1 /*
2 Minetest
3 Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
4 
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as published by
7 the Free Software Foundation; either version 2.1 of the License, or
8 (at your option) any later version.
9 
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 GNU Lesser General Public License for more details.
14 
15 You should have received a copy of the GNU Lesser General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19 
20 #pragma once
21 
22 #include "irr_v3d.h"
23 #include <iostream>
24 #include <map>
25 #include <vector>
26 
27 /*
28 	NodeTimer provides per-node timed callback functionality.
29 	Can be used for:
30 	- Furnaces, to keep the fire burnin'
31 	- "activated" nodes that snap back to their original state
32 	  after a fixed amount of time (mesecons buttons, for example)
33 */
34 
35 class NodeTimer
36 {
37 public:
38 	NodeTimer() = default;
NodeTimer(const v3s16 & position_)39 	NodeTimer(const v3s16 &position_):
40 		position(position_) {}
NodeTimer(f32 timeout_,f32 elapsed_,v3s16 position_)41 	NodeTimer(f32 timeout_, f32 elapsed_, v3s16 position_):
42 		timeout(timeout_), elapsed(elapsed_), position(position_) {}
43 	~NodeTimer() = default;
44 
45 	void serialize(std::ostream &os) const;
46 	void deSerialize(std::istream &is);
47 
48 	f32 timeout = 0.0f;
49 	f32 elapsed = 0.0f;
50 	v3s16 position;
51 };
52 
53 /*
54 	List of timers of all the nodes of a block
55 */
56 
57 class NodeTimerList
58 {
59 public:
60 	NodeTimerList() = default;
61 	~NodeTimerList() = default;
62 
63 	void serialize(std::ostream &os, u8 map_format_version) const;
64 	void deSerialize(std::istream &is, u8 map_format_version);
65 
66 	// Get timer
get(const v3s16 & p)67 	NodeTimer get(const v3s16 &p) {
68 		std::map<v3s16, std::multimap<double, NodeTimer>::iterator>::iterator n =
69 			m_iterators.find(p);
70 		if (n == m_iterators.end())
71 			return NodeTimer();
72 		NodeTimer t = n->second->second;
73 		t.elapsed = t.timeout - (n->second->first - m_time);
74 		return t;
75 	}
76 	// Deletes timer
remove(v3s16 p)77 	void remove(v3s16 p) {
78 		std::map<v3s16, std::multimap<double, NodeTimer>::iterator>::iterator n =
79 			m_iterators.find(p);
80 		if(n != m_iterators.end()) {
81 			double removed_time = n->second->first;
82 			m_timers.erase(n->second);
83 			m_iterators.erase(n);
84 			// Yes, this is float equality, but it is not a problem
85 			// since we only test equality of floats as an ordered type
86 			// and thus we never lose precision
87 			if (removed_time == m_next_trigger_time) {
88 				if (m_timers.empty())
89 					m_next_trigger_time = -1.;
90 				else
91 					m_next_trigger_time = m_timers.begin()->first;
92 			}
93 		}
94 	}
95 	// Undefined behaviour if there already is a timer
insert(NodeTimer timer)96 	void insert(NodeTimer timer) {
97 		v3s16 p = timer.position;
98 		double trigger_time = m_time + (double)(timer.timeout - timer.elapsed);
99 		std::multimap<double, NodeTimer>::iterator it =
100 			m_timers.insert(std::pair<double, NodeTimer>(
101 				trigger_time, timer
102 			));
103 		m_iterators.insert(
104 			std::pair<v3s16, std::multimap<double, NodeTimer>::iterator>(p, it));
105 		if (m_next_trigger_time == -1. || trigger_time < m_next_trigger_time)
106 			m_next_trigger_time = trigger_time;
107 	}
108 	// Deletes old timer and sets a new one
set(const NodeTimer & timer)109 	inline void set(const NodeTimer &timer) {
110 		remove(timer.position);
111 		insert(timer);
112 	}
113 	// Deletes all timers
clear()114 	void clear() {
115 		m_timers.clear();
116 		m_iterators.clear();
117 		m_next_trigger_time = -1.;
118 	}
119 
120 	// Move forward in time, returns elapsed timers
121 	std::vector<NodeTimer> step(float dtime);
122 
123 private:
124 	std::multimap<double, NodeTimer> m_timers;
125 	std::map<v3s16, std::multimap<double, NodeTimer>::iterator> m_iterators;
126 	double m_next_trigger_time = -1.0;
127 	double m_time = 0.0;
128 };
129