Game state is now preserved in a file

.gitignore

@@ -1 +1,2 @@
 main
+save.dat

game.c

@@ -1,10 +1,12 @@
 #include "game.h"
 #include <stdlib.h>
+#include <string.h>
 
 // Depending on the direction, move the tiles and check if we can merge with the
 // tiles in that direction. We merge the tiles only if they are of the same value
-void move(GameState_t *state, MOVE_DIRECTION direction) {
+void move(GameState_t *state, move_direction_t direction) {
   bool merged[BOARD_HEIGHT][BOARD_WIDTH] = {0};
+  bool moved = false;
   switch (direction) {
   case UP: {
     for (int y = 1; y < BOARD_HEIGHT; y++) {
@@ -43,6 +45,7 @@ void move(GameState_t *state, MOVE_DIRECTION direction) {
           state->board[y][x] = 0;
           state->score += state->board[target_y][x];
         }
+        moved = true;
       }
     }
     break;
@@ -77,6 +80,7 @@ void move(GameState_t *state, MOVE_DIRECTION direction) {
           state->board[y][x] = 0;
           state->score += state->board[target_y][x];
         }
+        moved = true;
       }
     }
     break;
@@ -111,6 +115,7 @@ void move(GameState_t *state, MOVE_DIRECTION direction) {
           state->board[y][x] = 0;
           state->score += state->board[y][target_x];
         }
+        moved = true;
       }
     }
     break;
@@ -145,22 +150,21 @@ void move(GameState_t *state, MOVE_DIRECTION direction) {
           state->board[y][x] = 0;
           state->score += state->board[y][target_x];
         }
+        moved = true;
       }
     }
     break;
   }
   }
+  if (moved)
     state->moves_made++;
 }
 
 void reset_board(GameState_t *state) {
-  for (int y = 0; y < BOARD_HEIGHT; y++) {
+  memset(state->board, 0, sizeof(state->board));
-    for (int x = 0; x < BOARD_WIDTH; x++) {
-      state->board[y][x] = 0;
-    }
-  }
   state->score = 0;
   state->moves_made = 0;
+  state->status = PLAYING;
 
   int tile_count = 0;
   while (tile_count != STARTING_TILES) {
@@ -172,6 +176,11 @@ void reset_board(GameState_t *state) {
     state->board[y][x] = (rand() % 10 == 0) ? 4 : 2; // 10% chance to spawn a 4
     tile_count++;
   }
+  FILE *f = fopen("save.dat", "wb");
+  if (f) {
+    fwrite(state, sizeof(GameState_t), 1, f);
+    fclose(f);
+  }
 }
 
 bool spawn_tile(GameState_t *state) {
@@ -197,3 +206,20 @@ bool spawn_tile(GameState_t *state) {
   state->board[spawn_y][spawn_x] = (rand() % 10 == 0) ? 4 : 2; // 10% chance to spawn a 4
   return true;
 }
+
+// This function will only run, if every tile is filled (checked by `spawn_tile`). We can take advantage of that and
+// just check every neighboring cell for equal values for merging
+bool can_move(GameState_t *state) {
+  for (int y = 0; y < BOARD_HEIGHT; y++) {
+    for (int x = 0; x < BOARD_WIDTH; x++) {
+      if (state->board[y][x] == 0)
+        return true;
+
+      if (x < BOARD_WIDTH - 1 && state->board[y][x] == state->board[y][x + 1])
+        return true;
+      if (y < BOARD_HEIGHT - 1 && state->board[y][x] == state->board[y + 1][x])
+        return true;
+    }
+  }
+  return false;
+}

game.h

@@ -1,19 +1,22 @@
 #pragma once
 #include <raylib.h>
+#include <stdio.h>
 
 #define BOARD_WIDTH 4
 #define BOARD_HEIGHT 4
 #define STARTING_TILES 3
 
-typedef enum { UP = 0, DOWN, LEFT, RIGHT } MOVE_DIRECTION;
+typedef enum { UP, DOWN, LEFT, RIGHT } move_direction_t;
+typedef enum { PLAYING, WON, LOST } game_status_t;
 
 typedef struct {
-    int board[BOARD_HEIGHT][BOARD_WIDTH];
+  unsigned int board[BOARD_HEIGHT][BOARD_WIDTH];
-    int score;
+  game_status_t status;
-    int moves_made;
+  unsigned int score;
+  unsigned int moves_made;
 } GameState_t;
 
-
+void move(GameState_t *state, move_direction_t direction);
-void move(GameState_t *state, MOVE_DIRECTION direction);
 void reset_board(GameState_t *state);
 bool spawn_tile(GameState_t *state);
+bool can_move(GameState_t *state);

main.c

@@ -1,6 +1,7 @@
 #include "raylib.h"
 #include <math.h>
 #include <stdbool.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 
@@ -30,8 +31,14 @@ int main() {
   srand(time(NULL));
 
   reset_board(&game_state);
+  FILE* game_file = fopen("save.dat", "rb");
+  if (game_file != NULL) {
+    fseek(game_file, 0, SEEK_SET);
+    fread(&game_state, sizeof(GameState_t), 1, game_file);
+    fclose(game_file);
+  }
 
-  InitWindow(800, 600, "2048");
+  InitWindow(WINDOW_WIDTH, WINDOW_HEIGHT, "2048");
   SetTargetFPS(30); // So my laptop doesn't burn
 
   while (!WindowShouldClose()) {
@@ -57,12 +64,35 @@ int main() {
       }
     }
 
-    DrawText(TextFormat("Score: %d", game_state.score), 600, BOARD_MARGIN, 20, BLACK);
+    DrawText(TextFormat("Score: %d", game_state.score), WINDOW_HEIGHT, BOARD_MARGIN, 20, BLACK);
-    DrawText(TextFormat("Moves used: %d", game_state.moves_made), 600, BOARD_MARGIN + 20, 20, BLACK);
+    DrawText(TextFormat("Moves used: %d", game_state.moves_made), WINDOW_HEIGHT, BOARD_MARGIN + 20, 20, BLACK);
+
+    if (game_state.status == PLAYING) {
+      DrawText("Drag with the mouse to move tiles", 400 - MeasureText("Drag with the mouse to move tiles", 20) / 2,
+               WINDOW_HEIGHT - 40, 20, GRAY);
 
       // Reset button
       DrawRectangle(500, 455, 275, 24, RED);
       DrawText("Reset", 500 + 275 / 2 - MeasureText("Reset", 20) / 2, 455 + 4, 20, WHITE);
+    } else {
+      Color overlay = Fade(BLACK, 0.7f);
+      DrawRectangle(0, 0, WINDOW_WIDTH, 700, overlay);
+
+      if (game_state.status == WON) {
+        DrawText("You win!", 400 - MeasureText("You win!", 40) / 2, 250, 40, GREEN);
+      } else if (game_state.status == LOST) {
+        DrawText("Game over!", 400 - MeasureText("Game over!", 40) / 2, 250, 40, RED);
+      }
+
+      // Draw the scores under the win/loss message
+      DrawText(TextFormat("Score: %d", game_state.score),
+               400 - MeasureText(TextFormat("Score: %d", game_state.score), 20) / 2, 290, 20, WHITE);
+      DrawText(TextFormat("Moves used: %d", game_state.moves_made),
+               400 - MeasureText(TextFormat("Moves used: %d", game_state.moves_made), 20) / 2, 310, 20, WHITE);
+
+      DrawRectangle(400 - 100, 450, 200, 40, RED);
+      DrawText("Try again", 400 - MeasureText("Try again", 20) / 2, 455 + 4, 20, WHITE);
+    }
 
     EndDrawing();
     handle_mouse_input(&game_state);

ui.c

@@ -3,6 +3,7 @@
 #include <math.h>
 #include <raylib.h>
 #include <stdbool.h>
+#include <stdio.h>
 
 static bool is_dragging;
 static Vector2 drag_start_pos;
@@ -10,11 +11,22 @@ static Vector2 drag_start_pos;
 void handle_mouse_input(GameState_t *game_state) {
   if (IsMouseButtonPressed(MOUSE_LEFT_BUTTON)) {
     drag_start_pos = GetMousePosition();
+
+    // Check for the normal reset button
+    if (game_state->status == PLAYING) {
       if (drag_start_pos.x >= 500 && drag_start_pos.x <= 775 && drag_start_pos.y >= 455 && drag_start_pos.y <= 479) {
         reset_board(game_state);
         return;
       }
+    } else {
+      // Check for the "Play again" button
+      if (drag_start_pos.x >= 300 && drag_start_pos.x <= 500 && drag_start_pos.y >= 450 && drag_start_pos.y <= 490) {
+        reset_board(game_state);
+        return;
+      }
+    }
 
+    if (game_state->status == PLAYING)
       is_dragging = true;
   } else if (IsMouseButtonReleased(MOUSE_LEFT_BUTTON) && is_dragging) {
     Vector2 current_pos = GetMousePosition();
@@ -39,7 +51,25 @@ void handle_mouse_input(GameState_t *game_state) {
           move(game_state, UP);
         }
       }
-      spawn_tile(game_state);
+      if (!spawn_tile(game_state) && !can_move(game_state)) {
+        game_state->status = LOST;
+        return;
+      }
+      // TODO: Allow for infinite play
+      for (int y = 0; y < BOARD_HEIGHT; y++) {
+        for (int x = 0; x < BOARD_WIDTH; x++) {
+          if (game_state->board[y][x] == 2048) {
+            game_state->status = WON;
+            return;
+          }
+        }
+      }
+
+      FILE *f = fopen("save.dat", "wb");
+      if (f) {
+        fwrite(game_state, sizeof(GameState_t), 1, f);
+        fclose(f);
+      }
     }
 
     is_dragging = false;

ui.h

@@ -6,4 +6,7 @@
 #define TILE_SPACING 10
 #define BOARD_MARGIN 50
 
+#define WINDOW_WIDTH 800
+#define WINDOW_HEIGHT 600
+
 void handle_mouse_input(GameState_t *game_state);