Series

Star Control

3 games, 1990–1996.

Games

Mechanics

Mechanic	Star Control II 1992
Fuel gauge	By distance
Gravity well	Constant pull
Hit points	Crew as hit points
Inertia	No drag · Earthling CruiserNone · Arilou Skiff
Weapon energy	Shared pool

A marked cell changed from the game before. “Uses” means the game has the mechanic, with no variant recorded yet.

Every claim, by mechanic and game

Concept	Star Control II 1992
Fuel gauge	While the flagship moves in HyperSpace, `MoveSIS` adds up how far the flagship moves on each axis (as absolute values) since it entered (`LoadHyperspace` zeroes the sums), takes the square root of the sum of their squares, and charges 1 unit of `FuelOnBoard` for each 16 logical units of that distance; the first charge comes at 32, since the count starts at 1 (computed). The fuel gauge shows `FuelOnBoard` divided by 100 (`FUEL_TANK_SCALE`), so each charge is 1/100 of a shown unit. Nothing is charged with an empty tank or while the `ARILOU_SPACE_SIDE` game state is above 1. The atlas reads those values as QuasiSpace: hyper.c loads the `ARISPACE` graphics into `hyperstars[2]`, picks the stars as `hyperstars[1 + (ARILOU_SPACE_SIDE >> 1)]`, and from 2 up `AddEncounterElement` returns at once, adding no encounter. Code
Gravity well	A Melee planet is an element with 200 hit points and a mass of 200, above `GRAVITY_MASS`'s threshold of 100 (10 times `MAX_SHIP_MASS`), whose per-frame postprocess is `CalculateGravity`. That routine pulls every other colliding element without such mass that lies within 255 display units of the planet (`GRAVITY_THRESHOLD`, tested on each axis and then as a radius, measured the short way across the arena's wrapped edges): it adds 1 world unit per frame to the element's velocity, aimed at the planet, whatever the distance, and flags a ship as in a gravity well. A block under `#ifdef NEVER`, never compiled, works out a pull from the distance, capped at 6, and only prints it. Code
Hit points	A ship's crew is its hit points: element.h defines `hit_points` as `crew_level`, and `do_damage` takes damage to a player's ship from its crew through `DeltaCrew`, which reports failure when the crew would reach 0 or less; the ship's life span is then set to 0 and it becomes nonsolid. `DeltaCrew` changes nothing for the enemy in the last battle (its comment: "Samatra can't be crew-modified"). The Earthling Cruiser's table entry gives 18 crew, at its maximum of 18 (`MAX_CREW`); in encounters and the last battle a ship takes its crew from the fleet instead, up to that maximum. Code
Inertia	In the 3DO source as The Ur-Quan Masters first imported it (2002), each pass of the battle loop sleeps until 5 ticks (`BATTLE_FRAME_RATE`) after the previous pass woke, on a clock of 120 ticks a second (`ONE_SECOND`), so battle runs at most 24 frames a second (computed: 120 / 5). The sleep is the port's `SleepTask`, in its SDL wrapper. When `nth_frame` is set, which encount.c does only while the cyborg option flies the player's ships in an encounter, the loop only yields (`TaskSwitch`) and does not wait. The atlas calls one pass a frame. Code The Earthling Cruiser's stats set `MAX_THRUST` 24, `THRUST_INCREMENT` 3, `TURN_WAIT` 1, and `THRUST_WAIT` 4. Speeds are in world units per frame; `DISPLAY_TO_WORLD` makes one display unit 4 world units. Each frame, `ship_preprocess` counts a ship's turn wait down, or, when it is 0 and a turn is held, steps the ship one of its 16 facings and sets the wait to `TURN_WAIT`. Thrust works the same way with its own wait: when the wait is 0 and thrust is held, `ship_preprocess` calls `inertial_thrust` once and sets the wait to `THRUST_WAIT`. Each such call is one thrust step, which adds `THRUST_INCREMENT` to the velocity along the facing, up to `MAX_THRUST` (sc2/speed-cap). So the Cruiser turns a facing every 2 frames and takes a thrust step every 5 frames. Each step raises its speed by 3 world units per frame (3/4 of a display unit per frame), to a top speed of 24 world units (6 display units) per frame, which it reaches from rest after 8 steps along an axis (computed). Comments beside the two thrust values read `DISPLAY_TO_WORLD (6)`, which is 24 and agrees with the code, and `DISPLAY_TO_WORLD (2)`, which is 8 and disagrees with the code's 3. Code `inertial_thrust` caps the speed itself, not each axis: after adding a thrust step it compares the sum of the squared components with `MAX_THRUST` squared, so a ship is no faster on a diagonal. Asteroids clamps each axis of its ship's velocity apart, so its diagonal is faster (asteroids/top-speed). A step that would pass the cap still applies if the result is slower than the current speed. At the cap, a step along the line of travel sets the velocity to exactly `MAX_THRUST` along the facing (if the ship isn't above the cap); a step off the line instead adds half a thrust step along the facing and takes a whole step off along the line of travel, kept if that ends within the cap or slower than before, so the course swings toward the facing. While the ship is flagged in a gravity well, a thrust step may take it past the cap up to `MAX_ALLOWED_SPEED`, 18 display units per frame. Code A ship that stops thrusting keeps its velocity: the frame's move step (process.c) adds the velocity to the position without changing it, and `ship_preprocess` changes it only through `inertial_thrust`, called while thrust is held. The Earthling Cruiser's own code (human.c) sets a velocity only for its missile. Other code can still change a ship's velocity, such as a planet's pull (sc2/gravity-well) and the Arilou Skiff's own routine (sc2/arilou). Code The Arilou Skiff's stats set `THRUST_INCREMENT` equal to `MAX_THRUST`, 40 world units (10 display units) per frame, with `TURN_WAIT` and `THRUST_WAIT` 0. For such a ship `inertial_thrust` sets the velocity straight to `MAX_THRUST` along the facing. The Skiff's own preprocess routine, which `ship_preprocess` runs before turning and thrust, zeroes its velocity whenever its thrust wait is 0, outside its jump (while it isn't `NONSOLID`). So the Skiff moves at full speed only on frames thrust is held and stops when it is released, with no inertia. Code
Weapon energy	A ship's battery pays for both its weapons and refills by itself. Each frame, `ship_preprocess` counts the energy counter down, or, when it is 0 and the battery is below full, adds `ENERGY_REGENERATION`; every successful `DeltaEnergy`, a refill or a shot's cost, resets the counter to `ENERGY_WAIT`. A weapon fires only if `DeltaEnergy` can take its whole cost. The Earthling Cruiser holds 18 (`MAX_ENERGY`), regains 1 unit every 9 frames (`ENERGY_WAIT` 8), pays 9 a missile (`WEAPON_ENERGY_COST`) at most once every 11 frames (`WEAPON_WAIT` 10), and 4 (`SPECIAL_ENERGY_COST`) for each use of its point-defense laser, taken only when a colliding, uncloaked object is within 100 display units (`LASER_RANGE`) to fire at. So a full battery holds two missiles and refills from empty in 162 frames, 6.75 seconds at 24 frames a second (computed). Code