1 files changed, 41 insertions, 0 deletions
diff --git a/src/tile.c b/src/tile.c
new file mode 100644
index 0000000..2688c2a
--- /dev/null
+++ b/src/tile.c
@@ -0,0 +1,41 @@
+#include "tile.h"
+
+int is_allowed_placement(Tile tile, int index, BoardUnit* board) {
+  if (board[index].feature != EMPTY) return 0;
+
+  int neighbor_count = 0;
+
+  for (int i = 0; i < 4; i++) {
+    char neighbor = board[index + NEIGHBOR_INCREMENTS[i]].feature;
+    if (neighbor != EMPTY) {
+      if (neighbor != tile.edges[i]) return 0;
+      neighbor_count++;
+    }
+  }
+
+  return neighbor_count > 0;
+}
+
+int place_tile(Tile tile, int index, BoardUnit* board, int force) {
+  if (!is_center_index(index)) return 0;
+  if (!force && !is_allowed_placement(tile, index, board)) return 0;
+
+  board[index].feature = tile.center;
+  for (int i = 0; i < 4; i++) {
+    board[index + NEIGHBOR_INCREMENTS[i]].feature = tile.edges[i];
+  }
+
+  return 1;
+}
+
+void rotate_tile(Tile* tile, int increment) {
+  char buffer[8];
+  for (int i = 0; i < 8; i++) {
+    buffer[i] = tile->edges[i % 4];
+  }
+
+  for (int i = 0; i < 4; i++) {
+    tile->edges[i] = buffer[i + (increment % 4)];
+  }
+}
+