Organizing your Game Data with C++ Maps

Maps are a great feature of C++ they allow us to store objects (made from classes) of any type and store them paired with any other variable. One useful combination I have used a fair bit in games programming is strings and Texture objects. The string represents the name of the graphics file and the Texture is an instance of a class provided by the graphics API, such as SFML.

To get started you would define your Texture class: A Texture class typically represents an image or texture that can be used for rendering. In the context of this tutorial, we assume that the Texture class has a constructor that takes a filename as an argument and loads the corresponding image file. You may also have other methods and properties in your Texture class depending on your specific needs.

Define your Texture class: A Texture class typically represents an image or texture that can be used for rendering. In the context of this tutorial, we assume that the Texture class has a constructor that takes a filename as an argument and loads the corresponding image file. You may also have other methods and properties in your Texture class depending on your specific needs.

class Texture {
public:
    // constructor
    Texture(std::string filename);
    // destructor
    ~Texture();
    // other methods and properties // ...
};

class Texture {

public:

// constructor

Texture(std::string filename);

// destructor

~Texture();

// other methods and properties // ...

};

Include the necessary headers: To use maps in C++, you need to include the <map> header. You also need to include the <string> header for working with strings.

#include <map>
#include <string>

1 2	#include <map> #include <string>

Declare the map that will store instances of the Texture class: In C++, a map is a container that stores key-value pairs. In this case, we want to store instances of the Texture class with a string key that represents each texture. To do this, we declare a map with a string key and a pointer to a Texture object as the value.

std::map<std::string, Texture*> textures;

1	std::map<std::string, Texture*> textures;

Add textures to the map: To add textures to the map, we first create instances of the Texture class using the constructor and pass in the corresponding filenames. We then add each Texture object to the map using a string key that represents the texture. In this example, we add two Texture objects to the map with the keys “texture1″ and “texture2″.

Texture* texture1 = new Texture("texture1.png");
Texture* texture2 = new Texture("texture2.png");
textures["texture1"] = texture1;
textures["texture2"] = texture2;

Texture* texture1 = new Texture("texture1.png");

Texture* texture2 = new Texture("texture2.png");

textures["texture1"] = texture1;

textures["texture2"] = texture2;

Access textures from the map: To access a Texture object from the map, we use the string key that was used to add the object to the map. In this example, we access the “texture1″ object and store it in a pointer called “texture”.

Texture* texture = textures["texture1"];

1	Texture* texture = textures["texture1"];

Delete Texture objects when you’re done with them: It’s important to properly manage memory when working with pointers to avoid memory leaks. In this case, we need to delete the Texture objects that were created with the “new” operator when we’re done with them.

delete texture1;
delete texture2;

1 2	delete texture1; delete texture2;

That’s it! With this code, you can easily store and access Texture objects using a string key. The map provides an efficient way to associate each Texture object with a unique key, and it simplifies the process of retrieving Texture objects by their key.