From ca10d8906811da9b84c5b3c1fedd16bc9a397bae Mon Sep 17 00:00:00 2001
From: Avi Weinstock <aweinstock314@gmail.com>
Date: Thu, 22 Jul 2021 23:03:52 -0400
Subject: [PATCH 1/2] Further improve handling of underground waypoints:

- Set the waypoint to the valid position after chunk load, so that respawns work.
- Search for the nearest valid surface before falling back to the top of the chunk, so that waypoints inside caves/buildings work.
---
 common/src/terrain/mod.rs |  5 ++++-
 server/src/sys/terrain.rs | 15 +++++++++++----
 2 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/common/src/terrain/mod.rs b/common/src/terrain/mod.rs
index aabb5d56a4..4b5280fc10 100644
--- a/common/src/terrain/mod.rs
+++ b/common/src/terrain/mod.rs
@@ -159,6 +159,10 @@ impl TerrainGrid {
     /// Find a location suitable for spawning an entity near the given
     /// position (but in the same chunk).
     pub fn find_space(&self, pos: Vec3<i32>) -> Vec3<i32> {
+        self.find_space_opt(pos).unwrap_or(pos)
+    }
+
+    pub fn find_space_opt(&self, pos: Vec3<i32>) -> Option<Vec3<i32>> {
         const SEARCH_DIST: i32 = 63;
         (0..SEARCH_DIST * 2 + 1)
             .map(|i| if i % 2 == 0 { i } else { -i } / 2)
@@ -171,7 +175,6 @@ impl TerrainGrid {
                             .map_or(true, |b| !b.is_solid())
                     })
             })
-            .unwrap_or(pos)
     }
 }
 
diff --git a/server/src/sys/terrain.rs b/server/src/sys/terrain.rs
index 25ce94cd7f..7964828669 100644
--- a/server/src/sys/terrain.rs
+++ b/server/src/sys/terrain.rs
@@ -8,10 +8,11 @@ use crate::{
     SpawnPoint, Tick,
 };
 use common::{
-    comp::{self, agent, bird_medium, Alignment, BehaviorCapability, ForceUpdate, Pos},
+    comp::{self, agent, bird_medium, Alignment, BehaviorCapability, ForceUpdate, Pos, Waypoint},
     event::{EventBus, ServerEvent},
     generation::{get_npc_name, EntityInfo},
     npc::NPC_NAMES,
+    resources::Time,
     terrain::TerrainGrid,
     LoadoutBuilder, SkillSetBuilder,
 };
@@ -104,6 +105,8 @@ impl<'a> System<'a> for Sys {
         Entities<'a>,
         WriteStorage<'a, RepositionOnChunkLoad>,
         WriteStorage<'a, ForceUpdate>,
+        WriteStorage<'a, Waypoint>,
+        ReadExpect<'a, Time>,
     );
 
     const NAME: &'static str = "terrain";
@@ -128,6 +131,8 @@ impl<'a> System<'a> for Sys {
             entities,
             mut reposition_on_load,
             mut force_update,
+            mut waypoints,
+            time,
         ): Self::SystemData,
     ) {
         let mut server_emitter = server_event_bus.emitter();
@@ -330,11 +335,13 @@ impl<'a> System<'a> for Sys {
 
             let chunk_pos = terrain.pos_key(pos.0.map(|e| e as i32));
             if let Some(chunk) = terrain.get_key(chunk_pos) {
-                pos.0 = chunk
-                    .find_accessible_pos(pos.0.xy().as_::<i32>(), false)
-                    .as_::<f32>();
+                pos.0 = terrain
+                    .find_space_opt(pos.0.as_::<i32>())
+                    .map(|x| x.as_::<f32>())
+                    .unwrap_or_else(|| chunk.find_accessible_pos(pos.0.xy().as_::<i32>(), false));
                 repositioned.push(entity);
                 let _ = force_update.insert(entity, ForceUpdate);
+                let _ = waypoints.insert(entity, Waypoint::new(pos.0, *time));
             }
         }
         for entity in repositioned {

From 5dd56b724cd5ee102ad003fa2bee4cfaedb19ddf Mon Sep 17 00:00:00 2001
From: Avi Weinstock <aweinstock314@gmail.com>
Date: Sat, 24 Jul 2021 13:09:10 -0400
Subject: [PATCH 2/2] Rename `find_space_opt` to `try_find_space`.

---
 common/src/terrain/mod.rs | 4 ++--
 server/src/sys/terrain.rs | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/common/src/terrain/mod.rs b/common/src/terrain/mod.rs
index 4b5280fc10..0bb91f5c9b 100644
--- a/common/src/terrain/mod.rs
+++ b/common/src/terrain/mod.rs
@@ -159,10 +159,10 @@ impl TerrainGrid {
     /// Find a location suitable for spawning an entity near the given
     /// position (but in the same chunk).
     pub fn find_space(&self, pos: Vec3<i32>) -> Vec3<i32> {
-        self.find_space_opt(pos).unwrap_or(pos)
+        self.try_find_space(pos).unwrap_or(pos)
     }
 
-    pub fn find_space_opt(&self, pos: Vec3<i32>) -> Option<Vec3<i32>> {
+    pub fn try_find_space(&self, pos: Vec3<i32>) -> Option<Vec3<i32>> {
         const SEARCH_DIST: i32 = 63;
         (0..SEARCH_DIST * 2 + 1)
             .map(|i| if i % 2 == 0 { i } else { -i } / 2)
diff --git a/server/src/sys/terrain.rs b/server/src/sys/terrain.rs
index 7964828669..ce1b16c31b 100644
--- a/server/src/sys/terrain.rs
+++ b/server/src/sys/terrain.rs
@@ -336,7 +336,7 @@ impl<'a> System<'a> for Sys {
             let chunk_pos = terrain.pos_key(pos.0.map(|e| e as i32));
             if let Some(chunk) = terrain.get_key(chunk_pos) {
                 pos.0 = terrain
-                    .find_space_opt(pos.0.as_::<i32>())
+                    .try_find_space(pos.0.as_::<i32>())
                     .map(|x| x.as_::<f32>())
                     .unwrap_or_else(|| chunk.find_accessible_pos(pos.0.xy().as_::<i32>(), false));
                 repositioned.push(entity);