如何使用 「getControlPoint（IDX處：詮釋，值PTR：UnsafeMutablePointer <Float>！）」 CAMediaTimingFunction

Question

我這個用戶功能OC與此

CAMediaTimingFunction *function = [CAMediaTimingFunction functionWithName: 
            kCAMediaTimingFunctionDefault]; 
//get control points 
CGPoint controlPoint1, controlPoint2; 
[function getControlPointAtIndex:1 values:(float *)&controlPoint1]; 
[function getControlPointAtIndex:2 values:(float *)&controlPoint2]; 

NSLog(@"%@, %@", NSStringFromCGPoint(controlPoint1), NSStringFromCGPoint(controlPoint2)); 
//{5.2386907149499368e-11, 7.9050503334599447e-323}, {0.0078125018189894035, 4.9406564584124654e-324} 

但如何將其轉換爲swift3.1，我做這個，但是錯了！

let timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionDefault) 

var point1 = Float(0.0), point2 = Float(0.0) 

timingFunction.getControlPoint(at: 1, values: &point1) 
timingFunction.getControlPoint(at: 2, values: &point2) 
print("\(String(describing: point1)),\(String(describing: point2))") 
// 0.25,0.25 

如何解決？我需要一些幫助。注意代碼打印。

Answer 1

let timingFunction = CAMediaTimingFunction(name: kCAMediaTimingFunctionDefault) 

    var point1: [Float] = [0.0,0.0] 
    var point2: [Float] = [0.0,0.0] 

    timingFunction.getControlPoint(at: 1, values: &point1) 
    timingFunction.getControlPoint(at: 2, values: &point2) 

    print("\(String(describing: point1)),\(String(describing: point2))") 

這是正確的轉換。