From 26aebfdb92eb6780b1eb7195670b042b97948b0f Mon Sep 17 00:00:00 2001
From: quou <quou@disroot.org>
Date: Thu, 1 May 2025 20:45:12 +1000
Subject: fixing bugs in the entity system

---
 world.cpp | 62 ++++++++++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 46 insertions(+), 16 deletions(-)

(limited to 'world.cpp')

diff --git a/world.cpp b/world.cpp
index bdd0e5a..a08c024 100644
--- a/world.cpp
+++ b/world.cpp
@@ -32,17 +32,6 @@ void* Slinky::get(Entity_Id eid, int mapping, int size) {
 	return e;
 }
 
-void Slinky::remove(Entity_Id eid, int mapping, int size) {
-	int end = (--count) * size;
-	assert(eid == entities[mapping]);
-	(void)eid;
-	memmove(
-		(char*)data + mapping * size,
-		(char*)data + end * size,
-		size
-	);
-}
-
 void Pool::init(Arena* a, Component_Mask m) {
 	int i, coff;
 	mask = m;
@@ -59,9 +48,11 @@ void Pool::init(Arena* a, Component_Mask m) {
 }
 
 Slinky& Pool::get_slinky(Arena* a) {
-	int idx = slinky_count - 1;
-	if (slinkies[idx].count < slinky_size) {
-		return slinkies[idx];
+	int i, e = slinky_count;
+	for (i = 0; i < e; i++) {
+		Slinky& s = slinkies[i];
+		if (s.count < slinky_size)
+			return s;
 	}
 	assert(slinky_count < max_slinkies);
 	Slinky& s = slinkies[slinky_count++];
@@ -78,9 +69,34 @@ void* Pool::add(Arena* a, Entity_Id eid) {
 }
 
 void Pool::remove(Entity_Id eid) {
-	Mapping m = mapping[entity_index(eid)];
+	Mapping& m = mapping[entity_index(eid)];
 	Slinky& s = slinkies[m.slinky];
-	s.remove(eid, m.mapping, size);
+	assert(m.slinky >= 0);
+	if (count > 1) {
+		int idx = slinky_count - 1;
+		Entity_Id le;
+		void* last;
+#ifdef DEBUG
+		last = 0;
+#endif
+		for (; idx >= 0; idx--) {
+			Slinky& s = slinkies[idx];
+			int& c = s.count;
+			if (c) {
+				c--;
+				last = (char*)s.data + c * size;
+				le = s.entities[c];
+				s.entities[c] = 0;
+				break;
+			}
+		}
+		assert(last != 0);
+		memcpy((char*)s.data + m.mapping * size, last, size);
+		s.entities[m.mapping] = le;
+		mapping[entity_index(le)] = m;
+		m = Mapping { -1, -1 };
+	} else
+		s.count--;
 	count--;
 }
 
@@ -122,6 +138,7 @@ void World::init(Arena* a) {
 	arena = a;
 	count = 0;
 	free_count = 0;
+	dq_count = 0;
 	for (i = 0; i < max_entities; i++)
 		versions[i] = 1;
 	for (i = 0; i < max_pools; i++)
@@ -232,3 +249,16 @@ void World::destroy(Entity_Id e) {
 	versions[entity_index(e)]++;
 }
 
+void World::qdestroy(Entity_Id e) {
+	assert(e);
+	assert(dq_count < max_entities);
+	dq[dq_count++] = e;
+}
+
+void World::update() {
+	int i, e = dq_count;
+	Entity_Id* d = dq;
+	for (i = 0; i < e; i++, d++)
+		destroy(*d);
+	dq_count = 0;
+}
-- 
cgit v1.2.3-54-g00ecf