Freedom transport

The ask was a trucking job with levels, trucks to buy, cargo that unlocks with level, and a minigame where you park your load perfectly in a bay. The usual way to build that is a random coordinate and a marker on the ground. That falls apart the first time a bay turns out to sit under a lamp post or against a fence.

So the bays came from the map itself. I read all 18,948 GTA map files, base game and DLC, and pulled out the 47,832 car generators, the spots where the game places parked vehicles. 227 of them are places where Rockstar parks trucks and trailers itself. For each candidate I measured the real collision geometry and props around it: flat ground, 16 metres of free run-up for the truck, and a wall or dock behind. Bays with a railing, lamp post, container or bollard in them were dropped. That left 146 bays at 34 locations. Fit checks with a full truck and trailer, and a later check of every approach route, took it to 141 bays at 31 locations, 89 of them at the container terminal; one warehouse went because no truck fits under the bridge on its only approach.

• Pick a run on the freight board: cargo, route, distance, estimated time, pay and XP. Seven cargo types unlock between level 1 and 16, from city freight to car transport.
• Take the company's MTL Packer from level 1, or drive your own Packer, Hauler, Phantom or Phantom Custom for 25 percent more pay and heavier cargo.
• Hitch the trailer, drive the route and keep the cargo intact. Collisions damage it, and refrigerated freight has a deadline.
• Reverse into the bay. A parking aid shows a top view with distance to the dock, side offset and angle, and a parking sensor beeps faster as the dock gets close.
• Report at the dock. The server measures the trailer itself, twice, 350 milliseconds apart, and pays one to three stars on angle, side offset and dock distance.

After a delivery the server offers a return load within 4 km when there is one, so a good driver can chain runs without driving back empty.

Up to four trucks can form a convoy. Everyone gets the same cargo, pickup and delivery, with their own trailer and pay. When there are fewer bays than trucks, the convoy queues for the dock and the next trailer is placed as soon as the bay is free. The bonus is 10 percent per mate, up to 30 percent, but only for mates who really drove along: the server checks positions every two seconds and counts a mate only if they stayed within 250 metres for at least half of the run.

Each run can be taken legally or as smuggling. A legal run comes with a freight document modelled on a real consignment note, which players can show to police like an ID card; it cannot be moved out of their pockets. A smuggling run carries goods like counterfeit clothing or stolen electronics, pays black money and comes without papers. An anonymous tip can reach police dispatch during the run, and police can inspect and seize the cargo.

The server owns everything: the board, bay reservations, trailer spawns, the parking measurement, damage and payment. It only accepts client values that can lower pay, never raise it, and it rejects a delivery that arrives faster than is physically possible. The client runs one manager thread during a run and only does per-frame work within 70 metres of the bay. A leaderboard ranks drivers on earnings, level and deliveries.