Add entity destruction.

3 files changed, 18 insertions, 1 deletions

diff --git a/bullet.c b/bullet.c
index f2e1a2e..9acefc2 100644
--- a/bullet.c
+++ b/bullet.c
@@ -75,6 +75,10 @@ void bullet_system(World* world) {
 			pos->x += bullet->vx;
 			pos->y += bullet->vy;
 			bullet->life--;
+
+			if (bullet->life <= 0) {
+				destroy_entity(world, i);
+			}
 		}
 	}
 }
diff --git a/world.c b/world.c
index b271c3d..3b736e6 100644
--- a/world.c
+++ b/world.c
@@ -7,11 +7,21 @@ void init_world(World* world) {
 Entity new_entity(World* world) {
 	Entity e;
 
-	e = world->entity_count++;
+	e = 
+		world->recycle_bin_count > 0 ?
+		world->recycle_bin[--world->recycle_bin_count] :
+		world->entity_count++;
+
 	world->bitmask[e] = 0;
+
 	return e;
 }
 
+void destroy_entity(World* world, Entity e) {
+	world->recycle_bin[world->recycle_bin_count++] = e;
+	world->bitmask[e] = 0;
+}
+
 void add_components(World* world, Entity e, CType bits) {
 	world->bitmask[e] |= bits;
 }
diff --git a/world.h b/world.h
index 3127f37..d9995ab 100644
--- a/world.h
+++ b/world.h
@@ -11,8 +11,10 @@ typedef struct World World;
 
 struct World {
 	int entity_count;
+	int recycle_bin_count;
 
 	unsigned char bitmask[max_entities];
+	Entity recycle_bin[max_entities];
 
 	CSprite        sprites       [max_entities];
 	CPosition      positions     [max_entities];
@@ -24,6 +26,7 @@ struct World {
 
 void init_world(World* world);
 Entity new_entity(World* world);
+void destroy_entity(World* world, Entity e);
 void add_components(World* world, Entity e, CType bits);
 void remove_components(World* world, Entity e, CType bits);