love2d simple draw exchange picture - lua

Question

I'm totally new to Lua and Love2D and probably do not understand the concepts at all.
Well this is a Love2D tutorial, and I want to change it so when I press "a", for example, on the keyboard, the object will exchange (from hamster to car) and so on.
Can you help me out?
-- Tutorial 1: Hamster Ball
-- Add an image to the game and move it around using
-- the arrow keys.
-- compatible with löve 0.6.0 and up
function love.load()
hamster = love.graphics.newImage("hamster.png")
auto = love.graphics.newImage("auto.png")
x = 50
y = 50
speed = 300
end
function love.update(dt)
if love.keyboard.isDown("right") then
x = x + (speed * dt)
end
if love.keyboard.isDown("left") then
x = x - (speed * dt)
end
if love.keyboard.isDown("down") then
y = y + (speed * dt)
end
if love.keyboard.isDown("up") then
y = y - (speed * dt)
end
if love.keyboard.isDown("escape") then
love.event.quit()
end
if love.keyboard.isDown("a") then
love.draw(auto,x,y)
end
end
function love.draw()
love.graphics.draw(hamster, x, y)
end

Answer 1

Well thanks Corbin, i figured it out without "state" local variable. Your solution was inspiring to me. Now it's working.
-- Tutorial 1: Hamster Ball
-- Add an image to the game and move it around using
-- the arrow keys.
-- compatible with löve 0.6.0 and up
function love.load()
hamster = love.graphics.newImage("hamster.png")
auto = love.graphics.newImage("auto.png")
activeImage = hamster
activeImageName = "hamster"
x = 50
y = 50
speed = 300
end
function love.update(dt)
if love.keyboard.isDown("right") then
x = x + (speed * dt)
end
if love.keyboard.isDown("left") then
x = x - (speed * dt)
end
if love.keyboard.isDown("down") then
y = y + (speed * dt)
end
if love.keyboard.isDown("up") then
y = y - (speed * dt)
end
if love.keyboard.isDown("escape") then
love.event.quit()
end
if love.keyboard.isDown("a") then
activeImage = auto
activeImageName = "auto"
end
if love.keyboard.isDown("h") then
activeImage = hamster
activeImageName = "hamster"
end
end
function love.draw()
love.graphics.draw(activeImage, x, y)
end

Answer 2

I'd suggest using love.update to only update state. Don't draw in it. Then do all of your drawing in love.draw. A solution might be:
local state = {}
function love.load()
hamster = love.graphics.newImage("hamster.png")
auto = love.graphics.newImage("auto.png")
state.activeImage = hamster
state.activeImageName = "hamster"
-- <snip> ...
end
function love.update(dt)
-- <snip> ...
if love.keyboard.isDown("a") then
if state.activeImageName == "hamster" then
state.activeImage = auto
state.activeImageName = "auto"
else
state.activeImage = hamster
state.activeImageName = "hamster"
end
end
end
function love.draw()
love.graphics.draw(state.activeImage, x, y)
end

Answer 3

This is probably not the best way to solve this, but it works - create an object which has an X value, a Y value, a speed value, and an IMG value. Set the X and Y to 50 and 50, the speed to 300, and set the IMG to nil. In the load function, set the IMG value to whichever image you would prefer it to start as. In the update function, check for a key press and when the key is pressed change the IMG value to the new image.
An example script for clarification:
player = {X = 50, Y = 50, speed = 300, IMG = nil}
function love.load()
hamster = love.graphics.newImage('hamster.png')
auto = love.graphics.newImage('auto.png')
player.IMG = hamster
end
function love.update(dt)
if love.keyboard.isDown('d') then
player.x = player.x + player.speed
elseif love.keyboard.isDown('a') then
player.x = player.x - player.speed
end
if love.keyboard.isDown('w') then
player.y = player.y + player.speed
elseif love.keyboard.isDown('s') then
player.y = player.y = player.speed
end
if love.keyboard.isDown('space') then
if player.IMG == hamster then
player.IMG = auto
else
player.IMG = hamster
end
end
function love.draw()
love.graphics.draw(player.IMG, player.X, player.Y)
end
Hopefully this helps!