From eefa69b53dba28d760061301df72bfe6163b0daa Mon Sep 17 00:00:00 2001
From: doop <56421834+dooplecks@users.noreply.github.com>
Date: Fri, 5 Jun 2026 02:05:20 -0400
Subject: [PATCH] Re-enable JParticle interpolation and fix emitter direction
 issue (#1968)

* Re-enable JParticle interpolation

* Ensure emitter direction is valid for JPA interp

Fixes #618.

* Don't `calcWorkData` if we don't need to
---
 libs/JSystem/src/JParticle/JPAParticle.cpp | 3 +--
 libs/JSystem/src/JParticle/JPAResource.cpp | 9 +++++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/libs/JSystem/src/JParticle/JPAParticle.cpp b/libs/JSystem/src/JParticle/JPAParticle.cpp
index d3490ab294..eb2395e346 100644
--- a/libs/JSystem/src/JParticle/JPAParticle.cpp
+++ b/libs/JSystem/src/JParticle/JPAParticle.cpp
@@ -206,8 +206,7 @@ void JPABaseParticle::init_c(JPAEmitterWorkData* work, JPABaseParticle* parent)
 
 #if TARGET_PC
 void JPABaseParticle::interp(JPAEmitterWorkData* work, void const* drawFunc) {
-    static bool enable = false;
-    if (!enable)
+    if (!dusk::frame_interp::is_enabled())
         return;
 
     // don't interpolate the first frame
diff --git a/libs/JSystem/src/JParticle/JPAResource.cpp b/libs/JSystem/src/JParticle/JPAResource.cpp
index 2ae4709fc3..59e679d449 100644
--- a/libs/JSystem/src/JParticle/JPAResource.cpp
+++ b/libs/JSystem/src/JParticle/JPAResource.cpp
@@ -761,6 +761,15 @@ bool JPAResource::calc(JPAEmitterWorkData* work, JPABaseEmitter* emtr) {
             }
         }
 
+#ifdef TARGET_PC
+        if (((pBsp && pBsp->getDirType() == 3) || (pCsp && pCsp->getDirType() == 3)) &&
+            dusk::frame_interp::is_enabled())
+        {
+            // ensure mGlobalEmtrDir is valid
+            calcWorkData_d(work);
+        }
+#endif
+
         JPANode<JPABaseParticle>* next = NULL;
         for (JPANode<JPABaseParticle>* node = emtr->mAlivePtclBase.getFirst(); node != emtr->mAlivePtclBase.getEnd(); node = next) {
             next = node->getNext();