Commit | Line | Data |
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4ddf6f1a JB |
1 | /* |
2 | * ===================================================================================== | |
3 | * | |
4 | * Filename: othello.c | |
5 | * | |
6 | * Description: Handle the othello board content | |
7 | * | |
8 | * Version: 1.0 | |
9 | * Created: 25/04/2017 15:16:08 | |
10 | * Revision: none | |
11 | * Compiler: gcc | |
12 | * | |
13 | * Author: Jerome Benoit (fraggle), jerome.benoit@piment-noir.org | |
14 | * Organization: Piment Noir | |
15 | * | |
16 | * ===================================================================================== | |
17 | */ | |
18 | ||
74e2b93b JB |
19 | #include <stdlib.h> |
20 | #include <stdbool.h> | |
a80646b7 | 21 | #include <string.h> |
4ddf6f1a | 22 | |
74e2b93b | 23 | #include "othello.h" |
a80646b7 | 24 | #include "debug.h" |
74e2b93b JB |
25 | |
26 | unsigned int current_player(unsigned int round_count) { | |
27 | ||
28 | if (round_count % 2 != 0) { | |
29 | return player_two; | |
30 | } else { | |
31 | return player_one; | |
32 | } | |
33 | } | |
34 | ||
a80646b7 JB |
35 | unsigned int current_opponent(unsigned int current_player) { |
36 | ||
37 | if (current_player == player_one) { | |
38 | return player_two; | |
39 | } else { | |
40 | return player_one; | |
41 | } | |
42 | } | |
43 | ||
44 | /* for consistency with ncurses, the board coordinates are in the following order: | |
45ce2fe3 | 45 | * O--x--> |
74e2b93b JB |
46 | * | |
47 | * y | |
48 | * | | |
54f1c58c JB |
49 | * v |
50 | * The origin O has (1, 1) coordinates */ | |
74e2b93b JB |
51 | |
52 | unsigned int get_box_value(int y, int x, unsigned int pawn_array[board_size][board_size]) { | |
53 | ||
54f1c58c | 54 | return pawn_array[y-1][x-1]; |
74e2b93b JB |
55 | } |
56 | ||
57 | bool is_box_type(int y, int x, unsigned int pawn_array[board_size][board_size], unsigned int type) { | |
58 | ||
59 | if (type > 2) { | |
60 | return NULL; | |
61 | } | |
62 | if (get_box_value(y, x, pawn_array) == type) { | |
63 | return true; | |
64 | } else { | |
65 | return false; | |
66 | } | |
67 | } | |
68 | ||
a80646b7 JB |
69 | static bool is_valid_coordinates(int y, int x) { |
70 | ||
71 | if ((y > 0 && y < board_size + 1) && \ | |
72 | (x > 0 && x < board_size + 1)) { | |
73 | return true; | |
74 | } else { | |
75 | return false; | |
76 | } | |
77 | } | |
78 | ||
79 | /* helper function to set a correct value at the (y, x) coordinates in the pawns array */ | |
80 | void set_pawn(int y, int x, unsigned int type, unsigned int pawn_array[board_size][board_size]) { | |
74e2b93b | 81 | |
a80646b7 JB |
82 | if (type > 0 && type < 3 && \ |
83 | is_valid_coordinates(y, x)) { | |
54f1c58c | 84 | pawn_array[y-1][x-1] = type; |
74e2b93b JB |
85 | } |
86 | } | |
87 | ||
a80646b7 JB |
88 | /* reverse the pawn at (y, x) coordinates if it exists */ |
89 | static void reverse_pawn(int y, int x, unsigned int pawn_array[board_size][board_size]) { | |
90 | ||
91 | if (is_box_type(y, x, pawn_array, black)) { | |
92 | set_pawn(y, x, white, pawn_array); | |
93 | } else if (is_box_type(y, x, pawn_array, white)) { | |
94 | set_pawn(y, x, black, pawn_array); | |
95 | } | |
96 | } | |
97 | ||
98 | void zero_pawns(unsigned int pawn_array[board_size][board_size]) { | |
54f1c58c | 99 | |
a80646b7 JB |
100 | for (int i = 1; i <= board_size; i++) { |
101 | for (int j = 1; j <= board_size; j++) { | |
102 | set_pawn(i, j, empty, pawn_array); | |
74e2b93b JB |
103 | } |
104 | } | |
74e2b93b JB |
105 | } |
106 | ||
107 | /* set the pawns in the start position */ | |
a80646b7 JB |
108 | void init_pawns(unsigned int pawn_array[board_size][board_size]) { |
109 | ||
110 | /* the 2D array zeroing is not necessary if it is properly initialized to zero */ | |
111 | zero_pawns(pawn_array); | |
112 | set_pawn(5, 4, black, pawn_array); | |
113 | set_pawn(4, 5, black, pawn_array); | |
114 | set_pawn(4, 4, white, pawn_array); | |
115 | set_pawn(5, 5, white, pawn_array); | |
74e2b93b JB |
116 | } |
117 | ||
a80646b7 | 118 | unsigned int count_pawns_type(unsigned int pawn_array[board_size][board_size], unsigned int type) { |
74e2b93b JB |
119 | unsigned int count = 0; |
120 | ||
121 | if (type > 2) { | |
a80646b7 | 122 | return 0; |
74e2b93b | 123 | } |
a80646b7 JB |
124 | for (int i = 1; i <= board_size; i++) { |
125 | for (int j = 1; j <= board_size; j++) { | |
45ce2fe3 | 126 | if (is_box_type(i, j, pawn_array, type)) { |
74e2b93b JB |
127 | count++; |
128 | } | |
129 | } | |
130 | } | |
131 | return count; | |
132 | } | |
54f1c58c | 133 | |
a80646b7 JB |
134 | static void direction_to_coordinates(unsigned int direction, int* start_y, int* start_x) { |
135 | ||
136 | if (direction == north) { | |
137 | *start_y = *start_y - 1; | |
138 | } else if (direction == north_east) { | |
139 | *start_y = *start_y - 1; | |
140 | *start_x = *start_x + 1; | |
141 | } else if (direction == east) { | |
142 | *start_x = *start_x + 1; | |
143 | } else if (direction == south_east) { | |
144 | *start_y = *start_y + 1; | |
145 | *start_x = *start_x + 1; | |
146 | } else if (direction == south) { | |
147 | *start_y = *start_y + 1; | |
148 | } else if (direction == south_west) { | |
149 | *start_y = *start_y + 1; | |
150 | *start_x = *start_x - 1; | |
151 | } else if (direction == west) { | |
152 | *start_x = *start_x - 1; | |
153 | } else if (direction == north_west) { | |
154 | *start_y = *start_y - 1; | |
155 | *start_x = *start_x - 1; | |
54f1c58c JB |
156 | } |
157 | } | |
158 | ||
159 | bool is_board_full(unsigned int pawn_array[board_size][board_size]) { | |
160 | ||
45ce2fe3 | 161 | /* an alternate method is to test the round count vs. 60 */ |
a80646b7 JB |
162 | for (int i = 1; i <= board_size; i++) { |
163 | for (int j = 1; j <= board_size; j++) { | |
54f1c58c JB |
164 | if (is_box_type(i, j, pawn_array , empty)) { |
165 | return false; | |
166 | } | |
167 | } | |
168 | } | |
169 | return true; | |
170 | } | |
171 | ||
a8b54576 JB |
172 | unsigned int eval_winner(unsigned int nb_white, unsigned int nb_black) { |
173 | ||
174 | if (nb_white > nb_black) { | |
175 | return player_two; | |
176 | } else if (nb_white < nb_black) { | |
177 | return player_one; | |
178 | } else { | |
179 | return 0; | |
180 | } | |
181 | } | |
182 | ||
a80646b7 JB |
183 | static unsigned int reverse_one_direction(int y, int x, int direction, unsigned int current_player, unsigned int pawn_array[board_size][board_size]) { |
184 | unsigned int nb_pawns_reserved = 0; | |
185 | int moving_y = y, moving_x = x; | |
45ce2fe3 | 186 | |
a80646b7 JB |
187 | /* count for pawn to reverse in the chosen direction */ |
188 | direction_to_coordinates(direction, &moving_y, &moving_x); | |
189 | while (true) { | |
190 | if (!is_valid_coordinates(moving_y, moving_x) || is_box_type(moving_y, moving_x, pawn_array, empty)) { | |
191 | return 0; | |
192 | } | |
193 | if (is_box_type(moving_y, moving_x, pawn_array, current_player)) { | |
194 | break; | |
195 | } | |
196 | nb_pawns_reserved++; | |
197 | direction_to_coordinates(direction, &moving_y, &moving_x); | |
198 | } | |
199 | ||
200 | /* now reverse the needed panws */ | |
201 | if (nb_pawns_reserved > 0) { | |
202 | moving_y = y, moving_x = x; | |
203 | direction_to_coordinates(direction, &moving_y, &moving_x); | |
204 | while (!is_box_type(moving_y, moving_x, pawn_array, current_player)) { | |
205 | reverse_pawn(moving_y, moving_x, pawn_array); | |
206 | direction_to_coordinates(direction, &moving_y, &moving_x); | |
207 | } | |
45ce2fe3 | 208 | } |
a80646b7 | 209 | return nb_pawns_reserved; |
54f1c58c JB |
210 | } |
211 | ||
a80646b7 JB |
212 | /* play the shot if legal and flip or reverse the necessary pawns */ |
213 | unsigned int valid_shot(int y, int x, unsigned int current_player, unsigned int pawn_array[board_size][board_size]) { | |
214 | unsigned int nb_pawns_reserved = 0; | |
215 | ||
216 | if (!is_valid_coordinates(y, x) || !is_box_type(y, x, pawn_array, empty)) { | |
217 | return 0; | |
218 | } | |
219 | ||
220 | for (unsigned int direction = north; direction <= north_west; direction++) { | |
221 | nb_pawns_reserved += reverse_one_direction(y, x, direction, current_player, pawn_array); | |
222 | } | |
223 | ||
224 | if (nb_pawns_reserved == 0) { | |
225 | return 0; | |
226 | } | |
54f1c58c | 227 | |
a80646b7 JB |
228 | set_pawn(y, x, current_player, pawn_array); |
229 | return nb_pawns_reserved; | |
54f1c58c | 230 | } |