SFML Simple Fast Media Library

• SFML stands for Simple Fast Media Library and although it isn't the only C++ graphics library for games and multimedia, it is very capable
• SFML contains code modules for common 2D game development tasks
• SFML uses OpenGL for 3D game capabilities and will automatically use OpenGL when used
• Using SFML allows for the creation of 2D graphics and animations (including scrolling game worlds), sound effects, music playback (including directional sound), input handling from keyboard, mouse, and gamepad, and online multiplayer features
• SFML code can be compiled and linked on major desktop and mobile operating systems
• Gaming monitors typically use resolutions such as 1920x1080 pixels or low resolution which uses 960x540 pixels
• Internal coordinates originate at (0,0) in the the top left corner

SFML Library

• This is included using #include <SFML/Graphics.hpp>

Namespace sf

• sf is the namespace for Simple Fast Media Library and it is used with the line using namespace sf;

Window

• A window provides the main graphical interface for a game
• A window displays game objects and handles input

Why Use a Window?

• The window provides the game screen, handles rendering of objects, and captures player input
• Windows can be created with the code sf::RenderWindow window(sf::VideoMode(1920, 1080), "Timber!!!");
• sf::RenderWindow creates the window
• sf::VideoMode(width, height) sets the size of the window
• "Timber!!!" sets the title

Functions Used with Window

• .isopen() checks if the window is open
• .pollEvent(event) captures events like keyboard, mouse, and close
• .clear() clears the previous frame
• .display() updates the window with new drawings

Texture

• A texture is an image that can be applied to a sprite
• Textures are stored in graphics memory to improve performance

Why Use Textures?

• Textures reduce memory usage by applying a single texture to different sprites vs loading multiple images
• SFML optimizes texture rendering for high performance, enabling faster rendering
• Used through sf::Texture textureBee;, and can be loaded from a directory using textureBee.loadFromFile("graphics/bee.png");
• sf::Texture loads the image
• loadFromFile() loads the image

Sprite

• A sprite is a 2D image object displayed on the screen to represent characters, backgrounds, and game objects
• To use sprites, load a Texture (an image file), assign the Texture to a Sprite, set the Position of the sprite, and draw the Sprite onto the screen
• sf::Texture loads the image from the file
• sf::Sprite holds the image and displays it on the screen
• setTexture() applies the texture to the sprite
• setPosition(x, y) moves the sprite to a specific location

Event

• An event is an action detected by the game, like keyboard presses, mouse clicks, or window close requests
• Events handle player input allowing interaction and detects window actions closing the window properly
• Events register mouse and keyboard activity

SFML Classes (Chapter 1)

• SFML's graphics and window classes set up the game window and render graphics

sf::VideoMode

• This defines the size of the game window
• sf::VideoMode(1920, 1080) is an example of usage
• width defines the width of the window and height defines the height of the window, both in pixels

sf::RenderWindow

• This creates a window where the game will be displayed
• sf::RenderWindow window(sf::VideoMode(1920, 1080), "Timber!!!"); is an example of usage
• sf::VideoMode(width, height) defines the resolution of the window
• "Timber!!!" defines the title of the window
• .isopen() checks if the window is open
• .close() closes the window
• .clear() clears the previous frame before drawing a new one
• .draw() draws a graphical object to the window
• .display() displays the updated frame

sf::Style

• This configures the appearance and interactive elements of a window when it is created
• sf::Style::None provides no decorations
• sf::Style::Titlebar adds a title bar but no borders or buttons
• sf::Style::Resize makes the window resizable
• sf::Style::Close adds a close button
• sf::Style::Fullscreen makes the window fullscreen covering the entire screen
• sf::Style::Default combines title bar, close button, resize, and normal borders
• Multiple styles can be combined to customize the window

sf::Texture

• This loads image files for game objects
• sf::Texture textureBackground; and textureBackground.loadFromFile("graphics/background.png"); is example of usage
• .loadFromFile("filename.png") loads an image file into a texture

sf::Sprite

• This represents game objects using textures
• sf::Sprite spriteBackground; and spriteBackground.setTexture(textureBackground); are examples of usage
• .setTexture(texture) assigns a texture to a sprite
• .setPosition(x, y) sets the position of the sprite on the screen

sf::Keyboard

• This detects keyboard input from the player
• if (sf::Keyboard::isKeyPressed(sf::Keyboard::Escape)){ window.close(); } is an example of usage
• .isKeyPressed(sf::Keyboard::KeyName) checks if a specific key is pressed
• Keyboard::Escape refers to the Escape key
• The Keyboard class defines a set of constants for each key

sf::View Class

• This defines and controls a 2D view within a window, adjusting the visible part of the world within the window, useful for camera movement, zooming, and scrolling
• A sf::View object can be created and have its properties modified (size, center, and rotation) and then applied to a window to change the visible portion of the window's content

Sf::FloatRect

• This defines a rectangle by its position (top-left corner), size, width and height
• sf::FloatRect(float left, float top, float width, float height) is an example of usage
• left is the X-coordinate of the top-left corner of the rectangle
• top is the Y-coordinate of the top-left corner of the rectangle
• width is the width of the rectangle
• height is the height of the rectangle

Classes and Functions Used in Timberman Game (Chapter 2)

sf::Clock

• This measures the time between frames to ensure smooth movement
• Clock clock can create a clock object to track time
• sf::Time dt = clock.restart(); is the proper usage
• .restart() resets the clock and returns the elapsed time since the last reset

sf::Time

• This represents a time period and is not a date-time class
• sf:: Time dt; is the example usage
• asSeconds() converts the time stored in a sf::Time object to a floating-point value representing the time in seconds

rand() in C++

• Both rand() and srand() are standard C++ functions for generating random numbers, defined in <cstdlib> or <stdlib.h>
• The rand() function generates a random integer
• Syntax: int rand();
• rand() returns a pseudo-random integer between 0 and RAND_MAX
• Pseudo-random numbers generated by rand() repeat unless the seed is changed using srand()

srand() Function

• This sets the seed for the random number generator.
• Syntax: void srand(unsigned int seed);
• If srand() is not called, the random number generator always starts with the same seed, making rand() produce the same sequence of numbers
• To get different sequence of random numbers, use the current time (using time (NULL))
• srand(time(NULL)) sets the seed for the random number generator using the current system time
• To generate a random number within a range, use the formula: int randomValue = min + rand() % (max - min + 1);

Key Points to Remember:

• rand(): Generates pseudo-random integers between 0 and RAND_MAX, which are not truly random

• srand(): Sets the seed for the random number generator and if not called, rand() will produce the same sequence of numbers every time the program is run

• Use srand() to Seed the Generator: Call srand() once to set a different seed for each run

Chapter 3

Pausing and restarting the game

SFML Text and Font Classes

• The sf::Font class in SFML loads and stores font files for rendering text
• loadFromFile(const std::string& filename) loads a font from a file, with filename as the path to the font file.
• sf::Text renders text to the screen, allowing modifications to size, color, style, and position
• .setString(const std::string& string) sets the text string to be displayed where string is the text
• .setCharacterSize(unsigned int size) Sets the size of the characters in the text where size is the size of the text in pixels
• .setFillColor(const sf::Color& color) sets the fill color of the text, where color is the color to apply to the text.
• setFont(const sf::Font& font) associates a font with the text object, where font is the sf::Font object to associate with the text.
• getLocalBounds() returns a bounding box representing the text dimensions
• .setOrigin() defines the point around which transformations occur with default being the top-left corner of the text.
• .setPosition(float x, float y) sets the position of the text in the window.

Vector2

• Vector2f is a 2D vector containing two floating-point values where x is the horizontal component and y is the vertical component.

• Implementing HUD (Heads UP Display)

•  std::stringstream ss is a class from <sstream> in C++ that treats strings as streams and allows efficient concatenation and formatting

• ss << "Score = " << score uses the stream insertion operator << to add data to the string stream ss

• scoreText.setString(ss.str()) where ss.str() is a function that converts the contents into a std::string with formatted string being the result of str() with scoreText being a graphical text object that updates its string value using setString