make legs affect movement speed with body (#12928)

Co-authored-by: DrSmugleaf <DrSmugleaf@users.noreply.github.com>

Content.Shared/Body/Components/BodyComponent.cs

@@ -21,6 +21,13 @@ public sealed class BodyComponent : Component, IDraggable
     [DataField("gibSound")]
     public SoundSpecifier GibSound = new SoundCollectionSpecifier("gib");
 
+    /// <summary>
+    /// The amount of legs required to move at full speed.
+    /// If 0, then legs do not impact speed.
+    /// </summary>
+    [DataField("requiredLegs")]
+    public int RequiredLegs;
+
     bool IDraggable.CanStartDrag(StartDragDropEvent args)
     {
         return true;

Content.Shared/Body/Systems/SharedBodySystem.Body.cs

@@ -164,6 +164,32 @@ public partial class SharedBodySystem
         }
     }
 
+    /// <summary>
+    /// Returns all body part slots in the graph, including ones connected by
+    /// body parts which are null.
+    /// </summary>
+    /// <param name="partId"></param>
+    /// <param name="part"></param>
+    /// <returns></returns>
+    public IEnumerable<BodyPartSlot> GetAllBodyPartSlots(EntityUid partId, BodyPartComponent? part = null)
+    {
+        if (!Resolve(partId, ref part, false))
+            yield break;
+
+        foreach (var slot in part.Children.Values)
+        {
+            if (!TryComp<BodyPartComponent>(slot.Child, out var childPart))
+                continue;
+
+            yield return slot;
+
+            foreach (var child in GetAllBodyPartSlots(slot.Child.Value, childPart))
+            {
+                yield return child;
+            }
+        }
+    }
+
     public virtual HashSet<EntityUid> GibBody(EntityUid? partId, bool gibOrgans = false,
         BodyComponent? body = null, bool deleteItems = false)
     {

Content.Shared/Body/Systems/SharedBodySystem.Parts.cs

@@ -6,6 +6,7 @@ using Content.Shared.Body.Organ;
 using Content.Shared.Body.Part;
 using Content.Shared.Damage;
 using Content.Shared.Damage.Prototypes;
+using Content.Shared.Movement.Components;
 using Content.Shared.Random.Helpers;
 using Robust.Shared.Containers;
 using Robust.Shared.GameStates;
@@ -211,6 +212,9 @@ public partial class SharedBodySystem
 
         if (part.Body is { } newBody)
         {
+            if (part.PartType == BodyPartType.Leg)
+                UpdateMovementSpeed(newBody);
+
             var partAddedEvent = new BodyPartAddedEvent(slot.Id, part);
             RaiseLocalEvent(newBody, ref partAddedEvent);
 
@@ -254,9 +258,10 @@ public partial class SharedBodySystem
             var args = new BodyPartRemovedEvent(slot.Id, part);
             RaiseLocalEvent(oldBody, ref args);
 
-            if (part.PartType == BodyPartType.Leg &&
+            if (part.PartType == BodyPartType.Leg)
-                !GetBodyChildrenOfType(oldBody, BodyPartType.Leg).Any())
             {
+                UpdateMovementSpeed(oldBody);
+                if(!GetBodyChildrenOfType(oldBody, BodyPartType.Leg).Any())
                     Standing.Down(oldBody);
             }
 
@@ -282,6 +287,44 @@ public partial class SharedBodySystem
         return true;
     }
 
+    public void UpdateMovementSpeed(EntityUid body, BodyComponent? component = null, MovementSpeedModifierComponent? movement = null)
+    {
+        if (!Resolve(body, ref component, ref movement, false))
+            return;
+
+        if (component.RequiredLegs <= 0)
+            return;
+
+        if (component.Root?.Child is not { } root)
+            return;
+
+        var allSlots = GetAllBodyPartSlots(root).ToHashSet();
+        var allLegs = new HashSet<EntityUid>();
+        foreach (var slot in allSlots)
+        {
+            if (slot.Type == BodyPartType.Leg && slot.Child is {  } child)
+                allLegs.Add(child);
+        }
+
+        var walkSpeed = 0f;
+        var sprintSpeed = 0f;
+        var acceleration = 0f;
+        foreach (var leg in allLegs)
+        {
+            if (!TryComp<MovementSpeedModifierComponent>(leg, out var legModifier))
+                continue;
+
+            walkSpeed += legModifier.BaseWalkSpeed;
+            sprintSpeed += legModifier.BaseSprintSpeed;
+            acceleration += legModifier.Acceleration;
+        }
+
+        walkSpeed /= component.RequiredLegs;
+        sprintSpeed /= component.RequiredLegs;
+        acceleration /= component.RequiredLegs;
+        Movement.ChangeBaseSpeed(body, walkSpeed, sprintSpeed, acceleration, movement);
+    }
+
     public bool DropPartAt(EntityUid? partId, EntityCoordinates dropAt, BodyPartComponent? part = null)
     {
         if (partId == null || !DropPart(partId, part))

Content.Shared/Body/Systems/SharedBodySystem.cs

@@ -1,4 +1,5 @@
 using Content.Shared.Damage;
+using Content.Shared.Movement.Systems;
 using Content.Shared.Standing;
 using Robust.Shared.Containers;
 using Robust.Shared.Prototypes;
@@ -14,6 +15,7 @@ public abstract partial class SharedBodySystem : EntitySystem
     [Dependency] protected readonly SharedContainerSystem Containers = default!;
     [Dependency] protected readonly DamageableSystem Damageable = default!;
     [Dependency] protected readonly StandingStateSystem Standing = default!;
+    [Dependency] protected readonly MovementSpeedModifierSystem Movement = default!;
 
     public override void Initialize()
     {

Resources/Prototypes/Body/Parts/animal.yml

@@ -37,6 +37,7 @@
   components:
   - type: BodyPart
     partType: Leg
+  - type: MovementSpeedModifier
 
 - type: entity
   id: FeetAnimal

Resources/Prototypes/Body/Parts/diona.yml

@@ -118,6 +118,9 @@
   - type: BodyPart
     partType: Leg
     symmetry: Left
+  - type: MovementSpeedModifier
+    baseWalkSpeed : 1.5
+    baseSprintSpeed : 3.5
 
 - type: entity
   id: RightLegDiona
@@ -131,6 +134,9 @@
   - type: BodyPart
     partType: Leg
     symmetry: Right
+  - type: MovementSpeedModifier
+    baseWalkSpeed : 1.5
+    baseSprintSpeed : 3.5
 
 - type: entity
   id: LeftFootDiona

Resources/Prototypes/Body/Parts/human.yml

@@ -136,6 +136,7 @@
   - type: BodyPart
     partType: Leg
     symmetry: Left
+  - type: MovementSpeedModifier
 
 - type: entity
   id: RightLegHuman
@@ -152,6 +153,7 @@
   - type: BodyPart
     partType: Leg
     symmetry: Right
+  - type: MovementSpeedModifier
 
 - type: entity
   id: LeftFootHuman

Resources/Prototypes/Body/Parts/reptilian.yml

@@ -134,6 +134,9 @@
   - type: BodyPart
     partType: Leg
     symmetry: Left
+  - type: MovementSpeedModifier
+    baseWalkSpeed : 2.7
+    baseSprintSpeed : 4.5
 
 - type: entity
   id: RightLegReptilian
@@ -150,6 +153,9 @@
   - type: BodyPart
     partType: Leg
     symmetry: Right
+  - type: MovementSpeedModifier
+    baseWalkSpeed : 2.7
+    baseSprintSpeed : 4.5
 
 - type: entity
   id: LeftFootReptilian

Resources/Prototypes/Body/Parts/skeleton.yml

@@ -149,6 +149,7 @@
     - type: BodyPart
       partType: Leg
       symmetry: Left
+    - type: MovementSpeedModifier
 
 - type: entity
   id: RightLegSkeleton
@@ -165,6 +166,7 @@
     - type: BodyPart
       partType: Leg
       symmetry: Right
+    - type: MovementSpeedModifier
 
 - type: entity
   id: LeftFootSkeleton

Resources/Prototypes/Body/Parts/slime.yml

@@ -135,6 +135,7 @@
     - type: BodyPart
       partType: Leg
       symmetry: Left
+    - type: MovementSpeedModifier
 
 - type: entity
   id: RightLegSlime
@@ -151,6 +152,7 @@
     - type: BodyPart
       partType: Leg
       symmetry: Right
+    - type: MovementSpeedModifier
 
 - type: entity
   id: LeftFootSlime

Resources/Prototypes/Body/Parts/vox.yml

@@ -136,6 +136,7 @@
     - type: BodyPart
       partType: Leg
       symmetry: Left
+    - type: MovementSpeedModifier
 
 - type: entity
   id: RightLegVox
@@ -152,6 +153,7 @@
     - type: BodyPart
       partType: Leg
       symmetry: Right
+    - type: MovementSpeedModifier
 
 - type: entity
   id: LeftFootVox

Resources/Prototypes/Entities/Mobs/NPCs/animals.yml

@@ -711,6 +711,7 @@
     speechSounds: Monkey
   - type: Body
     prototype: Primate
+    requiredLegs: 1 # TODO: More than 1 leg
   - type: DamageStateVisuals
     states:
       Alive:

Resources/Prototypes/Entities/Mobs/NPCs/regalrat.yml

@@ -50,6 +50,7 @@
         Piercing: 8
   - type: Body
     prototype: Rat
+    requiredLegs: 1 # TODO: More than 1 leg
   - type: Hunger # probably should be prototyped
     thresholds:
       Overfed: 200
@@ -225,6 +226,7 @@
         Piercing: 3
   - type: Body
     prototype: Rat
+    requiredLegs: 1 # TODO: More than 1 leg
   - type: Hunger # probably should be prototyped
     thresholds:
       Overfed: 200

Resources/Prototypes/Entities/Mobs/Species/base.yml

@@ -177,6 +177,7 @@
     species: Human
   - type: Body
     prototype: Human
+    requiredLegs: 2
   - type: Damageable
     damageContainer: Biological
   - type: RadiationReceiver
@@ -366,6 +367,7 @@
       species: Human
     - type: Body
       prototype: Human
+      requiredLegs: 2
     - type: Damageable
       damageContainer: Biological
     - type: MobState

Resources/Prototypes/Entities/Mobs/Species/diona.yml

@@ -15,6 +15,7 @@
     state: full
   - type: Body
     prototype: Diona
+    requiredLegs: 2
   - type: Damageable
     damageContainer: Biological
     damageModifierSet: Diona

Resources/Prototypes/Entities/Mobs/Species/dwarf.yml

@@ -24,6 +24,7 @@
     scale: 1, 0.8
   - type: Body
     prototype: Human
+    requiredLegs: 2
 
 - type: entity
   save: false

Resources/Prototypes/Entities/Mobs/Species/reptilian.yml

@@ -14,6 +14,7 @@
     state: full
   - type: Body
     prototype: Reptilian
+    requiredLegs: 2
   - type: LizardAccent
   - type: Speech
     speechSounds: Lizard

Resources/Prototypes/Entities/Mobs/Species/skeleton.yml

@@ -12,6 +12,7 @@
     state: full
   - type: Body
     prototype: Skeleton
+    requiredLegs: 2
     gibSound: /Audio/Effects/bone_rattle.ogg
   - type: Damageable
     damageContainer: Biological

Resources/Prototypes/Entities/Mobs/Species/slime.yml

@@ -11,6 +11,7 @@
     state: full
   - type: Body
     prototype: Slime
+    requiredLegs: 2
   - type: Humanoid
     species: SlimePerson
   - type: Speech

Resources/Prototypes/Entities/Mobs/Species/vox.yml

@@ -81,6 +81,7 @@
       - map: [ "pocket2" ]
   - type: Body
     prototype: Vox
+    requiredLegs: 2
   # Vox nitrogen stuff is handled in their metabolism
   - type: Respirator
     damage:
@@ -110,4 +111,5 @@
     species: Vox
   - type: Body
     prototype: Vox
+    requiredLegs: 2