Question: How do you handle keypresses in Love2D?

Answer

In Love2D, handling keypresses is done through the love.keypressed function. This callback function is triggered whenever a player presses a key. Below is an example of how to use love.keypressed to move a player character when arrow keys are pressed.

function love.load()
    -- Initial position of the player
    player = { x = 100, y = 100 }
end

function love.update(dt)
    -- Player movement would be handled here, if it were continuous
end

function love.keypressed(key, scancode, isrepeat)
    -- Adjust the player's position based on the keypress
    if key == "up" then
        player.y = player.y - 10
    elseif key == "down" then
        player.y = player.y + 10
    elseif key == "left" then
        player.x = player.x - 10
    elseif key == "right" then
        player.x = player.x + 10
    end
end

function love.draw()
    -- Draw the player as a rectangle
    love.graphics.rectangle("fill", player.x, player.y, 50, 50)
end

In this example, whenever one of the arrow keys is pressed, the love.keypressed function updates the player's x or y coordinates accordingly. The player object is then drawn at its new position during the love.draw() call.

The parameters of the love.keypressed function provide additional information:

• key: A string representing the key that was pressed.
• scancode: A platform-specific scancode representing the physical key on the keyboard.
• isrepeat: A boolean indicating whether this keypress event is a repeat (the key is being held down).

Note that the love.keypressed function will not continuously detect a key being held down; it only triggers once per press. To handle continuous key detection (for smooth movements, for example), you would typically check the key states in the love.update function using love.keyboard.isDown.

Here's an example of how to refactor the previous code to handle continuous key presses:

function love.update(dt)
    if love.keyboard.isDown("up") then
        player.y = player.y - 100 * dt
    end
    if love.keyboard.isDown("down") then
        player.y = player.y + 100 * dt
    end
    if love.keyboard.isDown("left") then
        player.x = player.x - 100 * dt
    end
    if love.keyboard.isDown("right") then
        player.x = player.x + 100 * dt
    end
end

-- Other functions remain unchanged.

With this implementation, the player's position is updated in love.update, allowing for smooth and continuous movement.