feat: custom death condition and actions

common/combat/alive.trait.js

@@ -1,3 +1,4 @@
+import {behaviorItemFromJSON, createContext} from '@avocado/behavior';
 import {compose} from '@avocado/core';
 import {StateProperty, Trait} from '@avocado/entity';
 
@@ -12,6 +13,70 @@ const decorate = compose(
 
 export class Alive extends decorate(Trait) {
 
+  static defaultParams() {
+    return {
+      deathActions: {
+        type: 'actions',
+        traversals: [
+          {
+            type: 'traversal',
+            steps: [
+              {
+                type: 'key',
+                key: 'entity',
+              },
+              {
+                type: 'key',
+                key: 'transition',
+              },
+              {
+                type: 'invoke',
+                args: [
+                  {
+                    type: 'literal',
+                    value: {
+                      opacity: 0,
+                      visibleScaleX: .3,
+                      visibleScaleY: 3,
+                    },
+                  },
+                  {
+                    type: 'literal',
+                    value: 0.2,
+                  },
+                ],
+              },
+            ],
+          },
+        ],
+      },
+      // By default, die when life <= 0.
+      deathCondition: {
+        type: 'condition',
+        operator: '<=',
+        operands: [
+          {
+            type: 'traversal',
+            steps: [
+              {
+                type: 'key',
+                key: 'entity',
+              },
+              {
+                type: 'key',
+                key: 'life',
+              },
+            ],
+          },
+          {
+            type: 'literal',
+            value: 0,
+          },
+        ],
+      },
+    };
+  }
+
   static defaultState() {
     return {
       life: 100,
@@ -19,6 +84,16 @@ export class Alive extends decorate(Trait) {
     };
   }
 
+  initialize() {
+    this._context = createContext();
+    this._context.add('entity', this.entity);
+    const actionsJSON = this.params.get('deathActions').toJS();
+    this._deathActions = behaviorItemFromJSON(actionsJSON);
+    const conditionJSON = this.params.get('deathCondition').toJS();
+    this._deathCondition = behaviorItemFromJSON(conditionJSON);
+    this._isDying = false;
+  }
+
   listeners() {
     return {
 
@@ -34,21 +109,28 @@ export class Alive extends decorate(Trait) {
     }
   }
 
-  tick(elapsed) {
+  methods() {
-    // ded
+    return {
-    // @todo Custom death conditions.
-    if (this.entity.life <= 0) {
-      const allowDeath = this.entity.invokeHookFlat('allowDeath');
-      const overrides = allowDeath.filter((response) => {
-        return false === response;
-      });
-      // Something saved the day.
-      if (overrides.length > 0) {
 
+      die: () => {
+        this._isDying = true;
+        this.entity.emit('dying');
+        this._deathActions.on('actionsFinished', () => {
+          this.entity.destroy();
+        });
+      },
+
+    };
+  }
+
+  tick(elapsed) {
+    if (this._isDying) {
+      this._deathActions.tick(this._context, elapsed);
     }
     else {
+      if (this._deathCondition.check(this._context)) {
         // It's a good day to die.
-        this.entity.destroy();
+        this.entity.die();
       }
     }
   }