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7f968603 SK |
1 | -module(life). |
2 | ||
3 | -export([bang/1]). | |
4 | ||
5 | ||
6 | -define(CHAR_DEAD, 32). % " " | |
7 | -define(CHAR_ALIVE, 111). % "o" | |
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8 | -define(CHAR_BAR, 45). % "-" |
9 | ||
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10 | -define(INTERVAL, 100). |
11 | ||
12 | ||
13 | %% ============================================================================ | |
14 | %% API | |
15 | %% ============================================================================ | |
16 | ||
17 | bang(Args) -> | |
18 | [X, Y] = [atom_to_integer(A) || A <- Args], | |
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19 | {Time, Board} = timer:tc(fun() -> init_board(X, Y) end), |
20 | Generation = 1, | |
21 | life_loop(X, Y, Generation, Time, Board). | |
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22 | |
23 | ||
24 | %% ============================================================================ | |
25 | %% Internal | |
26 | %% ============================================================================ | |
27 | ||
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28 | life_loop(X, Y, Generation, Time, Board) -> |
29 | ok = do_print_status(X, Y, Generation, Time), | |
7f968603 | 30 | ok = do_print_board(Board), |
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31 | |
32 | {NextTime, NextBoard} = timer:tc(fun() -> next_generation(X, Y, Board) end), | |
33 | NextGeneration = Generation + 1, | |
7f968603 | 34 | timer:sleep(?INTERVAL), |
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35 | life_loop(X, Y, NextGeneration, NextTime, NextBoard). |
36 | ||
37 | ||
38 | do_print_status(X, Y, Generation, TimeMic) -> | |
39 | TimeSec = TimeMic / 1000000, | |
40 | Bar = [?CHAR_BAR || _ <- lists:seq(1, X)], | |
41 | ok = io:format("~s~n", [Bar]), | |
42 | ok = io:format( | |
43 | "X: ~b Y: ~b CELLS: ~b GENERATION: ~b DURATION: ~f~n", | |
44 | [X, Y, X * Y, Generation, TimeSec] | |
45 | ), | |
46 | ok = io:format("~s~n", [Bar]). | |
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47 | |
48 | ||
49 | do_print_board(Board) -> | |
50 | CharLists = array:to_list( | |
51 | array:map( | |
52 | fun(_, Row) -> | |
53 | array:to_list( | |
54 | array:map( | |
55 | fun(_, State) -> | |
56 | state_to_char(State) | |
57 | end, | |
58 | Row | |
59 | ) | |
60 | ) | |
61 | end, | |
62 | Board | |
63 | ) | |
64 | ), | |
65 | ||
66 | ok = lists:foreach( | |
67 | fun(CharList) -> | |
68 | ok = io:format("~s~n", [CharList]) | |
69 | end, | |
70 | CharLists | |
71 | ). | |
72 | ||
73 | ||
74 | state_to_char(0) -> ?CHAR_DEAD; | |
75 | state_to_char(1) -> ?CHAR_ALIVE. | |
76 | ||
77 | ||
68194920 | 78 | next_generation(W, H, Board) -> |
7f968603 SK |
79 | array:map( |
80 | fun(Y, Row) -> | |
81 | array:map( | |
82 | fun(X, State) -> | |
83 | Neighbors = filter_offsides(H, W, neighbors(X, Y)), | |
84 | States = neighbor_states(Board, Neighbors), | |
85 | LiveNeighbors = lists:sum(States), | |
86 | new_state(State, LiveNeighbors) | |
87 | end, | |
88 | Row | |
89 | ) | |
90 | end, | |
91 | Board | |
92 | ). | |
93 | ||
94 | ||
95 | new_state(1, LiveNeighbors) when LiveNeighbors < 2 -> 0; | |
96 | new_state(1, LiveNeighbors) when LiveNeighbors < 4 -> 1; | |
97 | new_state(1, LiveNeighbors) when LiveNeighbors > 3 -> 0; | |
98 | new_state(0, LiveNeighbors) when LiveNeighbors =:= 3 -> 1; | |
99 | new_state(State, _LiveNeighbors) -> State. | |
100 | ||
101 | ||
102 | neighbor_states(Board, Neighbors) -> | |
103 | [array:get(X, array:get(Y, Board)) || {X, Y} <- Neighbors]. | |
104 | ||
105 | ||
106 | filter_offsides(H, W, Coordinates) -> | |
107 | [{X, Y} || {X, Y} <- Coordinates, is_onside(X, Y, H, W)]. | |
108 | ||
109 | ||
110 | is_onside(X, Y, H, W) when (X >= 0) and (Y >= 0) and (X < W) and (Y < H) -> true; | |
111 | is_onside(_, _, _, _) -> false. | |
112 | ||
113 | ||
114 | neighbors(X, Y) -> | |
115 | [{X + OffX, Y + OffY} || {OffX, OffY} <- offsets()]. | |
116 | ||
117 | ||
118 | offsets() -> | |
119 | [offset(D) || D <- directions()]. | |
120 | ||
121 | ||
122 | offset('N') -> { 0, -1}; | |
123 | offset('NE') -> { 1, -1}; | |
124 | offset('E') -> { 1, 0}; | |
125 | offset('SE') -> { 1, 1}; | |
126 | offset('S') -> { 0, 1}; | |
127 | offset('SW') -> {-1, 1}; | |
128 | offset('W') -> {-1, 0}; | |
129 | offset('NW') -> {-1, -1}. | |
130 | ||
131 | ||
132 | directions() -> | |
133 | ['N', 'NE', 'E', 'SE', 'S', 'SW', 'W', 'NW']. | |
134 | ||
135 | ||
136 | init_board(X, Y) -> | |
137 | array:map(fun(_, _) -> init_row(X) end, array:new(Y)). | |
138 | ||
139 | ||
140 | init_row(X) -> | |
141 | array:map(fun(_, _) -> init_cell_state() end, array:new(X)). | |
142 | ||
143 | ||
144 | init_cell_state() -> | |
145 | crypto:rand_uniform(0, 2). | |
146 | ||
147 | ||
148 | atom_to_integer(Atom) -> | |
149 | list_to_integer(atom_to_list(Atom)). |