Part 14

Source/Engine/Pickup.swift

@@ -0,0 +1,46 @@
+//
+//  Pickup.swift
+//  Engine
+//
+//  Created by Nick Lockwood on 27/01/2020.
+//  Copyright © 2020 Nick Lockwood. All rights reserved.
+//
+
+public enum PickupType {
+    case medkit
+    case shotgun
+}
+
+public struct Pickup: Actor {
+    public let type: PickupType
+    public var radius: Double = 0.5
+    public var position: Vector
+
+    public init(type: PickupType, position: Vector) {
+        self.type = type
+        self.position = position
+    }
+}
+
+public extension Pickup {
+    var isDead: Bool { return false }
+
+    var texture: Texture {
+        switch type {
+        case .medkit:
+            return .medkit
+        case .shotgun:
+            return .shotgunPickup
+        }
+    }
+
+    func billboard(for ray: Ray) -> Billboard {
+        let plane = ray.direction.orthogonal
+        return Billboard(
+            start: position - plane / 2,
+            direction: plane,
+            length: 1,
+            texture: texture
+        )
+    }
+}

Source/Engine/Player.swift

@@ -20,8 +20,9 @@ public struct Player: Actor {
     public var direction: Vector
     public var health: Double
     public var state: PlayerState = .idle
-    public var animation: Animation = .pistolIdle
-    public let attackCooldown: Double = 0.25
+    public private(set) var weapon: Weapon = .pistol
+    public private(set) var ammo: Double
+    public var animation: Animation
     public let soundChannel: Int
 
     public init(position: Vector, soundChannel: Int) {
@@ -30,6 +31,8 @@ public struct Player: Actor {
         self.direction = Vector(x: 1, y: 0)
         self.health = 100
         self.soundChannel = soundChannel
+        self.animation = weapon.attributes.idleAnimation
+        self.ammo = weapon.attributes.defaultAmmo
     }
 }
 
@@ -43,29 +46,60 @@ public extension Player {
     }
 
     var canFire: Bool {
+        guard ammo > 0 else {
+            return false
+        }
         switch state {
         case .idle:
             return true
         case .firing:
-            return animation.time >= attackCooldown
+            return animation.time >= weapon.attributes.cooldown
         }
     }
 
+    mutating func setWeapon(_ weapon: Weapon) {
+        self.weapon = weapon
+        animation = weapon.attributes.idleAnimation
+        ammo = weapon.attributes.defaultAmmo
+    }
+
+    mutating func inherit(from player: Player) {
+        health = player.health
+        setWeapon(player.weapon)
+        ammo = player.ammo
+    }
+
     mutating func update(with input: Input, in world: inout World) {
         let wasMoving = isMoving
         direction = direction.rotated(by: input.rotation)
         velocity = direction * input.speed * speed
         if input.isFiring, canFire {
             state = .firing
-            animation = .pistolFire
-            world.playSound(.pistolFire, at: position)
-            let ray = Ray(origin: position, direction: direction)
-            if let index = world.pickMonster(ray) {
-                world.hurtMonster(at: index, damage: 10)
-                world.playSound(.monsterHit, at: world.monsters[index].position)
-            } else {
-                let position = world.hitTest(ray)
-                world.playSound(.ricochet, at: position)
+            ammo -= 1
+            animation = weapon.attributes.fireAnimation
+            world.playSound(weapon.attributes.fireSound, at: position)
+            let projectiles = weapon.attributes.projectiles
+            var hitPosition, missPosition: Vector?
+            for _ in 0 ..< projectiles {
+                let spread = weapon.attributes.spread
+                let sine = Double.random(in: -spread ... spread)
+                let cosine = (1 - sine * sine).squareRoot()
+                let rotation = Rotation(sine: sine, cosine: cosine)
+                let direction = self.direction.rotated(by: rotation)
+                let ray = Ray(origin: position, direction: direction)
+                if let index = world.pickMonster(ray) {
+                    let damage = weapon.attributes.damage / Double(projectiles)
+                    world.hurtMonster(at: index, damage: damage)
+                    hitPosition = world.monsters[index].position
+                } else {
+                    missPosition = world.hitTest(ray)
+                }
+            }
+            if let hitPosition = hitPosition {
+                world.playSound(.monsterHit, at: hitPosition)
+            }
+            if let missPosition = missPosition {
+                world.playSound(.ricochet, at: missPosition)
             }
         }
         switch state {
@@ -74,7 +108,10 @@ public extension Player {
         case .firing:
             if animation.isCompleted {
                 state = .idle
-                animation = .pistolIdle
+                animation = weapon.attributes.idleAnimation
+                if ammo == 0 {
+                    setWeapon(.pistol)
+                }
             }
         }
         if isMoving, !wasMoving {
@@ -84,16 +121,3 @@ public extension Player {
         }
     }
 }
-
-public extension Animation {
-    static let pistolIdle = Animation(frames: [
-        .pistol
-    ], duration: 0)
-    static let pistolFire = Animation(frames: [
-        .pistolFire1,
-        .pistolFire2,
-        .pistolFire3,
-        .pistolFire4,
-        .pistol
-    ], duration: 0.5)
-}

Source/Engine/Renderer.swift

@@ -122,11 +122,14 @@ public extension Renderer {
         }
 
         // Player weapon
+        let weaponTexture = textures[world.player.animation.texture]
+        let aspectRatio = Double(weaponTexture.width) / Double(weaponTexture.height)
         let screenHeight = Double(bitmap.height)
+        let weaponWidth = screenHeight * aspectRatio
         bitmap.drawImage(
-            textures[world.player.animation.texture],
-            at: Vector(x: Double(bitmap.width) / 2 - screenHeight / 2, y: 0),
-            size: Vector(x: screenHeight, y: screenHeight)
+            weaponTexture,
+            at: Vector(x: Double(bitmap.width) / 2 - weaponWidth / 2, y: 0),
+            size: Vector(x: weaponWidth, y: screenHeight)
         )
 
         // Effects

Source/Engine/Sounds.swift

@@ -8,6 +8,8 @@
 
 public enum SoundName: String, CaseIterable {
     case pistolFire
+    case shotgunFire
+    case shotgunPickup
     case ricochet
     case monsterHit
     case monsterGroan
@@ -20,6 +22,7 @@ public enum SoundName: String, CaseIterable {
     case playerDeath
     case playerWalk
     case squelch
+    case medkit
 }
 
 public struct Sound {

Source/Engine/Textures.swift

@@ -22,8 +22,12 @@ public enum Texture: String, CaseIterable {
     case monsterHurt, monsterDeath1, monsterDeath2, monsterDead
     case pistol
     case pistolFire1, pistolFire2, pistolFire3, pistolFire4
+    case shotgun
+    case shotgunFire1, shotgunFire2, shotgunFire3, shotgunFire4
+    case shotgunPickup
     case switch1, switch2, switch3, switch4
     case elevatorFloor, elevatorCeiling, elevatorSideWall, elevatorBackWall
+    case medkit
 }
 
 public struct Textures {

Source/Engine/Thing.swift

@@ -13,4 +13,6 @@ public enum Thing: Int, Decodable {
     case door
     case pushwall
     case `switch`
+    case medkit
+    case shotgun
 }

Source/Engine/Weapon.swift

@@ -0,0 +1,75 @@
+//
+//  Weapon.swift
+//  Engine
+//
+//  Created by Nick Lockwood on 07/02/2020.
+//  Copyright © 2020 Nick Lockwood. All rights reserved.
+//
+
+public enum Weapon: Int {
+    case pistol
+    case shotgun
+}
+
+public extension Weapon {
+    struct Attributes {
+        let idleAnimation: Animation
+        let fireAnimation: Animation
+        let fireSound: SoundName
+        let damage: Double
+        let cooldown: Double
+        let projectiles: Int
+        let spread: Double
+        let defaultAmmo: Double
+    }
+
+    var attributes: Attributes {
+        switch self {
+        case .pistol:
+            return Attributes(
+                idleAnimation: .pistolIdle,
+                fireAnimation: .pistolFire,
+                fireSound: .pistolFire,
+                damage: 10,
+                cooldown: 0.25,
+                projectiles: 1,
+                spread: 0,
+                defaultAmmo: .infinity
+            )
+        case .shotgun:
+            return Attributes(
+                idleAnimation: .shotgunIdle,
+                fireAnimation: .shotgunFire,
+                fireSound: .shotgunFire,
+                damage: 50,
+                cooldown: 0.5,
+                projectiles: 5,
+                spread: 0.4,
+                defaultAmmo: 5
+            )
+        }
+    }
+}
+
+public extension Animation {
+    static let pistolIdle = Animation(frames: [
+        .pistol
+    ], duration: 0)
+    static let pistolFire = Animation(frames: [
+        .pistolFire1,
+        .pistolFire2,
+        .pistolFire3,
+        .pistolFire4,
+        .pistol
+    ], duration: 0.5)
+    static let shotgunIdle = Animation(frames: [
+        .shotgun
+    ], duration: 0)
+    static let shotgunFire = Animation(frames: [
+        .shotgunFire1,
+        .shotgunFire2,
+        .shotgunFire3,
+        .shotgunFire4,
+        .shotgun
+    ], duration: 0.5)
+}

Source/Engine/World.swift

@@ -16,6 +16,7 @@ public struct World {
     public private(set) var doors: [Door]
     public private(set) var pushwalls: [Pushwall]
     public private(set) var switches: [Switch]
+    public private(set) var pickups: [Pickup]
     public private(set) var monsters: [Monster]
     public private(set) var player: Player!
     public private(set) var effects: [Effect]
@@ -27,6 +28,7 @@ public struct World {
         self.doors = []
         self.pushwalls = []
         self.switches = []
+        self.pickups = []
         self.monsters = []
         self.effects = []
         self.isLevelEnded = false
@@ -124,6 +126,24 @@ public extension World {
         }
         player.avoidWalls(in: self)
 
+        // Handle pickups
+        for i in (0 ..< pickups.count).reversed() {
+            let pickup = pickups[i]
+            if player.intersection(with: pickup) != nil {
+                pickups.remove(at: i)
+                switch pickup.type {
+                case .medkit:
+                    player.health += 25
+                    playSound(.medkit, at: pickup.position)
+                    effects.append(Effect(type: .fadeIn, color: .green, duration: 0.5))
+                case .shotgun:
+                    player.setWeapon(.shotgun)
+                    playSound(.shotgunPickup, at: pickup.position)
+                    effects.append(Effect(type: .fadeIn, color: .white, duration: 0.5))
+                }
+            }
+        }
+
         // Check for stuck actors
         if player.isStuck(in: self) {
             hurtPlayer(1)
@@ -141,6 +161,7 @@ public extension World {
         let ray = Ray(origin: player.position, direction: player.direction)
         return monsters.map { $0.billboard(for: ray) } + doors.map { $0.billboard }
             + pushwalls.flatMap { $0.billboards(facing: player.position) }
+            + pickups.map { $0.billboard(for: ray) }
     }
 
     mutating func hurtPlayer(_ damage: Double) {
@@ -205,14 +226,17 @@ public extension World {
 
     mutating func setLevel(_ map: Tilemap) {
         let effects = self.effects
+        let player = self.player!
         self = World(map: map)
         self.effects = effects
+        self.player.inherit(from: player)
     }
 
     mutating func reset() {
         self.monsters = []
         self.doors = []
         self.switches = []
+        self.pickups = []
         self.isLevelEnded = false
         var pushwallCount = 0
         var soundChannel = 0
@@ -259,6 +283,10 @@ public extension World {
                 case .switch:
                     precondition(map[x, y].isWall, "Switch must be placed on a wall tile")
                     switches.append(Switch(position: position))
+                case .medkit:
+                    pickups.append(Pickup(type: .medkit, position: position))
+                case .shotgun:
+                    pickups.append(Pickup(type: .shotgun, position: position))
                 }
             }
         }