Disable selfbuff stacking

CHANGELOG.md

@@ -62,6 +62,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Improved running, wielding, and riding animations
 - Fixed offset of items carried on backs when wearing cloaks and backpacks
 - Linearize light colors on the CPU rather than in shaders on the GPU
+- You can no longer stack self buffs
 
 ### Removed
 - Medium and large potions from all loot tables

common/src/comp/ability.rs

@@ -955,6 +955,8 @@ pub enum CharacterAbility {
         buff_strength: f32,
         buff_duration: Option<Secs>,
         energy_cost: f32,
+        #[serde(default = "default_true")]
+        remove_previous: bool,
         #[serde(default)]
         combo_cost: u32,
         combo_scaling: Option<ScalingKind>,
@@ -1604,6 +1606,7 @@ impl CharacterAbility {
                 ref mut buff_strength,
                 buff_duration: _,
                 ref mut energy_cost,
+                remove_previous: _,
                 combo_cost: _,
                 combo_scaling: _,
                 meta: _,
@@ -2255,6 +2258,9 @@ impl CharacterAbility {
     }
 }
 
+/// Small helper for #[serde(default)] booleans
+fn default_true() -> bool { true }
+
 impl From<(&CharacterAbility, AbilityInfo, &JoinData<'_>)> for CharacterState {
     fn from((ability, ability_info, data): (&CharacterAbility, AbilityInfo, &JoinData)) -> Self {
         match ability {
@@ -2831,6 +2837,7 @@ impl From<(&CharacterAbility, AbilityInfo, &JoinData<'_>)> for CharacterState {
                 energy_cost: _,
                 combo_cost,
                 combo_scaling,
+                remove_previous,
                 meta: _,
             } => CharacterState::SelfBuff(self_buff::Data {
                 static_data: self_buff::StaticData {
@@ -2843,6 +2850,7 @@ impl From<(&CharacterAbility, AbilityInfo, &JoinData<'_>)> for CharacterState {
                     combo_cost: *combo_cost,
                     combo_scaling: *combo_scaling,
                     combo_on_use: data.combo.map_or(0, |c| c.counter()),
+                    remove_previous: *remove_previous,
                     ability_info,
                 },
                 timer: Duration::default(),

common/src/states/self_buff.rs

@@ -36,6 +36,9 @@ pub struct StaticData {
     /// This is the amount of combo held by the entity when this character state
     /// was entered
     pub combo_on_use: u32,
+    /// Controls whether `SelfBuff`s that were previously applied should be
+    /// removed
+    pub remove_previous: bool,
     /// What key is used to press ability
     pub ability_info: AbilityInfo,
 }
@@ -77,6 +80,21 @@ impl CharacterBehavior for Data {
                         entity: data.entity,
                         change: -(combo_consumption as i32),
                     });
+
+                    // Remove previous selfbuffs if we should
+                    if self.static_data.remove_previous {
+                        output_events.emit_server(ServerEvent::Buff {
+                            entity: data.entity,
+                            buff_change: BuffChange::RemoveByCategory {
+                                // TODO: Consider renaming [BuffCategory::RemoveOnLoadoutChange] to
+                                // something more generic?
+                                all_required: vec![BuffCategory::RemoveOnLoadoutChange],
+                                any_required: vec![],
+                                none_required: vec![],
+                            },
+                        });
+                    }
+
                     let scaling_factor = self.static_data.combo_scaling.map_or(1.0, |cs| {
                         cs.factor(
                             self.static_data.combo_on_use as f32,