From 50fe45efe68f01dc8dd79d4f040a776d5d043857 Mon Sep 17 00:00:00 2001
From: katsy <205-katsy@users.noreply.git.do.srb2.org>
Date: Fri, 10 Sep 2021 17:00:43 +0000
Subject: [PATCH] Refactor weather switching (fixes #541)

---
 src/p_mobj.c | 14 ++------
 src/p_spec.c | 93 ++++++++++------------------------------------------
 2 files changed, 21 insertions(+), 86 deletions(-)

diff --git a/src/p_mobj.c b/src/p_mobj.c
index 10220fff6..c32371888 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -11051,7 +11051,7 @@ void P_SpawnPrecipitation(void)
 	subsector_t *precipsector = NULL;
 	precipmobj_t *rainmo = NULL;
 
-	if (dedicated || !(cv_drawdist_precip.value) || curWeather == PRECIP_NONE)
+	if (dedicated || !(cv_drawdist_precip.value) || curWeather == PRECIP_NONE || curWeather == PRECIP_STORM_NORAIN)
 		return;
 
 	// Use the blockmap to narrow down our placing patterns
@@ -11097,22 +11097,14 @@ void P_SpawnPrecipitation(void)
 				continue;
 
 			rainmo = P_SpawnRainMobj(x, y, height, MT_RAIN);
+			if (curWeather == PRECIP_BLANK)
+				rainmo->precipflags |= PCF_INVISIBLE;
 		}
 
 		// Randomly assign a height, now that floorz is set.
 		rainmo->z = M_RandomRange(rainmo->floorz>>FRACBITS, rainmo->ceilingz>>FRACBITS)<<FRACBITS;
 	}
 
-	if (curWeather == PRECIP_BLANK)
-	{
-		curWeather = PRECIP_RAIN;
-		P_SwitchWeather(PRECIP_BLANK);
-	}
-	else if (curWeather == PRECIP_STORM_NORAIN)
-	{
-		curWeather = PRECIP_RAIN;
-		P_SwitchWeather(PRECIP_STORM_NORAIN);
-	}
 }
 
 //
diff --git a/src/p_spec.c b/src/p_spec.c
index 4b566acfb..90dca25af 100644
--- a/src/p_spec.c
+++ b/src/p_spec.c
@@ -1988,53 +1988,14 @@ void P_LinedefExecute(INT16 tag, mobj_t *actor, sector_t *caller)
 //
 void P_SwitchWeather(INT32 weathernum)
 {
-	boolean purge = false;
-	INT32 swap = 0;
+	boolean purge = true;
+	boolean raintype = (PRECIP_SNOW || PRECIP_RAIN || PRECIP_STORM || PRECIP_STORM_NOSTRIKES || PRECIP_BLANK);
 
-	switch (weathernum)
-	{
-		case PRECIP_NONE: // None
-			if (curWeather == PRECIP_NONE)
-				return; // Nothing to do.
-			purge = true;
-			break;
-		case PRECIP_STORM: // Storm
-		case PRECIP_STORM_NOSTRIKES: // Storm w/ no lightning
-		case PRECIP_RAIN: // Rain
-			if (curWeather == PRECIP_SNOW || curWeather == PRECIP_BLANK || curWeather == PRECIP_STORM_NORAIN)
-				swap = PRECIP_RAIN;
-			break;
-		case PRECIP_SNOW: // Snow
-			if (curWeather == PRECIP_SNOW)
-				return; // Nothing to do.
-			if (curWeather == PRECIP_RAIN || curWeather == PRECIP_STORM || curWeather == PRECIP_STORM_NOSTRIKES || curWeather == PRECIP_BLANK || curWeather == PRECIP_STORM_NORAIN)
-				swap = PRECIP_SNOW; // Need to delete the other precips.
-			break;
-		case PRECIP_STORM_NORAIN: // Storm w/o rain
-			if (curWeather == PRECIP_SNOW
-				|| curWeather == PRECIP_STORM
-				|| curWeather == PRECIP_STORM_NOSTRIKES
-				|| curWeather == PRECIP_RAIN
-				|| curWeather == PRECIP_BLANK)
-				swap = PRECIP_STORM_NORAIN;
-			else if (curWeather == PRECIP_STORM_NORAIN)
-				return;
-			break;
-		case PRECIP_BLANK:
-			if (curWeather == PRECIP_SNOW
-				|| curWeather == PRECIP_STORM
-				|| curWeather == PRECIP_STORM_NOSTRIKES
-				|| curWeather == PRECIP_RAIN)
-				swap = PRECIP_BLANK;
-			else if (curWeather == PRECIP_STORM_NORAIN)
-				swap = PRECIP_BLANK;
-			else if (curWeather == PRECIP_BLANK)
-				return;
-			break;
-		default:
-			CONS_Debug(DBG_GAMELOGIC, "P_SwitchWeather: Unknown weather type %d.\n", weathernum);
-			break;
-	}
+	if (weathernum == curWeather)
+		return;
+
+	if (weathernum == raintype && curWeather == raintype)
+		purge = false;
 
 	if (purge)
 	{
@@ -2051,7 +2012,7 @@ void P_SwitchWeather(INT32 weathernum)
 			P_RemovePrecipMobj(precipmobj);
 		}
 	}
-	else if (swap && !((swap == PRECIP_BLANK && curWeather == PRECIP_STORM_NORAIN) || (swap == PRECIP_STORM_NORAIN && curWeather == PRECIP_BLANK))) // Rather than respawn all that crap, reuse it!
+	else // Rather than respawn all that crap, reuse it!
 	{
 		thinker_t *think;
 		precipmobj_t *precipmobj;
@@ -2063,7 +2024,7 @@ void P_SwitchWeather(INT32 weathernum)
 				continue; // not a precipmobj thinker
 			precipmobj = (precipmobj_t *)think;
 
-			if (swap == PRECIP_RAIN) // Snow To Rain
+			if (weathernum == (PRECIP_RAIN || PRECIP_STORM || PRECIP_STORM_NOSTRIKES)) // Snow To Rain
 			{
 				precipmobj->flags = mobjinfo[MT_RAIN].flags;
 				st = &states[mobjinfo[MT_RAIN].spawnstate];
@@ -2078,7 +2039,7 @@ void P_SwitchWeather(INT32 weathernum)
 				precipmobj->precipflags |= PCF_RAIN;
 				//think->function.acp1 = (actionf_p1)P_RainThinker;
 			}
-			else if (swap == PRECIP_SNOW) // Rain To Snow
+			else if (weathernum == PRECIP_SNOW) // Rain To Snow
 			{
 				INT32 z;
 
@@ -2103,7 +2064,7 @@ void P_SwitchWeather(INT32 weathernum)
 
 				//think->function.acp1 = (actionf_p1)P_SnowThinker;
 			}
-			else if (swap == PRECIP_BLANK || swap == PRECIP_STORM_NORAIN) // Remove precip, but keep it around for reuse.
+			else // Remove precip, but keep it around for reuse.
 			{
 				//think->function.acp1 = (actionf_p1)P_NullPrecipThinker;
 
@@ -2116,49 +2077,34 @@ void P_SwitchWeather(INT32 weathernum)
 	{
 		case PRECIP_SNOW: // snow
 			curWeather = PRECIP_SNOW;
-
-			if (!swap)
+			
+			if (purge)
 				P_SpawnPrecipitation();
 
 			break;
 		case PRECIP_RAIN: // rain
 		{
-			boolean dontspawn = false;
-
-			if (curWeather == PRECIP_RAIN || curWeather == PRECIP_STORM || curWeather == PRECIP_STORM_NOSTRIKES)
-				dontspawn = true;
-
 			curWeather = PRECIP_RAIN;
 
-			if (!dontspawn && !swap)
+			if (purge)
 				P_SpawnPrecipitation();
 
 			break;
 		}
 		case PRECIP_STORM: // storm
 		{
-			boolean dontspawn = false;
-
-			if (curWeather == PRECIP_RAIN || curWeather == PRECIP_STORM || curWeather == PRECIP_STORM_NOSTRIKES)
-				dontspawn = true;
-
 			curWeather = PRECIP_STORM;
 
-			if (!dontspawn && !swap)
+			if (purge)
 				P_SpawnPrecipitation();
 
 			break;
 		}
 		case PRECIP_STORM_NOSTRIKES: // storm w/o lightning
 		{
-			boolean dontspawn = false;
-
-			if (curWeather == PRECIP_RAIN || curWeather == PRECIP_STORM || curWeather == PRECIP_STORM_NOSTRIKES)
-				dontspawn = true;
-
 			curWeather = PRECIP_STORM_NOSTRIKES;
 
-			if (!dontspawn && !swap)
+			if (purge)
 				P_SpawnPrecipitation();
 
 			break;
@@ -2166,14 +2112,11 @@ void P_SwitchWeather(INT32 weathernum)
 		case PRECIP_STORM_NORAIN: // storm w/o rain
 			curWeather = PRECIP_STORM_NORAIN;
 
-			if (!swap)
-				P_SpawnPrecipitation();
-
 			break;
-		case PRECIP_BLANK:
+		case PRECIP_BLANK: //preloaded
 			curWeather = PRECIP_BLANK;
 
-			if (!swap)
+			if (purge)
 				P_SpawnPrecipitation();
 
 			break;