Trying to animate a circle formation using Swift

Question

I am new to swift animations and would need some help in understanding this.

So say i have the following code which creates a circle based on the input provided.

    func drawCircle(percentage:CGFloat){
//Some circle drawing code and the circle is drawn using the percentage % provided.

}

i call this function with

drawCircle(0.5)

i will get this. enter image description here i call using

drawCircle(0.75)

i will get this. enter image description here So based on the percentage passed i create the circle/semi-circle/ring. Hope i am making some sense.

Now only part i want to animate is the circle formation. So say when i call drawCircle(0.5) it should animate smoothly from 0.0% to 0.5% Currently if i call my method with a timer and pass the parameters sequentially (0.00, 0.1, 0.2 etc to 0.5) it can work. An example: enter image description here

But I don't think it's the right way to do. So what am looking for is if there is a better way to do this using animations in swift where the transition from 0.0 to 0.5 is smooth.

[I don't want to change my existing codes for the circle creation. Its already an existing code base made by someone i am working and it has some time factor and risk to change anything right now on the existing code. Looking for something where the function "drawCircle(%)" can be used to achieve the desired output. Suggestions are always welcome.]

TIA>

Try to pass a small value with short intervals in your timer ex: 0.016 — Manikandan D, Jul 14 '15 at 15:37
Um I would just like to add that your current way of animating it is not very efficient and if you make your intervals very very small it will take so long you'll need a progress bar for your progress bar :) — Darvish Kamalia, Jul 14 '15 at 15:47
You can hook into every single frame of the drawing cycle using `CADisplayLink`. — Christian Schnorr, Jul 14 '15 at 16:20

score 2 · Accepted Answer · edited May 23 '17 at 10:26

2

Look up how to do animations with UIBezierPath and CAShapeLayer. Basically, you need to create a UIBezierPath with the equation for a circle. Then use the strokeEnd property to define how much of the circle should be animated. Here is an answer for reference, albeit in objective-c

Draw circle with UIBezierPath

edited May 23 '17 at 10:26

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answered Jul 14 '15 at 15:37

Darvish Kamalia

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Thanks. Ya thats the only way. Have changed my base code and working great. Thanks for your help. – KD. Jul 15 '15 at 08:12

Trying to animate a circle formation using Swift

1 Answers1