in binding/SkiaSharp/MathTypes.cs [639:650]
public static SKRectI Floor (SKRect value, bool inwards)
{
int x, y, r, b;
checked {
x = (int)(inwards && value.Width > 0 ? Math.Ceiling (value.Left) : Math.Floor (value.Left));
y = (int)(inwards && value.Height > 0 ? Math.Ceiling (value.Top) : Math.Floor (value.Top));
r = (int)(inwards && value.Width < 0 ? Math.Ceiling (value.Right) : Math.Floor (value.Right));
b = (int)(inwards && value.Height < 0 ? Math.Ceiling (value.Bottom) : Math.Floor (value.Bottom));
}
return new SKRectI (x, y, r, b);
}