Keyboard events

Use love.keyboard.isDown(“key-string”) to detect whether a key is being held down. Define functions love.keypressed(key) and love.keyreleased(key) to do something when a key is pressed or released.

Resources:

main.lua

--[[
    Move a circle around using keyboard input with ability to
    change color and speed.
    Mithat Konar
--]]
 
function love.load()
    -- circle's constants
    CIRCLE_SIZE = 30
    DEFAULT_SPEED = 100
    circle_speed = DEFAULT_SPEED
 
    -- circle's variables
    -- put circle in the center of the screen
    circleX = love.graphics.getWidth() / 2
    circleY = love.graphics.getHeight() / 2
 
    -- motion variables
    isMoveRight = false
    isMoveLeft = false
    isMoveDown = false
    isMoveUp = false
 
end
 
function love.keypressed(key)
    -- change color when key is pressed.
    if key == 'c' then
        local randomColor = {math.random(), math.random(), math.random()}
        love.graphics.setColor(randomColor)
    end
 
    -- change speed when 'j', 'k', and 'l' keys are pressed.
    if key == 'j' then
        circle_speed = circle_speed / 2
    end
    if key == 'k' then
        circle_speed = DEFAULT_SPEED
    end
    if key == 'l' then
        circle_speed = circle_speed * 2
    end    
end
 
function love.keyreleased(key)
    -- Change color when key is released
    if key == 'c' then
        local randomColor = {math.random(), math.random(), math.random()}
        love.graphics.setColor(randomColor)
    end
end
 
function love.update(dt)
    -- detect whether keys are pressed and move accordingly.
    -- test for both arrow and WASD keys
    if love.keyboard.isDown('right') or love.keyboard.isDown('d') then
        circleX = circleX + circle_speed * dt
    end
    if love.keyboard.isDown('left') or love.keyboard.isDown('a') then
        circleX = circleX - circle_speed * dt
    end
    if love.keyboard.isDown('up') or love.keyboard.isDown('w') then
        circleY = circleY - circle_speed * dt
    end
    if love.keyboard.isDown('down') or love.keyboard.isDown('s') then
        circleY = circleY + circle_speed * dt
    end
end
 
function love.draw()
    love.graphics.print(circleX .. ', ' .. circleY, 5, 5)
    love.graphics.print('Circle speed: ' .. circle_speed, 5, 25)
    love.graphics.circle('fill', circleX, circleY, CIRCLE_SIZE)
end