TP_13/exo2/lib/coordinates.c

   1 /*
   2  * =====================================================================================
   3  *
   4  *       Filename:  coordinates.c
   5  *
   6  *    Description:  Data definition and functions to manipulate elements in the grid
   7  *
   8  *        Version:  1.0
   9  *        Created:  16/03/2017 19:05:02
  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 "coordinates.h"
  20
  21 void zero_coordinates(coordinates_t* coordinates_array) {
  22
  23     for (unsigned i = 0; i < MAX_COORDINATES; i++) {
  24         coordinates_array[i] = set_coordinates(0, 0, 0);
  25     }
  26 }
  27
  28 coordinates_t set_coordinates(int y, int x, unsigned type) {
  29     coordinates_t new_coordinates;
  30
  31     new_coordinates.y = y;
  32     new_coordinates.x = x;
  33     new_coordinates.type = type;
  34     return new_coordinates;
  35 }
  36
  37 /* FIXME: Does it worth doing a coordinates_t get_coordinates(int y, int x, unsigned type); helper function? */
  38 /* Or a int get_coordinates_x(coordinates_t coordinates); helper function? */
  39
  40 /* this function do a lot of sanity checks before adding new board elements,
  41  * hence the loop. moving the checks in the main loop is also possible.
  42  * for now, just branch in the main loop given this function error value returned. */
  43 unsigned add_coordinates(coordinates_t new_coordinates, coordinates_t* coordinates_array, unsigned round) {
  44
  45     /* valid coordinates are in the [1-3] range */
  46     if (new_coordinates.y < 1 || new_coordinates.y > 3 || new_coordinates.x < 1 || new_coordinates.x > 3) {
  47         return 3; /* error value for invalid coordinates */
  48     } else if (round == MAX_COORDINATES - 1) {
  49         /* round is off-by-one vs. MAX_COORDINATES */
  50         coordinates_array[MAX_COORDINATES - 1] = new_coordinates;
  51         return 1; /* error value for full array */
  52     }
  53     for (unsigned i = 0; i < MAX_COORDINATES; i++) {
  54         /* check if already entered */
  55         if (new_coordinates.y == (coordinates_array + i)->y && new_coordinates.x == (coordinates_array + i)->x) {
  56             return 2; /* error value for duplicates */
  57         } else if ((coordinates_array + i)->y == 0 && (coordinates_array + i)->x == 0) {
  58             coordinates_array[i] = new_coordinates;
  59             return 0; /* error value when everything if fine */
  60         }
  61     }
  62     return 4; /* error value for unknown error case - should never happen - */
  63 }
  64
  65 static bool chk_line(coordinates_t* coordinates_array, int line_number, unsigned round) {
  66     unsigned nb_o_align = 0;
  67     unsigned nb_x_align = 0;
  68
  69     for (unsigned i = 0; i <= round; i++) {
  70         /* check if they are all the same */
  71         if ((coordinates_array + i)->y == line_number && (coordinates_array + i)->type == 0) {
  72             nb_o_align++;
  73         }
  74         if ((coordinates_array + i)->y == line_number && (coordinates_array + i)->type == 1) {
  75             nb_x_align++;
  76         }
  77     }
  78     if (nb_o_align == 3 || nb_x_align == 3) {
  79         return true;
  80     }
  81     return false;
  82 }
  83
  84 static bool chk_column(coordinates_t* coordinates_array, int column_number, unsigned round) {
  85     unsigned nb_o_align = 0;
  86     unsigned nb_x_align = 0;
  87
  88     for (unsigned i = 0; i <= round; i++) {
  89         /* check if they are all the same */
  90         if ((coordinates_array + i)->x == column_number && (coordinates_array + i)->type == 0) {
  91             nb_o_align++;
  92         }
  93         if ((coordinates_array + i)->x == column_number && (coordinates_array + i)->type == 1) {
  94             nb_x_align++;
  95         }
  96     }
  97     /* one column must be full of the same type */
  98     if (nb_o_align == 3 || nb_x_align == 3) {
  99         return true;
 100     }
 101     return false;
 102 }
 103
 104 static bool chk_diagonals(coordinates_t* coordinates_array, unsigned round) {
 105     unsigned nb_o_diag_one = 0, nb_o_diag_two = 0;
 106     unsigned nb_x_diag_one = 0, nb_x_diag_two = 0;
 107
 108     for (unsigned i = 0; i <= round; i++) {
 109         /* dumb count of each elements type in the two diagonals */
 110         for (int y_x_diag = 1; y_x_diag < 4; y_x_diag++) {
 111             if ((coordinates_array + i)->y == y_x_diag && (coordinates_array + i)->x == y_x_diag && (coordinates_array + i)->type == 0) {
 112                 nb_o_diag_one++;
 113             }
 114             if ((coordinates_array + i)->y == y_x_diag && (coordinates_array + i)->x == (4 - y_x_diag) && (coordinates_array + i)->type == 0) {
 115                 nb_o_diag_two++;
 116             }
 117             if ((coordinates_array + i)->y == y_x_diag && (coordinates_array + i)->x == y_x_diag && (coordinates_array + i)->type == 1) {
 118                 nb_x_diag_one++;
 119             }
 120             if ((coordinates_array + i)->y == y_x_diag && (coordinates_array + i)->x == (4 - y_x_diag) && (coordinates_array + i)->type == 1) {
 121                 nb_x_diag_two++;
 122             }
 123         }
 124         if (nb_o_diag_one == 3 || nb_o_diag_two == 3 || nb_x_diag_one == 3 || nb_x_diag_two == 3) {
 125             return true;
 126         }
 127     }
 128     return false;
 129 }
 130
 131 bool chk_win_conditions(coordinates_t* coordinates_array, unsigned round) {
 132
 133     /* winning conditions begin at round = 4 */
 134     if (round > 3) {
 135         if (chk_diagonals(coordinates_array, round)) {
 136             return true;
 137         }
 138         for (unsigned i = 1; i < 4; i++) {
 139             if (chk_line(coordinates_array, i, round) || \
 140                 chk_column(coordinates_array, i, round)) {
 141                 return true;
 142             }
 143         }
 144     }
 145     return false;
 146 }