lib/othello.c

   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
  19 #include <stdlib.h>
  20 #include <stdbool.h>
  21
  22 #include "othello.h"
  23
  24 unsigned int current_player(unsigned int round_count) {
  25
  26     if (round_count % 2 != 0) {
  27         return player_two;
  28     } else {
  29         return player_one;
  30     }
  31 }
  32
  33 /* for consitency with ncurses, the board coordinates are in the following order:
  34  * O--x-->
  35  * |
  36  * y
  37  * |
  38  * v
  39  * The origin O has (1, 1) coordinates */
  40
  41 unsigned int get_box_value(int y, int x, unsigned int pawn_array[board_size][board_size]) {
  42
  43     return pawn_array[y-1][x-1];
  44 }
  45
  46 bool is_box_type(int y, int x, unsigned int pawn_array[board_size][board_size], unsigned int type) {
  47
  48     if (type > 2) {
  49         return NULL;
  50     }
  51     if (get_box_value(y, x, pawn_array) == type) {
  52         return true;
  53     } else {
  54         return false;
  55     }
  56 }
  57
  58 /* helper function to set a value != empty at the (y, x) coordinates in the pawns array */
  59 int** set_pawn(int y, int x, unsigned int type, unsigned int pawn_array[board_size][board_size]) {
  60
  61     if (is_box_type(y, x, pawn_array, empty)) {
  62         pawn_array[y-1][x-1] = type;
  63         return (int**)pawn_array;
  64     } else {
  65         return NULL;
  66     }
  67 }
  68
  69 static int** zero_pawns(unsigned int pawn_array[board_size][board_size]) {
  70
  71     for (unsigned int i = 1; i <= board_size; i++) {
  72         for (unsigned int j = 1; j <= board_size; j++) {
  73             pawn_array = set_pawn(i, j, empty, pawn_array);
  74          }
  75     }
  76     return (int**)pawn_array;
  77 }
  78
  79 /* set the pawns in the start position */
  80 int** init_pawns(unsigned int pawn_array[board_size][board_size]) {
  81
  82     pawn_array = zero_pawns(pawn_array);
  83     pawn_array = set_pawn(5, 4, black, pawn_array);
  84     pawn_array = set_pawn(4, 5, black, pawn_array);
  85     pawn_array = set_pawn(4, 4, white, pawn_array);
  86     pawn_array = set_pawn(5, 5, white, pawn_array);
  87     return (int**)pawn_array;
  88 }
  89
  90 unsigned int count_pawn_type(unsigned int pawn_array[board_size][board_size], unsigned int type) {
  91     unsigned int count = 0;
  92
  93     if (type > 2) {
  94         return -1;
  95     }
  96     for (unsigned int i = 1; i <= board_size; i++) {
  97         for (unsigned int j = 1; j <= board_size; j++) {
  98             if (is_box_type(i, j, pawn_array, type)) {
  99                 count++;
 100             }
 101         }
 102     }
 103     return count;
 104 }
 105
 106 bool is_valid_input(int y, int x, unsigned int pawn_array[board_size][board_size]) {
 107
 108     /* FIXME: separate the tests to permit to print explicit error messages */
 109     if ((y > 0 && y < board_size + 1) && \
 110             (x > 0 && x < board_size + 1) && \
 111             is_box_type(y, x, pawn_array, empty)) {
 112         return true;
 113     } else {
 114         return false;
 115     }
 116 }
 117
 118 bool is_board_full(unsigned int pawn_array[board_size][board_size]) {
 119
 120     /* an alternate method is to test the round count vs. 60 */
 121     for (unsigned int i = 1; i <= board_size; i++) {
 122         for (unsigned int j = 1; j <= board_size; j++) {
 123             if (is_box_type(i, j, pawn_array , empty)) {
 124                 return false;
 125             }
 126         }
 127     }
 128     return true;
 129 }
 130
 131 unsigned int eval_winner(unsigned int nb_white, unsigned int nb_black) {
 132
 133     if (nb_white > nb_black) {
 134         return player_two;
 135     } else if (nb_white < nb_black) {
 136         return player_one;
 137     } else {
 138         return 0;
 139     }
 140 }
 141
 142 void direction_to_coordinates(unsigned int direction, int* start_y, int* start_x) {
 143
 144     if (direction == north) {
 145         *start_y = *start_y - 1;
 146     } else if (direction == north_east) {
 147         *start_y = *start_y - 1;
 148         *start_x = *start_x + 1;
 149     } else if (direction == east) {
 150         *start_x = *start_x + 1;
 151     } else if (direction == south_east) {
 152         *start_y = *start_y + 1;
 153         *start_x = *start_x + 1;
 154     } else if (direction == south) {
 155         *start_y = *start_y + 1;
 156     } else if (direction == south_west) {
 157         *start_y = *start_y + 1;
 158         *start_x = *start_x - 1;
 159     } else if (direction == west) {
 160         *start_x = *start_x - 1;
 161     } else if (direction == north_west) {
 162         *start_y = *start_y - 1;
 163         *start_x = *start_x - 1;
 164     }
 165 }
 166
 167 bool explore(int y, int x, int direction) {
 168
 169 }