CGExtensions

A Swift collection of useful extensions to CGFloat, CGPoint, CGVector, and CGGradient, plus test suites. If you need 2-dimensional vectors then you'll want this.

IMPORTANT

2016.12.03: This project has been deprecated and replaced by separate libraries compatible with Swift 3.0. Please refer to WTOpenSource.

Latest

2015.05.05: Added an extension to CGGradient to make it easier to create gradients from UIColor and corresponding location arrays. The extension defines the static method

static func gradientWithColors(colors: [UIColor], atLocations locations: [CGFloat],
        colorSpace: CGColorSpace = CGColorSpaceCreateDeviceRGB()) -> CGGradient

The location array doesn't even need to be in ascending order of its values nor do those values need to be in the range [0,1]. That's all taken care of automatically. Note that the colorSpace parameter is optional, with a default value appropriate for iOS devices.

Why?

If you look at the definition of CGFloat, you'll find quite a few init methods, some properties, and some extensions but if you look at CGPoint and CGVector you'll see that they leave much to be desired. In fact, if you do any two-dimensional game development then you know that CGVector - as defined - is no vector at all!

    /* Points. */

    struct CGPoint {
        var x: CGFloat
        var y: CGFloat
        init()
        init(x: CGFloat, y: CGFloat)
    }

    extension CGPoint {
        static var zeroPoint: CGPoint { get }
        init(x: Int, y: Int)
        init(x: Double, y: Double)
    }

    extension CGPoint : Equatable {
    }

    extension CGPoint : Reflectable {

        /// Returns a mirror that reflects `self`.
        func getMirror() -> MirrorType
    }

    /* Vectors. */

    var CGVECTOR_DEFINED: Int32 { get }

    struct CGVector {
        var dx: CGFloat
        var dy: CGFloat
        init()
        init(dx: CGFloat, dy: CGFloat)
    }

    extension CGVector {
        static var zeroVector: CGVector { get }
        init(dx: Int, dy: Int)
        init(dx: Double, dy: Double)
    }

    extension CGVector : Equatable {
    }

Well, not anymore. I've put together a comprehensive suite of methods for 2d vector manipulations, everything from addition of a vector to a point, to dot and cross products, to rotations. And, best of all, these have been extensively tested, as the accompanying test suites will attest.

How to install:

Just copy the source file CGExtensions.swift into your project. That's it. No frameworks.

Requirements:

I wrote this using an earlier version of XCode and Swift but I've now verified that these work fine with Xcode 6.3 (6D570) and Swift 1.2.

Test app:

There's no test app but there are test suites.

Creator

That would be me, Wagner Truppel. If you need or want to contact me, send a message to wagner at restlessbrain dot com.

License:

I'm sharing this work under the MIT License. See the LICENSE file for more information.