Resetting Cells to Clear

The CellsToClear variable is a crucial part of our game logic, and resetting it in the PlaceBombs() function is essential for proper game functionality. Let's dive into why this is necessary:

Purpose of CellsToClear

The CellsToClear variable keeps track of how many non-bomb cells the player needs to clear to win the game. It's initialized when we set up the game board, and it's decremented each time a non-bomb cell is cleared.

Why Reset in PlaceBombs()?

We reset CellsToClear in the PlaceBombs() function for a few important reasons:

1. Game Restart: When a new game starts, we need to reset all game state, including CellsToClear.
2. Dynamic Board Setup: If we allow for different board sizes or bomb counts between games, we need to recalculate CellsToClear each time.
3. Consistency: It ensures that CellsToClear is always set correctly, even if the function is called multiple times.

Let's look at the PlaceBombs() function:

1void MinesweeperGrid::PlaceBombs() {
2  int BombsToPlace{ Config::BOMB_COUNT };
3  CellsToClear = Config::GRID_COLUMNS 
4    * Config::GRID_ROWS
5    - Config::BOMB_COUNT; 
6  while (BombsToPlace > 0) {
7    const size_t RandomIndex{
8      Engine::Random::Int(
9        0, Children.size() - 1)
10    };
11    if (Children[RandomIndex].PlaceBomb()) {
12      --BombsToPlace;
13    }
14  }
15}

What Happens If We Don't Reset?

If we don't reset CellsToClear, several problems could occur:

1. Incorrect Win Condition: The player might win too early or too late if CellsToClear isn't correct.
2. Inconsistent Game State: Starting a new game might use the CellsToClear value from the previous game, leading to unexpected behavior.

Here's an example of what could go wrong:

1class MinesweeperGrid {
2public:
3  void NewGame() {
4    // Clear the board
5    for (auto& Cell : Children) {
6      Cell.Reset();
7    }
8    PlaceBombs(); // This resets CellsToClear
9  }
10
11  void HandleCellCleared(
12    const SDL_UserEvent& E) {
13    // ... other logic ...
14    --CellsToClear;
15    if (CellsToClear == 0) {
16      SDL_Event Event{ UserEvents::GAME_WON };
17      SDL_PushEvent(&Event);
18    }
19  }
20
21private:
22  int CellsToClear;
23  // ... other members ...
24};

If we didn't reset CellsToClear in PlaceBombs(), the NewGame() function might not properly reset the game state, potentially leading to immediate wins or losses in subsequent games.

By resetting CellsToClear in PlaceBombs(), we ensure that each new game starts with the correct number of cells to clear, maintaining the integrity of our game logic across multiple play sessions.