From 6f1ef88f1e5dc640bef97569dada36bcddbe5ec2 Mon Sep 17 00:00:00 2001
From: badlogic <badlogicgames@gmail.com>
Date: Fri, 4 May 2018 14:35:37 +0200
Subject: [PATCH] [c][c++] port of PathConstraint changes, see #1109.

---
 spine-c/spine-c/src/spine/PathConstraint.c    | 20 ++++++++++++++-----
 .../spine-cpp/src/spine/PathConstraint.cpp    | 17 ++++++++++++----
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/spine-c/spine-c/src/spine/PathConstraint.c b/spine-c/spine-c/src/spine/PathConstraint.c
index a66027233..148898048 100644
--- a/spine-c/spine-c/src/spine/PathConstraint.c
+++ b/spine-c/spine-c/src/spine/PathConstraint.c
@@ -84,8 +84,7 @@ void spPathConstraint_apply (spPathConstraint* self) {
 	int/*bool*/ translate = translateMix > 0, rotate = rotateMix > 0;
 	spPathAttachment* attachment = (spPathAttachment*)self->target->attachment;
 	spPathConstraintData* data = self->data;
-	spSpacingMode spacingMode = data->spacingMode;
-	int lengthSpacing = spacingMode == SP_SPACING_MODE_LENGTH;
+	int percentSpacing = data->spacingMode == SP_SPACING_MODE_PERCENT;
 	spRotateMode rotateMode = data->rotateMode;
 	int tangents = rotateMode == SP_ROTATE_MODE_TANGENT, scale = rotateMode == SP_ROTATE_MODE_CHAIN_SCALE;
 	int boneCount = self->bonesCount, spacesCount = tangents ? boneCount : boneCount + 1;
@@ -104,7 +103,7 @@ void spPathConstraint_apply (spPathConstraint* self) {
 	spaces[0] = 0;
 	lengths = 0;
 	spacing = self->spacing;
-	if (scale || lengthSpacing) {
+	if (scale || !percentSpacing) {
 		if (scale) {
 			if (self->lengthsCount != boneCount) {
 				if (self->lengths) FREE(self->lengths);
@@ -113,12 +112,20 @@ void spPathConstraint_apply (spPathConstraint* self) {
 			}
 			lengths = self->lengths;
 		}
+		int lengthSpacing = data->spacingMode == SP_SPACING_MODE_LENGTH;
 		for (i = 0, n = spacesCount - 1; i < n;) {
 			spBone *bone = bones[i];
 			setupLength = bone->data->length;
 			if (setupLength < EPSILON) {
 				if (scale) lengths[i] = 0;
 				spaces[++i] = 0;
+			} else if (percentSpacing) {
+				if (scale) {
+					float x = setupLength * bone->a, y = setupLength * bone->c;
+					float length = SQRT(x * x + y * y);
+					lengths[i] = length;
+				}
+				spaces[++i] = spacing;
 			} else {
 				x = setupLength * bone->a, y = setupLength * bone->c;
 				length = SQRT(x * x + y * y);
@@ -133,7 +140,7 @@ void spPathConstraint_apply (spPathConstraint* self) {
 	}
 
 	positions = spPathConstraint_computeWorldPositions(self, attachment, spacesCount, tangents,
-		data->positionMode == SP_POSITION_MODE_PERCENT, spacingMode == SP_SPACING_MODE_PERCENT);
+		data->positionMode == SP_POSITION_MODE_PERCENT, percentSpacing);
 	boneX = positions[0], boneY = positions[1], offsetRotation = self->data->offsetRotation;
 	tip = 0;
 	if (offsetRotation == 0)
@@ -373,7 +380,10 @@ float* spPathConstraint_computeWorldPositions(spPathConstraint* self, spPathAtta
 		x1 = x2;
 		y1 = y2;
 	}
-	if (percentPosition) position *= pathLength;
+	if (percentPosition)
+		position *= pathLength;
+	else
+		position *= pathLength / path->lengths[curveCount - 1];
 	if (percentSpacing) {
 		for (i = 0; i < spacesCount; i++)
 			spaces[i] *= pathLength;
diff --git a/spine-cpp/spine-cpp/src/spine/PathConstraint.cpp b/spine-cpp/spine-cpp/src/spine/PathConstraint.cpp
index 64fd8e66d..361afeb51 100644
--- a/spine-cpp/spine-cpp/src/spine/PathConstraint.cpp
+++ b/spine-cpp/spine-cpp/src/spine/PathConstraint.cpp
@@ -86,18 +86,18 @@ void PathConstraint::update() {
 	}
 
 	PathConstraintData &data = _data;
-	SpacingMode spacingMode = data._spacingMode;
-	bool lengthSpacing = spacingMode == SpacingMode_Length;
+	bool percentSpacing = data._spacingMode == SpacingMode_Percent;
 	RotateMode rotateMode = data._rotateMode;
 	bool tangents = rotateMode == RotateMode_Tangent, scale = rotateMode == RotateMode_ChainScale;
 	size_t boneCount = _bones.size();
 	int spacesCount = static_cast<int>(tangents ? boneCount : boneCount + 1);
 	_spaces.setSize(spacesCount, 0);
 	float spacing = _spacing;
-	if (scale || lengthSpacing) {
+	if (scale || !percentSpacing) {
 		if (scale) {
 			_lengths.setSize(boneCount, 0);
 		}
+		bool lengthSpacing = data._spacingMode == SpacingMode_Length;
 
 		for (int i = 0, n = spacesCount - 1; i < n;) {
 			Bone *boneP = _bones[i];
@@ -108,6 +108,13 @@ void PathConstraint::update() {
 					_lengths[i] = 0;
 				}
 				_spaces[++i] = 0;
+			} else if (percentSpacing) {
+				if (scale) {
+					float x = setupLength * bone._a, y = setupLength * bone._c;
+					float length = MathUtil::sqrt(x * x + y * y);
+					_lengths[i] = length;
+				}
+				_spaces[++i] = spacing;
 			} else {
 				float x = setupLength * bone._a;
 				float y = setupLength * bone._c;
@@ -127,7 +134,7 @@ void PathConstraint::update() {
 
 	Vector<float>& positions = computeWorldPositions(*attachment, spacesCount, tangents,
 													data.getPositionMode() == PositionMode_Percent,
-													spacingMode == SpacingMode_Percent);
+													percentSpacing);
 	float boneX = positions[0];
 	float boneY = positions[1];
 	float offsetRotation = data.getOffsetRotation();
@@ -399,6 +406,8 @@ PathConstraint::computeWorldPositions(PathAttachment &path, int spacesCount, boo
 
 	if (percentPosition) {
 		position *= pathLength;
+	} else {
+		position *= pathLength / path.getLengths()[curveCount - 1];
 	}
 
 	if (percentSpacing) {