PhysicsSystem

public class PhysicsSystem : PhysicsSolving

A simple physics engine used with PhysicsMotion and PathPhysicsMotion to calculate values for motions. It primarily uses a constant velocity, plus a friction component, to update movements of values over time. As of version 2.2.0 it also supports simple collision handling between two optional fixed start and end points, and a restitution value to control the value’s elasticity when colliding.

  • The velocity value to use in physics calculations.

    Declaration

    Swift

    public var velocity: Double { get set }

  • The friction value between 0.0 and 1.0, to be applied in physics calculations. Provided values outside of that range are clamped to the closest minimum or maximum value. A friction value of 0.0 is actually set internally to slightly above that in order to avoid divide by zero errors.

    Declaration

    Swift

    public var friction: Double { get set }

  • The restitution value from 0.0 to 1.0 which represents the elasticity of the object and used in collision calculations, with 0.0 representing a perfectly inelastic collision (in which the object does not rebound at all during a collision), and 1.0 representing a perfectly elastic collision (in which the object rebounds with no loss of velocity). Provided values outside of that range are clamped to the closest minimum or maximum value. The default value is 0.75.

    Declaration

    Swift

    public var restitution: Double { get set }

  • This Boolean represents whether collision detections are active in the physics simulation. If true, collisions will be checked using the start and end properties of each PropertyData object passed in to the solve(forPositions:timestamp:) method. The default value is false.

    Declaration

    Swift

    public var useCollisionDetection: Bool

  • The last timestamp sent via the solve method.

    Declaration

    Swift

    public internal(set) var lastTimestamp: TimeInterval { get }

  • Boolean value representing whether the physics system is currently paused.

    Declaration

    Swift

    public internal(set) var paused: Bool { get }

Initialization

  • A convenience initializer.

    Declaration

    Swift

    public convenience init(configuration: PhysicsConfiguration)

    Parameters

    configuration

    A configuration model containing data to set up the system to provide physics calculations.

  • Initializer.

    Declaration

    Swift

    public init(velocity: Double, friction: Double, restitution: Double? = nil, useCollisionDetection: Bool? = nil)

    Parameters

    velocity

    The velocity used to calculate new values in physics system. Any values are accepted due to the differing ranges of velocity magnitude required for various motion applications. Experiment to see what suits your needs best.
    friction

    The friction used to calculate new values in the physics system. Acceptable values are 0.0 (almost no friction) to 1.0 (no movement); values outside of this range will be clamped to the nearest edge.
    restitution

    The restitution value from 0.0 to 1.0 which represents the elasticity of the object and used in collision calculations, with 0.0 representing a perfectly inelastic collision (in which the object does not rebound at all during a collision), and 1.0 representing a perfectly elastic collision (in which the object rebounds with no loss of velocity).
    useCollisionDetection

    Determines whether collision detections are checked and acted on with the object being moved. The default value is false.

PhysicsSolving methods