ABMs: Make catch-up behaviour optional

Default is true for backwards compatibility
Update lua_api.txt

4 files changed, 25 insertions, 10 deletions

diff --git a/src/environment.cpp b/src/environment.cpp
index 88f25536f..0b37212e5 100644
--- a/src/environment.cpp
+++ b/src/environment.cpp
@@ -577,17 +577,21 @@ public:
 				i->timer -= trigger_interval;
 				actual_interval = trigger_interval;
 			}
-			float intervals = actual_interval / trigger_interval;
-			if(intervals == 0)
-				continue;
 			float chance = abm->getTriggerChance();
 			if(chance == 0)
 				chance = 1;
 			ActiveABM aabm;
 			aabm.abm = abm;
-			aabm.chance = chance / intervals;
-			if(aabm.chance == 0)
-				aabm.chance = 1;
+			if(abm->getSimpleCatchUp()) {
+				float intervals = actual_interval / trigger_interval;
+				if(intervals == 0)
+					continue;
+				aabm.chance = chance / intervals;
+				if(aabm.chance == 0)
+					aabm.chance = 1;
+			} else {
+				aabm.chance = chance;
+			}
 			// Trigger neighbors
 			std::set<std::string> required_neighbors_s
 					= abm->getRequiredNeighbors();
diff --git a/src/environment.h b/src/environment.h
index 17d7ff19d..42faf5f6d 100644
--- a/src/environment.h
+++ b/src/environment.h
@@ -155,6 +155,8 @@ public:
 	virtual float getTriggerInterval() = 0;
 	// Random chance of (1 / return value), 0 is disallowed
 	virtual u32 getTriggerChance() = 0;
+	// Whether to modify chance to simulate time lost by an unnattended block
+	virtual bool getSimpleCatchUp() = 0;
 	// This is called usually at interval for 1/chance of the nodes
 	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n){};
 	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n,
diff --git a/src/script/cpp_api/s_env.cpp b/src/script/cpp_api/s_env.cpp
index 9c733773a..b8717597a 100644
--- a/src/script/cpp_api/s_env.cpp
+++ b/src/script/cpp_api/s_env.cpp
@@ -143,8 +143,11 @@ void ScriptApiEnv::initializeEnvironment(ServerEnvironment *env)
 			int trigger_chance = 50;
 			getintfield(L, current_abm, "chance", trigger_chance);
 
-			LuaABM *abm = new LuaABM(L, id, trigger_contents,
-					required_neighbors, trigger_interval, trigger_chance);
+			bool simple_catch_up = true;
+			getboolfield(L, current_abm, "catch_up", simple_catch_up);
+
+			LuaABM *abm = new LuaABM(L, id, trigger_contents, required_neighbors,
+				trigger_interval, trigger_chance, simple_catch_up);
 
 			env->addActiveBlockModifier(abm);
 
diff --git a/src/script/lua_api/l_env.h b/src/script/lua_api/l_env.h
index 2e9fab777..4f204da81 100644
--- a/src/script/lua_api/l_env.h
+++ b/src/script/lua_api/l_env.h
@@ -184,16 +184,18 @@ private:
 	std::set<std::string> m_required_neighbors;
 	float m_trigger_interval;
 	u32 m_trigger_chance;
+	bool m_simple_catch_up;
 public:
 	LuaABM(lua_State *L, int id,
 			const std::set<std::string> &trigger_contents,
 			const std::set<std::string> &required_neighbors,
-			float trigger_interval, u32 trigger_chance):
+			float trigger_interval, u32 trigger_chance, bool simple_catch_up):
 		m_id(id),
 		m_trigger_contents(trigger_contents),
 		m_required_neighbors(required_neighbors),
 		m_trigger_interval(trigger_interval),
-		m_trigger_chance(trigger_chance)
+		m_trigger_chance(trigger_chance),
+		m_simple_catch_up(simple_catch_up)
 	{
 	}
 	virtual std::set<std::string> getTriggerContents()
@@ -212,6 +214,10 @@ public:
 	{
 		return m_trigger_chance;
 	}
+	virtual bool getSimpleCatchUp()
+	{
+		return m_simple_catch_up;
+	}
 	virtual void trigger(ServerEnvironment *env, v3s16 p, MapNode n,
 			u32 active_object_count, u32 active_object_count_wider);
 };