improve rain simulation (#4017)

* Uses vanilla logic to decide which blocks rain falls through.
 * Rain falls infinitely above the world, and stops at y=0.
 * Entities will now be extinguished if they are under rain-blocking
blocks, and fire will now be extinguished by rain similarly.
 * Create IsWeatherWetAtXYZ to identify wetness at a particular location. 
 * Use new code for enderman rain detection.
 * Fixes issue #916
 * Disable warnings for global constructors in the fire simulator.

Server/Plugins/APIDump/Classes/World.lua

@@ -2237,7 +2237,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the current world is raining (no thunderstorm).",
+				Notes = "Returns true if the current weather is rainy.",
 			},
 			IsWeatherRainAt =
 			{
@@ -2258,7 +2258,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the specified location is raining (takes biomes into account - it never rains in a desert).",
+				Notes = "Returns true if it is rainy at the specified location. This takes into account biomes.",
 			},
 			IsWeatherStorm =
 			{
@@ -2268,7 +2268,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the current world is stormy.",
+				Notes = "Returns true if the current weather is stormy.",
 			},
 			IsWeatherStormAt =
 			{
@@ -2289,7 +2289,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the specified location is stormy (takes biomes into account - no storm in a desert).",
+				Notes = "Returns true if it is stormy at the specified location. This takes into account biomes.",
 			},
 			IsWeatherSunny =
 			{
@@ -2320,7 +2320,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the current weather is sunny at the specified location (takes into account biomes).",
+				Notes = "Returns true if it is sunny at the specified location. This takes into account biomes.",
 			},
 			IsWeatherWet =
 			{
@@ -2330,7 +2330,7 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the current world has any precipitation (rain or storm).",
+				Notes = "Returns true if the world currently has any precipitation - rain, storm or snow.",
 			},
 			IsWeatherWetAt =
 			{
@@ -2351,7 +2351,24 @@ function OnAllChunksAvailable()</pre> All return values from the callbacks are i
 						Type = "boolean",
 					},
 				},
-				Notes = "Returns true if the specified location has any precipitation (rain or storm) (takes biomes into account, deserts are never wet).",
+				Notes = "Returns true if it is raining or storming at the specified location. This takes into account biomes.",
+			},
+			IsWeatherWetAtXYZ =
+			{
+				Params =
+				{
+					{
+						Name = "Pos",
+						Type = "Vector3i",
+					},
+				},
+				Returns =
+				{
+					{
+						Type = "boolean",
+					},
+				},
+				Notes = "Returns true if the specified location has wet weather (rain or storm), using the same logic as IsWeatherWetAt, except that any rain-blocking blocks above the specified position will block the precipitation and this function will return false.",
 			},
 			PrepareChunk =
 			{
@@ -3637,4 +3654,3 @@ World:ForEachEntity(
 		},
 	},
 }
-