerRadius="5"
                                            Rect="40,100,300,150" />
                </Image.Clip>
            </Image>

Note that the two geometries use identical rectangles, with the RoundRectangleGeometry adding a corner radius. I'd therefore expect the two resulting images to be similar. But they aren't:

Steps to Reproduce

1. Run the attached sample.
2. Browse to the "Clipping demos" page.

Expected Behavior

Image clipped with RoundRectangleGeometry is identical to RectangleGeometry clipping, but with rounded corners.

Actual Behavior

Image clipped with RoundRectangleGeometry is not clipped correctly.

Basic Information

• Version with issue: 5.0-pre1
• IDE: VSMac 8.7.8
• Platform Target Frameworks:
  • iOS: 14.0
  • Android: API 29
  • UWP: Not tried but will be a problem.

Reproduction Link

ShapesDemos.zip