/***
* Expand `rect' to the smallest standardized rect containing it with pixel-aligned origin and size.
* If @c scale is zero, then a scale of 1 will be used instead.
*
* @param rect the rectangle to align.
* @param scale the scale factor to use for pixel alignment.
*
* @return the input rectangle aligned to the nearest pixels using the provided scale factor.
*
* @see CGRectIntegral
*/
public static CGRect MDCRectAlignToScale(CGRect rect, nfloat scale)
{
if (rect.IsNull())
{
return(CGRect.Null);
}
if (MDCCGFloatEqual(scale, 0))
{
scale = 1;
}
if (MDCCGFloatEqual(scale, 1))
{
return(rect.Integral());
}
CGPoint originalMinimumPoint = new CGPoint(rect.GetMinX(), rect.GetMinY());
CGPoint newOrigin = new CGPoint(MDCFloor(originalMinimumPoint.X * scale) / scale,
MDCFloor(originalMinimumPoint.Y * scale) / scale);
CGSize adjustWidthHeight =
new CGSize(originalMinimumPoint.X - newOrigin.X, originalMinimumPoint.Y - newOrigin.Y);
return(new CGRect(newOrigin.X, newOrigin.Y,
MDCCeil((rect.Width + adjustWidthHeight.Width) * scale) / scale,
MDCCeil((rect.Height + adjustWidthHeight.Height) * scale) / scale));
}
public override bool FinishedLaunching (UIApplication application, NSDictionary launchOptions)
{
// Two disjoint rects
var r1 = new CGRect (50, 50, 10, 10);
var r2 = new CGRect (100, 100, 10, 10);
// This condradicts with Apple's doc – https://developer.apple.com/reference/coregraphics/cgrectnull
// The null rectangle. This is the rectangle returned when, for example, you intersect two disjoint rectangles.
// Note that the null rectangle is not the same as the zero rectangle.
// For example, the union of a rectangle with the null rectangle is the original rectangle (that is, the null rectangle contributes nothing).
var tmp = r1;
tmp.Intersect (r2); // this is mutable method
Console.WriteLine (tmp.IsNull ()); // Expected true, but result is false
tmp = CGRectIntersection (r1, r2);
Console.WriteLine (tmp.IsNull ()); // Expected true, actual true
// This should be CGRectNull
var rectNull = new CGRect (nfloat.PositiveInfinity, nfloat.PositiveInfinity, 0, 0);
Console.WriteLine (rectNull.IsNull ()); // Expected true, actual true
// CGRectEmpty and CGRectNull are different
var union1 = r1.UnionWith (CGRect.Empty); // new rect {0, 0, 60, 60}
Console.WriteLine (union1);
var union2 = r1.UnionWith (rectNull); // r1
Console.WriteLine (union2);
return true;
}
/***
* Align the centerPoint of a view so that its origin is pixel-aligned to the nearest pixel.
* Returns @c CGRectZero if @c scale is zero or @c bounds is @c CGRectNull.
*
* @param center the unaligned center of the view.
* @param bounds the bounds of the view.
* @param scale the native scaling factor for pixel alignment.
*
* @return the center point of the view such that its origin will be pixel-aligned.
*/
public static CGPoint MDCRoundCenterWithBoundsAndScale(CGPoint center,
CGRect bounds,
nfloat scale)
{
if (MDCCGFloatEqual(scale, 0) || bounds.IsNull())
{
return(CGPoint.Empty);
}
nfloat halfWidth = bounds.Width / 2;
nfloat halfHeight = bounds.Height / 2;
CGPoint origin = new CGPoint(center.X - halfWidth, center.Y - halfHeight);
origin = MDCPointRoundWithScale(origin, scale);
return(new CGPoint(origin.X + halfWidth, origin.Y + halfHeight));
}
