Crate oort_api

This is the API reference for Oort. For more general information see the wiki.

Starter Code

Oort expects your code to have a Ship type with a tick method. Each tutorial provides some starter code which includes this:

use oort_api::prelude::*;

pub struct Ship {}

impl Ship {
    pub fn new() -> Ship {
        Ship {}
    }

    pub fn tick(&mut self) {
    }
}

The game will call your new function when a ship is created and then call tick 60 times per second during the simulation.

struct Ship is useful for storing any state that needs to persist between ticks. enum Ship works too and can be helpful when this state differs between ship classes.

The statement use oort_api::prelude::* imports all the APIs so that you can use them simply as e.g. position(). See the prelude module documentation for the details on everything this imports. The important APIs are covered below.

Subsystems

All actions performed by a ship (such as firing weapons or scanning the radar) occur between ticks. In particular, setting the radar heading or the radio channel will affect the scan results or messages received on the next tick.

Ship Status and Control

Basic status:

• class() → Class: Get the ship class (Fighter, Cruiser, etc).
• position() → Vec2: Get the current position in meters.
• velocity() → Vec2: Get the current velocity in m/s.
• heading() → f64: Get the current heading in radians.
• angular_velocity() → f64: Get the current angular velocity in radians/s.
• health() → f64: Get the current health.
• fuel() → f64: Get the current fuel (delta-v).

Engine control:

• accelerate(acceleration: Vec2): Accelerate the ship. Units are m/s².
• turn(speed: f64): Rotate the ship. Unit is radians/s.
• torque(acceleration: f64): Angular acceleration. Unit is radians/s².

Engine limits:

• max_forward_acceleration() -> f64: Maximum forward acceleration.
• max_backward_acceleration() -> f64: Maximum backward acceleration.
• max_lateral_acceleration() -> f64: Maximum lateral acceleration.
• max_angular_acceleration() -> f64: Maximum angular acceleration.

Weapons

• fire(index: usize): Fire a weapon (gun or missile).
• aim(index: usize, angle: f64): Aim a weapon (for weapons on a turret).
• reload_ticks(index: usize) -> u32: Number of ticks until the weapon is ready to fire.
• explode(): Self-destruct.

Radar

Radar in Oort is modeled as a beam that can be pointed in any direction and which has a beam width between 1/720 to 1/4 of a circle (min 1/3600 for frigates and cruisers). Enemy ships illuminated by this beam reflect an amount of energy proportional to their radar cross section (larger for larger ships). The radar can return one contact per tick. Any changes to radar heading/width/filtering take effect on the next tick.

The position and velocity returned for a contact will have error inversely related to the signal strength.

Basic operation:

• set_radar_heading(angle: f64): Point the radar at the given heading.
• set_radar_width(width: f64): Adjust the beam width (in radians).
• scan() → Option<ScanResult>: Get the radar contact with the highest signal strength.
• struct ScanResult { position: Vec2, velocity: Vec2, class: Class }: Structure returned by scan.

Advanced filtering:

• set_radar_min_distance(dist: f64): Set the minimum distance filter.
• set_radar_max_distance(dist: f64): Set the maximum distance filter.

Electronic Counter Measures (ECM):

The goal of ECM is to make enemy radar less effective. For ECM to work, the enemy radar must be pointed towards your ship, and your ship’s radar must be pointed at the enemy. Your radar will not return contacts while ECM is enabled.

• EcmMode:
  • EcmMode::None: No ECM, radar will operate normally.
  • EcmMode::Noise: Decrease the enemy radar’s signal to noise ratio, making it more difficult to detect targets and reducing accuracy of returned contacts.
• set_radar_ecm_mode(mode: EcmMode): Set the ECM mode.

Retrieving current state:

• radar_heading() -> f64: Get current radar heading.
• radar_width() -> f64: Get current radar width.
• radar_min_distance() -> f64: Get current minimum distance filter.
• radar_max_distance() -> f64: Get current maximum distance filter.

Radio

The radio can be used to send or receive a [f64; 4] message per tick. There are 10 channels available (0 to 9), shared between all teams.

• set_radio_channel(channel: usize): Change the radio channel. Takes effect next tick.
• get_radio_channel() -> usize: Get the radio channel.
• send(data: [f64; 4]): Send a message on a channel.
• receive() -> Option<[f64; 4]>: Receive a message from the channel. The message with the strongest signal is returned.
• send_bytes(data: &[u8]): Send a message on a channel as bytes, the data will be zero-filled or truncated to a length of 32 bytes.
• receive_bytes() -> Option<[u8; 32]>: Just like receive, but instead the message will be returned as a byte array.
• select_radio(index: usize): Select the radio to control with subsequent API calls. Frigates have 4 radios and cruisers have 8.

Special Abilities

Some ship classes have a unique special ability. These abilities need to be activated, after which they will function for a short time before needing to reload. An ability can be deactivated early via the API. If an ability is activated and never deactivated, then it will automatically start back up again after its reload time passes.

• activate_ability(ability: Ability): Activates a special ability.
• deactivate_ability(ability: Ability): Deactivates a ship’s special ability.
• active_abilities() → ActiveAbilities: Returns the ship’s active abilities.
• Available abilities:
  • Ability::Boost: Fighter and missile only. Applies a 100 m/s² forward acceleration for 2s. Reloads in 10s.
  • Ability::Decoy: Torpedo only. Mimics the radar signature of a Cruiser for 0.5s. Reloads in 10s.
  • Ability::Shield: Cruiser only. Deflects damage for 1s. Reloads in 5s.

Scalar Math

• PI, TAU: Constants.
• x.abs(): Absolute value.
• x.sqrt(): Square root.
• x.sin(), x.cos(), x.tan(): Trigonometry.

See the Rust documentation for the full list of f64 methods.

Vector Math

Two-dimensional floating point vectors (Vec2) are ubiquitous in Oort and are used to represent positions, velocities, accelerations, etc.

• vec2(x: f64, y: f64) → Vec2: Create a vector.
• v.x, v.y → f64: Get a component of a vector.
• v1 +- v2 → Vec2: Basic arithmetic between vectors.
• v */ f64 → Vec2: Basic arithmetic between vectors and scalars.
• -v → Vec2: Negate a vector.
• v.length() → f64: Length.
• v.normalize() → Vec2: Normalize to a unit vector.
• v.rotate(angle: f64) → Vec2: Rotate counter-clockwise.
• v.angle() → f64: Angle of a vector.
• v1.dot(v2: Vec2) → f64: Dot product.
• v1.distance(v2: Vec2) → f64: Distance between two points.

The entire maths_rs crate is also available.

Debugging

Clicking on a ship in the UI displays status information and graphics indicating its acceleration, radar cone, etc. You can add to this with the functions below.

• debug!(...): Add status text.
• draw_line(v0: Vec2, v1: Vec2, color: u32): Draw a line.
• draw_triangle(center: Vec2, radius: f64, color: u32): Draw a triangle.
• draw_square(center: Vec2, radius: f64, color: u32): Draw a square.
• draw_diamond(center: Vec2, radius: f64, color: u32): Draw a diamond.
• draw_polygon(center: Vec2, radius: f64, sides: i32, angle: f64, color: u32): Draw a regular polygon.
• draw_text!(topleft: Vec2, color: u32, ...): Draw text.

Entering debug mode by pressing the ‘g’ key also displays debug graphics from all ships.

Miscellaneous

• current_tick() → u32: Returns the number of ticks elapsed since the simulation started.
• current_time() → f64: Returns the number of seconds elapsed since the simulation started.
• angle_diff(a: f64, b: f64) → f64: Returns the shortest (possibly negative) distance between two angles.
• rand(low: f64, high: f64) → f64: Get a random number.
• seed() → u128: Returns a seed useful for initializing a random number generator.
• scenario_name() → &str: Returns the name of the current scenario.
• world_size() → f64: Returns the width of the world in meters.
• id() → u32: Returns a per-ship ID that is unique within a team.
• TICK_LENGTH: Length of a single game tick in seconds. There are 60 ticks per second.

Extra Crates

The following crates are available for use in your code:

• byteorder: Utilities to read and write binary data, useful for radio.
• maths_rs: A linear algebra library.
• oorandom: A random number generation library.

Ship Classes

• Fighter: Small, fast, and lightly armored.
  • Health: 100
  • Acceleration: Forward: 60 m/s², Lateral: 30 m/s², Reverse: 30 m/s², Angular: 2π rad/s²
  • Weapon 0: Gun, Speed: 1000 m/s, Reload: 66ms
  • Weapon 1: Missile, Reload: 5s
• Frigate: Medium size with heavy armor and an extremely powerful main gun.
  • Health: 10000
  • Acceleration: Forward: 10 m/s², Lateral: 5 m/s², Reverse: 5 m/s², Angular: π/4 rad/s²
  • Weapon 0: Gun, Speed: 4000 m/s, Reload: 2 seconds
  • Weapon 1: Gun, Speed: 1000 m/s, Reload: 66ms, Turreted
  • Weapon 2: Gun, Speed: 1000 m/s, Reload: 66ms, Turreted
  • Weapon 3: Missile, Reload: 2s
• Cruiser: Large, slow, and heavily armored. Rapid fire missile launchers and devastating torpedos.
  • Health: 20000
  • Acceleration: Forward: 5 m/s², Lateral: 2.5 m/s², Reverse: 2.5 m/s², Angular: π/8 rad/s²
  • Weapon 0: Gun, Speed: 2000 m/s, Burst size: 6, Reload: 5s, Turreted
  • Weapon 1: Missile, Reload: 1.2s
  • Weapon 2: Missile, Reload: 1.2s
  • Weapon 3: Torpedo, Reload: 3s
• Missile: Highly maneuverable but unarmored. Explodes on contact or after an explode call.
  • Health: 20
  • Fuel: 2000 m/s
  • Acceleration: Forward: 300 m/s², Reverse: 0 m/s², Lateral: 100 m/s², Angular: 4π rad/s²
• Torpedo: Better armor, larger warhead, but less maneuverable than a missile. Explodes on contact or after an explode call.
  • Health: 100
  • Fuel: 3000 m/s
  • Acceleration: Forward: 70 m/s², Reverse: 0 m/s², Lateral: 20 m/s², Angular: 2π rad/s²

Modules

• prelude
  All APIs.

Macros

• debug
  Adds text to be displayed when the ship is selected by clicking on it.
• draw_text
  Adds text to be drawn in the world, visible in debug mode.

Structs

• ActiveAbilities
  List of active abilities for an entity.
• ClassStats
  Stats for a class of ship

Enums

• Ability
  Special abilities available to different ship classes.
• Class
  Identifiers for each class of ship.
• EcmMode
  Electronic Counter Measures (ECM) modes.
• SystemState

Constants

• ABILITIES
  Array of all ability types.
• MAX_ENVIRONMENT_SIZE

Type Aliases

• Message
  Message sent and received on the radio.