A Swift collection of useful extensions to CGPoint, CGVector, and CGGradient.
If you need 2-dimensional vectors then you'll probably like this library.
If you look at the definitions of 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!
public struct CGPoint
{
public var x: CGFloat
public var y: CGFloat
public init()
public init(x: CGFloat, y: CGFloat)
}
extension CGPoint
{
public static var zero: CGPoint { get }
public init(x: Int, y: Int)
public init(x: Double, y: Double)
public init?(dictionaryRepresentation dict: CFDictionary)
}
extension CGPoint : Equatable {}
public struct CGVector
{
public var dx: CGFloat
public var dy: CGFloat
public init()
public init(dx: CGFloat, dy: CGFloat)
}
extension CGVector
{
public static var zero: CGVector { get }
public init(dx: Int, dy: Int)
public init(dx: Double, dy: Double)
}
extension CGVector : Equatable {}Well, not anymore. I've put together a comprehensive suite of methods for two-dimensional vector manipulations, everything from addition of a vector to a point, to dot and cross products, to rotations, to finding projections, all extensively tested.
Here is the full list of API additions to these types:
public enum WTCoreGraphicsExtensionsError : Error
{
case negativeTolerance
case negativeMagnitude
case notNormalizable
case divisionByZero
}
public extension CGFloat
{
static public let tolerance: CGFloat
}
public extension CGPoint
{
public init(x: Float, y: Float)
public static func random(_ a: CGFloat, _ b: CGFloat) -> CGPoint
public func isNearlyEqual(to other: CGPoint, tolerance: CGFloat = default) throws -> Bool
public func isNearlyZero(tolerance: CGFloat = default) throws -> Bool
public func distance(to other: CGPoint) -> CGFloat
public func distanceSquared(to other: CGPoint) -> CGFloat
public func manhattanDistance(to other: CGPoint) -> CGFloat
public func vector(to other: CGPoint) -> CGVector
public func vector(from other: CGPoint) -> CGVector
public static func vector(from point1: CGPoint, to point2: CGPoint) -> CGVector
public static func +(lhs: CGPoint, rhs: CGVector) -> CGPoint
public static func -(lhs: CGPoint, rhs: CGVector) -> CGPoint
public static func -(lhs: CGPoint, rhs: CGPoint) -> CGVector
public static func +=(lhs: inout CGPoint, rhs: CGVector)
public static func -=(lhs: inout CGPoint, rhs: CGVector)
}
extension CGPoint : Hashable
{
public var hashValue: Int { get }
}
public extension CGVector
{
public init(dx: Float, dy: Float)
public init(from p1: CGPoint, to p2: CGPoint)
public init(magnitude m: CGFloat, angle a: CGFloat) throws
public init(magnitude m: CGFloat, sine sina: CGFloat, cosine cosa: CGFloat) throws
public static func random(_ a: CGFloat, _ b: CGFloat) -> CGVector
public static var unitVectorX: CGVector { get }
public static var unitVectorY: CGVector { get }
public func isNearlyEqual(to other: CGVector, tolerance: CGFloat = default) throws -> Bool
public func isNearlyZero(tolerance: CGFloat = default) throws -> Bool
public var magnitude: CGFloat { get }
public var magnitudeSquared: CGFloat { get }
public var manhattanMagnitude: CGFloat { get }
public var isNormalizable: Bool { get }
public mutating func normalize() throws
public var normalized: CGVector? { get }
public mutating func scaleMagnitude(to value: CGFloat) throws
public func magnitudeScaled(to value: CGFloat) -> CGVector?
public mutating func scaleMagnitudeDownToIfLarger(than maxValue: CGFloat) throws
public func magnitudeScaledDownToIfLarger(than maxValue: CGFloat) throws -> CGVector
public mutating func scaleMagnitudeUpToIfSmaller(than minValue: CGFloat) throws
public func magnitudeScaledUpToIfSmaller(than minValue: CGFloat) throws -> CGVector
public func dot(with other: CGVector) -> CGFloat
public func cross(with other: CGVector) -> CGFloat
public var angleFromXAxis: CGFloat { get }
public var sinAngleFromXAxis: CGFloat { get }
public var cosAngleFromXAxis: CGFloat { get }
public var tanAngleFromXAxis: CGFloat { get }
public func smallestAngle(with other: CGVector) -> CGFloat
public func projectionParallel(to other: CGVector) -> CGVector
public func isNearlyParallel(to other: CGVector, tolerance: CGFloat = default) throws -> Bool
public func projectionPerpendicular(to other: CGVector) -> CGVector
public func isNearlyPerpendicular(to other: CGVector, tolerance: CGFloat = default) throws -> Bool
public mutating func rotateClockwise(by angle: CGFloat)
public func rotatedClockwise(by angle: CGFloat) -> CGVector
public mutating func rotateClockwise(sine sina: CGFloat, cosine cosa: CGFloat)
public func rotatedClockwise(sine sina: CGFloat, cosine cosa: CGFloat) -> CGVector
public mutating func rotateCounterClockwise(by angle: CGFloat)
public func rotatedCounterClockwise(by angle: CGFloat) -> CGVector
public mutating func rotateCounterClockwise(sine sina: CGFloat, cosine cosa: CGFloat)
public func rotatedCounterClockwise(sine sina: CGFloat, cosine cosa: CGFloat) -> CGVector
public static func +(lhs: CGVector, rhs: CGVector) -> CGVector
public static func -(lhs: CGVector, rhs: CGVector) -> CGVector
public static func *(lhs: CGFloat, rhs: CGVector) -> CGVector
public static func *(lhs: CGVector, rhs: CGFloat) -> CGVector
public static func /(lhs: CGVector, rhs: CGFloat) throws -> CGVector
public prefix static func -(vector: CGVector) -> CGVector
public static func +=(lhs: inout CGVector, rhs: CGVector)
public static func -=(lhs: inout CGVector, rhs: CGVector)
public static func *=(lhs: inout CGVector, rhs: CGFloat)
public static func /=(lhs: inout CGVector, rhs: CGFloat) throws
}
extension CGVector : Hashable
{
public var hashValue: Int { get }
}
public extension CGGradient
{
public enum CGGradientError : Error
{
case mismatchedColorAndLocationArraySizes
case invalidNumberOfColorLocationPairs
case invalidColorLocations
}
public static func rgbaGradient(with colors: [UIColor],
at locations: @autoclosure @escaping [CGFloat]) throws -> CGGradient?
}WTCoreGraphicsExtensions adds 68 properties and functions, all tested by 138 tests with over 92%
coverage. The missing 8% test-coverage is due to the fact that CGGradient is a very opaque type so once
rgbaGradient(with:at:) creates it, there's nothing that can be extracted from it to compare with in a test.
WTCoreGraphicsExtensions depends on two of my other libraries:
Changes to WTCoreGraphicsExtensions are listed here.
WTCoreGraphicsExtensions is available through CocoaPods. To install it, simply add the following line to your Podfile:
pod "WTCoreGraphicsExtensions"WTCoreGraphicsExtensions is available under the MIT license. See the LICENSE file for more info.