From a9c81140964b9d0228bdf895cb63bd37d5d98e44 Mon Sep 17 00:00:00 2001
From: kts of kettek <kts@kettek.net>
Date: Sun, 30 Jan 2022 00:24:56 -0800
Subject: [PATCH] Add basic animal AI

---
 Engine/src/live/AnimalEntity.ts | 86 ++++++++++++++++++++-------------
 1 file changed, 53 insertions(+), 33 deletions(-)

diff --git a/Engine/src/live/AnimalEntity.ts b/Engine/src/live/AnimalEntity.ts
index 2d45683..45245ab 100644
--- a/Engine/src/live/AnimalEntity.ts
+++ b/Engine/src/live/AnimalEntity.ts
@@ -1,6 +1,6 @@
 import * as planck from 'planck'
 import { AnimalDefinition, CreatureDefinition } from '../data/animals'
-import { Action } from "./Action"
+import { Action, adjustAction } from "./Action"
 import { Entity, Sensor } from "./Entity"
 import { PuddleEntity } from './PuddleEntity'
 import { WorldContext } from './World'
@@ -11,9 +11,13 @@ export class AnimalEntity extends Entity {
   isPlayer: boolean = false
   isMonster: boolean = false
   thinkTimer: number = 0 // Time since last thought, used by AI.
-  target?: Entity
+  wanderTimer: number = 0 // Time since last wander.
+  nextWander: number = 100 // Time to next wander.
+  smelledTarget?: Entity
+  seenTarget?: Entity
   def: AnimalDefinition
   mode: CreatureDefinition
+  desiredActions: Action[] = []
 
   constructor(def: AnimalDefinition) {
     super(`${def.name}.animal.stand.west.0`)
@@ -110,7 +114,7 @@ export class AnimalEntity extends Entity {
       if (Math.abs(this.velocity[1]) < this.mode.maxSpeed) {
         this.velocity[1] -= Math.sin(r) * this.mode.acceleration
       }
-      let cardinal = this.getCardinal()
+      let cardinal = this.getCardinal(this.direction)
       this.sprite.setKey = 'run'
       if (this.sprite.subsetKey !== cardinal || this.sprite.subsetKey !== 'run') {
         this.sprite.setCtor(`${this.sprite.spriteKey}.${this.sprite.animationKey}.${this.sprite.setKey}.${cardinal}.${this.sprite.frameIndex}`)
@@ -119,7 +123,7 @@ export class AnimalEntity extends Entity {
     } else {
       this.sprite.animate = false
       this.sprite.setKey = 'stand'
-      this.sprite.setCtor(`${this.sprite.spriteKey}.${this.sprite.animationKey}.${this.sprite.setKey}.${this.getCardinal()}.0`)
+      this.sprite.setCtor(`${this.sprite.spriteKey}.${this.sprite.animationKey}.${this.sprite.setKey}.${this.getCardinal(this.direction)}.0`)
     }
 
     //
@@ -129,9 +133,9 @@ export class AnimalEntity extends Entity {
     // Eh... let's manually handle velocity
     this.body?.setLinearVelocity(planck.Vec2(this.velocity[0], this.velocity[1]))
   }
-  getCardinal(): string {
+  getCardinal(direction: number): string {
     const degreesPerDirection = 360 / 4
-    const angle = this.direction + degreesPerDirection / 2
+    const angle = direction + degreesPerDirection / 2
 
     if (angle >= 0 * degreesPerDirection && angle < 1 * degreesPerDirection) {
       return 'west'
@@ -144,19 +148,51 @@ export class AnimalEntity extends Entity {
   }
   think(delta: number) {
     this.thinkTimer += delta
-    while (this.thinkTimer >= 500) {
+    while (this.thinkTimer >= 100) {
       if (!this.isMonster) {
-        if (this.target) {
-          // Flee from target
+        if (this.seenTarget) {
+          let r = Math.atan2(this.y-this.seenTarget.y, this.x-this.seenTarget.x)
+          let a = r * (180 / Math.PI)
+          if (a < 0) {
+            a += 360
+          }
+          a -= 180
+          if (a < 0) {
+            a = 360 - a
+          }
+          this.desiredActions = adjustAction([], this.getCardinal(a), 0.85)
+          this.desiredActions = adjustAction(this.desiredActions, this.getCardinal(Math.random()*360), Math.random())
+        } else if (this.smelledTarget) {
+          let r = Math.atan2(this.y-this.smelledTarget.y, this.x-this.smelledTarget.x)
+          let a = r * (180 / Math.PI)
+          if (a < 0) {
+            a += 360
+          }
+          a -= 180
+          if (a < 0) {
+            a = 360 - a
+          }
+          // 5% to walk away, otherwise just chill.
+          if (Math.random() > 0.95) {
+            this.desiredActions = adjustAction([], this.getCardinal(a), 0.85)
+          }
         } else {
-          // Wander.
+          this.wanderTimer += delta
+          if (this.wanderTimer >= this.nextWander) {
+            this.nextWander = Math.max(10, Math.random() * 100)
+            if (Math.random() > 0.15) {
+              this.desiredActions = []
+            } else {
+              this.desiredActions = adjustAction([], this.getCardinal(Math.random()*360), 1)
+            }
+            this.wanderTimer = 0
+          }
         }
       }
-      this.thinkTimer -= 500
+      this.thinkTimer -= 100
+      this.act(this.desiredActions)
     }
   }
-  setTarget(entity: Entity) {
-  }
   sense(sensor: Sensor, entity: AnimalEntity) {
     if (this.isPlayer) return
     if (sensor.type === 'long') {
@@ -175,38 +211,22 @@ export class AnimalEntity extends Entity {
   }
   smell(entity: AnimalEntity) {
     if (entity.isPlayer) {
-      if (!this.isMonster) {
-        console.log('alert, we can smell player')
-      } else {
-        console.log('we smell the player, wander towards them')
-      }
+      this.smelledTarget = entity
     }
   }
   unsmell(entity: AnimalEntity) {
     if (entity.isPlayer) {
-      if (!this.isMonster) {
-        console.log('no longer smell player, wander around')
-      } else {
-        console.log('no longer smell player, wander around')
-      }
+      this.smelledTarget = undefined
     }
   }
   see(entity: AnimalEntity) {
     if (entity.isPlayer) {
-      if (!this.isMonster) {
-        console.log('oh no, run from player')
-      } else {
-        console.log('oh ho, chase player')
-      }
+      this.seenTarget = entity
     }
   }
   unsee(entity: AnimalEntity) {
     if (entity.isPlayer) {
-      if (!this.isMonster) {
-        console.log('oh ye, we safe')
-      } else {
-        console.log('hunt last seen location')
-      }
+      this.seenTarget = undefined
     }
   }
 }