You know how System.Drawing.Rectangle was replaced by System.Windows.Int32Rect? (As far as non-floating-point shapes are concerned ...)
Is there a similar new object for an integer point or size? If not, I'll just use System.Drawing - but that kinda seems like a minor mix of two platforms that ought not to me mixed.
Anyway, what do you think about this?
The drawing primitives in WPF store all measurements/locations values in doubles - apparently all except Int32Rect, as you pointed out. The reasoning behind this design is due to how WPF is not bound directly from pixel-to-display - it uses "device independent pixels" (DIPs) which can be scaled for whatever device on which it is being rendered. This gives WPF the ability to scale and translate everything that it is displaying very easily.
As for System.Windows.Int32Rect, the only place I see it being used inside the API is for capturing and cropping pixels. This makes sense - when doing a screen capture, you're wanting to get exactly the pixels that are currently displayed on the device.