Remove 'lightintensity' UDMF key from Things, replaced it with the Thing's alpha instead

src/level/doomdata.h

@@ -220,6 +220,7 @@ struct MapThing2
 	short		angle;
 	short		type;
 	short		flags;
+	float		alpha;
 	uint8_t		special;
 	uint8_t		args[5];
 };
@@ -239,6 +240,7 @@ struct IntThing
 
 	short pitch; // UDMF
 	float height; // UDMF
+	float alpha;
 
 	TArray<UDMFKey> props;
 };

src/level/level.cpp

@@ -150,6 +150,7 @@ void FProcessor::LoadThings ()
 			Level.Things[i].args[3] = Things[i].args[3];
 			Level.Things[i].args[4] = Things[i].args[4];
 			Level.Things[i].pitch = 0;
+			Level.Things[i].alpha = Things[i].alpha;
 		}
 		delete[] Things;
 	}
@@ -174,6 +175,7 @@ void FProcessor::LoadThings ()
 			Level.Things[i].args[3] = 0;
 			Level.Things[i].args[4] = 0;
 			Level.Things[i].pitch = 0;
+			Level.Things[i].alpha = 1.0f;
 		}
 		delete[] mt;
 	}

src/level/level_light.cpp

@@ -324,16 +324,8 @@ void FLevel::CreateLights()
 		// this is known as "intensity" on dynamic lights (and in UDB)
 		lightdistance = thing->args[3];
 
-		for (unsigned int propIndex = 0; propIndex < thing->props.Size(); propIndex++)
-		{
-			const UDMFKey &key = thing->props[propIndex];
-
-			// static light intensity (not to be confused with dynamic lights' intensity, which is actually static light distance
-			if (!stricmp(key.key, "lightintensity"))
-			{
-				lightintensity = atof(key.value);
-			}
-		}
+		// static light intensity (not to be confused with dynamic lights' intensity, which is actually static light distance
+		lightintensity = thing->alpha;
 
 		if (lightdistance > 0.0f && lightintensity > 0.0f && lightcolor != 0)
 		{

src/level/level_udmf.cpp

@@ -219,6 +219,11 @@ void FProcessor::ParseThing(IntThing *th)
 		{
 			th->args[4] = CheckInt(key);
 		}
+		th->alpha = 1.0f;
+		if (!stricmp(key, "alpha"))
+		{
+			th->alpha = CheckFloat(key);
+		}
 
 		// now store the key in its unprocessed form
 		UDMFKey k = {key, value};