Hands-on: Vehicle Roulette

Time to combine functions and arrays into something fun. We’ll build a vehicle roulette — press a key, and the script picks a random vehicle from a pool and spawns it right next to you. Press again to swap it for another. Will you get a sports car or a tractor? Only one way to find out.

Here’s the final script:

{$CLEO .cs}

const KEY_SPIN = 116 // F5
const NUM_VEHICLES = 8

// vehicle model pool
int models[NUM_VEHICLES]
models[0] = 415 // cheetah
models[1] = 451 // turismo
models[2] = 522 // nrg-500
models[3] = 432 // rhino
models[4] = 509 // bike
models[5] = 510 // mountain bike
models[6] = 539 // vortex
models[7] = 531 // tractor

Car currentCar
int currentModel = -1

while true
    wait 0

    if not is_key_just_pressed KEY_SPIN
    then
        continue
    end

    // remove previous vehicle if it exists
    if currentModel <> -1
    then
        cleanup(currentCar, currentModel)
    end

    // pick a random vehicle
    int index = generate_random_int_in_range {min} 0 {max} NUM_VEHICLES
    currentModel = models[index]

    // load, spawn, show
    loadModel(currentModel)
    currentCar = spawnNearPlayer(currentModel)

    print_formatted_now "You got model %d! Press F5 for another spin." 3000 currentModel
end


function loadModel(modelId: int)
    request_model modelId
    while not has_model_loaded modelId
        wait 0
    end
end

function spawnNearPlayer(modelId: int): int
    float pos[3]
    Char playerChar = get_player_char {player} 0
    ...pos = get_offset_from_char_in_world_coords playerChar {xOffset} 0 {yOffset} 5.0 {zOffset} 0

    Car vehicle = create_car modelId {at} ...pos
    return vehicle
end

function cleanup(vehicle: Car, modelId: int)
    delete_car vehicle
    mark_model_as_no_longer_needed modelId
end

Let’s break it down.

The Vehicle Pool

An array stores the model IDs of all candidate vehicles. Adding or removing vehicles is as simple as editing this list and updating NUM_VEHICLES:

const NUM_VEHICLES = 8

int models[NUM_VEHICLES]
models[0] = 415 // cheetah
models[1] = 451 // turismo
models[2] = 522 // nrg-500
models[3] = 432 // rhino
models[4] = 509 // bike
models[5] = 510 // mountain bike
models[6] = 539 // vortex
models[7] = 531 // tractor

The mix of sports cars, bikes, a tank, and a tractor makes each spin genuinely unpredictable.

Three Functions

The script defines three focused functions, each handling one responsibility:

loadModel — The familiar request-and-wait pattern from the functions lesson, packaged for reuse:

function loadModel(modelId: int)
    request_model modelId
    while not has_model_loaded modelId
        wait 0
    end
end

spawnNearPlayer — Creates the car in front of the player, and returns the handle:

function spawnNearPlayer(modelId: int): int
    float pos[3]
    Char playerChar = get_player_char {player} 0
    ...pos = get_offset_from_char_in_world_coords playerChar {xOffset} 0 {yOffset} 5.0 {zOffset} 0

    Car vehicle = create_car modelId {at} ...pos
    return vehicle
end

cleanup — Deletes the old vehicle and releases its model to free memory:

function cleanup(vehicle: Car, modelId: int)
    delete_car vehicle
    mark_model_as_no_longer_needed modelId
end

Each function is small, readable, and does one thing.

The Main Loop

The script uses while true with a key-press check — the same pattern from Chapter II. The is_key_just_pressed condition fires only once per press, preventing a held key from triggering multiple spins:

while true
    wait 0

    if not is_key_just_pressed KEY_SPIN
    then
        continue
    end
    ...
end

When the player presses F5, the script cleans up the previous car (if any), picks a random index from the models array, and calls the functions in sequence:

int index = generate_random_int_in_range {min} 0 {max} NUM_VEHICLES
currentModel = models[index]

loadModel(currentModel)
currentCar = spawnNearPlayer(currentModel)

generate_random_int_in_range picks an index between 0 (inclusive) and NUM_VEHICLES (exclusive). That index pulls a model ID from the array, which flows through loadModel and spawnNearPlayer.

Save the file as vehicle_roulette.txt, press F7, and try your luck!

What’s next?

Try these modifications and recompile:

• Add more vehicles to the pool (find model IDs in the vehicles.ide).
• use get_name_of_vehicle_model and show the vehicle name instead of the model number
• Add a spin counter and print “Spin #N” with each roll.
• Make it cost $500 per spin — check the player’s money before proceeding, and show a “Not enough cash!” message if they can’t afford it.