From 8d0a087e6c36b1704579fabb1be0825fea0ad1b4 Mon Sep 17 00:00:00 2001
From: Marisa the Magician <marisa@sayachan.org>
Date: Fri, 14 Mar 2025 16:19:00 +0100
Subject: [PATCH] Reduce perf hit of bullet trails by only spawning underwater
 bubbles actually underwater, instead of always spawning them and then relying
 on them despawning themselves after checking their own water level. Further
 optimization could be possible if I found a way to divide the trace results
 into segments based on intersections with water volumes. This would save on
 countless calls to Vec3Offset and PointInSector. Something to keep in mind, I
 suppose. While I was at it, I did make the underwater check into a new
 utility function. It is more or less based on how updating water level is
 done internally, but saves time by just checking a single point rather than
 an actor's full height. Not sure if I'll need to use it elsewhere, but if
 that turns out to not be the case I'll change it to a private function of the
 SWWMBulletTrail class afterwards.

---
 language.version                     |  4 ++--
 zscript/swwm_common_fx.zsc           |  9 ++++++++-
 zscript/utility/swwm_utility_map.zsc | 29 ++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/language.version b/language.version
index 55ce61373..2daf15ef5 100644
--- a/language.version
+++ b/language.version
@@ -1,3 +1,3 @@
 [default]
-SWWM_MODVER="\cyDEMOLITIONIST \cw1.3pre r1198 \cu(vie 14 mar 2025 15:59:42 CET)\c-";
-SWWM_SHORTVER="\cw1.3pre r1198 \cu(2025-03-14 15:59:42)\c-";
+SWWM_MODVER="\cyDEMOLITIONIST \cw1.3pre r1200 \cu(vie 14 mar 2025 16:23:20 CET)\c-";
+SWWM_SHORTVER="\cw1.3pre r1200 \cu(2025-03-14 16:23:20)\c-";
diff --git a/zscript/swwm_common_fx.zsc b/zscript/swwm_common_fx.zsc
index 5b3bf3668..e492fedc7 100644
--- a/zscript/swwm_common_fx.zsc
+++ b/zscript/swwm_common_fx.zsc
@@ -1400,11 +1400,18 @@ Class SWWMBulletTrail : LineTracer
 			b.target = target;
 			b.A_CheckTerrain();
 		}
+		Vector3 ppos;
+		SWWMAnimSprite b;
+		bool bInWater;
 		for ( int i=5; i<t.Results.Distance; i+=10 )
 		{
 			if ( Random[Boolet](0,bubblesparse) ) continue;
 			if ( !Random[Boolet](0,i/100) ) continue;	// fall off w/ distance
-			let b = SWWMAnimSprite.SpawnAt(smoky?'SWWMHalfSmoke':'SWWMHalfBubble',level.Vec3Offset(pos,dir*i));
+			ppos = level.Vec3Offset(pos,dir*i);
+			bInWater = SWWMUtility.PointInWater(ppos);
+			if ( smoky && !bInWater ) b = SWWMAnimSprite.SpawnAt('SWWMHalfSmoke',ppos);
+			else if ( !smoky && bInWater ) b = SWWMAnimSprite.SpawnAt('SWWMHalfBubble',ppos);
+			else continue;
 			b.Scale *= FRandom[Boolet](.4,.6);
 		}
 		t.Destroy();
diff --git a/zscript/utility/swwm_utility_map.zsc b/zscript/utility/swwm_utility_map.zsc
index 9768026f7..dd50d49c1 100644
--- a/zscript/utility/swwm_utility_map.zsc
+++ b/zscript/utility/swwm_utility_map.zsc
@@ -599,6 +599,35 @@ extend Class SWWMUtility
 		return HitNormal;
 	}
 
+	static bool PointInWater( Vector3 p )
+	{
+		Sector s = level.PointInSector(p.xy);
+		if ( s.moreflags&Sector.SECMF_UNDERWATER ) // check underwater sector
+			return true;
+		else if ( s.heightsec && (s.heightsec.moreflags&Sector.SECMF_UNDERWATERMASK) ) // check height transfer
+		{
+			let hsec = s.heightsec;
+			double fh = hsec.floorplane.ZAtPoint(p.xy);
+			if ( p.z <= fh )
+				return true;
+			if ( !(hsec.moreflags&Sector.SECMF_FAKEFLOORONLY) && (p.z > hsec.ceilingplane.ZAtPoint(p.xy)) )
+				return true;
+		}
+		else // check 3D floors
+		{
+			for ( int i=0; i<s.Get3DFloorCount(); i++ )
+			{
+				let ff = s.Get3DFloor(i);
+				if ( !(ff.flags&F3DFloor.FF_EXISTS) || (ff.flags&F3DFloor.FF_SOLID) || !(ff.flags&F3DFloor.FF_SWIMMABLE) ) continue;
+				double ff_bottom = ff.bottom.ZAtPoint(p.xy);
+				double ff_top = ff.top.ZAtPoint(p.xy);
+				if ( (ff_top <= p.z) || (ff_bottom > p.z) ) continue;
+				return true;
+			}
+		}
+		return false;
+	}
+
 	static bool, TextureID DefaceTexture( TextureID checkme )
 	{
 		String tn = TexMan.GetName(checkme);