weapon

Documentation

Overview

Package weapon is Linefire's weapon catalogue: what each weapon does, how often it can be used, what its shots look like and what they cost the target.

It holds the DEFINITIONS, not the firing. How a shot is spawned, aimed and resolved depends on the world it is fired into — a cave with walls, or a desktop overlay — so that stays with each game. What must not differ is the weapon itself: a missile has to hit as hard and reload as slowly in Linefire Skirmish as it does here, or the two are different games wearing the same art.

The numbers are in Linefire's units: world units, frames at 60 TPS, and hull points. A consumer on a different scale should convert them rather than reinterpret them.

Index

• Constants
• Variables
• type Aim
• type Kind
• type Sound
• type Weapon
  • func For(cat int) Weapon

Constants

const (
	CatFront = iota
	CatMissile
	CatMine
	CatLaser
	CatDevourer
)

Catalogue indices: which weapon TYPE, used to key an arsenal or a pickup.

Variables

var Catalog = []Weapon{
	CatFront: {
		Name: "Front Gun", Kind: KindProjectile, Aim: AimForward, Cooldown: 8,
		Damage: 1, Col: color.RGBA{0xff, 0xf0, 0xc0, 0xff},
		Fire:  Sound{"shot_soft", 101, 0.3},
		Speed: 9.0, Life: 90,
		Core: color.RGBA{0xe8, 0xff, 0xff, 0xff}, Glow: color.RGBA{0x80, 0xff, 0xff, 0xff},
		Width: 1.6, GlowWidth: 2.0,
	},
	CatMissile: {
		Name: "Missile", Kind: KindProjectile, Aim: AimCursor, Cooldown: 45,
		Damage: 4, Col: color.RGBA{0xff, 0xa0, 0x40, 0xff},
		Fire:  Sound{"shot_launch", 130, 0.5},
		Speed: 7.0, Life: 110, AOE: 70.0,
		Core: color.RGBA{0xff, 0xa0, 0x40, 0xff}, Glow: color.RGBA{0xff, 0x60, 0x20, 0xff},
		Width: 2.4, GlowWidth: 5.0,
	},
	CatMine: {
		Name: "Mine", Kind: KindMine, Aim: AimDrop, Cooldown: 16,
		Damage: 5, Col: color.RGBA{0xff, 0x80, 0x30, 0xff},
		Fire:      Sound{"shot_thunk", 140, 0.45},
		AOE:       64.0,
		ArmFrames: 45, TriggerRadius: 36.0, MaxLive: 5,
	},
	CatLaser: {
		Name: "Laser", Kind: KindLaser, Aim: AimCursor, Cooldown: 4,
		Damage: 1, Col: color.RGBA{0x90, 0xff, 0x90, 0xff},
		Fire: Sound{"beam", 150, 0.3},

		Reach: 2000,
	},
	CatDevourer: {
		Name: "Devourer", Kind: KindDevourer, Aim: AimDrop, Cooldown: 90,
		Damage: 300, Col: color.RGBA{0xc0, 0x40, 0xff, 0xff},
		Fire: Sound{"shot_thunk", 70, 0.7},
	},
}

Catalog is every weapon that can be collected and mounted.

Types

type Aim

type Aim int

Aim is how a weapon is pointed when used.

const (
	AimForward Aim = iota // along the ship heading, from the gun muzzle
	AimCursor             // toward a chosen point, from the ship centre
	AimDrop               // no direction: placed at the ship (mines)
)

type Kind

type Kind int

Kind is how a weapon delivers damage.

const (
	KindProjectile Kind = iota // a bullet or missile (AOE > 0 makes it explode)
	KindMine                   // a deployed proximity mine
	KindLaser                  // a continuous beam that pierces everything it crosses
	KindDevourer               // a deployed black hole: arms, drags everything in, collapses
)

type Sound

type Sound struct {
	Base   string
	Seed   int64
	Volume float64
}

Sound names the gion recipe a weapon plays when it fires. An empty Base is silent, which is what the laser wants — it hums on a loop instead.

type Weapon

type Weapon struct {
	Name     string
	Kind     Kind
	Aim      Aim
	Cooldown int // frames between uses

	Damage int        // hull damage (centre damage for an AOE weapon)
	Col    color.RGBA // floating damage-number colour
	Fire   Sound

	// Projectile.
	Speed     float64
	Life      int
	AOE       float64    // explosion radius; 0 = direct hit
	Core      color.RGBA // shot core colour
	Glow      color.RGBA // shot glow colour
	Width     float64    // crisp stroke width, logical px
	GlowWidth float64    // glow stroke width, logical px

	// Mine.
	ArmFrames     int
	TriggerRadius float64
	MaxLive       int // cap on this weapon's live mines

	// Laser.
	Reach float64 // max beam length, world units
}

Weapon is a data-driven weapon definition. The same struct describes the gun, the missile and the mine: a new weapon is new data plus a case in whatever fires it, not a new fire function.

func For

func For(cat int) Weapon

For returns a weapon by catalogue index, or the front gun for an index that is not in the catalogue — every ship can at least shoot.