LÖVE Documentation 0.5.0

Synopsis

World:setCallback( f )

Arguments

f A Lua function.

Returns

(Nothing)

Examples

Example 101: Mini Physics Callbacks

-- Example: Mini Physics Callbacks
text = "No collision yet."
function load()
-- Set a font.
local font = love.graphics.newFont(love.default_font, 12)
love.graphics.setFont(font)
-- Create a world with size 2000 in every direction.
world = love.physics.newWorld(2000, 2000)
world:setGravity(0, 50)
-- Create the ground body at (0, 0) with mass 0.
ground = love.physics.newBody(world, 0, 0, 0)
-- Create the ground shape at (400,500) with size (600,10).
ground_shape = love.physics.newRectangleShape(ground, 400, 500, 600, 10)
ground_shape:setData("Ground") -- Set a string userdata
-- Load the image of the ball.
ball = love.graphics.newImage("images/love-ball.png")
-- Create a Body for the circle.
body = love.physics.newBody(world, 400, 200)
-- Attatch a shape to the body.
circle_shape = love.physics.newCircleShape(body, 28)
circle_shape:setData("Ball") -- Set a string userdata
-- Calculate the mass of the body based on attatched shapes.
-- This gives realistic simulations.
body:setMassFromShapes()
-- Set the collision callback.
world:setCallback(collision)
end
function update(dt)
-- Update the world.
world:update(dt)
end
function draw()
-- Draws the ground.
love.graphics.polygon(love.draw_line, ground_shape:getPoints())
-- Draw the circle.
love.graphics.draw(ball,body:getX(), body:getY(), body:getAngle())
-- Draw text.
love.graphics.draw(text, 50, 50)
end
function keypressed(k)
if k == love.key_space then
-- Apply a random impulse
body:applyImpulse(100000-math.random(0, 200000), 0)
end
end
-- This is called every time a collision occurs.
function collision(a, b, c)
text = "Collided: " .. a .. " and " .. b
end