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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" | |
7a9e70eb SK |
8 | -define(CHAR_BAR, 45). % "-" |
9 | ||
7f968603 SK |
10 | -define(INTERVAL, 100). |
11 | ||
12 | ||
39738e22 SK |
13 | -record(state, {x :: non_neg_integer() |
14 | ,y :: non_neg_integer() | |
3968ca95 | 15 | ,n :: pos_integer() |
eba1d8be | 16 | ,bar :: nonempty_string() |
39738e22 | 17 | ,board :: array() |
3968ca95 | 18 | ,gen_count :: pos_integer() |
39738e22 SK |
19 | ,gen_duration :: non_neg_integer() |
20 | ,print_time :: non_neg_integer() | |
b4e740f3 SK |
21 | }). |
22 | ||
23 | ||
7f968603 SK |
24 | %% ============================================================================ |
25 | %% API | |
26 | %% ============================================================================ | |
27 | ||
28 | bang(Args) -> | |
29 | [X, Y] = [atom_to_integer(A) || A <- Args], | |
7a9e70eb | 30 | {Time, Board} = timer:tc(fun() -> init_board(X, Y) end), |
b4e740f3 SK |
31 | State = #state{x = X |
32 | ,y = Y | |
33 | ,n = X * Y | |
34 | ,bar = [?CHAR_BAR || _ <- lists:seq(1, X)] | |
35 | ,board = Board | |
690cd0ad | 36 | ,gen_count = 1 % Consider inital state to be generation 1 |
b4e740f3 | 37 | ,gen_duration = Time |
690cd0ad | 38 | ,print_time = 0 % There was no print time yet |
b4e740f3 SK |
39 | }, |
40 | life_loop(State). | |
7f968603 SK |
41 | |
42 | ||
43 | %% ============================================================================ | |
44 | %% Internal | |
45 | %% ============================================================================ | |
46 | ||
b4e740f3 SK |
47 | life_loop( |
48 | #state{x = X | |
49 | ,y = Y | |
50 | ,n = N | |
51 | ,bar = Bar | |
52 | ,board = Board | |
53 | ,gen_count = GenCount | |
54 | ,gen_duration = Time | |
6fc17e92 | 55 | ,print_time = LastPrintTime |
b4e740f3 SK |
56 | }=State) -> |
57 | ||
6fc17e92 SK |
58 | {PrintTime, ok} = timer:tc( |
59 | fun() -> | |
60 | do_print_screen(Board, Bar, X, Y, N, GenCount, Time, LastPrintTime) | |
61 | end | |
62 | ), | |
7a9e70eb | 63 | |
160a4566 SK |
64 | {NewTime, NewBoard} = timer:tc( |
65 | fun() -> | |
66 | next_generation(X, Y, Board) | |
67 | end | |
68 | ), | |
69 | ||
b4e740f3 SK |
70 | NewState = State#state{board = NewBoard |
71 | ,gen_count = GenCount + 1 | |
72 | ,gen_duration = NewTime | |
6fc17e92 | 73 | ,print_time = PrintTime |
b4e740f3 SK |
74 | }, |
75 | ||
7f968603 | 76 | timer:sleep(?INTERVAL), |
b4e740f3 | 77 | life_loop(NewState). |
7a9e70eb SK |
78 | |
79 | ||
6fc17e92 SK |
80 | do_print_screen(Board, Bar, X, Y, N, GenCount, Time, PrintTime) -> |
81 | ok = do_print_status(Bar, X, Y, N, GenCount, Time, PrintTime), | |
82 | ok = do_print_board(Board). | |
83 | ||
84 | ||
85 | do_print_status(Bar, X, Y, N, GenCount, TimeMic, PrintTimeMic) -> | |
7a9e70eb | 86 | TimeSec = TimeMic / 1000000, |
6fc17e92 | 87 | PrintTimeSec = PrintTimeMic / 1000000, |
7a9e70eb SK |
88 | ok = io:format("~s~n", [Bar]), |
89 | ok = io:format( | |
6fc17e92 SK |
90 | "X: ~b Y: ~b CELLS: ~b GENERATION: ~b DURATION: ~f PRINT TIME: ~f~n", |
91 | [X, Y, N, GenCount, TimeSec, PrintTimeSec] | |
7a9e70eb SK |
92 | ), |
93 | ok = io:format("~s~n", [Bar]). | |
7f968603 SK |
94 | |
95 | ||
96 | do_print_board(Board) -> | |
1332e0c3 | 97 | RowStrings = array:to_list( |
7f968603 SK |
98 | array:map( |
99 | fun(_, Row) -> | |
100 | array:to_list( | |
101 | array:map( | |
102 | fun(_, State) -> | |
103 | state_to_char(State) | |
104 | end, | |
105 | Row | |
106 | ) | |
107 | ) | |
108 | end, | |
109 | Board | |
110 | ) | |
111 | ), | |
112 | ||
113 | ok = lists:foreach( | |
1332e0c3 SK |
114 | fun(RowString) -> |
115 | ok = io:format("~s~n", [RowString]) | |
7f968603 | 116 | end, |
1332e0c3 | 117 | RowStrings |
7f968603 SK |
118 | ). |
119 | ||
120 | ||
121 | state_to_char(0) -> ?CHAR_DEAD; | |
122 | state_to_char(1) -> ?CHAR_ALIVE. | |
123 | ||
124 | ||
68194920 | 125 | next_generation(W, H, Board) -> |
7f968603 SK |
126 | array:map( |
127 | fun(Y, Row) -> | |
128 | array:map( | |
129 | fun(X, State) -> | |
130 | Neighbors = filter_offsides(H, W, neighbors(X, Y)), | |
131 | States = neighbor_states(Board, Neighbors), | |
132 | LiveNeighbors = lists:sum(States), | |
133 | new_state(State, LiveNeighbors) | |
134 | end, | |
135 | Row | |
136 | ) | |
137 | end, | |
138 | Board | |
139 | ). | |
140 | ||
141 | ||
142 | new_state(1, LiveNeighbors) when LiveNeighbors < 2 -> 0; | |
143 | new_state(1, LiveNeighbors) when LiveNeighbors < 4 -> 1; | |
144 | new_state(1, LiveNeighbors) when LiveNeighbors > 3 -> 0; | |
145 | new_state(0, LiveNeighbors) when LiveNeighbors =:= 3 -> 1; | |
146 | new_state(State, _LiveNeighbors) -> State. | |
147 | ||
148 | ||
149 | neighbor_states(Board, Neighbors) -> | |
150 | [array:get(X, array:get(Y, Board)) || {X, Y} <- Neighbors]. | |
151 | ||
152 | ||
153 | filter_offsides(H, W, Coordinates) -> | |
154 | [{X, Y} || {X, Y} <- Coordinates, is_onside(X, Y, H, W)]. | |
155 | ||
156 | ||
157 | is_onside(X, Y, H, W) when (X >= 0) and (Y >= 0) and (X < W) and (Y < H) -> true; | |
158 | is_onside(_, _, _, _) -> false. | |
159 | ||
160 | ||
161 | neighbors(X, Y) -> | |
162 | [{X + OffX, Y + OffY} || {OffX, OffY} <- offsets()]. | |
163 | ||
164 | ||
165 | offsets() -> | |
166 | [offset(D) || D <- directions()]. | |
167 | ||
168 | ||
169 | offset('N') -> { 0, -1}; | |
170 | offset('NE') -> { 1, -1}; | |
171 | offset('E') -> { 1, 0}; | |
172 | offset('SE') -> { 1, 1}; | |
173 | offset('S') -> { 0, 1}; | |
174 | offset('SW') -> {-1, 1}; | |
175 | offset('W') -> {-1, 0}; | |
176 | offset('NW') -> {-1, -1}. | |
177 | ||
178 | ||
179 | directions() -> | |
180 | ['N', 'NE', 'E', 'SE', 'S', 'SW', 'W', 'NW']. | |
181 | ||
182 | ||
183 | init_board(X, Y) -> | |
184 | array:map(fun(_, _) -> init_row(X) end, array:new(Y)). | |
185 | ||
186 | ||
187 | init_row(X) -> | |
188 | array:map(fun(_, _) -> init_cell_state() end, array:new(X)). | |
189 | ||
190 | ||
191 | init_cell_state() -> | |
192 | crypto:rand_uniform(0, 2). | |
193 | ||
194 | ||
195 | atom_to_integer(Atom) -> | |
196 | list_to_integer(atom_to_list(Atom)). |