[libgdx] Skip bones in update cache when a slider mix is 0.

spine-libgdx/spine-libgdx/src/com/esotericsoftware/spine/Bone.java

@@ -65,4 +65,11 @@ public class Bone extends PosedActive<BoneData, BoneLocal, BonePose> {
 	public Array<Bone> getChildren () {
 		return children;
 	}
+
+	void resetUpdate () {
+		applied.update = 0;
+		Bone[] children = this.children.items;
+		for (int i = 0, n = this.children.size; i < n; i++)
+			children[i].resetUpdate();
+	}
 }

spine-libgdx/spine-libgdx/src/com/esotericsoftware/spine/BonePose.java

@@ -15,24 +15,23 @@ public class BonePose extends BoneLocal implements Update {
 	Bone bone;
 	float a, b, worldX;
 	float c, d, worldY;
+	int update;
 
 	BonePose () {
 	}
 
-	/** Computes the world transform using the parent bone and this bone's local applied transform. */
-	public void updateWorldTransform (Skeleton skeleton) {
-		update(skeleton, null);
+	/** Called by {@link Skeleton#updateCache()} to compute the world transform, if needed. */
+	public void update (Skeleton skeleton, Physics physics) {
+		if (update != skeleton.update) updateWorldTransform(skeleton);
 	}
 
-	/** Computes the world transform using the parent bone and this bone's local transform.
-	 * <p>
-	 * See {@link #updateWorldTransform(float, float, float, float, float, float, float)}. */
-	/** Computes the world transform using the parent bone and the specified local transform. The applied transform is set to the
-	 * specified local transform. Child bones are not updated.
+	/** Computes the world transform using the parent bone's applied pose and this pose. Child bones are not updated.
 	 * <p>
 	 * See <a href="https://esotericsoftware.com/spine-runtime-skeletons#World-transforms">World transforms</a> in the Spine
 	 * Runtimes Guide. */
-	public void update (Skeleton skeleton, Physics physics) {
+	public void updateWorldTransform (Skeleton skeleton) {
+		update = skeleton.update;
+
 		if (bone.parent == null) { // Root bone.
 			float sx = skeleton.scaleX, sy = skeleton.scaleY;
 			float rx = (rotation + shearX) * degRad;
@@ -140,6 +139,8 @@ public class BonePose extends BoneLocal implements Update {
 	 * Some information is ambiguous in the world transform, such as -1,-1 scale versus 180 rotation. The local transform after
 	 * calling this method is equivalent to the local transform used to compute the world transform, but may not be identical. */
 	public void updateLocalTransform (Skeleton skeleton) {
+		update = skeleton.update;
+
 		if (bone.parent == null) {
 			x = worldX - skeleton.x;
 			y = worldY - skeleton.y;
@@ -353,8 +354,8 @@ public class BonePose extends BoneLocal implements Update {
 
 	/** Rotates the world transform the specified amount.
 	 * <p>
-	 * After changes are made to the world transform, {@link #updateLocalTransform(Skeleton)} should be called and
-	 * {@link #update(Skeleton, Physics)} will need to be called on any child bones, recursively. */
+	 * After changes are made to the world transform, {@link #updateLocalTransform(Skeleton)} should be called on this bone and any
+	 * child bones, recursively. */
 	public void rotateWorld (float degrees) {
 		degrees *= degRad;
 		float sin = sin(degrees), cos = cos(degrees);

spine-libgdx/spine-libgdx/src/com/esotericsoftware/spine/Skeleton.java

@@ -61,6 +61,7 @@ public class Skeleton {
 	@Null Skin skin;
 	final Color color;
 	float x, y, scaleX = 1, scaleY = 1, time;
+	int update;
 
 	public Skeleton (SkeletonData data) {
 		if (data == null) throw new IllegalArgumentException("data cannot be null.");
@@ -224,6 +225,8 @@ public class Skeleton {
 	 * See <a href="https://esotericsoftware.com/spine-runtime-skeletons#World-transforms">World transforms</a> in the Spine
 	 * Runtimes Guide. */
 	public void updateWorldTransform (Physics physics) {
+		update++;
+
 		Posed[] resetCache = this.resetCache.items;
 		for (int i = 0, n = this.resetCache.size; i < n; i++)
 			resetCache[i].resetAppliedPose();
@@ -241,6 +244,8 @@ public class Skeleton {
 	public void updateWorldTransform (Physics physics, BonePose parent) {
 		if (parent == null) throw new IllegalArgumentException("parent cannot be null.");
 
+		update++;
+
 		Posed[] resetCache = this.resetCache.items;
 		for (int i = 0, n = this.resetCache.size; i < n; i++)
 			resetCache[i].resetAppliedPose();

spine-libgdx/spine-libgdx/src/com/esotericsoftware/spine/Slider.java

@@ -55,12 +55,17 @@ public class Slider extends Constraint<Slider, SliderData, SliderPose> {
 		if (pose.mix == 0) return;
 		SliderPose pose = applied;
 		data.animation.apply(skeleton, pose.time, pose.time, false, null, pose.mix, MixBlend.replace, MixDirection.in, true);
+
+		Timeline[] timelines = data.animation.timelines.items;
+		int timelineCount = data.animation.timelines.size;
+		Bone[] bones = skeleton.bones.items;
+		for (int i = 0; i < timelineCount; i++)
+			if (timelines[i] instanceof BoneTimeline boneTimeline) bones[boneTimeline.getBoneIndex()].resetUpdate();
 	}
 
 	void sort (Skeleton skeleton) {
 		Timeline[] timelines = data.animation.timelines.items;
 		int timelineCount = data.animation.timelines.size;
-
 		Bone[] bones = skeleton.bones.items;
 		for (int i = 0; i < timelineCount; i++)
 			if (timelines[i] instanceof BoneTimeline boneTimeline) skeleton.sortBone(bones[boneTimeline.getBoneIndex()]);
@@ -72,6 +77,7 @@ public class Slider extends Constraint<Slider, SliderData, SliderPose> {
 			Timeline t = timelines[i];
 			if (t instanceof BoneTimeline timeline) {
 				Bone bone = bones[timeline.getBoneIndex()];
+				skeleton.resetCache(bone);
 				skeleton.sortReset(bone.children);
 				bone.sorted = false;
 			} else if (t instanceof SlotTimeline timeline)

spine-libgdx/spine-libgdx/src/com/esotericsoftware/spine/TransformConstraint.java

@@ -94,7 +94,7 @@ public class TransformConstraint extends Constraint<TransformConstraint, Transfo
 				}
 			}
 			if (localTarget)
-				bone.update(skeleton, null);
+				bone.updateWorldTransform(skeleton);
 			else
 				bone.updateLocalTransform(skeleton);
 		}