1 files changed, 122 insertions, 0 deletions
diff --git a/src/board.c b/src/board.c
new file mode 100644
index 0000000..8c33ae3
--- /dev/null
+++ b/src/board.c
@@ -0,0 +1,122 @@
+#include <stdio.h>
+#include "board.h"
+
+void print_board(char* board) {
+  for (int row = 0; row < BOARD_ROW_BYTES; row++) {
+    for (int i = 0; i < BOARD_ROW_BYTES; i++) {
+      int index = BOARD_ROW_BYTES * row + i;
+      if (board[index] == EMPTY && is_center_index(index)) printf("*");
+      else printf("%c", board[index]);
+    }
+    printf("\n");
+  }
+}
+
+void initialize_board(char* board) {
+  for (int i = 0; i < BOARD_BYTES; i++) {
+    board[i] = EMPTY;
+  }
+}
+
+int is_center_index(int index) {
+  return ((index / BOARD_ROW_BYTES) % 2 == 1) && ((index % BOARD_ROW_BYTES) % 2 == 1);
+}
+
+int is_allowed_placement(char* tile, int index, char* board) {
+  if (board[index] != EMPTY) return 0;
+
+  int neighbor_count = 0;
+
+  for (int i = 0; i < 4; i++) {
+    char neighbor = board[index + neighbor_increments[i]];
+    if (neighbor != EMPTY) {
+      if (neighbor != tile[i + 1]) return 0;
+      neighbor_count++;
+    }
+  }
+
+  return neighbor_count > 0;
+}
+
+int place_tile(char* tile, int index, char* board, int force) {
+  if (!is_center_index(index)) {
+    printf("Not a valid tile index: %i\n", index);
+    return 0;
+  }
+
+  if (!force && !is_allowed_placement(tile, index, board)) {
+    printf("Can not place tile %s\n", tile);
+    return 0;
+  }
+
+  board[index] = tile[0];
+  for (int i = 0; i < 4; i++) {
+    board[index + neighbor_increments[i]] = tile[i + 1];
+  }
+
+  return 1;
+}
+
+void traverse_structure(char id, int index, char* board, char* structures) {
+  structures[index] = id;
+  for (int i = 0; i < 4; i++) {
+    int new_byte = index + neighbor_increments[i];
+    if (board[new_byte] == board[index] && structures[new_byte] == EMPTY) {
+      traverse_structure(id, new_byte, board, structures);
+    }
+  }
+}
+
+void create_structure_mask(char* board, char* structures) {
+  char structure_id = '1';
+  for (int i = 0; i < BOARD_BYTES; i++) {
+    if (structures[i] == EMPTY && board[i] != EMPTY && board[i] != 'F') {
+      traverse_structure(structure_id, i, board, structures);
+      structure_id += 1;
+    }
+  }
+}
+
+int translate_coordinate(int center_index) {
+  return (2 * (center_index / BOARD_WIDTH) + 1) *
+         (2 * BOARD_WIDTH + 1) +
+         (2 * (center_index % BOARD_WIDTH) + 1);
+}
+
+int evaluate_structure(int index, char* board, char* structures) {
+  int value = 0;
+
+  char structure = board[index];
+  char structure_id = structures[index];
+  printf("Evaluating group %c (%c)\n", structure_id, structure);
+
+  for (int i = 0; i < BOARD_WIDTH; i++) {
+    for (int j = 0; j < BOARD_WIDTH; j++) {
+      int index = translate_coordinate(i * BOARD_WIDTH + j);
+      if (board[index] != EMPTY) { // Empty tiles doesn't count
+        for (int k = 0; k < 4; k++) {
+          if (structures[index + neighbor_increments[k]] == structure_id) {
+            printf("Found at tile %i\n", i * BOARD_WIDTH + j);
+            value++;
+            break;
+          }
+        }
+      }
+    }
+  }
+
+  printf("Value: %i\n", value);
+  return value;
+}
+
+void write_board(char* board, char* filename) {
+  FILE* file = fopen(filename, "w");
+  fprintf(file, "%s\n", board);
+  fclose(file);
+}
+
+void read_board(char* board, char* filename) {
+  FILE* file = fopen(filename, "r");
+  fgets(board, BOARD_BYTES, file);
+  fclose(file);
+}