[libgdx] Transform constraint fixes, javadoc.

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

@@ -38,7 +38,7 @@ import com.esotericsoftware.spine.Skeleton.Physics;
  * See <a href="https://esotericsoftware.com/spine-physics-constraints">Physics constraints</a> in the Spine User Guide. */
 public class PhysicsConstraint implements Updatable {
 	final PhysicsConstraintData data;
-	public Bone bone;
+	Bone bone;
 	float inertia, strength, damping, massInverse, wind, gravity, mix;
 
 	boolean reset = true;

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

@@ -287,7 +287,7 @@ public class SkeletonBinary extends SkeletonLoader {
 				data.localTo = (flags & 4) != 0;
 				data.relative = (flags & 8) != 0;
 				data.clamp = (flags & 16) != 0;
-				nn = flags >> 5;
+				Object[] froms = data.properties.setSize(nn = flags >> 5);
 				for (int ii = 0, tn; ii < nn; ii++) {
 					FromProperty from = switch (input.readByte()) {
 					case 0 -> new FromRotate();
@@ -299,7 +299,7 @@ public class SkeletonBinary extends SkeletonLoader {
 					default -> null;
 					};
 					from.offset = input.readFloat() * scale;
-					Object[] properties = from.to.setSize(tn = input.readInt(true));
+					Object[] tos = from.to.setSize(tn = input.readByte());
 					for (int t = 0; t < tn; t++) {
 						ToProperty to = switch (input.readByte()) {
 						case 0 -> new ToRotate();
@@ -313,8 +313,9 @@ public class SkeletonBinary extends SkeletonLoader {
 						to.offset = input.readFloat() * scale;
 						to.max = input.readFloat() * scale;
 						to.scale = input.readFloat();
-						properties[i] = to;
+						tos[i] = to;
 					}
+					froms[ii] = from;
 				}
 				flags = input.read();
 				if ((flags & 1) != 0) data.mixRotate = input.readFloat();

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

@@ -272,8 +272,8 @@ public class SkeletonJson extends SkeletonLoader {
 				default -> throw new SerializationException("Invalid transform constraint from property: " + fromEntry.name);
 				};
 				from.offset = fromEntry.getFloat("offset", 0) * scale;
-				for (JsonValue toEntry = constraintMap.getChild("to"); toEntry != null; toEntry = toEntry.next) {
+				for (JsonValue toEntry = fromEntry.getChild("to"); toEntry != null; toEntry = toEntry.next) {
-					ToProperty to = switch (fromEntry.name) {
+					ToProperty to = switch (toEntry.name) {
 					case "rotate" -> new ToRotate();
 					case "x" -> new ToX();
 					case "y" -> new ToY();
@@ -287,6 +287,7 @@ public class SkeletonJson extends SkeletonLoader {
 					to.scale = toEntry.getFloat("scale");
 					from.to.add(to);
 				}
+				if (from.to.notEmpty()) data.properties.add(from);
 			}
 
 			data.mixRotate = constraintMap.getFloat("mixRotate", 1);

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

@@ -105,14 +105,20 @@ public class TransformConstraint implements Updatable {
 			var bone = (Bone)bones[i];
 			for (int f = 0; f < fn; f++) {
 				var from = (FromProperty)fromItems[f];
-				if (from.mix(this) != 0) {
+				float mix = from.mix(this);
+				if (mix != 0) {
 					float value = from.value(target, localFrom) - from.offset;
 					Object[] toItems = from.to.items;
 					for (int t = 0, tn = from.to.size; t < tn; t++) {
 						var to = (ToProperty)toItems[t];
 						float clamped = to.offset + value * to.scale;
-						if (clamp) clamped = clamp(clamped, to.offset, to.max);
+						if (clamp) {
-						to.apply(this, bone, clamped, localTo, relative);
+							if (to.offset < to.max)
+								clamped = clamp(clamped, to.offset, to.max);
+							else
+								clamped = clamp(clamped, to.max, to.offset);
+						}
+						to.apply(bone, clamped, localTo, relative, mix);
 					}
 				}
 			}

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

@@ -121,6 +121,7 @@ public class TransformConstraintData extends ConstraintData {
 		this.mixShearY = mixShearY;
 	}
 
+	/** Reads the target bone's local transform instead of its world transform. */
 	public boolean getLocalFrom () {
 		return localFrom;
 	}
@@ -129,6 +130,7 @@ public class TransformConstraintData extends ConstraintData {
 		this.localFrom = localFrom;
 	}
 
+	/** Sets the constrained bones' local transforms instead of their world transforms. */
 	public boolean getLocalTo () {
 		return localTo;
 	}
@@ -137,6 +139,7 @@ public class TransformConstraintData extends ConstraintData {
 		this.localTo = localTo;
 	}
 
+	/** Adds the target bone transform to the constrained bones instead of setting it absolutely. */
 	public boolean getRelative () {
 		return relative;
 	}
@@ -145,6 +148,7 @@ public class TransformConstraintData extends ConstraintData {
 		this.relative = relative;
 	}
 
+	/** Prevents constrained bones from exceeding the ranged defined by {@link ToProperty#offset} and {@link ToProperty#max}. */
 	public boolean getClamp () {
 		return clamp;
 	}
@@ -153,19 +157,34 @@ public class TransformConstraintData extends ConstraintData {
 		this.clamp = clamp;
 	}
 
+	/** Source property for a {@link TransformConstraint}. */
 	static abstract public class FromProperty {
+		/** The value of this property that corresponds to {@link ToProperty#offset}. */
 		public float offset;
+
+		/** Constrained properties. */
 		public final Array<ToProperty> to = new Array();
 
+		/** Reads this property from the specified bone. */
 		abstract public float value (Bone target, boolean local);
 
+		/** Reads the mix for this property from the specified constraint. */
 		abstract public float mix (TransformConstraint constraint);
 	}
 
+	/** Constrained property for a {@link TransformConstraint}. */
 	static abstract public class ToProperty {
-		public float offset, max, scale;
+		/** The value of this property that corresponds to {@link FromProperty#offset}. */
+		public float offset;
 
-		abstract public void apply (TransformConstraint constraint, Bone bone, float value, boolean local, boolean relative);
+		/** The maximum value of this property when {@link TransformConstraintData#clamp clamped}. */
+		public float max;
+
+		/** The scale of the {@link FromProperty} value in relation to this property. */
+		public float scale;
+
+		/** Applies the value to this property. */
+		abstract public void apply (Bone bone, float value, boolean local, boolean relative, float mix);
 	}
 
 	static public class FromRotate extends FromProperty {
@@ -179,20 +198,20 @@ public class TransformConstraintData extends ConstraintData {
 	}
 
 	static public class ToRotate extends ToProperty {
-		public void apply (TransformConstraint constraint, Bone bone, float value, boolean local, boolean relative) {
+		public void apply (Bone bone, float value, boolean local, boolean relative, float mix) {
 			if (local) {
 				if (!relative) value -= bone.arotation;
-				bone.arotation += value * constraint.mixRotate;
+				bone.arotation += value * mix;
 			} else {
 				float a = bone.a, b = bone.b, c = bone.c, d = bone.d;
-				float r = value * degRad;
+				value *= degRad;
-				if (!relative) r -= atan2(c, a);
+				if (!relative) value -= atan2(c, a);
-				if (r > PI)
+				if (value > PI)
-					r -= PI2;
+					value -= PI2;
-				else if (r < -PI) //
+				else if (value < -PI) //
-					r += PI2;
+					value += PI2;
-				r *= constraint.mixRotate;
+				value *= mix;
-				float cos = cos(r), sin = sin(r);
+				float cos = cos(value), sin = sin(value);
 				bone.a = cos * a - sin * c;
 				bone.b = cos * b - sin * d;
 				bone.c = sin * a + cos * c;
@@ -212,13 +231,13 @@ public class TransformConstraintData extends ConstraintData {
 	}
 
 	static public class ToX extends ToProperty {
-		public void apply (TransformConstraint constraint, Bone bone, float value, boolean local, boolean relative) {
+		public void apply (Bone bone, float value, boolean local, boolean relative, float mix) {
 			if (local) {
 				if (!relative) value -= bone.ax;
-				bone.ax += value * constraint.mixX;
+				bone.ax += value * mix;
 			} else {
 				if (!relative) value -= bone.worldX;
-				bone.worldX += value * constraint.mixX;
+				bone.worldX += value * mix;
 			}
 		}
 	}
@@ -234,20 +253,20 @@ public class TransformConstraintData extends ConstraintData {
 	}
 
 	static public class ToY extends ToProperty {
-		public void apply (TransformConstraint constraint, Bone bone, float value, boolean local, boolean relative) {
+		public void apply (Bone bone, float value, boolean local, boolean relative, float mix) {
 			if (local) {
 				if (!relative) value -= bone.ay;
-				bone.ay += value * constraint.mixY;
+				bone.ay += value * mix;
 			} else {
 				if (!relative) value -= bone.worldY;
-				bone.worldY += value * constraint.mixY;
+				bone.worldY += value * mix;
 			}
 		}
 	}
 
 	static public class FromScaleX extends FromProperty {
 		public float value (Bone target, boolean local) {
-			return local ? target.arotation : (float)Math.sqrt(target.a * target.a + target.c * target.c);
+			return local ? target.ascaleX : (float)Math.sqrt(target.a * target.a + target.c * target.c);
 		}
 
 		public float mix (TransformConstraint constraint) {
@@ -256,19 +275,19 @@ public class TransformConstraintData extends ConstraintData {
 	}
 
 	static public class ToScaleX extends ToProperty {
-		public void apply (TransformConstraint constraint, Bone bone, float value, boolean local, boolean relative) {
+		public void apply (Bone bone, float value, boolean local, boolean relative, float mix) {
 			if (local) {
 				if (relative)
-					bone.ascaleX *= 1 + ((value - 1) * constraint.mixScaleX);
+					bone.ascaleX *= 1 + ((value - 1) * mix);
 				else if (bone.ascaleX != 0) //
-					bone.ascaleX = 1 + (value / bone.ascaleX - 1) * constraint.mixScaleX;
+					bone.ascaleX = 1 + (value / bone.ascaleX - 1) * mix;
 			} else {
 				float s;
 				if (relative)
-					s = 1 + (value - 1) * constraint.mixScaleX;
+					s = 1 + (value - 1) * mix;
 				else {
 					s = (float)Math.sqrt(bone.a * bone.a + bone.c * bone.c);
-					if (s != 0) s = 1 + (value / s - 1) * constraint.mixScaleX;
+					if (s != 0) s = 1 + (value / s - 1) * mix;
 				}
 				bone.a *= s;
 				bone.c *= s;
@@ -278,7 +297,7 @@ public class TransformConstraintData extends ConstraintData {
 
 	static public class FromScaleY extends FromProperty {
 		public float value (Bone target, boolean local) {
-			return local ? target.arotation : (float)Math.sqrt(target.b * target.b + target.d * target.d);
+			return local ? target.ascaleY : (float)Math.sqrt(target.b * target.b + target.d * target.d);
 		}
 
 		public float mix (TransformConstraint constraint) {
@@ -287,19 +306,19 @@ public class TransformConstraintData extends ConstraintData {
 	}
 
 	static public class ToScaleY extends ToProperty {
-		public void apply (TransformConstraint constraint, Bone bone, float value, boolean local, boolean relative) {
+		public void apply (Bone bone, float value, boolean local, boolean relative, float mix) {
 			if (local) {
 				if (relative)
-					bone.ascaleY *= 1 + ((value - 1) * constraint.mixScaleY);
+					bone.ascaleY *= 1 + ((value - 1) * mix);
 				else if (bone.ascaleY != 0) //
-					bone.ascaleY = 1 + (value / bone.ascaleY - 1) * constraint.mixScaleY;
+					bone.ascaleY = 1 + (value / bone.ascaleY - 1) * mix;
 			} else {
 				float s;
 				if (relative)
-					s = 1 + (value - 1) * constraint.mixScaleY;
+					s = 1 + (value - 1) * mix;
 				else {
 					s = (float)Math.sqrt(bone.b * bone.b + bone.d * bone.d);
-					if (s != 0) s = 1 + (value / s - 1) * constraint.mixScaleY;
+					if (s != 0) s = 1 + (value / s - 1) * mix;
 				}
 				bone.b *= s;
 				bone.d *= s;
@@ -309,13 +328,7 @@ public class TransformConstraintData extends ConstraintData {
 
 	static public class FromShearY extends FromProperty {
 		public float value (Bone target, boolean local) {
-			if (local) return target.ashearY;
+			return local ? target.ashearY : (atan2(target.d, target.b) - atan2(target.c, target.a)) * radDeg - 90;
-			float r = atan2(target.d, target.b) - atan2(target.c, target.a);
-			if (r > PI)
-				r -= PI2;
-			else if (r < -PI) //
-				r += PI2;
-			return r;
 		}
 
 		public float mix (TransformConstraint constraint) {
@@ -324,12 +337,13 @@ public class TransformConstraintData extends ConstraintData {
 	}
 
 	static public class ToShearY extends ToProperty {
-		public void apply (TransformConstraint constraint, Bone bone, float value, boolean local, boolean relative) {
+		public void apply (Bone bone, float value, boolean local, boolean relative, float mix) {
 			if (local) {
 				if (!relative) value -= bone.ashearY;
-				bone.ashearY += value * constraint.mixShearY;
+				bone.ashearY += value * mix;
 			} else {
 				float b = bone.b, d = bone.d, by = atan2(d, b);
+				value = (value + 90) * degRad;
 				if (relative)
 					value -= PI / 2;
 				else {
@@ -339,7 +353,7 @@ public class TransformConstraintData extends ConstraintData {
 					else if (value < -PI) //
 						value += PI2;
 				}
-				value = by + value * constraint.mixShearY;
+				value = by + value * mix;
 				float s = (float)Math.sqrt(b * b + d * d);
 				bone.b = cos(value) * s;
 				bone.d = sin(value) * s;