love::script Class Reference

This module provides all the global functions and events that are called. More...

Public Member Functions
void	conf (config &t)
	Modify some configuration options. More...
void	load ()
	This function is called exactly once at the beginning of the game. More...
void	update (float delta)
	Callback function used to update the state of the game every frame. More...
void	draw ()
	Callback function used to draw on the screen every frame. More...
void	reset ()
	Called when the game is requested to be reset. More...
void	gamepadpressed (Joystick *joystick, const std::string &button)
	Called when a joystick button is pressed. More...
void	gamepadreleased (Joystick *joystick, const std::string &button)
	Called when a joystick button is released. More...
void	joystickpressed (Joystick *joystick, int button)
	Called when a joystick button is pressed. More...
void	joystickreleased (Joystick *joystick, int button)
	Called when a joystick button is released. More...
void	mousepressed (int x, int y, const std::string &button)
	Called when a mouse button is pressed. More...
void	mousereleased (int x, int y, const std::string &button)
	Called when a mouse button is released. More...
void	mousemoved (int x, int y, int dx, int dy)
	Called when the mouse is moved. More...
void	keypressed (const std::string &key, int scancode)
	Called when a key on the keyboard has been pressed. More...
void	keyreleased (const std::string &key, int scancode)
	Called when a key on the keyboard is released. More...
std::string	savestate ()
	Called when requested to save the current state. More...
bool	loadstate (const std::string &data)
	Called when requested to load a state. More...
void	cheatreset ()
	Called when requested to reset the state of all the cheats to their default state. More...
void	cheatset (int index, bool enabled, const std::string &code)
	Called when requested to enable or disable a cheat. More...
void	exit ()
	Callback function triggered when the game is closed. More...

Detailed Description

This module provides all the global functions and events that are called.

The following main.chai is an example of some of these callbacks being used in unison.

global logo
 
def load() {
  logo = love.graphics.newImage("logo.png")
}
 
def draw() {
  love.graphics.print("Hello World!", 400, 300)
  love.graphics.draw(logo, 100, 100)
}
 
def update(dt) {
  // Change something on the screen.
}

Member Function Documentation

cheatreset()

void love::script::cheatreset

(

)

Called when requested to reset the state of all the cheats to their default state.

Example

global invincible = false
 
def cheatreset() {
    invincible = false
}

See also

cheatset

cheatset()

void love::script::cheatset	(	int	index,
		bool	enabled,
		const std::string &	code
	)

Called when requested to enable or disable a cheat.

Parameters

index	The index of the cheat.
enabled	Whether the cheat is to be enabled or disabled.
code	The code for the cheat.

Example

global invincible = false
 
def cheatset(index, enabled, code) {
    if (code == "invincible") {
        // Enable or disable invincibility
        invincible = enabled
    }
}

See also

cheatreset

conf()

void love::script::conf

(

config &

t

)

Modify some configuration options.

Parameters

t	The config object to modify.

This callback can live in the conf.chai file.

Example

def conf(t) {
  // The ChaiLove version this game was made for.
  t.version = "0.29.0"
 
  // The width and height of the game.
  t.window.width = 1024
  t.window.height = 768
}

See also

love.config

draw()

void love::script::draw

(

)

Callback function used to draw on the screen every frame.

Example

Draw an image that was loaded in script::load (putting graphics.newImage in script::draw would cause the image to be reloaded every frame, which would cause issues).

global hamster
 
dev load() {
  hamster = love.graphics.newImage("hamster.png")
}
 
def draw() {
  love.graphics.draw(hamster, 100, 100)
}

exit()

void love::script::exit

(

)

Callback function triggered when the game is closed.

Example

def exit() {
    print("Thanks for playing. Please play again soon!")
}

gamepadpressed()

void love::script::gamepadpressed	(	Joystick *	joystick,
		const std::string &	button
	)

Called when a joystick button is pressed.

Parameters

joystick	The joystick object.
button	The name of which button was released.

Example

global buttonPressed = ""
 
def draw() {
  love.graphics.print("Button Pressed: " + buttonPressed, 100, 100)
}
 
def gamepadpressed(joy, button) {
  buttonPressed = button
}

See also

gamepadreleased

gamepadreleased()

void love::script::gamepadreleased	(	Joystick *	joystick,
		const std::string &	button
	)

Called when a joystick button is released.

Parameters

joystick	The joystick object.
button	The name of which button was released.

Example

global buttonReleased = ""
 
def draw() {
  love.graphics.print("Button Released: " + buttonReleased, 100, 100)
}
 
def gamepadreleased(joy, button) {
  buttonReleased = button
}

See also

gamepadpressed

joystickpressed()

void love::script::joystickpressed	(	Joystick *	joystick,
		int	button
	)

Called when a joystick button is pressed.

Parameters

joystick	The joystick object.
button	The number representing the button that was released.

See also

joystickreleased

joystickreleased()

void love::script::joystickreleased	(	Joystick *	joystick,
		int	button
	)

Called when a joystick button is released.

Parameters

joystick	The joystick object.
button	The number representing the button that was pushed.

See also

joystickpressed

keypressed()

void love::script::keypressed	(	const std::string &	key,
		int	scancode
	)

Called when a key on the keyboard has been pressed.

Parameters

key	The name of the key that was pressed.
scancode	The scancode of the key that was pressed.

Example

def keypressed(key, scancode) {
    print("Key Pressed: " + key)
    print("Scancode: " + to_string(scancode))
}

See also

keyreleased

keyreleased()

void love::script::keyreleased	(	const std::string &	key,
		int	scancode
	)

Called when a key on the keyboard is released.

Parameters

key	The name of the key that was released.
scancode	The scancode of the key that was released.

Example

def keyreleased(key, scancode) {
    print("Key Released: " + key)
    print("Scancode: " + to_string(scancode))
}

See also

keypressed

load()

void love::script::load

(

)

This function is called exactly once at the beginning of the game.

Example

Establish some variables/resources on the game load, so that they can be used repeatedly in other functions (such as script::draw).

global hamster
 
def load() {
  hamster = love.graphics.newImage("hamster.png")
}
 
def draw() {
  love.graphics.draw(hamster, 100, 100)
}

loadstate()

bool love::script::loadstate

(

const std::string &

data

)

Called when requested to load a state.

Parameters

data	A JSON array representing the state to load.

Returns

bool True if loading the state succeeded.

Example

global score = 0
 
def loadstate(data) {
    var info = from_json(data)
    score = info["score"]
    return true
}

See also

savestate

mousemoved()

void love::script::mousemoved	(	int	x,
		int	y,
		int	dx,
		int	dy
	)

Called when the mouse is moved.

Parameters

x	The mouse position on the x-axis.
y	The mouse position on the y-axis.
dx	The amount moved along the x-axis since the last time love.mousemoved was called.
dy	The amount moved along the y-axis since the last time love.mousemoved was called.

Example

global mousex = 0
global mousey = 0
 
def draw() {
  love.graphics.setColor(255, 255, 255)
  love.graphics.point(mousex, mousey)
}
 
def mousemoved(x, y, dx, dy) {
  mousex = x
  mousey = y
}

mousepressed()

void love::script::mousepressed	(	int	x,
		int	y,
		const std::string &	button
	)

Called when a mouse button is pressed.

Parameters

x	The mouse position on the x-axis.
y	The mouse position on the y-axis.
button	The mouse button name of which was pressed.

Example

global buttonPressed = "None"
global mousex = 0
global mousey = 0
 
def draw() {
  love.graphics.print("Mouse Button Pressed: " + buttonPressed, mousex, mousey)
}
 
def mousepressed(x, y, button) {
  buttonPressed = button
  mousex = x
  mousey = y
}

See also

mousereleased

mousereleased()

void love::script::mousereleased	(	int	x,
		int	y,
		const std::string &	button
	)

Called when a mouse button is released.

Parameters

x	The mouse position on the x-axis.
y	The mouse position on the y-axis.
button	The mouse button name of which was released.

Example

global buttonReleased = "None"
global mousex = 0
global mousey = 0
 
def draw() {
  love.graphics.print("Mouse Button Released: " + buttonReleased, mousex, mousey)
}
 
def mousereleased(x, y, button) {
  buttonReleased = button
  mousex = x
  mousey = y
}

See also

mousepressed

reset()

void love::script::reset

(

)

Called when the game is requested to be reset.

Example

global textX = 10
 
dev update(dt) {
  textX += dt * 20
}
 
def draw() {
  love.graphics.print("Hello World", textX, 100)
}
 
def reset() {
  textX = 10
}

savestate()

std::string love::script::savestate

(

)

Called when requested to save the current state.

Returns

string A JSON array representing the current state.

Example

global score = 0
 
def savestate() {
    return to_json([
        "score": score
    ])
}

See also

loadstate

update()

void love::script::update

(

float

delta

)

Callback function used to update the state of the game every frame.

Parameters

delta

Time since the last update in seconds.

Example

Change a variable var at a constant rate (+/- 3 per second in this example).

var position = 10
var rate = 3
 
def update(dt) {
  if (love.keyboard.isDown("down")) {
    position -= dt * rate
  }
  if (love.keyboard.isDown("up")) {
    position += dt * rate
  }
}