lmgl::core::Engine Class Reference

A singleton class that manages the main application loop using GLFW. More...

#include <engine.hpp>

Public Member Functions
bool	init (int w, int h, std::string title, bool resizable=true, bool vsync=true)
	Initialize the engine with the specified window dimensions and title.
void	run (std::function< void(float)> update_callback)
	Run the main application loop.
void	free ()
	Free resources and clean up the engine.
bool	is_running () const
	Check if the engine is still running.
void	shutdown ()
	Shuts the engine down and closes the window.
void	clear (float r, float g, float b, float a=1.0f)
	Clear the screen.
void	set_vsync (VSyncMode mode)
	Set VSync mode.
int	get_width () const
	Retrieves the window's width.
int	get_height () const
	Retrieves the window's height.
float	get_aspect_ratio () const
	Returns the aspect ratio of the window (width/height).
void	set_size (int width, int height)
	Sets the window to a new size.
void	set_title (const std::string &title)
	Sets the window title to a new string.
void	set_fullscreen (bool fullscreen)
	Toggles fullscreen mode.
bool	is_fullscreen () const
	Checks if the window is in fullscreen mode.
void	maximize ()
	Maximizes the window to occupy the entirety of the screen.
void	minimize ()
	Minimizes the window.
void	restore ()
	Restores the window from minimized/maximized state.
bool	is_key_pressed (Key key) const
	Checks if a key is currently pressed.
bool	is_key_just_pressed (Key key) const
	Checks if a key was just pressed this frame.
bool	is_key_just_released (Key key) const
	Checks if a key was just released this frame.
bool	is_mouse_button_pressed (MouseButton button) const
	Checks if a mouse button is pressed.
double	get_mouse_x () const
	Retrieves the x position of the mouse in the window.
double	get_mouse_y () const
	Retrieves the y position of the mouse in the window.
void	get_mouse_delta (double &dx, double &dy) const
	Retrieves the mouse position change (delta) between the last frame and the current frame.
void	set_mouse_position (double x, double y)
	Sets the mouse position to a (x,y) coordinate.
void	set_cursor_mode (CursorMode mode)
	Sets a new cursor mode to the engine.
void	get_scroll_offset (double &xoffs, double &yoffs) const
	Retrieves the offset of scroll on x and y axes since the last frame.
GLFWwindow *	get_window () const
	Get the GLFW window associated with the engine.
void	set_resize_callback (std::function< void(int, int)> callback)
	Sets the callback responsible for window resizing.
float	get_delta_time () const
	Get the delta time between the current and last frame.
float	get_time () const
	Retrieves the total time elapsed since the engine's start.
float	get_fps () const
	Retrieves the current FPS count.

Static Public Member Functions
static Engine &	get_instance ()
	Get the singleton instance of the Engine.

Detailed Description

A singleton class that manages the main application loop using GLFW.

This class provides methods to initialize the engine, run the main loop, and clean up resources. It also tracks the delta time between frames. The engine is designed to be used in applications that require a rendering loop, such as games or graphical simulations.

Note

This class is implemented as a singleton to ensure that only one instance of the engine exists throughout the application lifecycle.

Member Function Documentation

clear()

void lmgl::core::Engine::clear	(	float	r,
		float	g,
		float	b,
		float	a = 1.0f )

Clear the screen.

This method can be used to clear the screen before rendering a new frame.

Parameters

r	Red component of the clear color (0.0 to 1.0).
g	Green component of the clear color (0.0 to 1.0).
b	Blue component of the clear color (0.0 to 1.0).
a	Alpha component of the clear color (0.0 to 1.0), default is 1.0.

free()

void lmgl::core::Engine::free

(

)

Free resources and clean up the engine.

Destroys the GLFW window and terminates GLFW.

get_aspect_ratio()

float lmgl::core::Engine::get_aspect_ratio

(

)

const

Returns the aspect ratio of the window (width/height).

Returns

the aspect ratio of the window.

get_delta_time()

float lmgl::core::Engine::get_delta_time ( ) const

inline

Get the delta time between the current and last frame.

This value is useful for frame-independent movement and animations.

@returnDelta time in seconds.

get_fps()

float lmgl::core::Engine::get_fps ( ) const

inline

Retrieves the current FPS count.

Returns

The current FPS count.

get_height()

int lmgl::core::Engine::get_height ( ) const

inline

Retrieves the window's height.

Returns

the window height.

get_instance()

Engine & lmgl::core::Engine::get_instance ( )

static

Get the singleton instance of the Engine.

Maintains a static reference to the single Engine instance. If the instance does not exist, it is created.

Returns

Reference to the singleton Engine instance.

get_mouse_delta()

void lmgl::core::Engine::get_mouse_delta	(	double &	dx,
		double &	dy ) const

Retrieves the mouse position change (delta) between the last frame and the current frame.

Parameters

dx	return parameter for the mouse position delta on the x axis
dy	return parameter for the mouse position delta on the y axis

get_mouse_x()

double lmgl::core::Engine::get_mouse_x ( ) const

inline

Retrieves the x position of the mouse in the window.

Returns

The x position of the mouse in the window.

get_mouse_y()

double lmgl::core::Engine::get_mouse_y ( ) const

inline

Retrieves the y position of the mouse in the window.

Returns

The y position of the mouse in the window.

get_scroll_offset()

void lmgl::core::Engine::get_scroll_offset	(	double &	xoffs,
		double &	yoffs ) const

Retrieves the offset of scroll on x and y axes since the last frame.

Parameters

xoffs	the offset of scroll on the x axis since the last frame
yoffs	the offset of scroll on the y axis since the last frame

get_time()

float lmgl::core::Engine::get_time ( ) const

inline

Retrieves the total time elapsed since the engine's start.

Returns

The total time elapsed since the engine's start.

get_width()

int lmgl::core::Engine::get_width ( ) const

inline

Retrieves the window's width.

Returns

the window width.

get_window()

GLFWwindow * lmgl::core::Engine::get_window ( ) const

inline

Get the GLFW window associated with the engine.

The returned pointer can be used for further GLFW operations.

Returns

Pointer to the GLFWwindow.

init()

bool lmgl::core::Engine::init	(	int	w,
		int	h,
		std::string	title,
		bool	resizable = true,
		bool	vsync = true )

Initialize the engine with the specified window dimensions and title.

Initializes GLFW, creates a window, and sets up the necessary context for rendering. Returns true if initialization is successful, false otherwise.

Parameters

w	Width of the window.
h	Height of the window.
title	Title of the window.

Returns

True if initialization was successful, false otherwise.

is_fullscreen()

bool lmgl::core::Engine::is_fullscreen ( ) const

inline

Checks if the window is in fullscreen mode.

Returns

the fullsscreen state (true/false).

is_key_just_pressed()

bool lmgl::core::Engine::is_key_just_pressed

(

Key

key

)

const

Checks if a key was just pressed this frame.

Parameters

key	the key to check

Returns

whether the key was just pressed this frame or not.

is_key_just_released()

bool lmgl::core::Engine::is_key_just_released

(

Key

key

)

const

Checks if a key was just released this frame.

Parameters

key	the key to check

Returns

whether the key was just released this frame or not.

is_key_pressed()

bool lmgl::core::Engine::is_key_pressed

(

Key

key

)

const

Checks if a key is currently pressed.

Parameters

key	the key to check

Returns

whether the key is currently pressed or not.

is_mouse_button_pressed()

bool lmgl::core::Engine::is_mouse_button_pressed

(

MouseButton

button

)

const

Checks if a mouse button is pressed.

Parameters

button

the mouse button to check

Returns

whether the mouse button is pressed or not.

is_running()

bool lmgl::core::Engine::is_running

(

)

const

Check if the engine is still running.

The engine is considered running as long as the window has not been closed.

Returns

True if the window is open, false otherwise.

run()

void lmgl::core::Engine::run

(

std::function< void(float)>

update_callback

)

Run the main application loop.

The loop continues until the window is closed. The provided update callback is called each frame with the delta time as an argument.

Parameters

update_callback

A function to be called each frame with delta time.

set_cursor_mode()

void lmgl::core::Engine::set_cursor_mode

(

CursorMode

mode

)

Sets a new cursor mode to the engine.

Parameters

mode	the new cursor mode to set

set_fullscreen()

void lmgl::core::Engine::set_fullscreen

(

bool

fullscreen

)

Toggles fullscreen mode.

Fullscreen mode forces the window to render as fullscreen, overriding system controls.

Parameters

fullscreen

the new fullscreen state (true/false)

set_mouse_position()

void lmgl::core::Engine::set_mouse_position	(	double	x,
		double	y )

Sets the mouse position to a (x,y) coordinate.

Parameters

x	the new x coordinate component of the mouse position
y	the new y coordinate component of the mouse position

set_size()

void lmgl::core::Engine::set_size	(	int	width,
		int	height )

Sets the window to a new size.

Parameters

width	the new window width
height	the new window height

set_title()

void lmgl::core::Engine::set_title

(

const std::string &

title

)

Sets the window title to a new string.

Parameters

title

the new title to set.

set_vsync()

void lmgl::core::Engine::set_vsync

(

VSyncMode

mode

)

Set VSync mode.

Parameters

mode	The VSync mode to set

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The documentation for this class was generated from the following files:

• include/lmgl/core/engine.hpp
• src/core/engine.cpp