6b476b7 · metal-metaballs

PixelImage.xcodeproj/project.pbxproj+15

@@ -249,6 +249,7 @@

249249 242686821C63B72A00D62456 /* Resources */,

250250 C7A2DF67265A9D17DEFBD193 /* Embed Pods Frameworks */,

251251 FADC01F75BFAC01F0260D1C9 /* Copy Pods Resources */,

252+ DD0396CE594E3EAC8D18CC6C /* Tailor */,

252253 );

253254 buildRules = (

254255 );

@@ -322,6 +323,20 @@

322323 shellScript = "\"${SRCROOT}/Pods/Target Support Files/Pods-PixelImage/Pods-PixelImage-frameworks.sh\"\n";

323324 showEnvVarsInLog = 0;

324325 };

326+ DD0396CE594E3EAC8D18CC6C /* Tailor */ = {

327+ isa = PBXShellScriptBuildPhase;

328+ buildActionMask = 2147483647;

329+ files = (

330+ );

331+ inputPaths = (

332+ );

333+ name = Tailor;

334+ outputPaths = (

335+ );

336+ runOnlyForDeploymentPostprocessing = 0;

337+ shellPath = /bin/sh;

338+ shellScript = "if hash tailor 2>/dev/null; then\n tailor --except=function-whitespace,leading-whitespace,constant-k-prefix --max-severity error\nelse\n echo \"warning: Please install Tailor from https://tailor.sh\"\nfi";

339+ };

325340 EF55C7246917A184756D93D8 /* Check Pods Manifest.lock */ = {

326341 isa = PBXShellScriptBuildPhase;

327342 buildActionMask = 2147483647;

PixelImage.xcworkspace/xcuserdata/vini.xcuserdatad/UserInterfaceState.xcuserstate

Binary file not shown.

PixelImage/AppDelegate.swift−4

@@ -13,7 +13,6 @@ class AppDelegate: UIResponder, UIApplicationDelegate {

1313

1414 var window: UIWindow?

1515

16−

1716 func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

1817 // Override point for customization after application launch.

1918 return true

@@ -40,7 +39,4 @@ class AppDelegate: UIResponder, UIApplicationDelegate {

4039 func applicationWillTerminate(application: UIApplication) {

4140 // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.

4241 }

43−

44−

4542}

46−

PixelImage/Interpolation.swift−2

@@ -1,4 +1,3 @@

1−

21func interpolateCubeEaseIn<T: Numeric>(linear: T) -> T {

32 return linear ^ 3

43}

@@ -14,4 +13,3 @@ func interpolateSquareEaseOut<T: Numeric>(linear: T) -> T {

1413func interpolateSmooth<T: Numeric>(linear: T) -> T {

1514 return ((linear) * (linear) * (linear) * ((linear) * ((linear) * 6 - 15) + 10))

1615}

17−

PixelImage/Matrix.swift+1−1

@@ -1,4 +1,3 @@

1−

21import UIKit

32

43class Graph<T> {

@@ -27,6 +26,7 @@ class Graph<T> {

2726 adjacencyMatrix.reset(i, j)

2827 adjacencyMatrix.reset(j, i)

2928 }

29+

3030}

3131

3232struct Matrix: CustomStringConvertible {

PixelImage/MetaballDataSource.swift+2−2

@@ -1,4 +1,3 @@

1−

21import Metal

32

43protocol MetaballDataSource {

@@ -11,4 +10,5 @@ extension MetaballDataSource {

1110 return metaballGraph.vertices

1211 }

1312 }

14−}

13+

14+}

PixelImage/Metal.swift+1−1

@@ -40,4 +40,4 @@ class MTLComputeContext {

4040 deinit {

4141 free(imageBuffer)

4242 }

43−}

43+}

PixelImage/MetalMetaballRenderer.swift+25−27

@@ -39,8 +39,7 @@ class MetalMetaballRenderer {

3939

4040 let width = Int(frame.width)

4141 let height = Int(frame.height)

42− let textureDescriptor =

43− MTLTextureDescriptor.texture2DDescriptorWithPixelFormat(.BGRA8Unorm, width: width, height: height, mipmapped: false)

42+ let textureDescriptor = MTLTextureDescriptor.texture2DDescriptorWithPixelFormat(.BGRA8Unorm, width: width, height: height, mipmapped: false)

4443

4544 let texture1 = context.device.newTextureWithDescriptor(textureDescriptor)

4645 activeComputeContext = MTLComputeContext(size: targetView.size, texture: texture1)

@@ -55,7 +54,8 @@ class MetalMetaballRenderer {

5554

5655 state = .Ending

5756

58− dispatch_async(dispatch_get_global_queue(Int(QOS_CLASS_USER_INTERACTIVE.rawValue), 0)) { () -> Void in

57+ let userInteractiveQueue = dispatch_get_global_queue(Int(QOS_CLASS_USER_INTERACTIVE.rawValue), 0)

58+ dispatch_async(userInteractiveQueue) { () -> Void in

5959

6060 let computeContext = self.activeComputeContext

6161 swap(&self.activeComputeContext, &self.idleComputeContext)

@@ -74,10 +74,10 @@ class MetalMetaballRenderer {

7474

7575 dispatch_semaphore_signal(self.semaphore)

7676

77− dispatch_async(dispatch_get_main_queue(), { () -> Void in

77+ dispatch_async(dispatch_get_main_queue()) { () -> Void in

7878 // Send image to view

7979 self.targetView.image = uiimage

80− })

80+ }

8181 }

8282 }

8383

@@ -94,8 +94,7 @@ class MetalMetaballRenderer {

9494

9595 // Configure info for computing

9696 let threadGroupCounts = MTLSizeMake(8, 8, 1)

97− let threadGroups = MTLSizeMake(width / threadGroupCounts.width,

98− height / threadGroupCounts.height, 1)

97+ let threadGroups = MTLSizeMake(width / threadGroupCounts.width, height / threadGroupCounts.height, 1)

9998

10099 // Send commands to metal and render

101100 let commandBuffer = context.commandQueue.commandBuffer()

@@ -113,7 +112,6 @@ class MetalMetaballRenderer {

113112

114113 commandBuffer.commit()

115114 commandBuffer.waitUntilCompleted()

116−

117115 } catch _ {

118116 print("Error!")

119117 }

@@ -123,8 +121,7 @@ class MetalMetaballRenderer {

123121 let texture = computeContext.texture

124122

125123 // Get image info

126− let imageSize = CGSizeMake(CGFloat(texture.width),

127− CGFloat(texture.height))

124+ let imageSize = CGSizeMake(CGFloat(texture.width), CGFloat(texture.height))

128125 let width = Int(imageSize.width)

129126 let height = Int(imageSize.height)

130127 let imageByteCount = width * height * 4

@@ -137,27 +134,20 @@ class MetalMetaballRenderer {

137134 }

138135

139136 // Transfer texture info into image buffer

140− texture.getBytes(computeContext.imageBuffer, bytesPerRow: bytesPerRow,

141− fromRegion: region, mipmapLevel: 0)

137+ texture.getBytes(computeContext.imageBuffer, bytesPerRow: bytesPerRow, fromRegion: region, mipmapLevel: 0)

142138

143139 // Get info for UIImage

144− let provider = CGDataProviderCreateWithData(nil, computeContext.imageBuffer,

145− imageByteCount, nil)

140+ let provider = CGDataProviderCreateWithData(nil, computeContext.imageBuffer, imageByteCount, nil)

146141 let bitsPerComponent = 8

147142 let bitsperPixel = 32

148143 let colorSpaceRef = CGColorSpaceCreateDeviceRGB()

149− let bitmapInfo = CGBitmapInfo(rawValue:

150− CGImageAlphaInfo.PremultipliedLast.rawValue |

151− CGBitmapInfo.ByteOrder32Big.rawValue)

144+ let bitmapInfoRaw = CGImageAlphaInfo.PremultipliedLast.rawValue | CGBitmapInfo.ByteOrder32Big.rawValue

145+ let bitmapInfo = CGBitmapInfo(rawValue: bitmapInfoRaw)

152146 let renderingIntent = CGColorRenderingIntent.RenderingIntentDefault

153147

154148 // Create UIImage from image buffer

155− let imageRef = CGImageCreate(width, height,

156− bitsPerComponent, bitsperPixel, bytesPerRow,

157− colorSpaceRef, bitmapInfo, provider,

158− nil, false, renderingIntent)

159− let image = UIImage(CGImage: imageRef!, scale: 0.0,

160− orientation: UIImageOrientation.Up)

149+ let imageRef = CGImageCreate(width, height, bitsPerComponent, bitsperPixel, bytesPerRow, colorSpaceRef, bitmapInfo, provider, nil, false, renderingIntent)

150+ let image = UIImage(CGImage: imageRef!, scale: 0.0, orientation: .Up)

161151

162152 return image

163153 }

@@ -165,7 +155,9 @@ class MetalMetaballRenderer {

165155 func metaballEdgesBuffer() -> MTLBuffer {

166156 let floats = dataSource.metaballGraph.adjacencyMatrix.buffer

167157

168− let buffer = context.device.newBufferWithBytes(floats, length: floats.count * sizeof(Float), options: .StorageModeShared)

158+ let bufferLength = floats.count * sizeof(Float)

159+ let device = context.device

160+ let buffer = device.newBufferWithBytes(floats, length: bufferLength, options: .StorageModeShared)

169161

170162 return buffer

171163 }

@@ -175,7 +167,11 @@ class MetalMetaballRenderer {

175167 // Exclude metaballs far from the view's bounds

176168 let border: CGFloat = 100

177169 let metaballs = self.dataSource.metaballs

178− var floats: [Float] = metaballs.reduce([Float](count: 5, repeatedValue: 0)) { (var array, metaball) -> [Float] in

170+

171+ var floats = [Float](count: 5, repeatedValue: 0)

172+ floats = metaballs.reduce(floats) {

173+ (var array, metaball) -> [Float] in

174+

179175 let x = CGFloat(metaball.midX)

180176 let y = CGFloat(metaball.midY)

181177 if -border < x ≤ targetView.width + border &&

@@ -196,8 +192,10 @@ class MetalMetaballRenderer {

196192 floats[0] = Float(floats.count) / 5

197193

198194 // Create buffer

199− let buffer = context.device.newBufferWithBytes(floats, length: floats.count * sizeof(Float), options: .StorageModeShared)

200−

195+ let bufferLength = floats.count * sizeof(Float)

196+ let device = context.device

197+ let buffer = device.newBufferWithBytes(floats, length: bufferLength, options: .StorageModeShared)

198+

201199 return buffer

202200 }

203201}

PixelImage/SwiftSugar/Dictionary.swift+1−1

@@ -1,7 +1,7 @@

11extension Dictionary {

22 subscript(keys: [Key]) -> [Value] {

33 get {

4− return keys.unwrappedMap({ self[$0] })

4+ return keys.unwrappedMap { self[$0] }

55 }

66 set (values) {

77 for (key, value) in zip(keys, values) {

PixelImage/SwiftSugar/Foundation/NSNumber.swift+4−1

@@ -2,10 +2,13 @@ import Foundation

22

33extension NSNumber: DoubleValuable {

44 var toDouble: Double {

5− get { return self.doubleValue }

5+ get {

6+ return self.doubleValue

7+ }

68 }

79

810 static func fromDouble(double: Double) -> Self {

911 return self.init(double: double)

1012 }

13+

1114}

PixelImage/SwiftSugar/Numeric.swift+15−4

@@ -20,43 +20,54 @@ protocol Numeric: DoubleValuable, Incrementable, Comparable,

2020 postfix func ++ (inout _: Self) -> Self

2121}

2222

23−protocol FastNumeric: Numeric { }

23+protocol FastNumeric: Numeric {}

2424

2525extension Double: FastNumeric {

2626 var toDouble: Double {

27− get { return self }

27+ get {

28+ return self

29+ }

2830 }

2931

3032 static func fromDouble(double: Double) -> Double {

3133 return double

3234 }

35+

3336}

3437

3538extension Float: FastNumeric {

3639 var toDouble: Double {

37− get { return Double(self) }

40+ get {

41+ return Double(self)

42+ }

3843 }

3944

4045 static func fromDouble(double: Double) -> Float {

4146 return Float(double)

4247 }

48+

4349}

4450

4551extension Int: FastNumeric {

4652 var toDouble: Double {

47− get { return Double(self) }

53+ get {

54+ return Double(self)

55+ }

4856 }

4957

5058 static func fromDouble(double: Double) -> Int {

5159 return Int(double)

5260 }

61+

5362}

5463

5564//

5665extension Int {

66+

5767 func times(@noescape block: () throws -> ()) rethrows {

5868 for _ in 1...self {

5969 try block()

6070 }

6171 }

72+

6273}

PixelImage/SwiftSugar/PowerOperator.swift+1−1

@@ -2,7 +2,7 @@ import Darwin

22

33infix operator ^ { associativity right precedence 131 }

44

5−func ^<T: DoubleValuable>(left: T, right: T) -> T {

5+func ^ <T: DoubleValuable>(left: T, right: T) -> T {

66 return T.fromDouble(pow(left.toDouble, right.toDouble))

77}

88

PixelImage/SwiftSugar/Sequences/Memoize.swift+51−46

@@ -7,62 +7,66 @@ protocol MemoizedSequence: LazySequenceType {

77 memoizedFunction: (IndexType -> ReturnType))

88}

99

10+struct HashMemoizedSequence<IndexType: Hashable, ReturnType>:

11+ MemoizedSequence {

1012

11−struct HashMemoizedSequence <IndexType: Hashable, ReturnType>:

12−MemoizedSequence {

13+ let memoizedFunction: (IndexType -> ReturnType)

14+ let increment: ((inout IndexType) -> Void)

15+ let firstIndex: IndexType

1316

14− let memoizedFunction: (IndexType -> ReturnType)

15− let increment: ((inout IndexType) -> Void)

16− let firstIndex: IndexType

17+ var index: IndexType

1718

18− var index: IndexType

19+ init(first: IndexType,

20+ incrementer: ((inout IndexType) -> Void),

21+ memoizedFunction: (IndexType -> ReturnType)) {

1922

20− init(first: IndexType,

21− incrementer: ((inout IndexType) -> Void),

22− memoizedFunction: (IndexType -> ReturnType)) {

23+ self.firstIndex = first

2324

24− self.firstIndex = first

25+ self.index = first

26+ self.increment = incrementer

27+ self.memoizedFunction = memoizedFunction

28+ }

2529

26− self.index = first

27− self.increment = incrementer

28− self.memoizedFunction = memoizedFunction

29− }

30+ init(first: IndexType,

31+ incrementer: ((inout IndexType) -> Void),

32+ closure: ((IndexType -> ReturnType, IndexType) -> ReturnType)) {

33+ let memoizedFunction = memoize(closure)

3034

31− init(first: IndexType,

32− incrementer: ((inout IndexType) -> Void),

33− closure: ((IndexType -> ReturnType, IndexType) -> ReturnType)) {

34− let memoizedFunction = memoize(closure)

35−

36− self.init(first: first, incrementer: incrementer,

37− memoizedFunction: memoizedFunction)

38− }

35+ self.init(first: first, incrementer: incrementer,

36+ memoizedFunction: memoizedFunction)

37+ }

3938

40− init(first: IndexType,

41− incrementer: ((inout IndexType) -> Void),

42− function: (IndexType -> ReturnType)) {

39+ init(first: IndexType,

40+ incrementer: ((inout IndexType) -> Void),

41+ function: (IndexType -> ReturnType)) {

4342

44− let memoizedFunction = memoize(function)

43+ let memoizedFunction = memoize(function)

4544

46− self.init(first: first, incrementer: incrementer,

47− memoizedFunction: memoizedFunction)

48− }

45+ self.init(first: first, incrementer: incrementer,

46+ memoizedFunction: memoizedFunction)

47+ }

4948}

5049

5150extension HashMemoizedSequence: GeneratorType {

51+

5252 mutating func next() -> ReturnType? {

5353 let result = memoizedFunction(index)

5454 increment(&index)

5555 return result

5656 }

57+

5758}

5859

5960extension HashMemoizedSequence: LazySequenceType {

61+

6062 func generate() -> HashMemoizedSequence {

6163 return self

6264 }

65+

6366}

6467

6568extension HashMemoizedSequence where ReturnType: Comparable {

69+

6670 @warn_unused_result

6771 func contains(element: ReturnType) -> Bool {

6872 var index = firstIndex

@@ -79,6 +83,7 @@ extension HashMemoizedSequence where ReturnType: Comparable {

7983 increment(&index)

8084 }

8185 }

86+

8287}

8388

8489extension HashMemoizedSequence where IndexType: Incrementable {

@@ -104,29 +109,29 @@ extension HashMemoizedSequence where IndexType: Incrementable {

104109}

105110

106111extension HashMemoizedSequence where IndexType: Incrementable,

107− IndexType: IntegerLiteralConvertible {

112+IndexType: IntegerLiteralConvertible {

108113 init(_ closure: ((IndexType -> ReturnType, IndexType) -> ReturnType)) {

109− self.firstIndex = 1

110− self.index = 1

111− self.increment = { (inout index: IndexType) in

112− index++

113− }

114− self.memoizedFunction = memoize(closure)

114+ self.firstIndex = 1

115+ self.index = 1

116+ self.increment = { (inout index: IndexType) in

117+ index++

118+ }

119+ self.memoizedFunction = memoize(closure)

115120 }

116121

117122 init(_ function: (IndexType -> ReturnType)) {

118− self.firstIndex = 1

119− self.index = 1

120− self.increment = { (inout index: IndexType) in

121− index++

122− }

123− self.memoizedFunction = memoize(function)

123+ self.firstIndex = 1

124+ self.index = 1

125+ self.increment = { (inout index: IndexType) in

126+ index++

127+ }

128+ self.memoizedFunction = memoize(function)

124129 }

125130}

126131

127−func memoize <H: Hashable, R> (closure: ((H -> R, H) -> R) ) -> (H -> R) {

132+func memoize<H: Hashable, R>(closure: ((H -> R, H) -> R)) -> (H -> R) {

128133

129− var table = [H : R]()

134+ var table = [H: R]()

130135

131136 var auxiliaryFunction: (H -> R)!

132137 auxiliaryFunction = { index in

@@ -143,9 +148,9 @@ func memoize <H: Hashable, R> (closure: ((H -> R, H) -> R) ) -> (H -> R) {

143148 return auxiliaryFunction

144149}

145150

146−func memoize <H: Hashable, R> (function: (H -> R) ) -> (H -> R) {

151+func memoize<H: Hashable, R>(function: (H -> R)) -> (H -> R) {

147152

148− var table = [H : R]()

153+ var table = [H: R]()

149154

150155 let result: (H -> R) = { index in

151156 if let result = table[index] {

PixelImage/SwiftSugar/SignOperator.swift+8−9

@@ -1,13 +1,12 @@

1−

21prefix operator ± { }

32

4−prefix func ± <T: Numeric> (number: T) -> T {

3+prefix func ± <T: Numeric>(number: T) -> T {

54

6− if number > 0 {

7− return 1

8− } else if number == 0 {

9− return 0

10− } else {

11− return -1

12− }

5+ if number > 0 {

6+ return 1

7+ } else if number == 0 {

8+ return 0

9+ } else {

10+ return -1

11+ }

1312}

PixelImage/SwiftSugar/String.swift+4−1

@@ -1,9 +1,12 @@

11extension String: DoubleValuable {

22 var toDouble: Double {

3− get { return Double(self) ?? Double(0) }

3+ get {

4+ return Double(self) ?? Double(0)

5+ }

46 }

57

68 static func fromDouble(double: Double) -> String {

79 return "\(double)"

810 }

11+

912}

PixelImage/SwiftSugar/TestCommons.swift+2−1

@@ -8,7 +8,7 @@

88

99import Darwin

1010

11−class Random <T: Numeric> {

11+class Random<T: Numeric> {

1212

1313 let max: Double = Double(INT32_MAX)

1414 let exponent: Double = 7

@@ -92,4 +92,5 @@ class Random <T: Numeric> {

9292 let result = Double((2 * rawRandom) - 1)

9393 return T.fromDouble(result)

9494 }

95+

9596}

PixelImage/UIKit.swift+52−18

@@ -31,6 +31,7 @@ extension CGVector {

3131 dx = dx / norm

3232 dy = dy / norm

3333 }

34+

3435}

3536

3637extension CGFloat: DoubleValuable {

@@ -42,19 +43,28 @@ extension CGFloat: DoubleValuable {

4243 static func fromDouble(double: Double) -> CGFloat {

4344 return CGFloat(double)

4445 }

46+

4547}

4648

4749extension CGFloat: Numeric {}

4850

4951extension CGRect {

5052 var x: CGFloat {

51− get { return origin.x }

52− set { origin.x = newValue }

53+ get {

54+ return origin.x

55+ }

56+ set {

57+ origin.x = newValue

58+ }

5359 }

5460

5561 var y: CGFloat {

56− get { return origin.y }

57− set { origin.y = newValue }

62+ get {

63+ return origin.y

64+ }

65+ set {

66+ origin.y = newValue

67+ }

5868 }

5969}

6070

@@ -66,41 +76,65 @@ extension CGSize {

6676

6777extension UIView {

6878 var origin: CGPoint {

69− get { return frame.origin }

70− set { frame.origin = newValue }

79+ get {

80+ return frame.origin

81+ }

82+ set {

83+ frame.origin = newValue

84+ }

7185 }

7286

7387 var size: CGSize {

74− get { return frame.size }

75− set { frame.size = newValue }

88+ get {

89+ return frame.size

90+ }

91+ set {

92+ frame.size = newValue

93+ }

7694 }

7795

7896 var width: CGFloat {

79− get { return frame.width }

80− set { frame.size = CGSize(width: newValue, height: height) }

97+ get {

98+ return frame.width

99+ }

100+ set {

101+ frame.size = CGSize(width: newValue, height: height)

102+ }

81103 }

82104

83105 var height: CGFloat {

84− get { return frame.height }

85− set { frame.size = CGSize(width: width, height: newValue) }

106+ get {

107+ return frame.height

108+ }

109+ set {

110+ frame.size = CGSize(width: width, height: newValue)

111+ }

86112 }

87113

88114 var middle: CGPoint {

89115 get {

90− return CGPoint(x: origin.x + width/2, y: origin.y + height/2)

116+ return CGPoint(x: origin.x + width / 2, y: origin.y + height / 2)

91117 }

92118 set {

93− origin = CGPoint(x: newValue.x - width/2, y: newValue.y - height/2)

119+ origin = CGPoint(x: newValue.x - width / 2, y: newValue.y - height / 2)

94120 }

95121 }

96122

97123 var midX: CGFloat {

98− get { return middle.x }

99− set { middle = CGPoint(x: newValue, y: midY) }

124+ get {

125+ return middle.x

126+ }

127+ set {

128+ middle = CGPoint(x: newValue, y: midY)

129+ }

100130 }

101131

102132 var midY: CGFloat {

103− get { return middle.y }

104− set { middle = CGPoint(x: midX, y: newValue) }

133+ get {

134+ return middle.y

135+ }

136+ set {

137+ middle = CGPoint(x: midX, y: newValue)

138+ }

105139 }

106140}

PixelImage/ViewController.swift+8−7

@@ -1,4 +1,3 @@

1−

21import UIKit

32

43class ViewController: UIViewController, MetaballDataSource {

@@ -33,7 +32,7 @@ class ViewController: UIViewController, MetaballDataSource {

3332 metaballGraph.addEdge(2, 3)

3433

3534 let border = 20

36− let metaballViewFrame = CGRect(x: border/2, y: border/2, width: width, height: height)

35+ let metaballViewFrame = CGRect(x: border / 2, y: border / 2, width: width, height: height)

3736 renderer = MetalMetaballRenderer(dataSource: self, frame: metaballViewFrame)

3837 metaballView = renderer.targetView

3938

@@ -61,11 +60,12 @@ class ViewController: UIViewController, MetaballDataSource {

6160

6261 func animateEdge(i: Int, _ j: Int, fadeIn: Bool) {

6362 let parameters = EdgeAnimationParameters(startDate: NSDate(), duration: edgeAnimationDuration, fadeIn: fadeIn, i: i, j: j)

64− NSTimer.scheduledTimerWithTimeInterval(1.0/60.0, target: self, selector: "animateEdgeWithTimer:", userInfo: parameters, repeats: true)

63+ NSTimer.scheduledTimerWithTimeInterval(1.0 / 60.0, target: self, selector: "animateEdgeWithTimer:", userInfo: parameters, repeats: true)

6564 }

6665

6766 func animateEdge(withTimer timer: NSTimer) {

68− let (animationStart, duration, fadeIn, i, j) = (timer.userInfo as! EdgeAnimationParameters).unpack()

67+ guard let userInfo = timer.userInfo as? EdgeAnimationParameters else { preconditionFailure() }

68+ let (animationStart, duration, fadeIn, i, j) = (userInfo).unpack()

6969

7070 let now = NSDate()

7171 var timeElapsed = Float(now.timeIntervalSinceDate(animationStart))

@@ -89,9 +89,9 @@ class ViewController: UIViewController, MetaballDataSource {

8989

9090 if selectedMetaball == nil {

9191 for metaball in metaballs where

92− abs(metaball.midX - location.x) < 50 && abs(metaball.midY - location.y) < 50 {

93− selectedMetaball = metaball

94− break

92+ abs(metaball.midX - location.x) < 50 && abs(metaball.midY - location.y) < 50 {

93+ selectedMetaball = metaball

94+ break

9595 }

9696 }

9797

@@ -105,6 +105,7 @@ class ViewController: UIViewController, MetaballDataSource {

105105 selectedMetaball = nil

106106 }

107107 }

108+

108109}

109110

110111class Metaball: UIView {

PixelImage/shaders.metal+9−5

@@ -11,7 +11,11 @@ struct metaballData {

1111 float b;

1212};

1313

14−kernel void drawMetaballs(texture2d<float, access::write> outTexture[[texture(0)]], constant float *edgesBuffer[[buffer(1)]], constant metaballData *metaballBuffer[[buffer(0)]], uint2 gid[[thread_position_in_grid]]) {

14+kernel void

15+ drawMetaballs(texture2d<float, access::write> outTexture[[texture(0)]],

16+ constant float *edgesBuffer[[buffer(1)]],

17+ constant metaballData *metaballBuffer[[buffer(0)]],

18+ uint2 gid[[thread_position_in_grid]]) {

1519

1620 char numberOfMetaballs = metaballBuffer[0].x - 1;

1721

@@ -28,11 +32,12 @@ kernel void drawMetaballs(texture2d<float, access::write> outTexture[[texture(0)

2832 for (x = 1; x <= numberOfMetaballs; x += 1) {

2933 metaballData metaball = metaballBuffer[x];

3034 float2 metaballPosition = float2(metaball.x, metaball.y);

31− float2 vector = float2(metaballPosition.x - gid.x, metaballPosition.y - gid.y);

35+ float2 vector

36+ = float2(metaballPosition.x - gid.x, metaballPosition.y - gid.y);

3237 float squaredDistance = dot(vector, vector);

3338 float realDistance = sqrt(squaredDistance);

3439 metaballDistances[x - 1] = squaredDistance;

35− metaballDirections[x - 1] = vector/realDistance;

40+ metaballDirections[x - 1] = vector / realDistance;

3641 metaballColors[x - 1] = float3(metaball.r, metaball.g, metaball.b);

3742 }

3843

@@ -71,14 +76,13 @@ kernel void drawMetaballs(texture2d<float, access::write> outTexture[[texture(0)

7176

7277 float metaballValue = step(0.5, weightedValue + weightedLink);

7378 sum += metaballValue;

74−

7579 }

7680 }

7781

7882 bendClose = bendClose / bendCloseCount;

7983

8084 if (bendClose != 0.0) {

81− bendClose = (bendClose - 0.4) * (1/(0.6-0.4));

85+ bendClose = (bendClose - 0.4) * (1 / (0.6 - 0.4));

8286 } else {

8387 bendClose = 0.0;

8488 }