From c4a6875133b91f5b3026e10279f68cd1633f5eb0 Mon Sep 17 00:00:00 2001
From: Avi Weinstock <aweinstock314@gmail.com>
Date: Wed, 24 Mar 2021 15:42:37 -0400
Subject: [PATCH] Fix airships getting stuck in trees and campfires spawning
 too close to new-style dungeon stairs.

---
 CHANGELOG.md                  |  1 +
 server/src/rtsim/tick.rs      | 17 ++++++++++-------
 server/src/sys/agent.rs       | 35 ++++++++++++++++++++++++-----------
 world/src/site/dungeon/mod.rs |  2 +-
 4 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2ad473f0b6..a10ea27e91 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Server kicks old client when a user is trying to log in again (often the case when a user's original connection gets dropped)
 - Added a raycast check to beams to prevent their effect applying through walls
+- Flying agents raycast more angles to check for obstacles.
 
 ## [0.9.0] - 2021-03-20
 
diff --git a/server/src/rtsim/tick.rs b/server/src/rtsim/tick.rs
index 238e921566..8f5030ee15 100644
--- a/server/src/rtsim/tick.rs
+++ b/server/src/rtsim/tick.rs
@@ -102,7 +102,7 @@ impl<'a> System<'a> for Sys {
                 .map(|e| e as f32)
                 + Vec3::new(0.5, 0.5, 0.0);
             let body = entity.get_body();
-            let pos = comp::Pos(spawn_pos);
+            let mut pos = comp::Pos(spawn_pos);
             let agent = Some(comp::Agent::new(
                 None,
                 matches!(body, comp::Body::Humanoid(_)),
@@ -112,12 +112,15 @@ impl<'a> System<'a> for Sys {
             ));
             let rtsim_entity = Some(RtSimEntity(id));
             let event = match body {
-                comp::Body::Ship(ship) => ServerEvent::CreateShip {
-                    pos,
-                    ship,
-                    mountable: false,
-                    agent,
-                    rtsim_entity,
+                comp::Body::Ship(ship) => {
+                    pos.0 += Vec3::unit_z() * body.flying_height();
+                    ServerEvent::CreateShip {
+                        pos,
+                        ship,
+                        mountable: false,
+                        agent,
+                        rtsim_entity,
+                    }
                 },
                 _ => ServerEvent::CreateNpc {
                     pos: comp::Pos(spawn_pos),
diff --git a/server/src/sys/agent.rs b/server/src/sys/agent.rs
index d80439aa8b..5608cc3477 100644
--- a/server/src/sys/agent.rs
+++ b/server/src/sys/agent.rs
@@ -680,7 +680,7 @@ impl<'a> AgentData<'a> {
                             .cast()
                             .1
                             .map_or(true, |b| b.is_some());
-                        let ground_too_close = self
+                        let mut ground_too_close = self
                             .body
                             .map(|body| {
                                 let height_approx = self.pos.0.y
@@ -691,19 +691,32 @@ impl<'a> AgentData<'a> {
                                         .unwrap_or(0.0);
 
                                 height_approx < body.flying_height()
-                                    || read_data
-                                        .terrain
-                                        .ray(
-                                            self.pos.0,
-                                            self.pos.0 - body.flying_height() * Vec3::unit_z(),
-                                        )
-                                        .until(|b: &Block| b.is_solid() || b.is_liquid())
-                                        .cast()
-                                        .1
-                                        .map_or(false, |b| b.is_some())
                             })
                             .unwrap_or(false);
 
+                        const NUM_RAYS: usize = 5;
+                        for i in 0..=NUM_RAYS {
+                            let magnitude = self.body.map_or(20.0, |b| b.flying_height());
+                            // Lerp between a line straight ahead and straight down to detect a
+                            // wedge of obstacles we might fly into (inclusive so that both vectors
+                            // are sampled)
+                            if let Some(dir) = Lerp::lerp(
+                                -Vec3::unit_z(),
+                                Vec3::new(bearing.x, bearing.y, 0.0),
+                                i as f32 / NUM_RAYS as f32,
+                            )
+                            .try_normalized()
+                            {
+                                ground_too_close |= read_data
+                                    .terrain
+                                    .ray(self.pos.0, self.pos.0 + magnitude * dir)
+                                    .until(|b: &Block| b.is_solid() || b.is_liquid())
+                                    .cast()
+                                    .1
+                                    .map_or(false, |b| b.is_some())
+                            }
+                        }
+
                         if obstacle_ahead || ground_too_close {
                             1.0 //fly up when approaching obstacles
                         } else {
diff --git a/world/src/site/dungeon/mod.rs b/world/src/site/dungeon/mod.rs
index 934cc358b1..7af91c00d0 100644
--- a/world/src/site/dungeon/mod.rs
+++ b/world/src/site/dungeon/mod.rs
@@ -201,7 +201,7 @@ impl Dungeon {
         let pos = self.origin.map2(FLOOR_SIZE, |e, sz| e + sz as i32 / 2);
         if area.contains_point(pos - self.origin) {
             supplement.add_entity(
-                EntityInfo::at(Vec3::new(pos.x as f32, pos.y as f32, self.alt as f32) + 2.5)
+                EntityInfo::at(Vec3::new(pos.x as f32, pos.y as f32, self.alt as f32) + 5.0)
                     .into_waypoint(),
             );
         }