Implementing a Linked List for Multiple Bullets in SDL2

If you want to allow multiple bullets to be fired at once in your game, using a linked list is a great way to manage the bullets. Here’s a simple way to set it up.

Step 1: Define the Bullet Structure

Your bullet could be defined in a way that includes the necessary properties:

typedef struct Bullet {
    int x, y; // Position of the bullet
    int width, height; // Dimensions
    struct Bullet* next; // Pointer to the next bullet
} Bullet;
    

Step 2: Create Functions for Linked List Operations

You’ll need a few functions to manage your linked list:

Function to Create a Bullet

Bullet* createBullet(int x, int y) {
    Bullet* newBullet = malloc(sizeof(Bullet));
    if (!newBullet) return NULL; // Check for memory allocation
    newBullet->x = x;
    newBullet->y = y;
    newBullet->width = 50; // Example values
    newBullet->height = 50; // Example values
    newBullet->next = NULL;
    return newBullet;
}
    

Function to Add a Bullet to the List

void addBullet(Bullet** head, int x, int y) {
    Bullet* newBullet = createBullet(x, y);
    newBullet->next = *head; // Add to the front of the list
    *head = newBullet;
}
    

Step 3: Update Bullets in the Game Loop

As you process the game loop, you can update and render the bullets:

void updateBullets(Bullet* head) {
    Bullet* current = head;
    while (current != NULL) {
        current->y -= 5; // Move bullet up (example)
        // Here you'd use SDL to render the bullet
        current = current->next;
    }
}
    

Step 4: Handle Spacebar Press

To fire a bullet, check for the spacebar press and add a bullet to the list:

if (spacebarPressed) { // Replace with your actual input check
    addBullet(&bulletList, playerX, playerY); // Use player's position
}
    

Step 5: Clean Up

Lastly, don’t forget to free the memory for each bullet when they’re no longer needed:

void freeBullets(Bullet* head) {
    Bullet* temp;
    while (head != NULL) {
        temp = head;
        head = head->next;
        free(temp);
    }
}
    

This should give you a good foundation for managing multiple bullets in your game. Just remember to call your update and render functions in your main game loop, and keep your linked list tidy by freeing up memory when you’re done with your bullets!