Initial commit

src/nodetimer.h

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+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "irr_v3d.h"
+#include <iostream>
+#include <map>
+#include <vector>
+
+/*
+	NodeTimer provides per-node timed callback functionality.
+	Can be used for:
+	- Furnaces, to keep the fire burnin'
+	- "activated" nodes that snap back to their original state
+	  after a fixed amount of time (mesecons buttons, for example)
+*/
+
+class NodeTimer
+{
+public:
+	NodeTimer() = default;
+	NodeTimer(const v3s16 &position_):
+		position(position_) {}
+	NodeTimer(f32 timeout_, f32 elapsed_, v3s16 position_):
+		timeout(timeout_), elapsed(elapsed_), position(position_) {}
+	~NodeTimer() = default;
+
+	void serialize(std::ostream &os) const;
+	void deSerialize(std::istream &is);
+
+	f32 timeout = 0.0f;
+	f32 elapsed = 0.0f;
+	v3s16 position;
+};
+
+/*
+	List of timers of all the nodes of a block
+*/
+
+class NodeTimerList
+{
+public:
+	NodeTimerList() = default;
+	~NodeTimerList() = default;
+
+	void serialize(std::ostream &os, u8 map_format_version) const;
+	void deSerialize(std::istream &is, u8 map_format_version);
+
+	// Get timer
+	NodeTimer get(const v3s16 &p) {
+		std::map<v3s16, std::multimap<double, NodeTimer>::iterator>::iterator n =
+			m_iterators.find(p);
+		if (n == m_iterators.end())
+			return NodeTimer();
+		NodeTimer t = n->second->second;
+		t.elapsed = t.timeout - (n->second->first - m_time);
+		return t;
+	}
+	// Deletes timer
+	void remove(v3s16 p) {
+		std::map<v3s16, std::multimap<double, NodeTimer>::iterator>::iterator n =
+			m_iterators.find(p);
+		if(n != m_iterators.end()) {
+			double removed_time = n->second->first;
+			m_timers.erase(n->second);
+			m_iterators.erase(n);
+			// Yes, this is float equality, but it is not a problem
+			// since we only test equality of floats as an ordered type
+			// and thus we never lose precision
+			if (removed_time == m_next_trigger_time) {
+				if (m_timers.empty())
+					m_next_trigger_time = -1.;
+				else
+					m_next_trigger_time = m_timers.begin()->first;
+			}
+		}
+	}
+	// Undefined behaviour if there already is a timer
+	void insert(NodeTimer timer) {
+		v3s16 p = timer.position;
+		double trigger_time = m_time + (double)(timer.timeout - timer.elapsed);
+		std::multimap<double, NodeTimer>::iterator it =
+			m_timers.insert(std::pair<double, NodeTimer>(
+				trigger_time, timer
+			));
+		m_iterators.insert(
+			std::pair<v3s16, std::multimap<double, NodeTimer>::iterator>(p, it));
+		if (m_next_trigger_time == -1. || trigger_time < m_next_trigger_time)
+			m_next_trigger_time = trigger_time;
+	}
+	// Deletes old timer and sets a new one
+	inline void set(const NodeTimer &timer) {
+		remove(timer.position);
+		insert(timer);
+	}
+	// Deletes all timers
+	void clear() {
+		m_timers.clear();
+		m_iterators.clear();
+		m_next_trigger_time = -1.;
+	}
+
+	// Move forward in time, returns elapsed timers
+	std::vector<NodeTimer> step(float dtime);
+
+private:
+	std::multimap<double, NodeTimer> m_timers;
+	std::map<v3s16, std::multimap<double, NodeTimer>::iterator> m_iterators;
+	double m_next_trigger_time = -1.0;
+	double m_time = 0.0;
+};