How to generate CGPoint-Array out of UIBezierPath (to touch-slide object along given path)
cgpoint, ios, objective-c, uibezierpath
Solution
Use the `CGPathApply()` function to iterate over all elements in a path. As one of the arguments, you have to specify a pointer to a function that will then be called for each path element. The path element data structure (of type `CGPathElement`) then contains the point(s) that describe it.
Use `NSValue` as a wrapper to add the points to an `NSMutableArray`.
Problem
I have a UIBezierPath (curved like an '8', with only 4 points in it) and I need to make some kind of CGPoint-Array out of it. Any ideas? thanx! edit: I have my bezier initlialized like that ``` -(void) initBezier { theBezierPath = [UIBezierPath bezierPath]; [theBezierPath moveToPoint:P(211.00, 31.00)]; [theBezierPath addCurveToPoint:P(870.00, 191.00) controlPoint1:P(432.00, -11.00) controlPoint2:P(593.00, 209.00)]; [theBezierPath addCurveToPoint:P(731.00, 28.00) controlPoint1:P(1061.95, 178.53) controlPoint2:P(944.69, 5.78)]; [theBezierPath addCurveToPoint:P(189.00, 190.00) controlPoint1:P(529.00, 49.00) controlPoint2:P(450.00, 189.00)]; [theBezierPath addCurveToPoint:P(211.00, 31.00) controlPoint1:P(-33.01, 190.85) controlPoint2:P(71.00, 37.00)]; } ``` and I animate an object on it with ``` anim = [CAKeyframeAnimation animationWithKeyPath:@"emitterPosition"]; anim.path = theBezierPath.CGPath; anim.calculationMode = kCAAnimationCubicPaced; anim.repeatCount = HUGE_VALF; anim.duration = tme; ``` I want to animate the object on the path pixel by pixel (via touch-position). I want the object to "snap" a given coordinate of a touch to the nearest point on the curve so it touch-slides the object along the path.