[cpp] Port cf45806b, 409bf9d6, 0e16ef9c from libgdx

spine-cpp/include/spine/DrawOrderFolderTimeline.h

@@ -0,0 +1,74 @@
+/******************************************************************************
+ * Spine Runtimes License Agreement
+ * Last updated April 5, 2025. Replaces all prior versions.
+ *
+ * Copyright (c) 2013-2025, 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.
+ *
+ * THE SPINE RUNTIMES ARE 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
+ * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#ifndef Spine_DrawOrderFolderTimeline_h
+#define Spine_DrawOrderFolderTimeline_h
+
+#include <spine/Timeline.h>
+
+namespace spine {
+	/// Changes a subset of a skeleton's Skeleton::getDrawOrder().
+	class SP_API DrawOrderFolderTimeline : public Timeline {
+		friend class SkeletonBinary;
+
+		friend class SkeletonJson;
+
+		RTTI_DECL
+
+	public:
+		DrawOrderFolderTimeline(size_t frameCount, Array<int> &slots, size_t slotCount);
+
+		virtual void apply(Skeleton &skeleton, float lastTime, float time, Array<Event *> *events, float alpha, MixBlend blend,
+						   MixDirection direction, bool appliedPose) override;
+
+		size_t getFrameCount();
+
+		/// The Skeleton::getSlots() indices that this timeline affects, in setup order.
+		Array<int> &getSlots();
+
+		/// The draw order for each frame. See setFrame().
+		Array<Array<int>> &getDrawOrders();
+
+		/// Sets the time and draw order for the specified frame.
+		/// @param frame Between 0 and frameCount, inclusive.
+		/// @param time The frame time in seconds.
+		/// @param drawOrder Ordered getSlots() indices, or null to use setup pose order.
+		void setFrame(size_t frame, float time, Array<int> *drawOrder);
+
+	private:
+		Array<int> _slots;
+		Array<bool> _inFolder;
+		Array<Array<int>> _drawOrders;
+
+		void setup(Skeleton &skeleton);
+		void apply(Skeleton &skeleton, Array<int> &drawOrder);
+	};
+}
+
+#endif /* Spine_DrawOrderFolderTimeline_h */

spine-cpp/include/spine/Skeleton.h

@@ -88,6 +88,8 @@ namespace spine {
 
 		friend class DeformTimeline;
 
+		friend class DrawOrderFolderTimeline;
+
 		friend class DrawOrderTimeline;
 
 		friend class EventTimeline;

spine-cpp/include/spine/SkeletonBinary.h

@@ -257,6 +257,8 @@ namespace spine {
 
 		void readTimeline(DataInput &input, Array<Timeline *> &timelines, BoneTimeline2 &timeline, float scale);
 
+		void readDrawOrder(DataInput &input, size_t slotCount, Array<int> &drawOrder);
+
 		void setBezier(DataInput &input, CurveTimeline &timeline, int bezier, int frame, int value, float time1, float time2, float value1,
 					   float value2, float scale);
 	};

spine-cpp/include/spine/SkeletonData.h

@@ -88,6 +88,9 @@ namespace spine {
 		/// @return May be NULL.
 		Animation *findAnimation(const String &animationName);
 
+		/// Collects animations used by slider constraints.
+		Array<Animation *> &findSliderAnimations(Array<Animation *> &animations);
+
 		/// The skeleton's name, which by default is the name of the skeleton data file when possible, or null when a name hasn't been
 		/// set.
 		const String &getName();

spine-cpp/include/spine/SkeletonJson.h

@@ -111,6 +111,8 @@ namespace spine {
 
 		void readVertices(Json *attachmentMap, VertexAttachment *attachment, size_t verticesLength);
 
+		bool readDrawOrder(SkeletonData *skeletonData, Json *keyMap, int slotCount, const Array<int> *folderSlots, Array<int> &drawOrder);
+
 		void setError(Json *root, const String &value1, const String &value2);
 
 		int findSlotIndex(SkeletonData *skeletonData, const String &slotName, Array<Timeline *> timelines);

spine-cpp/include/spine/SliderData.h

@@ -45,6 +45,7 @@ namespace spine {
 	/// Stores the setup pose for a Slider
 	class SP_API SliderData : public ConstraintDataGeneric<Slider, SliderPose> {
 		friend class SkeletonBinary;
+		friend class SkeletonData;
 		friend class SkeletonJson;
 		friend class Slider;
 		friend class SliderMixTimeline;

spine-cpp/include/spine/spine.h

@@ -55,6 +55,7 @@
 #include <spine/ArrayUtils.h>
 #include <spine/CurveTimeline.h>
 #include <spine/DeformTimeline.h>
+#include <spine/DrawOrderFolderTimeline.h>
 #include <spine/DrawOrderTimeline.h>
 #include <spine/Event.h>
 #include <spine/EventData.h>

spine-cpp/src/spine/AnimationState.cpp

@@ -33,6 +33,7 @@
 #include <spine/AttachmentTimeline.h>
 #include <spine/Bone.h>
 #include <spine/BoneData.h>
+#include <spine/DrawOrderFolderTimeline.h>
 #include <spine/DrawOrderTimeline.h>
 #include <spine/Event.h>
 #include <spine/EventTimeline.h>
@@ -444,7 +445,8 @@ void EventQueue::drain() {
 				break;
 			case EventType_Event:
 				if (!trackEntry->_listenerObject)
-					SP_INVOKE_ANIMATION_LISTENER(trackEntry->_listener, state, queueEntry._type, trackEntry, queueEntry._event, trackEntry->_listenerUserData);
+					SP_INVOKE_ANIMATION_LISTENER(trackEntry->_listener, state, queueEntry._type, trackEntry, queueEntry._event,
+												 trackEntry->_listenerUserData);
 				else
 					trackEntry->_listenerObject->callback(&state, queueEntry._type, trackEntry, queueEntry._event);
 				if (!state._listenerObject)
@@ -1203,7 +1205,8 @@ continue_outer:
 			timelineMode[i] = Subsequent;
 		} else {
 			if (to == NULL || timeline->getRTTI().isExactly(AttachmentTimeline::rtti) || timeline->getRTTI().isExactly(DrawOrderTimeline::rtti) ||
-				timeline->getRTTI().isExactly(EventTimeline::rtti) || !to->_animation->hasTimeline(ids)) {
+				timeline->getRTTI().isExactly(DrawOrderFolderTimeline::rtti) || timeline->getRTTI().isExactly(EventTimeline::rtti) ||
+				!to->_animation->hasTimeline(ids)) {
 				timelineMode[i] = First;
 			} else {
 				for (TrackEntry *next = to->_mixingTo; next != NULL; next = next->_mixingTo) {

spine-cpp/src/spine/DrawOrderFolderTimeline.cpp

@@ -0,0 +1,115 @@
+/******************************************************************************
+ * Spine Runtimes License Agreement
+ * Last updated April 5, 2025. Replaces all prior versions.
+ *
+ * Copyright (c) 2013-2025, 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.
+ *
+ * THE SPINE RUNTIMES ARE 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
+ * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#include <spine/DrawOrderFolderTimeline.h>
+
+#include <spine/Animation.h>
+#include <spine/Event.h>
+#include <spine/Property.h>
+#include <spine/Skeleton.h>
+#include <spine/Slot.h>
+#include <spine/SlotData.h>
+
+using namespace spine;
+
+RTTI_IMPL(DrawOrderFolderTimeline, Timeline)
+
+DrawOrderFolderTimeline::DrawOrderFolderTimeline(size_t frameCount, Array<int> &slots, size_t slotCount) : Timeline(frameCount, 1) {
+	PropertyId ids[] = {((PropertyId) Property_DrawOrder << 32)};
+	setPropertyIds(ids, 1);
+
+	_slots.addAll(slots);
+	_drawOrders.ensureCapacity(frameCount);
+	_inFolder.setSize(slotCount, false);
+	for (size_t i = 0; i < _slots.size(); ++i) _inFolder[_slots[i]] = true;
+	for (size_t i = 0; i < frameCount; ++i) {
+		Array<int> vec;
+		_drawOrders.add(vec);
+	}
+}
+
+void DrawOrderFolderTimeline::apply(Skeleton &skeleton, float lastTime, float time, Array<Event *> *events, float alpha, MixBlend blend,
+									MixDirection direction, bool appliedPose) {
+	SP_UNUSED(lastTime);
+	SP_UNUSED(events);
+	SP_UNUSED(alpha);
+	SP_UNUSED(appliedPose);
+
+	if (direction == MixDirection_Out) {
+		if (blend == MixBlend_Setup) setup(skeleton);
+	} else if (time < _frames[0]) {
+		if (blend == MixBlend_Setup || blend == MixBlend_First) setup(skeleton);
+	} else {
+		Array<int> &drawOrder = _drawOrders[Animation::search(_frames, time)];
+		if (drawOrder.size() == 0)
+			setup(skeleton);
+		else
+			apply(skeleton, drawOrder);
+	}
+}
+
+size_t DrawOrderFolderTimeline::getFrameCount() {
+	return _frames.size();
+}
+
+Array<int> &DrawOrderFolderTimeline::getSlots() {
+	return _slots;
+}
+
+Array<Array<int>> &DrawOrderFolderTimeline::getDrawOrders() {
+	return _drawOrders;
+}
+
+void DrawOrderFolderTimeline::setFrame(size_t frame, float time, Array<int> *drawOrder) {
+	_frames[frame] = time;
+	_drawOrders[frame].clear();
+	if (drawOrder != NULL) _drawOrders[frame].addAll(*drawOrder);
+}
+
+void DrawOrderFolderTimeline::setup(Skeleton &skeleton) {
+	Array<Slot *> &drawOrder = skeleton._drawOrder;
+	Array<Slot *> &allSlots = skeleton._slots;
+	for (size_t i = 0, found = 0, done = _slots.size();; ++i) {
+		if (_inFolder[drawOrder[i]->getData().getIndex()]) {
+			drawOrder[i] = allSlots[_slots[found]];
+			if (++found == done) break;
+		}
+	}
+}
+
+void DrawOrderFolderTimeline::apply(Skeleton &skeleton, Array<int> &drawOrderIndices) {
+	Array<Slot *> &drawOrder = skeleton._drawOrder;
+	Array<Slot *> &allSlots = skeleton._slots;
+	for (size_t i = 0, found = 0, done = _slots.size();; ++i) {
+		if (_inFolder[drawOrder[i]->getData().getIndex()]) {
+			drawOrder[i] = allSlots[_slots[drawOrderIndices[found]]];
+			if (++found == done) break;
+		}
+	}
+}

spine-cpp/src/spine/SkeletonBinary.cpp

@@ -47,6 +47,7 @@
 #include <spine/ColorTimeline.h>
 #include <spine/ArrayUtils.h>
 #include <spine/DeformTimeline.h>
+#include <spine/DrawOrderFolderTimeline.h>
 #include <spine/DrawOrderTimeline.h>
 #include <spine/Event.h>
 #include <spine/EventData.h>
@@ -1304,33 +1305,33 @@ Animation *SkeletonBinary::readAnimation(DataInput &input, const String &name, S
 	}
 
 	// Draw order timeline.
+	size_t slotCount = skeletonData._slots.size();
 	size_t drawOrderCount = (size_t) input.readInt(true);
 	if (drawOrderCount > 0) {
 		DrawOrderTimeline *timeline = new (__FILE__, __LINE__) DrawOrderTimeline(drawOrderCount);
-		size_t slotCount = skeletonData._slots.size();
 		for (size_t i = 0; i < drawOrderCount; ++i) {
 			float time = input.readFloat();
-			size_t offsetCount = (size_t) input.readInt(true);
 			Array<int> drawOrder;
-			drawOrder.setSize(slotCount, 0);
-			for (int ii = (int) slotCount - 1; ii >= 0; --ii) drawOrder[ii] = -1;
-			Array<int> unchanged;
-			unchanged.setSize(slotCount - offsetCount, 0);
-			size_t originalIndex = 0, unchangedIndex = 0;
-			for (size_t ii = 0; ii < offsetCount; ++ii) {
-				size_t slotIndex = (size_t) input.readInt(true);
-				// Collect unchanged items.
-				while (originalIndex != slotIndex) unchanged[unchangedIndex++] = (int) originalIndex++;
-				// Set changed items.
-				size_t index = originalIndex;
-				drawOrder[index + (size_t) input.readInt(true)] = (int) originalIndex++;
-			}
-			// Collect remaining unchanged items.
-			while (originalIndex < slotCount) unchanged[unchangedIndex++] = (int) originalIndex++;
-			// Fill in unchanged items.
-			for (int ii = (int) slotCount - 1; ii >= 0; --ii)
-				if (drawOrder[ii] == -1) drawOrder[ii] = unchanged[--unchangedIndex];
-			timeline->setFrame(i, time, &drawOrder);
+			readDrawOrder(input, slotCount, drawOrder);
+			timeline->setFrame(i, time, drawOrder.size() == 0 ? NULL : &drawOrder);
+		}
+		timelines.add(timeline);
+	}
+
+	// Draw order folder timelines.
+	size_t folderCount = (size_t) input.readInt(true);
+	for (size_t i = 0; i < folderCount; ++i) {
+		size_t folderSlotCount = (size_t) input.readInt(true);
+		Array<int> folderSlots;
+		folderSlots.setSize(folderSlotCount, 0);
+		for (size_t ii = 0; ii < folderSlotCount; ++ii) folderSlots[ii] = input.readInt(true);
+		size_t keyCount = (size_t) input.readInt(true);
+		DrawOrderFolderTimeline *timeline = new (__FILE__, __LINE__) DrawOrderFolderTimeline(keyCount, folderSlots, slotCount);
+		for (size_t ii = 0; ii < keyCount; ++ii) {
+			float time = input.readFloat();
+			Array<int> drawOrder;
+			readDrawOrder(input, folderSlotCount, drawOrder);
+			timeline->setFrame(ii, time, drawOrder.size() == 0 ? NULL : &drawOrder);
 		}
 		timelines.add(timeline);
 	}
@@ -1409,6 +1410,27 @@ void SkeletonBinary::readTimeline(DataInput &input, Array<Timeline *> &timelines
 	timelines.add(&timeline);
 }
 
+void SkeletonBinary::readDrawOrder(DataInput &input, size_t slotCount, Array<int> &drawOrder) {
+	size_t changeCount = (size_t) input.readInt(true);
+	drawOrder.clear();
+	if (changeCount == 0) return;
+
+	drawOrder.setSize(slotCount, 0);
+	for (int i = (int) slotCount - 1; i >= 0; --i) drawOrder[i] = -1;
+	Array<int> unchanged;
+	unchanged.setSize(slotCount - changeCount, 0);
+	size_t originalIndex = 0, unchangedIndex = 0;
+	for (size_t i = 0; i < changeCount; ++i) {
+		size_t slotIndex = (size_t) input.readInt(true);
+		while (originalIndex != slotIndex) unchanged[unchangedIndex++] = (int) originalIndex++;
+		size_t index = originalIndex;
+		drawOrder[index + (size_t) input.readInt(true)] = (int) originalIndex++;
+	}
+	while (originalIndex < slotCount) unchanged[unchangedIndex++] = (int) originalIndex++;
+	for (int i = (int) slotCount - 1; i >= 0; --i)
+		if (drawOrder[i] == -1) drawOrder[i] = unchanged[--unchangedIndex];
+}
+
 void SkeletonBinary::setBezier(DataInput &input, CurveTimeline &timeline, int bezier, int frame, int value, float time1, float time2, float value1,
 							   float value2, float scale) {
 	float cx1 = input.readFloat();

spine-cpp/src/spine/SkeletonData.cpp

@@ -39,6 +39,7 @@
 #include <spine/Skin.h>
 #include <spine/SlotData.h>
 #include <spine/TransformConstraintData.h>
+#include <spine/SliderData.h>
 
 #include <spine/ArrayUtils.h>
 
@@ -84,6 +85,17 @@ Animation *SkeletonData::findAnimation(const String &animationName) {
 	return ArrayUtils::findWithName(_animations, animationName);
 }
 
+Array<Animation *> &SkeletonData::findSliderAnimations(Array<Animation *> &animations) {
+	for (size_t i = 0, n = _constraints.size(); i < n; i++) {
+		ConstraintData *constraint = _constraints[i];
+		if (constraint->getRTTI().instanceOf(SliderData::rtti)) {
+			SliderData *data = static_cast<SliderData *>(constraint);
+			if (data->_animation != NULL) animations.add(data->_animation);
+		}
+	}
+	return animations;
+}
+
 const String &SkeletonData::getName() {
 	return _name;
 }

spine-cpp/src/spine/SkeletonJson.cpp

@@ -47,6 +47,7 @@
 #include <spine/ColorTimeline.h>
 #include <spine/ArrayUtils.h>
 #include <spine/DeformTimeline.h>
+#include <spine/DrawOrderFolderTimeline.h>
 #include <spine/DrawOrderTimeline.h>
 #include <spine/Event.h>
 #include <spine/EventData.h>
@@ -1242,8 +1243,13 @@ Animation *SkeletonJson::readAnimation(Json *map, SkeletonData *skeletonData) {
 			return NULL;
 		}
 		for (Json *slotMap = attachmentsMap->_child; slotMap; slotMap = slotMap->_next) {
-			int slotIndex = findSlotIndex(skeletonData, slotMap->_name, timelines);
-			if (slotIndex == -1) return NULL;
+			SlotData *slot = skeletonData->findSlot(slotMap->_name);
+			if (!slot) {
+				ArrayUtils::deleteElements(timelines);
+				setError(NULL, "Attachment slot not found: ", slotMap->_name);
+				return NULL;
+			}
+			int slotIndex = slot->getIndex();
 			for (Json *attachmentMap = slotMap->_child; attachmentMap; attachmentMap = attachmentMap->_next) {
 				Attachment *attachment = skin->getAttachment(slotIndex, attachmentMap->_name);
 				if (!attachment) {
@@ -1327,36 +1333,48 @@ Animation *SkeletonJson::readAnimation(Json *map, SkeletonData *skeletonData) {
 		int frame = 0;
 		for (Json *keyMap = drawOrder->_child; keyMap; keyMap = keyMap->_next, ++frame) {
 			Array<int> drawOrder2;
-			Json *offsets = Json::getItem(keyMap, "offsets");
-			if (offsets) {
-				drawOrder2.setSize(slotCount, 0);
-				for (int i = slotCount - 1; i >= 0; i--) drawOrder2[i] = -1;
-				Array<int> unchanged;
-				unchanged.setSize(slotCount - offsets->_size, 0);
-				int originalIndex = 0, unchangedIndex = 0;
-				for (Json *offsetMap = offsets->_child; offsetMap; offsetMap = offsetMap->_next) {
-					SlotData *slot = skeletonData->findSlot(Json::getString(offsetMap, "slot", 0));
-					if (!slot) {
-						ArrayUtils::deleteElements(timelines);
-						return NULL;
-					}
-					/* Collect unchanged items. */
-					while (originalIndex != slot->_index) unchanged[unchangedIndex++] = originalIndex++;
-					/* Set changed items. */
-					int index = originalIndex;
-					drawOrder2[index + Json::getInt(offsetMap, "offset", 0)] = originalIndex++;
-				}
-				/* Collect remaining unchanged items. */
-				while (originalIndex < slotCount) unchanged[unchangedIndex++] = originalIndex++;
-				/* Fill in unchanged items. */
-				for (int i = slotCount - 1; i >= 0; i--)
-					if (drawOrder2[i] == -1) drawOrder2[i] = unchanged[--unchangedIndex];
+			if (!readDrawOrder(skeletonData, keyMap, slotCount, NULL, drawOrder2)) {
+				ArrayUtils::deleteElements(timelines);
+				return NULL;
 			}
-			timeline->setFrame(frame, Json::getFloat(keyMap, "time", 0), &drawOrder2);
+			timeline->setFrame(frame, Json::getFloat(keyMap, "time", 0), drawOrder2.size() == 0 ? NULL : &drawOrder2);
 		}
 		timelines.add(timeline);
 	}
 
+	// Draw order folder timelines.
+	Json *drawOrderFolder = Json::getItem(map, "drawOrderFolder");
+	if (drawOrderFolder) {
+		for (Json *timelineMap = drawOrderFolder->_child; timelineMap; timelineMap = timelineMap->_next) {
+			Json *slotEntry = Json::getItem(timelineMap, "slots");
+			Array<int> folderSlots;
+			folderSlots.setSize(slotEntry ? slotEntry->_size : 0, 0);
+			int ii = 0;
+			for (Json *entry = slotEntry ? slotEntry->_child : NULL; entry; entry = entry->_next, ++ii) {
+				SlotData *slot = skeletonData->findSlot(entry->_valueString);
+				if (!slot) {
+					ArrayUtils::deleteElements(timelines);
+					setError(NULL, "Draw order folder slot not found: ", entry->_valueString);
+					return NULL;
+				}
+				folderSlots[ii] = slot->getIndex();
+			}
+			Json *keyMap = Json::getItem(timelineMap, "keys");
+			DrawOrderFolderTimeline *timeline = new (__FILE__, __LINE__)
+				DrawOrderFolderTimeline(keyMap ? keyMap->_size : 0, folderSlots, skeletonData->_slots.size());
+			int frame = 0;
+			for (Json *entry = keyMap ? keyMap->_child : NULL; entry; entry = entry->_next, ++frame) {
+				Array<int> folderDrawOrder;
+				if (!readDrawOrder(skeletonData, entry, (int) folderSlots.size(), &folderSlots, folderDrawOrder)) {
+					ArrayUtils::deleteElements(timelines);
+					return NULL;
+				}
+				timeline->setFrame(frame, Json::getFloat(entry, "time", 0), folderDrawOrder.size() == 0 ? NULL : &folderDrawOrder);
+			}
+			timelines.add(timeline);
+		}
+	}
+
 	// Event timeline.
 	Json *events = Json::getItem(map, "events");
 	if (events) {
@@ -1462,6 +1480,49 @@ int SkeletonJson::findSlotIndex(SkeletonData *skeletonData, const String &slotNa
 	return slotIndex;
 }
 
+bool SkeletonJson::readDrawOrder(SkeletonData *skeletonData, Json *keyMap, int slotCount, const Array<int> *folderSlots, Array<int> &drawOrder) {
+	Json *changes = Json::getItem(keyMap, "offsets");
+	drawOrder.clear();
+	if (changes == NULL) return true;
+
+	drawOrder.setSize(slotCount, 0);
+	for (int i = slotCount - 1; i >= 0; i--) drawOrder[i] = -1;
+	Array<int> unchanged;
+	unchanged.setSize(slotCount - changes->_size, 0);
+	int originalIndex = 0, unchangedIndex = 0;
+	for (Json *offsetMap = changes->_child; offsetMap; offsetMap = offsetMap->_next) {
+		const char *slotName = Json::getString(offsetMap, "slot", 0);
+		SlotData *slot = skeletonData->findSlot(slotName);
+		if (slot == NULL) {
+			setError(NULL, "Draw order slot not found: ", slotName);
+			return false;
+		}
+		int index;
+		if (folderSlots == NULL) {
+			index = slot->getIndex();
+		} else {
+			index = -1;
+			for (int i = 0; i < slotCount; i++) {
+				if ((*folderSlots)[i] == slot->getIndex()) {
+					index = i;
+					break;
+				}
+			}
+			if (index == -1) {
+				setError(NULL, "Slot not in folder: ", slotName);
+				return false;
+			}
+		}
+		while (originalIndex != index) unchanged[unchangedIndex++] = originalIndex++;
+		int drawOrderIndex = originalIndex;
+		drawOrder[drawOrderIndex + Json::getInt(offsetMap, "offset", 0)] = originalIndex++;
+	}
+	while (originalIndex < slotCount) unchanged[unchangedIndex++] = originalIndex++;
+	for (int i = slotCount - 1; i >= 0; i--)
+		if (drawOrder[i] == -1) drawOrder[i] = unchanged[--unchangedIndex];
+	return true;
+}
+
 void SkeletonJson::setError(Json *root, const String &value1, const String &value2) {
 	_error = String(value1).append(value2);
 	delete root;