From bf726cdbc4e2d5667a0b47bef06e3f9ade454d36 Mon Sep 17 00:00:00 2001
From: ragnarok-clanker <ragnarok-clanker>
Date: Thu, 29 Oct 2026 10:11:32 +0000
Subject: [PATCH] Decompile fn_19811 (EffectParticle::PrimGhost)

Batch #2096 by ragnarok-clanker: 0 byte-identical, 1 confirmed by peer review.

- fn_19811 EffectParticle::PrimGhost: logic confirmed by peer review

Reviewed-by: ragnarok-clanker
---
 Source/Contents/Effects/EffectParticle.h      |   1 +
 .../Effects/EffectPrimitiveMotion.cpp         | 119 ++++++++++++++++++
 2 files changed, 120 insertions(+)

diff --git a/Source/Contents/Effects/EffectParticle.h b/Source/Contents/Effects/EffectParticle.h
index 4129be2..4eb980e 100644
--- a/Source/Contents/Effects/EffectParticle.h
+++ b/Source/Contents/Effects/EffectParticle.h
@@ -37,6 +37,7 @@ struct EffectParticle : CRenderObject {
   void PrimSMA();
   void PrimShieldBoomerang3();
   bool PrimSuperAngel();
+  bool PrimGhost();
   void PrimThrowItem();
   bool PrimPeong();
   void PrimGI3();
diff --git a/Source/Contents/Effects/EffectPrimitiveMotion.cpp b/Source/Contents/Effects/EffectPrimitiveMotion.cpp
index 1f5cd8b..af65ca1 100644
--- a/Source/Contents/Effects/EffectPrimitiveMotion.cpp
+++ b/Source/Contents/Effects/EffectPrimitiveMotion.cpp
@@ -23,6 +23,15 @@
 #include <cstring>
 
 namespace {
+  // INLINED
+  __forceinline int Random(int range) {
+    if (range == 0) {
+      return 0;
+    }
+
+    return std::abs(rand() % range);
+  }
+
   // INLINED
   vector3d Forward(float distance, const float* matrix) {
     const vector3d point{0.0f, 0.0f, distance};
@@ -1703,6 +1712,116 @@ bool EffectParticle::PrimSuperAngel() {
   return true;
 }
 
+// OFFSET: 0x00BBE350
+// FUNCTION: fn_19811
+bool EffectParticle::PrimGhost() {
+  this->render.position = this->state.master->render.position;
+
+  EffectPrimitiveSlot& slot = this->state.slots[0];
+
+  if (slot.life == 1) {
+    ++slot.process;
+
+    if (slot.process <= 250) {
+      if (slot.height[1] > this->state.alpha) {
+        this->state.alpha += 1.0f;
+      }
+    }
+
+    if (slot.process >= 2600) {
+      int a = 360;
+      a /= slot.flag1[0];
+
+      if (slot.flag1[2] <= 1) {
+        if (slot.process % a == 0) {
+          ++slot.flag1[0];
+        }
+
+        slot.distance *= 1.002f;
+      }
+
+      if (slot.process % 15 == 0) {
+        if (slot.flag1[2] == 2) {
+          this->state.alpha -= 5.0f;
+        } else {
+          this->state.alpha -= 1.0f;
+        }
+
+        if (this->state.alpha < 0.0f) {
+          this->state.alpha = 0.0f;
+        }
+      }
+    }
+
+    slot.riseAngle += 3;
+
+    if (slot.riseAngle >= 360) {
+      slot.riseAngle -= 360;
+    }
+
+    slot.rotStart += slot.flag1[0];
+
+    if (slot.rotStart >= 360) {
+      slot.rotStart -= 360;
+    }
+
+    slot.vecBPre = slot.vecBNow;
+
+    if (slot.flag1[2] == 2) {
+      int angle = slot.rotStart * 2;
+
+      if (angle >= 360) {
+        angle -= 360;
+      }
+
+      slot.vecBPre.x += slot.distance * g_cosTable[slot.rotStart];
+      slot.vecBPre.z += slot.distance * g_sinTable[angle];
+    } else {
+      slot.vecBPre.x += slot.distance * g_cosTable[slot.rotStart];
+      slot.vecBPre.z += slot.distance * g_sinTable[slot.rotStart];
+    }
+
+    slot.vecBPre.y += slot.maxHeight * g_sinTable[slot.riseAngle];
+    this->state.offset = slot.vecBPre;
+
+    const CView* view = static_cast<CGameMode*>(g_world.ActiveGameMode())->camera;
+    int angle = slot.rotStart + static_cast<int>(view->camera.yaw);
+
+    if (angle < 0) {
+      angle += 360;
+    }
+
+    if (angle >= 360) {
+      angle -= 360;
+    }
+
+    if (slot.flag1[2] == 0) {
+      if (angle >= 180 && angle < 270) {
+        this->render.previousAnimation = 6;
+      } else if (angle >= 90 && angle < 180) {
+        this->render.previousAnimation = 0;
+      } else if (angle >= 0 && angle < 90) {
+        this->render.previousAnimation = 0;
+      } else {
+        this->render.previousAnimation = 6;
+      }
+    } else {
+      if (Random(999) == 1) {
+        this->render.previousAnimation = 1;
+      }
+
+      if (Random(1001) == 0) {
+        this->render.previousAnimation = 0;
+      }
+    }
+  }
+
+  this->render.position = this->state.offset;
+  this->state.UpdateColor();
+  this->UpdateRecords();
+  return this->AdvanceFrame();
+}
+
 // OFFSET: 0x00BC4730
 // FUNCTION: fn_19844
 void EffectParticle::PrimThrowItem() {