CODEWITHSUNDEEP
functionmathlualove2d
user2418051
user2418051

Reputation: 81

Change the object (car) speed

I need to change the object speed after I changed his rotation.

function love.update(dt)

if car['speed'] > 0 then
    car['x'] = car['x'] + math.cos(car['angle'])
    car['y'] = car['y'] + math.sin(car['angle'])
end

if love.keyboard.isDown("w") then
    car['speed'] = car['speed'] + dt
end

if love.keyboard.isDown("a") then
    car['angle'] = car['angle'] - (1 * dt)
end

if love.keyboard.isDown("d") then
    car['angle'] = car['angle'] + (1 * dt)
end
end

After I changing the speed in the "w" I want it to change the speed of the car (x,y). But when I trying to add the speed its just changing the rotation and ruining it..

Upvotes: 1

Views: 92

Answers (1)

Michal Kottman
Michal Kottman

Reputation: 16753

The required change is very simple: just scale the cos and sin by the car speed:

if car['speed'] > 0 then
    car['x'] = car['x'] + car['speed'] * math.cos(car['angle'])
    car['y'] = car['y'] + car['speed'] * math.sin(car['angle'])
end

Also, in Lua, car['speed'] is equivalent to car.speed (syntactic sugar). Some people find this easier to read. The code above could be written as:

if car.speed > 0 then
    car.x = car.x + car.speed * math.cos(car.angle)
    car.y = car.y + car.speed * math.sin(car.angle)
end

PS: Don't forget to slow down the car ;)

Upvotes: 2

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