From 304e9894966e78902af1f9d084034c2c873de4a7 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Wed, 15 Feb 2017 23:06:24 +0100
Subject: [PATCH] - allow splashing on non-swimmable, non-solid 3D floors if
 they are marked liquid and have a splash assigned.

---
 src/p_trace.cpp | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/p_trace.cpp b/src/p_trace.cpp
index 3597535e5..818372e74 100644
--- a/src/p_trace.cpp
+++ b/src/p_trace.cpp
@@ -41,6 +41,7 @@
 #include "r_defs.h"
 #include "p_spec.h"
 #include "g_levellocals.h"
+#include "p_terrain.h"
 
 //==========================================================================
 //
@@ -135,6 +136,13 @@ static void GetPortalTransition(DVector3 &pos, sector_t *&sec)
 	}
 }
 
+static bool isLiquid(F3DFloor *ff)
+{
+	if (ff->flags & FF_SWIMMABLE) return true;
+	auto terrain = ff->model->GetTerrain(ff->flags & FF_INVERTPLANES ? sector_t::floor : sector_t::ceiling);
+	return Terrains[terrain].IsLiquid && Terrains[terrain].Splash != -1;
+}
+
 //==========================================================================
 //
 // Trace entry point
@@ -300,9 +308,9 @@ void FTraceInfo::Setup3DFloors()
 			if (!(rover->flags&FF_EXISTS))
 				continue;
 
-			if (rover->flags&FF_SWIMMABLE && Results->Crossed3DWater == NULL)
+			if (Results->Crossed3DWater == NULL)
 			{
-				if (Check3DFloorPlane(rover, false))
+				if (Check3DFloorPlane(rover, false) && isLiquid(rover))
 				{
 					// only consider if the plane is above the actual floor.
 					if (rover->top.plane->ZatPoint(Results->HitPos) > bf)
@@ -767,7 +775,7 @@ bool FTraceInfo::TraceTraverse (int ptflags)
 		{
 			for (auto rover : CurSector->e->XFloor.ffloors)
 			{
-				if ((rover->flags & FF_EXISTS) && (rover->flags&FF_SWIMMABLE))
+				if ((rover->flags & FF_EXISTS) && isLiquid(rover))
 				{
 					if (Check3DFloorPlane(rover, false))
 					{