如何在Objective-C中将点转换为弧度? [英] How to convert points to radians in Objective-C?

问题描述

在我的应用中，我正在使用UIBezierPath将圆弧绘制成一个圆.我正在尝试将数字与弧度相关联.因此，假设用户有一定数量的点，并且这些点的上限为100点.我希望100点为360度.我希望圆的前33％为绿色，然后从圆的34％至下一个66％用橙色描边，然后从67％到100％用红色描边.

In my app I'm using UIBezierPath to draw an arc into a circle. I'm trying to correlate a number to radians. So let's say a user has a certain number of points, and the points are capped at 100 points. I want 100 points to be 360 degrees. I want the first 33% of the circle to be green, and then from 34% to the next 66% of the circle to be stroked in orange, and then from 67% to 100% in red.

我在这里遇到的问题是将圆的百分比转换为弧度.创建UIBezier路径时，我需要提供一个startAngle和endAngle，将这些点转换为弧度值时会遇到一些麻烦.

The issue I'm having here is converting percents of a circle to radians. When creating a UIBezier path, I need to provide a startAngle and endAngle, and I'm having a bit of trouble converting these points to radian values.

我将如何解决这个问题?

How would I go about solving this?

谢谢

推荐答案

Objective-C

Objective-C

CGFloat fullCircle = 2 * M_PI ;             // M_PI Pi number which is half of the circle in radian
CGFloat startPoint = 0.0      ;
CGFloat endPoint   = fullCircle * 0.33 ;

// Assuming circling clockwise

// .... Draw first step UIBezierPath

startPoint = endPoint        ;
endPoint = startPoint + fullCircle * 0.33 ;
// .... Draw second step UIBezierPath

startPoint = endPoint        ;
endPoint = fullCircle - startPoint ;       // This to make sure the whole circle will be covered
// .... Draw the last step UIBezierPath

迅速

let fullCircle = 2 * M_PI             // M_PI Pi number which is half of the circle in radian
var startPoint: Float = 0.0
var endPoint: Float = fullCircle * 0.33

// Assuming circling clockwise
// .... Draw first step UIBezierPath

startPoint = endPoint
endPoint = startPoint + fullCircle * 0.33
// .... Draw second step UIBezierPath

startPoint = endPoint
endPoint = fullCircle - startPoint       // This to make sure the whole circle will be covered
// .... Draw the last step UIBezierPath

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