From f40ef0f5cc3d451c3789112e760719abb393ac03 Mon Sep 17 00:00:00 2001
From: Daniel Karbach <daniel.karbach@localhorst.tv>
Date: Mon, 9 Nov 2015 17:45:37 +0100
Subject: [PATCH] index chunk access in entity/world intersection test

the cache is your friend
---
 src/world/world.cpp | 19 +++++++++++--------
 1 file changed, 11 insertions(+), 8 deletions(-)

diff --git a/src/world/world.cpp b/src/world/world.cpp
index 5e3420d..b07d05a 100644
--- a/src/world/world.cpp
+++ b/src/world/world.cpp
@@ -524,15 +524,18 @@ bool World::Intersection(const Entity &e, const EntityState &s, std::vector<Worl
 	glm::ivec3 reference = s.pos.chunk;
 	glm::mat4 M = s.Transform(reference);
 
+	ExactLocation::Coarse begin(reference - 1);
+	ExactLocation::Coarse end(reference + 2);
+
 	bool any = false;
-	for (Chunk &cur_chunk : chunks) {
-		if (manhattan_radius(cur_chunk.Position() - reference) > 1) {
-			// chunk is not one of the 3x3x3 surrounding the entity
-			// since there's no entity which can extent over 16 blocks, they can be skipped
-			continue;
-		}
-		if (cur_chunk.Intersection(e, M, cur_chunk.Transform(reference), col)) {
-			any = true;
+	for (ExactLocation::Coarse pos(begin); pos.z < end.y; ++pos.z) {
+		for (pos.y = begin.y; pos.y < end.y; ++pos.y) {
+			for (pos.x = begin.x; pos.x < end.x; ++pos.x) {
+				Chunk *chunk = chunks.Get(pos);
+				if (chunk && chunk->Intersection(e, M, chunk->Transform(reference), col)) {
+					any = true;
+				}
+			}
 		}
 	}
 	return any;
-- 
2.39.2