Colors and double merge blocks

Ok, this was much easier than I thought it would be to implement

.gitignore

@@ -0,0 +1 @@
+main

main.c

@@ -7,16 +7,34 @@
 #define BOARD_HEIGHT 4
 #define STARTING_TILES 3
 
+const char* tile_colors[] = {
+    "\033[0m",           // 0 - Reset/default (empty tile)
+    "\033[48;5;230m",    // 2 - Light beige
+    "\033[48;5;223m",    // 4 - Tan
+    "\033[48;5;216m",    // 8 - Orange-ish
+    "\033[48;5;209m",    // 16 - Light orange
+    "\033[48;5;208m",    // 32 - Orange
+    "\033[48;5;202m",    // 64 - Dark orange
+    "\033[48;5;226m",    // 128 - Yellow
+    "\033[48;5;220m",    // 256 - Gold
+    "\033[48;5;214m",    // 512 - Orange-gold
+    "\033[48;5;208m",    // 1024 - Bright orange
+    "\033[48;5;202m",    // 2048 - Red-orange
+    "\033[48;5;196m",    // 4096 - Red
+    "\033[48;5;160m",    // 8192 - Dark red
+};
+
 typedef enum { UP = 0, DOWN, LEFT, RIGHT } MOVE_DIRECTION;
 static int board[BOARD_HEIGHT][BOARD_WIDTH] = {0};
 
 void print_board() {
   for (int y = 0; y < BOARD_HEIGHT; y++) {
     for (int x = 0; x < BOARD_WIDTH; x++) {
-      printf("%d ", board[y][x]);
+      printf("%s%d ", tile_colors[board[y][x]], board[y][x]);
     }
     printf("\n");
   }
+  printf("\033[0m"); // Reset color
 }
 
 // Depending on the direction, move the tiles and check if we can merge with the
@@ -24,6 +42,7 @@ void print_board() {
 // TODO: Add a guard agains double merge!
 // 2 2 0 4 => 8 0 0 0 which is incorrect and should be 4 4 0 0
 void move(MOVE_DIRECTION direction) {
+  bool merged[BOARD_HEIGHT][BOARD_WIDTH] = {0};
   switch (direction) {
   case UP: {
     for (int y = 1; y < BOARD_HEIGHT; y++) {
@@ -39,7 +58,7 @@ void move(MOVE_DIRECTION direction) {
         for (int py = y - 1; py >= 0; py--) { // Go from the tile's current position up to the top of the board
           if (board[py][x] == 0) {
             target_y = py;
-          } else if (board[py][x] == board[y][x]) {
+          } else if (board[py][x] == board[y][x] && !merged[py][x]) {
             target_y = py;
             break;
           } else {
@@ -57,6 +76,7 @@ void move(MOVE_DIRECTION direction) {
           board[target_y][x] = board[y][x];
           board[y][x] = 0;
         } else if (board[target_y][x] == board[y][x]) {
+          merged[target_y][x] = true;
           board[target_y][x] *= 2;
           board[y][x] = 0;
         }
@@ -74,7 +94,7 @@ void move(MOVE_DIRECTION direction) {
         for (int py = y + 1; py < BOARD_HEIGHT; py++) {
           if (board[py][x] == 0) {
             target_y = py;
-          } else if (board[py][x] == board[y][x]) {
+          } else if (board[py][x] == board[y][x] && !merged[py][x]) {
             target_y = py;
             break;
           } else {
@@ -89,6 +109,7 @@ void move(MOVE_DIRECTION direction) {
           board[target_y][x] = board[y][x];
           board[y][x] = 0;
         } else if (board[target_y][x] == board[y][x]) {
+              merged[target_y][x] = true;
           board[target_y][x] *= 2;
           board[y][x] = 0;
         }
@@ -106,7 +127,7 @@ void move(MOVE_DIRECTION direction) {
         for (int px = x - 1; px >= 0; px--) {
           if (board[y][px] == 0) {
             target_x = px;
-          } else if (board[y][px] == board[y][x]) {
+          } else if (board[y][px] == board[y][x] && !merged[y][px]) {
             target_x = px;
             break;
           } else {
@@ -121,6 +142,7 @@ void move(MOVE_DIRECTION direction) {
           board[y][target_x] = board[y][x];
           board[y][x] = 0;
         } else if (board[y][target_x] == board[y][x]) {
+          merged[y][target_x] = true;
           board[y][target_x] *= 2;
           board[y][x] = 0;
         }
@@ -138,7 +160,7 @@ void move(MOVE_DIRECTION direction) {
         for (int px = x + 1; px < BOARD_WIDTH; px++) {
           if (board[y][px] == 0) {
             target_x = px;
-          } else if (board[y][px] == board[y][x]) {
+          } else if (board[y][px] == board[y][x] && !merged[y][px]) {
             target_x = px;
             break;
           } else {
@@ -153,6 +175,7 @@ void move(MOVE_DIRECTION direction) {
           board[y][target_x] = board[y][x];
           board[y][x] = 0;
         } else if (board[y][target_x] == board[y][x]) {
+            merged[y][target_x] = true;
           board[y][target_x] *= 2;
           board[y][x] = 0;
         }