From 5ea20bd1c0bdefd511898584e1cde2832076d529 Mon Sep 17 00:00:00 2001
From: Kanewersa <30356293+Kanewersa@users.noreply.github.com>
Date: Sun, 23 May 2021 14:33:21 +0200
Subject: [PATCH] Remove resources on collision

---
 survival/generators/resource_generator.py | 9 +++++++++
 survival/systems/collision_system.py      | 6 +++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/survival/generators/resource_generator.py b/survival/generators/resource_generator.py
index a625709..ada4820 100644
--- a/survival/generators/resource_generator.py
+++ b/survival/generators/resource_generator.py
@@ -1,8 +1,10 @@
 import random
 
+from survival import GameMap
 from survival.components.OnCollisionComponent import OnCollisionComponent
 from survival.components.position_component import PositionComponent
 from survival.components.sprite_component import SpriteComponent
+from survival.esper import World
 from survival.settings import RESOURCES_AMOUNT
 
 
@@ -22,6 +24,7 @@ class ResourceGenerator:
             pos = PositionComponent(empty_pos, empty_grid_pos)
             sprite = SpriteComponent(random.choice(sprites))
             col = OnCollisionComponent()
+            col.addCallback(self.remove_resource, world=self.world, game_map=self.map, entity=obj)
             self.world.add_component(obj, pos)
             self.world.add_component(obj, sprite)
             self.world.add_component(obj, col)
@@ -32,3 +35,9 @@ class ResourceGenerator:
         while self.map.is_colliding(free_pos):
             free_pos = [random.randrange(self.map.width), random.randrange(self.map.height)]
         return free_pos
+
+    @staticmethod
+    def remove_resource(world: World, game_map: GameMap, entity: int):
+        pos = world.component_for_entity(entity, PositionComponent)
+        game_map.remove_entity(pos.grid_position)
+        world.delete_entity(entity, immediate=True)
diff --git a/survival/systems/collision_system.py b/survival/systems/collision_system.py
index 267b278..b9cc0f7 100644
--- a/survival/systems/collision_system.py
+++ b/survival/systems/collision_system.py
@@ -26,7 +26,11 @@ class CollisionSystem(esper.Processor):
                 self.world.remove_component(ent, MovingComponent)
                 onCol.callAll()
                 colliding_object: int = self.map.get_entity(moving.target)
-                if colliding_object is not None and self.world.has_component(colliding_object, OnCollisionComponent):
+
+                if colliding_object is None or not self.world.entity_exists(colliding_object):
+                    continue
+
+                if self.world.has_component(colliding_object, OnCollisionComponent):
                     self.world.component_for_entity(colliding_object, OnCollisionComponent).callAll()
 
             else: