Why isn't my bird jumping when i press the space bar for my flappy bird game?

Question

I am new to lua and love. I am attempting to make a flappy bird game. When the game runs, the bird does not jump. the bird just floats until it crashes and the game ends. Also, only my original pipes are shown, no new pipes are being spawned. How do i get the bird to jump when i hit the space key and keep spawning pipes? below is my code:

--sets up game window
function love.load()
    love.window.setMode(400, 600)
    love.window.setTitle("Flappy Bird")


    --load assets
    bg= love.graphics.newImage("flappy background.png")
    bird = love.graphics.newImage("bird image.png")

    pipeImage = love.graphics.newImage("pipe-up.png")
    jumpSound = love.audio.newSource("jump sound.wav", "static")
    scoreSound = love.audio.newSource("scoring.wav", "static")
    gameOverSound = love.audio.newSource("game over.wav", "static")


    --initialize game variables
    x = 502
    jumpHeight = 500
    velocity = -300
    gapHeight = 150
    pipeX = 400
    pipeY = love.math.random(100, 400)
    scored = false
    score = 0
    gameover = false
end

--draw game objects
function love.draw()
     
    --Get the dimensions of the window
    local windowWidth, windowHeight = love.graphics.getDimensions()

    --Calculate the scaling factor for the background image
    local sx = windowWidth / bg:getWidth()
    local sy = windowHeight / bg:getHeight()

    --Draw the scaled background image
    love.graphics.draw(bg, 0, 0, 0, sx, sy)

    love.graphics.draw(bird, x, y)
    love.graphics.draw(pipeImage, pipeX, pipeY - pipeImage:getHeight() - gapHeight)
    love.graphics.draw(pipeImage, pipeX, pipeY + gapHeight)
    love.graphics.print("Score: " .. score, 10, 10)
end

--adds movement to bird
function love.keypressed(key)
    if key == "space" and not gameover then
        velocity = -jumpHeight 
        jumpSound:play() -- play the jump sound effect
    elseif key == "r" and gameover then
            --reinitialize game variables
        x = 50
        y = 300
        velocity = -120
        pipeX = 400
        pipeY = love.math.random(100, 400)
        scored = false
        score = 0
        gameover = false
    end
end

--checks collison with pipes
function checkCollision(x1, y1, w1, h1, x2, y2, w2, h2)
    return x1 < x2 + w2 and
    x2 < x1 + w1 and
    y1 < y2 + h2 and
    y2 < y1 + h1
end

function love.update(dt)
    if not gameover then
        --update the bird's position and velocity
        velocity = velocity + gravity * dt
        y = y + velocity * dt

        --update the pipe's position
        pipeX = pipeX - 200 * dt

        --reset the pipe's position if it goes offscreen
        if pipeX < -pipeImage:getWidth() then
            pipeX = -120
            pipeY = love.math.random(100, 400)
            scored = false
        end

        --check for collision with pipes
        if checkCollision(x, y, bird:getWidth(), bird:getHeight(), pipeX, pipeY - pipeImage:getHeight() - gapHeight, pipeImage:getWidth(), pipeImage:getHeight()) or
        checkCollision(x, y, bird:getWidth(), bird:getHeight(), pipeX, pipeY + gapHeight, pipeImage:getWidth(), pipeImage:getHeight()) or
        y < 0 or
        y > love.graphics.getHeight() then
            gameover = true
            gameOverSound:play()
        end

        --check for scoring
        if x > pipeX + pipeImage:getWidth() and not scored then
            score = score + 1
            scored = true
            scoreSound:play()
        end
    end
end

--adds game over screen
function drawGameOver()
    love.graphics.print("Game Over", 100, 100)
    love.graphics.print("Score: " .. score, 100, 150)
end

function love.draw()
    if not gameover then
        --Get the dimensions of the window
        local windowWidth, windowHeight = love.graphics.getDimensions()

        --Calculate the scaling factor for the background image
        local sx = windowWidth / bg:getWidth()
        local sy = windowHeight / bg:getHeight()

        --Draw the scaled background image
        love.graphics.draw(bg, 0, 0, 0, sx, sy)

    end
end
        y = 300
        love.graphics.draw(bird, x, y)
        love.graphics.draw(pipeImage, pipeX, pipeY - pipeImage:getHeight() - gapHeight)
        love.graphics.draw(pipeImage, pipeX, pipeY + gapHeight)
        love.graphics.print("Score: " .. score, 10, 10)
    else
        drawGameOver()
    end
end

--restarts the game
function love.keypressed(key)
    if key == "r" and gameover then
        --reinitialize game variables
        x = 50
        y = 300
        velocity = 0
        pipeX = 400
        pipeY = love.math.random(100, 400)
        scored = false
        score = 0
        gameover = false
        gravity = 0

I tried adjusting the jumpheight, velocity, and gravity variables to fix the issue but to no avvail. I also combined the keypressed functions into one thinking the restart function was coming before the jump function, but that did not work either. What am i doing wrong?

Answer 1

It seems that in your code to make the bird jump you did something wrong.

function love.keypressed(key)
    if key == "space" and not gameover then
        velocity = -jumpHeight

You are making the velocity of the bird equal to -jumpHeight. You should try replacing velocity = -jumpHeight with y = y + jumpHeight.

Regarding your second question on how to keep spawning pipes. You could detect if the pipe is off screen by checking the pipeX value (In this case most likely when pipeX < 0). If it is you can reset pipeX and pipeY like you do when you reset the game.