[cocos2d-objc] Added IK example. Also added SkeletonAnimation preUpdateWorldTransformListener and postUpdateWorldTransformsListener which allow modifying a skeleton pre- and post-calculation of the world transformations. See #1532.

CHANGELOG.md

@@ -53,9 +53,12 @@
 
 ### Cocos2d-Objc
 * Added mix-and-match example to demonstrate the new Skin API.
+* Added `IKExample`.
+* Added `SkeletonAnimation preUpdateWorldTransformsListener` and `SkeletonAnimation postUpdateWorldTransformsListener`. When set, these callbacks will be invokved before and after the skeleton's `updateWorldTransforms()` method is called. See the `IKExample` how it can be used.
 
 ### SFML
 * Added mix-and-match example to demonstrate the new Skin API.
+* Added `IKExample`.
 
 ## C++
 * **Breaking Changes**
@@ -88,6 +91,7 @@
 * Updated to cocos2d-x 3.17.1
 * Added mix-and-match example to demonstrate the new Skin API.
 * Exmaple project requires Visual Studio 2019 on Windows
+* Added `IKExample`.
 * Added `SkeletonAnimation::setPreUpdateWorldTransformsListener()` and `SkeletonAnimation::setPreUpdateWorldTransformsListener()`. When set, these callbacks will be invokved before and after the skeleton's `updateWorldTransforms()` method is called. See the `IKExample` how it can be used.
 
 ### SFML

examples/export/runtimes.sh

@@ -64,7 +64,7 @@ cp -f ../raptor/export/raptor-pro.json "$ROOT/spine-cocos2d-objc/Resources/"
 cp -f ../raptor/export/raptor.atlas "$ROOT/spine-cocos2d-objc/Resources/"
 cp -f ../raptor/export/raptor.png "$ROOT/spine-cocos2d-objc/Resources/"
 
-cp -f ../spineboy/export/spineboy-ess.json "$ROOT/spine-cocos2d-objc/Resources/"
+cp -f ../spineboy/export/spineboy-pro.json "$ROOT/spine-cocos2d-objc/Resources/"
 cp -f ../spineboy/export/spineboy.atlas "$ROOT/spine-cocos2d-objc/Resources/"
 cp -f ../spineboy/export/spineboy.png "$ROOT/spine-cocos2d-objc/Resources/"
 

spine-cocos2d-objc/Resources-ios/AppDelegate.m

@@ -1,7 +1,7 @@
 
 #import "cocos2d.h"
 #import "AppDelegate.h"
-#import "SpineboyExample.h"
+#import "IKExample.h"
 
 @implementation AppController
 
@@ -24,7 +24,7 @@
   			CCSetupShowDebugStats: @YES,
 		}];
     
-    [[CCDirector sharedDirector] runWithScene:[SpineboyExample scene]];
+    [[CCDirector sharedDirector] runWithScene:[IKExample scene]];
     
     return YES;
 }

spine-cocos2d-objc/Resources-ios/Info.plist

@@ -49,6 +49,8 @@
 		<string>UIInterfaceOrientationLandscapeLeft</string>
 		<string>UIInterfaceOrientationLandscapeRight</string>
 	</array>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
 	<key>UISupportedInterfaceOrientations~ipad</key>
 	<array>
 		<string>UIInterfaceOrientationLandscapeLeft</string>

spine-cocos2d-objc/example/CoinExample.m

@@ -28,7 +28,7 @@
  *****************************************************************************/
 
 #import "CoinExample.h"
-#import "SpineBoyExample.h"
+#import "IKExample.h"
 
 @implementation CoinExample
 
@@ -66,7 +66,7 @@
 	else if (skeletonNode.timeScale == 1)
 		skeletonNode.timeScale = 0.3f;
 	else
-		[[CCDirector sharedDirector] replaceScene:[SpineboyExample scene]];
+		[[CCDirector sharedDirector] replaceScene:[IKExample scene]];
 }
 #endif
 

spine-cocos2d-objc/example/IKExample.h

@@ -0,0 +1,40 @@
+/******************************************************************************
+ * Spine Runtimes License Agreement
+ * Last updated May 1, 2019. Replaces all prior versions.
+ *
+ * Copyright (c) 2013-2019, Esoteric Software LLC
+ *
+ * Integration of the Spine Runtimes into software or otherwise creating
+ * derivative works of the Spine Runtimes is permitted under the terms and
+ * conditions of Section 2 of the Spine Editor License Agreement:
+ * http://esotericsoftware.com/spine-editor-license
+ *
+ * Otherwise, it is permitted to integrate the Spine Runtimes into software
+ * or otherwise create derivative works of the Spine Runtimes (collectively,
+ * "Products"), provided that each user of the Products must obtain their own
+ * Spine Editor license and redistribution of the Products in any form must
+ * include this license and copyright notice.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, BUSINESS
+ * INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#import "cocos2d.h"
+#import <spine/spine-cocos2d-objc.h>
+
+@interface IKExample : CCNode {
+	SkeletonAnimation* skeletonNode;
+	CGPoint position;
+}
+
++ (CCScene*) scene;
+
+@end

spine-cocos2d-objc/example/IKExample.m

@@ -0,0 +1,118 @@
+/******************************************************************************
+ * Spine Runtimes License Agreement
+ * Last updated May 1, 2019. Replaces all prior versions.
+ *
+ * Copyright (c) 2013-2019, Esoteric Software LLC
+ *
+ * Integration of the Spine Runtimes into software or otherwise creating
+ * derivative works of the Spine Runtimes is permitted under the terms and
+ * conditions of Section 2 of the Spine Editor License Agreement:
+ * http://esotericsoftware.com/spine-editor-license
+ *
+ * Otherwise, it is permitted to integrate the Spine Runtimes into software
+ * or otherwise create derivative works of the Spine Runtimes (collectively,
+ * "Products"), provided that each user of the Products must obtain their own
+ * Spine Editor license and redistribution of the Products in any form must
+ * include this license and copyright notice.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
+ * NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, BUSINESS
+ * INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#import "IKExample.h"
+#import "SpineboyExample.h"
+
+// This example demonstrates how to set the position
+// of a bone based on the touch position, which in
+// turn will make an IK chain follow that bone
+// smoothly.
+@implementation IKExample
+
++ (CCScene*) scene {
+	CCScene *scene = [CCScene node];
+	[scene addChild:[IKExample node]];
+	return scene;
+}
+
+-(id) init {
+	self = [super init];
+	if (!self) return nil;
+
+	// Load the Spineboy skeleton and create a SkeletonAnimation node from it
+	// centered on the screen.
+
+	skeletonNode = [SkeletonAnimation skeletonWithFile:@"spineboy-pro.json" atlasFile:@"spineboy.atlas" scale:0.4];
+	CGSize windowSize = [[CCDirector sharedDirector] viewSize];
+	[skeletonNode setPosition:ccp(windowSize.width / 2, 20)];
+	[self addChild:skeletonNode];
+	self.userInteractionEnabled = YES;
+    self.contentSize = windowSize;
+	
+	// Queue the "walk" animation on the first track.
+	[skeletonNode setAnimationForTrack:0 name:@"walk" loop:YES];
+	
+	// Queue the "aim" animation on a higher track.
+	// It consists of a single frame that positions
+	// the back arm and gun such that they point at
+	// the "crosshair" bone. By setting this
+	// animation on a higher track, it overrides
+	// any changes to the back arm and gun made
+	// by the walk animation, allowing us to
+	// mix the two. The mouse position following
+	// is performed in the lambda below.
+	[skeletonNode setAnimationForTrack:1 name:@"aim" loop:YES];
+
+	// Position the "crosshair" bone at the mouse
+	// location.
+	//
+	// When setting the crosshair bone position
+	// to the mouse position, we need to translate
+	// from "skeleton space" to "local bone space".
+	// Note that the local bone space is calculated
+	// using the bone's parent worldToLocal() function!
+	//
+	// After updating the bone position based on the
+	// converted mouse location, we call updateWorldTransforms()
+	// again so the change of the IK target position is
+	// applied to the rest of the skeleton.
+	__weak IKExample* scene = self;
+	skeletonNode.postUpdateWorldTransformsListener = ^(SkeletonAnimation* node) {
+		if (scene != NULL) {
+			__strong IKExample* sceneStrong = scene;
+			spBone* crosshair = [node findBone:@"crosshair"]; // The bone should be cached
+			float localX = 0, localY = 0;
+			spBone_worldToLocal(crosshair->parent, sceneStrong->position.x, sceneStrong->position.y, &localX, &localY);
+			crosshair->x = localX;
+			crosshair->y = localY;
+			crosshair->appliedValid = FALSE;
+			spBone_updateWorldTransform(crosshair);
+		}
+    };
+	return self;
+}
+
+#if ( TARGET_OS_IPHONE || TARGET_IPHONE_SIMULATOR )
+- (void)touchBegan:(UITouch *)touch withEvent:(UIEvent *)event {
+	position = [skeletonNode convertToNodeSpace:touch.locationInWorld];
+	printf("%f %f\n", position.x, position.y);
+}
+
+- (void)touchMoved:(UITouch *)touch withEvent:(UIEvent *)event {
+	position = [skeletonNode convertToNodeSpace:touch.locationInWorld];
+	printf("%f %f\n", position.x, position.y);
+}
+
+- (void)touchEnded:(UITouch *)touch withEvent:(UIEvent *)event {
+	[[CCDirector sharedDirector] replaceScene:[SpineboyExample scene]];
+}
+#endif
+
+@end

spine-cocos2d-objc/example/SpineboyExample.m

@@ -42,7 +42,7 @@
 	self = [super init];
 	if (!self) return nil;
 
-	skeletonNode = [SkeletonAnimation skeletonWithFile:@"spineboy-ess.json" atlasFile:@"spineboy.atlas" scale:0.4];
+	skeletonNode = [SkeletonAnimation skeletonWithFile:@"spineboy-pro.json" atlasFile:@"spineboy.atlas" scale:0.4];
 	[skeletonNode setMixFrom:@"walk" to:@"jump" duration:0.2f];
 	[skeletonNode setMixFrom:@"jump" to:@"run" duration:0.2f];
 

spine-cocos2d-objc/spine-cocos2d-objc.xcodeproj/project.pbxproj

@@ -8,7 +8,6 @@
 
 /* Begin PBXBuildFile section */
 		43C3282F170B0C19004A9460 /* spine-cocos2d-objc.m in Sources */ = {isa = PBXBuildFile; fileRef = 43C3282D170B0C19004A9460 /* spine-cocos2d-objc.m */; settings = {COMPILER_FLAGS = "-fno-objc-arc"; }; };
-		43C3286C170B0DA6004A9460 /* spineboy-ess.json in Resources */ = {isa = PBXBuildFile; fileRef = 43C32868170B0DA6004A9460 /* spineboy-ess.json */; };
 		43C3286E170B0DA6004A9460 /* spineboy.atlas in Resources */ = {isa = PBXBuildFile; fileRef = 43C3286A170B0DA6004A9460 /* spineboy.atlas */; };
 		43C3286F170B0DA6004A9460 /* spineboy.png in Resources */ = {isa = PBXBuildFile; fileRef = 43C3286B170B0DA6004A9460 /* spineboy.png */; };
 		43C3287D170B0DBE004A9460 /* Default-568h@2x.png in Resources */ = {isa = PBXBuildFile; fileRef = 43C32871170B0DBE004A9460 /* Default-568h@2x.png */; };
@@ -34,6 +33,8 @@
 		765A2EF61D7D7A08003FB779 /* goblins.atlas in Resources */ = {isa = PBXBuildFile; fileRef = 765A2EF41D7D7A08003FB779 /* goblins.atlas */; };
 		765A2EF71D7D7A08003FB779 /* goblins.png in Resources */ = {isa = PBXBuildFile; fileRef = 765A2EF51D7D7A08003FB779 /* goblins.png */; };
 		76BF7E071E66ED9C00485998 /* GLUtils.c in Sources */ = {isa = PBXBuildFile; fileRef = 76BF7E051E66ED9C00485998 /* GLUtils.c */; };
+		76C893BC23672757009D8DC8 /* IKExample.m in Sources */ = {isa = PBXBuildFile; fileRef = 76C893B623672757009D8DC8 /* IKExample.m */; };
+		76C893BF236728A4009D8DC8 /* spineboy-pro.json in Resources */ = {isa = PBXBuildFile; fileRef = 76C893BE236728A4009D8DC8 /* spineboy-pro.json */; };
 		76EE4E461EB36DE6000254F4 /* Array.c in Sources */ = {isa = PBXBuildFile; fileRef = 76EE4E421EB36DE6000254F4 /* Array.c */; };
 		76EE4E471EB36DE6000254F4 /* ClippingAttachment.c in Sources */ = {isa = PBXBuildFile; fileRef = 76EE4E431EB36DE6000254F4 /* ClippingAttachment.c */; };
 		76EE4E481EB36DE6000254F4 /* SkeletonClipping.c in Sources */ = {isa = PBXBuildFile; fileRef = 76EE4E441EB36DE6000254F4 /* SkeletonClipping.c */; };
@@ -138,7 +139,6 @@
 /* Begin PBXFileReference section */
 		43C3282D170B0C19004A9460 /* spine-cocos2d-objc.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = "spine-cocos2d-objc.m"; path = "src/spine/spine-cocos2d-objc.m"; sourceTree = "<group>"; };
 		43C3282E170B0C19004A9460 /* spine-cocos2d-objc.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = "spine-cocos2d-objc.h"; path = "src/spine/spine-cocos2d-objc.h"; sourceTree = "<group>"; };
-		43C32868170B0DA6004A9460 /* spineboy-ess.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; name = "spineboy-ess.json"; path = "Resources/spineboy-ess.json"; sourceTree = "<group>"; };
 		43C3286A170B0DA6004A9460 /* spineboy.atlas */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; name = spineboy.atlas; path = Resources/spineboy.atlas; sourceTree = "<group>"; };
 		43C3286B170B0DA6004A9460 /* spineboy.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; name = spineboy.png; path = Resources/spineboy.png; sourceTree = "<group>"; };
 		43C32871170B0DBE004A9460 /* Default-568h@2x.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; name = "Default-568h@2x.png"; path = "Resources-ios/Default-568h@2x.png"; sourceTree = "<group>"; };
@@ -171,6 +171,9 @@
 		765A2EF51D7D7A08003FB779 /* goblins.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; name = goblins.png; path = Resources/goblins.png; sourceTree = "<group>"; };
 		76BF7E051E66ED9C00485998 /* GLUtils.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; name = GLUtils.c; path = src/spine/GLUtils.c; sourceTree = "<group>"; };
 		76BF7E061E66ED9C00485998 /* GLUtils.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = GLUtils.h; path = src/spine/GLUtils.h; sourceTree = "<group>"; };
+		76C893B623672757009D8DC8 /* IKExample.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; name = IKExample.m; path = example/IKExample.m; sourceTree = "<group>"; };
+		76C893BB23672757009D8DC8 /* IKExample.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; name = IKExample.h; path = example/IKExample.h; sourceTree = "<group>"; };
+		76C893BE236728A4009D8DC8 /* spineboy-pro.json */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.json; name = "spineboy-pro.json"; path = "Resources/spineboy-pro.json"; sourceTree = "<group>"; };
 		76EE4E421EB36DE6000254F4 /* Array.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; name = Array.c; path = "../spine-c/spine-c/src/spine/Array.c"; sourceTree = "<group>"; };
 		76EE4E431EB36DE6000254F4 /* ClippingAttachment.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; name = ClippingAttachment.c; path = "../spine-c/spine-c/src/spine/ClippingAttachment.c"; sourceTree = "<group>"; };
 		76EE4E441EB36DE6000254F4 /* SkeletonClipping.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; name = SkeletonClipping.c; path = "../spine-c/spine-c/src/spine/SkeletonClipping.c"; sourceTree = "<group>"; };
@@ -282,6 +285,8 @@
 				43C32823170B0BC7004A9460 /* spine-cocos2d-objc */,
 				43F7FF8C1927F96700CA4038 /* SpineboyExample.h */,
 				43F7FF8D1927F96700CA4038 /* SpineboyExample.m */,
+				76C893BB23672757009D8DC8 /* IKExample.h */,
+				76C893B623672757009D8DC8 /* IKExample.m */,
 				43F7FF8A1927F96700CA4038 /* GoblinsExample.h */,
 				43F7FF8B1927F96700CA4038 /* GoblinsExample.m */,
 				76F5BDA81D2BDE67005917E5 /* RaptorExample.h */,
@@ -364,6 +369,7 @@
 		43C32867170B0C7F004A9460 /* Resources */ = {
 			isa = PBXGroup;
 			children = (
+				76C893BE236728A4009D8DC8 /* spineboy-pro.json */,
 				76EE4E4E1EB36E53000254F4 /* coin.atlas */,
 				76EE4E4F1EB36E53000254F4 /* coin-pro.json */,
 				76EE4E501EB36E53000254F4 /* coin.png */,
@@ -376,7 +382,6 @@
 				76F5BDA01D2BDE1C005917E5 /* tank-pro.json */,
 				76F5BDA11D2BDE1C005917E5 /* tank.png */,
 				43F7010D1927FBC700CA4038 /* goblins-pro.json */,
-				43C32868170B0DA6004A9460 /* spineboy-ess.json */,
 				43C3286A170B0DA6004A9460 /* spineboy.atlas */,
 				43C3286B170B0DA6004A9460 /* spineboy.png */,
 			);
@@ -484,6 +489,7 @@
 			developmentRegion = English;
 			hasScannedForEncodings = 0;
 			knownRegions = (
+				English,
 				en,
 			);
 			mainGroup = 9A5D248C170A94DA0030D4DD;
@@ -540,7 +546,6 @@
 			files = (
 				765A2EF61D7D7A08003FB779 /* goblins.atlas in Resources */,
 				76F5BDA51D2BDE1C005917E5 /* tank.atlas in Resources */,
-				43C3286C170B0DA6004A9460 /* spineboy-ess.json in Resources */,
 				43C3286E170B0DA6004A9460 /* spineboy.atlas in Resources */,
 				43C3286F170B0DA6004A9460 /* spineboy.png in Resources */,
 				43C3287D170B0DBE004A9460 /* Default-568h@2x.png in Resources */,
@@ -557,6 +562,7 @@
 				76EE4E511EB36E53000254F4 /* coin.atlas in Resources */,
 				76F5BDA21D2BDE1C005917E5 /* raptor.atlas in Resources */,
 				43C32883170B0DBE004A9460 /* Icon-Small.png in Resources */,
+				76C893BF236728A4009D8DC8 /* spineboy-pro.json in Resources */,
 				43C32884170B0DBE004A9460 /* Icon-Small@2x.png in Resources */,
 				43C32885170B0DBE004A9460 /* Icon.png in Resources */,
 				76F5BDA71D2BDE1C005917E5 /* tank.png in Resources */,
@@ -607,6 +613,7 @@
 				76F28D311DEC810300CDE54D /* Slot.c in Sources */,
 				43C32A06170B0F93004A9460 /* main.m in Sources */,
 				76F28D351DEC810300CDE54D /* VertexAttachment.c in Sources */,
+				76C893BC23672757009D8DC8 /* IKExample.m in Sources */,
 				76FAC1961E3FA15E001CCC8C /* Color.c in Sources */,
 				76F28D331DEC810300CDE54D /* TransformConstraint.c in Sources */,
 				43C32A09170B10FF004A9460 /* AppDelegate.m in Sources */,

spine-cocos2d-objc/src/spine/SkeletonAnimation.h

@@ -39,6 +39,7 @@ typedef void(^spEndListener)(spTrackEntry* entry);
 typedef void(^spDisposeListener)(spTrackEntry* entry);
 typedef void(^spCompleteListener)(spTrackEntry* entry);
 typedef void(^spEventListener)(spTrackEntry* entry, spEvent* event);
+typedef void(^spUpdateWorldTransformsListener)(SkeletonAnimation* node);
 
 /** Draws an animated skeleton, providing an AnimationState for applying one or more animations and queuing animations to be
  * played later. */
@@ -90,5 +91,7 @@ typedef void(^spEventListener)(spTrackEntry* entry, spEvent* event);
 @property (nonatomic, copy) spDisposeListener disposeListener;
 @property (nonatomic, copy) spCompleteListener completeListener;
 @property (nonatomic, copy) spEventListener eventListener;
+@property (nonatomic, copy) spUpdateWorldTransformsListener preUpdateWorldTransformsListener;
+@property (nonatomic, copy) spUpdateWorldTransformsListener postUpdateWorldTransformsListener;
 
 @end

spine-cocos2d-objc/src/spine/SkeletonAnimation.m

@@ -80,6 +80,8 @@ static _TrackEntryListeners* getListeners (spTrackEntry* entry) {
 @synthesize endListener = _endListener;
 @synthesize completeListener = _completeListener;
 @synthesize eventListener = _eventListener;
+@synthesize preUpdateWorldTransformsListener = _preUpdateWorldTransformsListener;
+@synthesize postUpdateWorldTransformsListener = _postUpdateWorldTransformsListener;
 
 + (id) skeletonWithData:(spSkeletonData*)skeletonData ownsSkeletonData:(bool)ownsSkeletonData {
 	return [[[self alloc] initWithData:skeletonData ownsSkeletonData:ownsSkeletonData] autorelease];
@@ -141,6 +143,8 @@ static _TrackEntryListeners* getListeners (spTrackEntry* entry) {
 	[_disposeListener release];
 	[_completeListener release];
 	[_eventListener release];
+	[_preUpdateWorldTransformsListener release];
+	[_postUpdateWorldTransformsListener release];
 
 	[super dealloc];
 }
@@ -150,7 +154,9 @@ static _TrackEntryListeners* getListeners (spTrackEntry* entry) {
 	spSkeleton_update(_skeleton, deltaTime);
 	spAnimationState_update(_state, deltaTime);
 	spAnimationState_apply(_state, _skeleton);
+	if (_preUpdateWorldTransformsListener) _preUpdateWorldTransformsListener(self);
 	spSkeleton_updateWorldTransform(_skeleton);
+	if (_postUpdateWorldTransformsListener) _postUpdateWorldTransformsListener(self);
 }
 
 - (void) setAnimationStateData:(spAnimationStateData*)stateData {

spine-cocos2dx/example/Classes/IKExample.cpp

@@ -33,6 +33,10 @@
 USING_NS_CC;
 using namespace spine;
 
+// This example demonstrates how to set the position
+// of a bone based on the touch position, which in
+// turn will make an IK chain follow that bone
+// smoothly.
 Scene* IKExample::scene () {
     Scene *scene = Scene::create();
     scene->addChild(IKExample::create());
@@ -88,7 +92,7 @@ bool IKExample::init () {
 	// again so the change of the IK target position is
 	// applied to the rest of the skeleton.
 	skeletonNode->setPostUpdateWorldTransformsListener([this] (SkeletonAnimation* node) -> void {
-		Bone* crosshair = node->findBone("crosshair");
+		Bone* crosshair = node->findBone("crosshair"); // The bone should be cached
 		float localX = 0, localY = 0;
 		crosshair->getParent()->worldToLocal(position.x, position.y, localX, localY);
 		crosshair->setX(localX);