love.wheelmoved
 Available since LÖVE 0.10.0  
 This function is not supported in earlier versions. 
Callback function triggered when the mouse wheel is moved.
Function
Synopsis
love.wheelmoved( x, y )
Arguments
- number x
- Amount of horizontal mouse wheel movement. Positive values indicate movement to the right.
- number y
- Amount of vertical mouse wheel movement. Positive values indicate upward movement.
Returns
Nothing.
Examples
local text = ""
 
function love.wheelmoved(x, y)
    if y > 0 then
        text = "Mouse wheel moved up"
    elseif y < 0 then
        text = "Mouse wheel moved down"
    end
end
 
function love.draw()
    love.graphics.print(text, 10, 10)
end 
 
Smooth scrolling
function love.load()
    posx, posy = love.graphics.getWidth() * 0.5, love.graphics.getHeight() * 0.5
    velx, vely = 0, 0 -- The scroll velocity
end
 
function love.draw()
    love.graphics.rectangle( 'line', posx, posy, 50, 50 )
end
 
function love.update( dt )
    posx = posx + velx * dt
    posy = posy + vely * dt
 
    -- Gradually reduce the velocity to create smooth scrolling effect.
    velx = velx - velx * math.min( dt * 10, 1 )
    vely = vely - vely * math.min( dt * 10, 1 )
end
 
function love.wheelmoved( dx, dy )
    velx = velx + dx * 20
    vely = vely + dy * 20
end See Also
 
    © 2006–2020 LÖVE Development Team
Licensed under the GNU Free Documentation License, Version 1.3.
    https://love2d.org/wiki/love.wheelmoved