From 520d73edf61d890036f8ee592b5836d6b2a30345 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Wed, 9 Jan 2019 00:04:28 +0100
Subject: [PATCH] - moved the impact decal counter into FLevelLocals and do the
 counting in a less problematic fashion.

This was yet another piece of code that lived or died with the assumption that there can only be one level, stored in global variables.
---
 src/g_levellocals.h           |  1 +
 src/g_shared/a_decals.cpp     | 28 ++++++++++++----------------
 src/g_shared/a_sharedglobal.h |  3 +--
 src/p_saveg.cpp               |  3 ++-
 4 files changed, 16 insertions(+), 19 deletions(-)

diff --git a/src/g_levellocals.h b/src/g_levellocals.h
index 7825f5f17f..970fb03727 100644
--- a/src/g_levellocals.h
+++ b/src/g_levellocals.h
@@ -210,6 +210,7 @@ struct FLevelLocals : public FLevelData
 	bool		brightfog;
 	bool		lightadditivesurfaces;
 	bool		notexturefill;
+	int			ImpactDecalCount;
 
 	FDynamicLight *lights;
 
diff --git a/src/g_shared/a_decals.cpp b/src/g_shared/a_decals.cpp
index fcf1843919..c7a70e3b5c 100644
--- a/src/g_shared/a_decals.cpp
+++ b/src/g_shared/a_decals.cpp
@@ -550,37 +550,39 @@ CUSTOM_CVAR (Int, cl_maxdecals, 1024, CVAR_ARCHIVE)
 	}
 	else
 	{
-		while (ImpactCount > self)
+		ForAllLevels([&](FLevelLocals *Level)
 		{
-			DThinker *thinker = DThinker::FirstThinker (STAT_AUTODECAL);
-			if (thinker != NULL)
+			while (Level->ImpactDecalCount > self)
 			{
-				thinker->Destroy();
+				DThinker *thinker = DThinker::FirstThinker(STAT_AUTODECAL);
+				if (thinker != NULL)
+				{
+					thinker->Destroy();
+				}
 			}
-		}
+		});
 	}
 }
 
 DImpactDecal::DImpactDecal ()
 : DBaseDecal (STAT_AUTODECAL, 0.)
 {
-	ImpactCount++;
 }
 
 DImpactDecal::DImpactDecal (double z)
 : DBaseDecal (STAT_AUTODECAL, z)
 {
-	ImpactCount++;
 }
 
 void DImpactDecal::CheckMax ()
 {
-	if (ImpactCount >= cl_maxdecals)
+	if (++Level->ImpactDecalCount >= cl_maxdecals)
 	{
 		DThinker *thinker = DThinker::FirstThinker (STAT_AUTODECAL);
 		if (thinker != NULL)
 		{
 			thinker->Destroy();
+			Level->ImpactDecalCount--;
 		}
 	}
 }
@@ -615,7 +617,6 @@ DImpactDecal *DImpactDecal::StaticCreate (const FDecalTemplate *tpl, const DVect
 			else lowercolor = color;
 			StaticCreate (tpl_low, pos, wall, ffloor, lowercolor);
 		}
-		DImpactDecal::CheckMax();
 		decal = Create<DImpactDecal>(pos.Z);
 		if (decal == NULL)
 		{
@@ -626,6 +627,7 @@ DImpactDecal *DImpactDecal::StaticCreate (const FDecalTemplate *tpl, const DVect
 		{
 			return NULL;
 		}
+		decal->CheckMax();
 
 		tpl->ApplyToDecal (decal, wall);
 		if (color != 0)
@@ -651,12 +653,12 @@ DBaseDecal *DImpactDecal::CloneSelf (const FDecalTemplate *tpl, double ix, doubl
 		return NULL;
 	}
 
-	DImpactDecal::CheckMax();
 	DImpactDecal *decal = Create<DImpactDecal>(iz);
 	if (decal != NULL)
 	{
 		if (decal->StickToWall (wall, ix, iy, ffloor).isValid())
 		{
+			decal->CheckMax();
 			tpl->ApplyToDecal (decal, wall);
 			decal->AlphaColor = AlphaColor;
 			decal->RenderFlags = (decal->RenderFlags & RF_DECALMASK) |
@@ -671,12 +673,6 @@ DBaseDecal *DImpactDecal::CloneSelf (const FDecalTemplate *tpl, double ix, doubl
 	return decal;
 }
 
-void DImpactDecal::OnDestroy ()
-{
-	ImpactCount--;
-	Super::OnDestroy();
-}
-
 CCMD (countdecals)
 {
 	Printf ("%d impact decals\n", ImpactCount);
diff --git a/src/g_shared/a_sharedglobal.h b/src/g_shared/a_sharedglobal.h
index 278d0455b8..c6d2412c6a 100644
--- a/src/g_shared/a_sharedglobal.h
+++ b/src/g_shared/a_sharedglobal.h
@@ -68,11 +68,10 @@ public:
 	static DImpactDecal *StaticCreate(const FDecalTemplate *tpl, const DVector3 &pos, side_t *wall, F3DFloor * ffloor, PalEntry color = 0);
 
 	void BeginPlay ();
-	void OnDestroy() override;
 
 protected:
 	DBaseDecal *CloneSelf(const FDecalTemplate *tpl, double x, double y, double z, side_t *wall, F3DFloor * ffloor) const;
-	static void CheckMax ();
+	void CheckMax ();
 
 private:
 	DImpactDecal();
diff --git a/src/p_saveg.cpp b/src/p_saveg.cpp
index edefa49396..c86e76f149 100644
--- a/src/p_saveg.cpp
+++ b/src/p_saveg.cpp
@@ -983,7 +983,8 @@ void G_SerializeLevel(FSerializer &arc, FLevelLocals *Level, bool hubload)
 		("corpsequeue", Level->CorpseQueue)
 		("spotstate", Level->SpotState)
 		("fragglethinker", Level->FraggleScriptThinker)
-		("acsthinker", Level->ACSThinker);
+		("acsthinker", Level->ACSThinker)
+		("impactdecalcount", Level->ImpactDecalCount);
 
 	// Hub transitions must keep the current total time
 	if (!hubload)