From 98c10437c5fcc54fea4ceb726bf72f816c9fda09 Mon Sep 17 00:00:00 2001
From: Mario Zechner <badlogicgames@gmail.com>
Date: Thu, 6 Oct 2022 16:48:46 +0200
Subject: [PATCH] [c] Port of commit 3ea4f66. AnimationState, fixed rotation
 mix when direction changes. See #2158.

---
 spine-c/spine-c/src/spine/AnimationState.c | 25 ++++++++++++----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/spine-c/spine-c/src/spine/AnimationState.c b/spine-c/spine-c/src/spine/AnimationState.c
index 23375ac96..941f7b895 100644
--- a/spine-c/spine-c/src/spine/AnimationState.c
+++ b/spine-c/spine-c/src/spine/AnimationState.c
@@ -673,18 +673,21 @@ void _spAnimationState_applyRotateTimeline(spAnimationState *self, spTimeline *t
 			lastTotal = 0;
 			lastDiff = diff;
 		} else {
-			lastTotal = timelinesRotation[i];    /* Angle and direction of mix, including loops. */
-			lastDiff = timelinesRotation[i + 1]; /* Difference between bones. */
+			lastTotal = timelinesRotation[i];
+			lastDiff = timelinesRotation[i + 1];
 		}
-		current = diff > 0;
-		dir = lastTotal >= 0;
-		/* Detect cross at 0 (not 180). */
-		if (SIGNUM(lastDiff) != SIGNUM(diff) && ABS(lastDiff) <= 90) {
-			/* A cross after a 360 rotation is a loop. */
-			if (ABS(lastTotal) > 180) lastTotal += 360 * SIGNUM(lastTotal);
-			dir = current;
-		}
-		total = diff + lastTotal - FMOD(lastTotal, 360); /* Store loops as part of lastTotal. */
+        float loops = lastTotal - FMOD(lastTotal, 360);
+        total = diff + loops;
+        int current = diff >= 0, dir = lastTotal >= 0;
+        if (ABS(lastDiff) <= 90 && SIGNUM(lastDiff) != SIGNUM(diff)) {
+            if (ABS(lastTotal - loops) > 180) {
+                total += 360 * SIGNUM(lastTotal);
+                dir = current;
+            } else if (loops != 0)
+                total -= 360 * SIGNUM(lastTotal);
+            else
+                dir = current;
+        }
 		if (dir != current) total += 360 * SIGNUM(lastTotal);
 		timelinesRotation[i] = total;
 	}