/*

  Copyright (C) 2015 Apple Inc. All Rights Reserved.

  See LICENSE.txt for this sample’s licensing information

  Abstract:

  Defines basic graphics utilities used throughout Adventure

*/

import SpriteKit

func loadFramesFromAtlasWithName(atlasName: String) -> [SKTexture] {

    let atlas = SKTextureAtlas(named: atlasName)

    return sorted(atlas.textureNames as [String]).map { atlas.textureNamed($0) }

}

func unitRandom() -> CGFloat {

    let quotient = Double(arc4random()) / Double(UInt32.max)

    return CGFloat(quotient)

}

// The assets are all facing Y down, so offset by half pi to get into X right facing

func adjustAssetOrientation(r: CGFloat) -> CGFloat {

    return r + (CGFloat(M_PI) * 0.5)

}

extension CGPoint {

    func distanceToPoint(point: CGPoint) -> CGFloat {

        return hypot(x - point.x, y - point.y)

    }

    func radiansToPoint(point: CGPoint) -> CGFloat {

        var deltaX = point.x - x

        var deltaY = point.y - y

        return atan2(deltaY, deltaX)

    }

}

// Adds the coordinates of the two points together.

func +(lhs: CGPoint, rhs: CGPoint) -> CGPoint {

    return CGPoint(x: lhs.x + rhs.x, y: lhs.y + rhs.y)

}

func runOneShotEmitter(emitter: SKEmitterNode, withDuration duration: CGFloat) {

    let waitAction = SKAction.waitForDuration(NSTimeInterval(duration))

    let birthRateSet = SKAction.runBlock { emitter.particleBirthRate = 0.0 }

    let waitAction2 = SKAction.waitForDuration(NSTimeInterval(emitter.particleLifetime + emitter.particleLifetimeRange))

    let removeAction = SKAction.removeFromParent()

    var sequence = [ waitAction, birthRateSet, waitAction2, removeAction]

    emitter.runAction(SKAction.sequence(sequence))

}