LÖVE - Learn Lua for iOS Game Development - page 253

if x < 0 or x > _W then dirX = − dirX end
if y < 0 or y > _H then dirY = − dirY end
end
end

So, whenever we move away from the window, the love.focus function is triggered, and that sets
the current variable to true or false depending on if the window has focus. In the update, we
increment the position of our image if the current variable is not false or nil . So, the moment we
switch away from the application window, the image freezes, and when we click the window again, it
starts to move.

love.update function,

love.keypressed function.

theImage = love.graphics.newImage("myImage3.png")
x = 50
y = 50
love.graphics.setColor(0,0,0,255)
love.graphics.setBackgroundColor(255,255,255,255)
end

function love.draw()
love.graphics.draw(theImage, x, y)
end

function love.keypressed(key, unicode)
if key=="up" then
y = y - dirY
elseif key =="down" then
y = y + dirY
elseif key=="left" then
x = x - dirX
elseif key =="right" then
x = x + dirX
end
end

In this example, the image only moves when the relevant keys are pressed.