Redesign the spatial index API and add raycast example

build/entity.rs

@@ -527,7 +527,7 @@ const AGEABLE_MOB: Class = Class {
 
 const ANIMAL: Class = Class {
     name: "animal",
-    inherit: Some(&PATHFINDER_MOB),
+    inherit: Some(&AGEABLE_MOB),
     fields: &[],
     events: &[],
 };

examples/cow_sphere.rs

@@ -34,7 +34,7 @@ struct Game {
 
 const MAX_PLAYERS: usize = 10;
 
-const SPAWN_POS: BlockPos = BlockPos::new(0, 99, -35);
+const SPAWN_POS: BlockPos = BlockPos::new(0, 100, -35);
 
 #[async_trait]
 impl Config for Game {
@@ -139,7 +139,6 @@ impl Config for Game {
 
         let radius = 6.0 + ((time * TAU / 2.5).sin() + 1.0) / 2.0 * 10.0;
 
-        // TODO: use eye position.
         let player_pos = server
             .clients
             .iter()
@@ -147,19 +146,22 @@ impl Config for Game {
             .map(|c| c.1.position())
             .unwrap_or_default();
 
+        // TODO: hardcoded eye pos.
+        let eye_pos = Vec3::new(player_pos.x, player_pos.y + 1.6, player_pos.z);
+
         for (cow_id, p) in cows.iter().cloned().zip(fibonacci_spiral(cow_count)) {
             let cow = server.entities.get_mut(cow_id).expect("missing cow");
             let rotated = p * rot;
-            let transformed = rotated * radius + [0.5, 100.0, 0.5];
+            let transformed = rotated * radius + [0.5, SPAWN_POS.y as f64 + 1.0, 0.5];
 
             let yaw = f32::atan2(rotated.z as f32, rotated.x as f32).to_degrees() - 90.0;
             let (looking_yaw, looking_pitch) =
-                to_yaw_and_pitch((player_pos - transformed).normalized());
+                to_yaw_and_pitch((eye_pos - transformed).normalized());
 
             cow.set_position(transformed);
             cow.set_yaw(yaw);
-            cow.set_pitch(looking_pitch);
-            cow.set_head_yaw(looking_yaw);
+            cow.set_pitch(looking_pitch as f32);
+            cow.set_head_yaw(looking_yaw as f32);
         }
     }
 }

examples/raycast.rs

@@ -0,0 +1,172 @@
+use std::collections::HashSet;
+use std::net::SocketAddr;
+use std::sync::atomic::{AtomicUsize, Ordering};
+
+use log::LevelFilter;
+use valence::async_trait;
+use valence::block::{BlockPos, BlockState};
+use valence::client::GameMode;
+use valence::config::{Config, ServerListPing};
+use valence::dimension::DimensionId;
+use valence::entity::{EntityData, EntityKind};
+use valence::server::{Server, SharedServer, ShutdownResult};
+use valence::text::{Color, TextFormat};
+use valence::util::from_yaw_and_pitch;
+use vek::Vec3;
+
+pub fn main() -> ShutdownResult {
+    env_logger::Builder::new()
+        .filter_module("valence", LevelFilter::Trace)
+        .parse_default_env()
+        .init();
+
+    valence::start_server(Game {
+        player_count: AtomicUsize::new(0),
+    })
+}
+
+struct Game {
+    player_count: AtomicUsize,
+}
+
+const MAX_PLAYERS: usize = 10;
+
+const SPAWN_POS: BlockPos = BlockPos::new(0, 100, -8);
+
+const PLAYER_EYE_HEIGHT: f64 = 1.6;
+
+#[async_trait]
+impl Config for Game {
+    fn max_connections(&self) -> usize {
+        // We want status pings to be successful even if the server is full.
+        MAX_PLAYERS + 64
+    }
+
+    fn online_mode(&self) -> bool {
+        // You'll want this to be true on real servers.
+        false
+    }
+
+    async fn server_list_ping(
+        &self,
+        _server: &SharedServer,
+        _remote_addr: SocketAddr,
+    ) -> ServerListPing {
+        ServerListPing::Respond {
+            online_players: self.player_count.load(Ordering::SeqCst) as i32,
+            max_players: MAX_PLAYERS as i32,
+            description: "Hello Valence!".color(Color::AQUA),
+            favicon_png: Some(include_bytes!("../assets/favicon.png")),
+        }
+    }
+
+    fn init(&self, server: &mut Server) {
+        let (world_id, world) = server.worlds.create(DimensionId::default());
+        world.meta.set_flat(true);
+
+        let size = 5;
+        for z in -size..size {
+            for x in -size..size {
+                world.chunks.create([x, z]);
+            }
+        }
+
+        world.chunks.set_block_state(SPAWN_POS, BlockState::BEDROCK);
+
+        const SHEEP_COUNT: usize = 10;
+        for i in 0..SHEEP_COUNT {
+            let offset = (i as f64 - (SHEEP_COUNT - 1) as f64 / 2.0) * 1.25;
+
+            let (_, sheep) = server.entities.create(EntityKind::Sheep);
+            sheep.set_world(world_id);
+            sheep.set_position([offset + 0.5, SPAWN_POS.y as f64 + 1.0, 0.0]);
+            sheep.set_yaw(180.0);
+            sheep.set_head_yaw(180.0);
+
+            if let EntityData::Sheep(sheep) = sheep.data_mut() {
+                // Shear the sheep.
+                sheep.set_sheep_state(0b1_0000);
+            }
+        }
+    }
+
+    fn update(&self, server: &mut Server) {
+        let (world_id, world) = server.worlds.iter_mut().next().unwrap();
+
+        let mut hit_entities = HashSet::new();
+
+        server.clients.retain(|_, client| {
+            if client.created_tick() == server.shared.current_tick() {
+                if self
+                    .player_count
+                    .fetch_update(Ordering::SeqCst, Ordering::SeqCst, |count| {
+                        (count < MAX_PLAYERS).then_some(count + 1)
+                    })
+                    .is_err()
+                {
+                    client.disconnect("The server is full!".color(Color::RED));
+                    return false;
+                }
+
+                client.spawn(world_id);
+                client.set_game_mode(GameMode::Creative);
+                client.teleport(
+                    [
+                        SPAWN_POS.x as f64 + 0.5,
+                        SPAWN_POS.y as f64 + 1.0,
+                        SPAWN_POS.z as f64 + 0.5,
+                    ],
+                    0.0,
+                    0.0,
+                );
+
+                world.meta.player_list_mut().insert(
+                    client.uuid(),
+                    client.username().to_owned(),
+                    client.textures().cloned(),
+                    client.game_mode(),
+                    0,
+                    None,
+                );
+
+                client.send_message(
+                    "Look at a sheep to change its ".italic()
+                        + "color".italic().color(Color::GREEN)
+                        + ".",
+                )
+            }
+
+            if client.is_disconnected() {
+                self.player_count.fetch_sub(1, Ordering::SeqCst);
+                world.meta.player_list_mut().remove(client.uuid());
+                return false;
+            }
+
+            let client_pos = client.position();
+
+            let origin = Vec3::new(client_pos.x, client_pos.y + PLAYER_EYE_HEIGHT, client_pos.z);
+            let direction = from_yaw_and_pitch(client.yaw() as f64, client.pitch() as f64);
+
+            if let Some(hit) = world.spatial_index.raycast(origin, direction, |hit| {
+                server
+                    .entities
+                    .get(hit.entity)
+                    .map_or(false, |e| e.kind() == EntityKind::Sheep)
+            }) {
+                hit_entities.insert(hit.entity);
+            }
+
+            true
+        });
+
+        for (id, e) in server.entities.iter_mut() {
+            if let EntityData::Sheep(sheep) = e.data_mut() {
+                if hit_entities.contains(&id) {
+                    sheep.set_sheep_state(5);
+                } else {
+                    sheep.set_sheep_state(0);
+                }
+            }
+        }
+    }
+}

src/block_pos.rs

@@ -32,10 +32,7 @@ impl Encode for BlockPos {
                 let (x, y, z) = (self.x as u64, self.y as u64, self.z as u64);
                 (x << 38 | z << 38 >> 26 | y & 0xfff).encode(w)
             }
-            _ => bail!(
-                "block position {:?} is out of range",
-                (self.x, self.y, self.z)
-            ),
+            _ => bail!("out of range: {self:?}"),
         }
     }
 }

src/bvh.rs

@@ -3,10 +3,13 @@
 //! [bvh]: https://en.wikipedia.org/wiki/Bounding_volume_hierarchy
 //! [`SpatialIndex`]: crate::spatial_index::SpatialIndex
 
+use std::iter::FusedIterator;
 use std::mem;
 
 use approx::relative_eq;
-use rayon::iter::{IntoParallelRefIterator, ParallelIterator};
+use rayon::iter::{
+    IndexedParallelIterator, IntoParallelRefIterator, IntoParallelRefMutIterator, ParallelIterator,
+};
 use vek::Aabb;
 
 #[derive(Clone)]
@@ -16,13 +19,6 @@ pub struct Bvh<T> {
     root: NodeIdx,
 }
 
-#[derive(Clone, Copy, PartialEq, Eq)]
-pub enum TraverseStep<T> {
-    Miss,
-    Hit,
-    Return(T),
-}
-
 #[derive(Clone)]
 struct InternalNode {
     bb: Aabb<f64>,
@@ -33,7 +29,7 @@ struct InternalNode {
 #[derive(Clone)]
 struct LeafNode<T> {
     bb: Aabb<f64>,
-    id: T,
+    data: T,
 }
 
 // TODO: we could use usize here to store more elements.
@@ -53,7 +49,7 @@ impl<T: Send + Sync> Bvh<T> {
         self.internal_nodes.clear();
 
         self.leaf_nodes
-            .extend(leaves.into_iter().map(|(id, bb)| LeafNode { bb, id }));
+            .extend(leaves.into_iter().map(|(id, bb)| LeafNode { bb, data: id }));
 
         let leaf_count = self.leaf_nodes.len();
 
@@ -98,40 +94,88 @@ impl<T: Send + Sync> Bvh<T> {
         debug_assert_eq!(self.internal_nodes.len(), self.leaf_nodes.len() - 1);
     }
 
-    pub fn traverse<F, U>(&self, mut f: F) -> Option<U>
-    where
-        F: FnMut(Option<&T>, Aabb<f64>) -> TraverseStep<U>,
-    {
+    pub fn traverse(&self) -> Option<Node<T>> {
         if !self.leaf_nodes.is_empty() {
-            self.traverse_rec(self.root, &mut f)
+            Some(Node::from_idx(self, self.root))
         } else {
             None
         }
     }
 
-    fn traverse_rec<F, U>(&self, idx: NodeIdx, f: &mut F) -> Option<U>
-    where
-        F: FnMut(Option<&T>, Aabb<f64>) -> TraverseStep<U>,
-    {
-        if idx < self.internal_nodes.len() as NodeIdx {
-            let internal = &self.internal_nodes[idx as usize];
-
-            match f(None, internal.bb) {
-                TraverseStep::Miss => None,
-                TraverseStep::Hit => self
-                    .traverse_rec(internal.left, f)
-                    .or_else(|| self.traverse_rec(internal.right, f)),
-                TraverseStep::Return(u) => Some(u),
+    pub fn iter(
+        &self,
+    ) -> impl ExactSizeIterator<Item = (&T, Aabb<f64>)> + FusedIterator + Clone + '_ {
+        self.leaf_nodes.iter().map(|leaf| (&leaf.data, leaf.bb))
     }
+
+    #[allow(dead_code)]
+    pub fn iter_mut(
+        &mut self,
+    ) -> impl ExactSizeIterator<Item = (&mut T, Aabb<f64>)> + FusedIterator + '_ {
+        self.leaf_nodes
+            .iter_mut()
+            .map(|leaf| (&mut leaf.data, leaf.bb))
+    }
+
+    pub fn par_iter(&self) -> impl IndexedParallelIterator<Item = (&T, Aabb<f64>)> + Clone + '_ {
+        self.leaf_nodes.par_iter().map(|leaf| (&leaf.data, leaf.bb))
+    }
+
+    #[allow(dead_code)]
+    pub fn par_iter_mut(
+        &mut self,
+    ) -> impl IndexedParallelIterator<Item = (&mut T, Aabb<f64>)> + '_ {
+        self.leaf_nodes
+            .par_iter_mut()
+            .map(|leaf| (&mut leaf.data, leaf.bb))
+    }
+}
+
+pub enum Node<'a, T> {
+    Internal(Internal<'a, T>),
+    Leaf { data: &'a T, bb: Aabb<f64> },
+}
+
+impl<'a, T> Node<'a, T> {
+    fn from_idx(bvh: &'a Bvh<T>, idx: NodeIdx) -> Self {
+        if idx < bvh.internal_nodes.len() as NodeIdx {
+            Self::Internal(Internal { bvh, idx })
         } else {
-            let leaf = &self.leaf_nodes[(idx - self.internal_nodes.len() as NodeIdx) as usize];
+            let leaf = &bvh.leaf_nodes[(idx - bvh.internal_nodes.len() as NodeIdx) as usize];
+            Self::Leaf {
+                data: &leaf.data,
+                bb: leaf.bb,
+            }
+        }
+    }
 
-            match f(Some(&leaf.id), leaf.bb) {
-                TraverseStep::Miss | TraverseStep::Hit => None,
-                TraverseStep::Return(u) => Some(u),
+    pub fn bb(&self) -> Aabb<f64> {
+        match self {
+            Node::Internal(int) => int.bb(),
+            Node::Leaf { bb, .. } => *bb,
         }
     }
 }
+
+pub struct Internal<'a, T> {
+    bvh: &'a Bvh<T>,
+    idx: NodeIdx,
+}
+
+impl<'a, T> Internal<'a, T> {
+    pub fn split(self) -> (Aabb<f64>, Node<'a, T>, Node<'a, T>) {
+        let internal = &self.bvh.internal_nodes[self.idx as usize];
+
+        let bb = internal.bb;
+        let left = Node::from_idx(self.bvh, internal.left);
+        let right = Node::from_idx(self.bvh, internal.right);
+
+        (bb, left, right)
+    }
+
+    pub fn bb(&self) -> Aabb<f64> {
+        self.bvh.internal_nodes[self.idx as usize].bb
+    }
 }
 
 fn build_rec<T: Send>(
@@ -266,34 +310,3 @@ impl<T: Send + Sync> Default for Bvh<T> {
         Self::new()
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn empty() {
-        let mut bvh = Bvh::new();
-
-        bvh.traverse(|_, _| TraverseStep::Return(()));
-        bvh.build([]);
-
-        bvh.build([(5, Aabb::default())]);
-        bvh.traverse(|_, _| TraverseStep::Return(()));
-    }
-
-    #[test]
-    fn overlapping() {
-        let mut bvh = Bvh::new();
-
-        bvh.build([
-            ((), Aabb::default()),
-            ((), Aabb::default()),
-            ((), Aabb::default()),
-            ((), Aabb::default()),
-            ((), Aabb::new_empty(5.0.into())),
-        ]);
-
-        bvh.traverse(|_, _| TraverseStep::Return(()));
-    }
-}

src/spatial_index.rs

@@ -1,10 +1,13 @@
 //! Efficient spatial entity queries.
 
+use std::iter::FusedIterator;
+
+use rayon::iter::{IndexedParallelIterator, ParallelIterator};
 use vek::{Aabb, Vec3};
 
-use crate::bvh::Bvh;
-pub use crate::bvh::TraverseStep;
+use crate::bvh::{Bvh, Node};
 use crate::entity::{Entities, EntityId};
+use crate::util::ray_box_intersect;
 use crate::world::WorldId;
 
 /// A data structure for fast spatial queries on entity [hitboxes]. This is used
@@ -25,9 +28,9 @@ impl SpatialIndex {
     }
 
     #[doc(hidden)]
-    #[deprecated = "This is for documentation tests only"]
+    #[deprecated = "This is for documentation tests only!"]
     pub fn example_new() -> Self {
-        println!("Don't call me!");
+        dbg!("Don't call me from outside tests!");
         Self::new()
     }
 
@@ -69,86 +72,157 @@ impl SpatialIndex {
         C: FnMut(Aabb<f64>) -> bool,
         F: FnMut(EntityId, Aabb<f64>) -> Option<T>,
     {
-        self.traverse(|e, bb| {
-            if collides(bb) {
-                e.and_then(|id| f(id, bb))
-                    .map_or(TraverseStep::Hit, TraverseStep::Return)
-            } else {
-                TraverseStep::Miss
-            }
-        })
-    }
-
-    // TODO: accept predicate here. Might want to skip invisible entities, for
-    // instance.
-    pub fn raycast(&self, origin: Vec3<f64>, direction: Vec3<f64>) -> Option<RaycastHit> {
-        debug_assert!(
-            direction.is_normalized(),
-            "the ray direction must be normalized"
-        );
-
-        let mut hit: Option<RaycastHit> = None;
-
-        self.traverse::<_, ()>(|entity, bb| {
-            if let Some((near, far)) = ray_box_intersection(origin, direction, bb) {
-                if hit.as_ref().map_or(true, |hit| near < hit.near) {
-                    if let Some(entity) = entity {
-                        hit = Some(RaycastHit {
-                            entity,
-                            bb,
-                            near,
-                            far,
-                        });
-                    }
-                    TraverseStep::Hit
-                } else {
-                    // Do not explore subtrees that cannot produce an intersection closer than the
-                    // closest we've seen so far.
-                    TraverseStep::Miss
-                }
-            } else {
-                TraverseStep::Miss
-            }
-        });
-
-        hit
-    }
-
-    pub fn raycast_all<F, T>(&self, origin: Vec3<f64>, direction: Vec3<f64>, mut f: F) -> Option<T>
+        fn query_rec<C, F, T>(node: Node<EntityId>, collides: &mut C, f: &mut F) -> Option<T>
         where
-        F: FnMut(RaycastHit) -> Option<T>,
+            C: FnMut(Aabb<f64>) -> bool,
+            F: FnMut(EntityId, Aabb<f64>) -> Option<T>,
         {
-        debug_assert!(
-            direction.is_normalized(),
-            "the ray direction must be normalized"
-        );
+            match node {
+                Node::Internal(int) => {
+                    let (bb, left, right) = int.split();
 
-        self.traverse(
-            |entity, bb| match (ray_box_intersection(origin, direction, bb), entity) {
-                (Some((near, far)), Some(entity)) => {
-                    let hit = RaycastHit {
-                        entity,
+                    if collides(bb) {
+                        query_rec(left, collides, f).or_else(|| query_rec(right, collides, f))
+                    } else {
+                        None
+                    }
+                }
+                Node::Leaf { data, bb } => {
+                    if collides(bb) {
+                        f(*data, bb)
+                    } else {
+                        None
+                    }
+                }
+            }
+        }
+
+        query_rec(self.bvh.traverse()?, &mut collides, &mut f)
+    }
+
+    /// Casts a ray defined by `origin` and `direction` through entity hitboxes
+    /// and returns the closest intersection for which `f` returns `true`.
+    ///
+    /// `f` is a predicate which can be used to filter intersections. For
+    /// instance, if a ray is shot from a player's eye position, you probably
+    /// don't want the ray to intersect with the player's own hitbox.
+    ///
+    /// If no intersections are found or if `f` never returns `true` then `None`
+    /// is returned. Additionally, the given ray direction must be
+    /// normalized.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # #[allow(deprecated)]
+    /// # let si = valence::spatial_index::SpatialIndex::example_new();
+    /// use valence::vek::*;
+    ///
+    /// let origin = Vec3::new(0.0, 0.0, 0.0);
+    /// let direction = Vec3::new(1.0, 1.0, 1.0).normalized();
+    ///
+    /// // Assume `si` is the spatial index.
+    /// if let Some(hit) = si.raycast(origin, direction, |_| true) {
+    ///     println!("Raycast hit! {hit:?}");
+    /// }
+    /// ```
+    pub fn raycast<F>(
+        &self,
+        origin: Vec3<f64>,
+        direction: Vec3<f64>,
+        mut f: F,
+    ) -> Option<RaycastHit>
+    where
+        F: FnMut(&RaycastHit) -> bool,
+    {
+        fn raycast_rec(
+            node: Node<EntityId>,
+            hit: &mut Option<RaycastHit>,
+            near: f64,
+            far: f64,
+            origin: Vec3<f64>,
+            direction: Vec3<f64>,
+            f: &mut impl FnMut(&RaycastHit) -> bool,
+        ) {
+            if let Some(hit) = hit {
+                if hit.near <= near {
+                    return;
+                }
+            }
+
+            match node {
+                Node::Internal(int) => {
+                    let (_, left, right) = int.split();
+
+                    let int_left = ray_box_intersect(origin, direction, left.bb());
+                    let int_right = ray_box_intersect(origin, direction, right.bb());
+
+                    match (int_left, int_right) {
+                        (Some((near_left, far_left)), Some((near_right, far_right))) => {
+                            // Explore closest subtree first.
+                            if near_left < near_right {
+                                raycast_rec(left, hit, near_left, far_left, origin, direction, f);
+                                raycast_rec(
+                                    right, hit, near_right, far_right, origin, direction, f,
+                                );
+                            } else {
+                                raycast_rec(
+                                    right, hit, near_right, far_right, origin, direction, f,
+                                );
+                                raycast_rec(left, hit, near_left, far_left, origin, direction, f);
+                            }
+                        }
+                        (Some((near, far)), None) => {
+                            raycast_rec(left, hit, near, far, origin, direction, f)
+                        }
+                        (None, Some((near, far))) => {
+                            raycast_rec(right, hit, near, far, origin, direction, f)
+                        }
+                        (None, None) => {}
+                    }
+                }
+                Node::Leaf { data, bb } => {
+                    let this_hit = RaycastHit {
+                        entity: *data,
                         bb,
                         near,
                         far,
                     };
-                    f(hit).map_or(TraverseStep::Hit, TraverseStep::Return)
+
+                    if f(&this_hit) {
+                        *hit = Some(this_hit);
+                    }
+                }
             }
-                (Some(_), None) => TraverseStep::Hit,
-                (None, _) => TraverseStep::Miss,
-            },
-        )
         }
 
-    /// Explores the spatial index according to `f`.
-    ///
-    /// This is a low-level function that should only be used if the other
-    /// methods on this type are too restrictive.
-    pub fn traverse<F, T>(&self, mut f: F) -> Option<T>
-    where
-        F: FnMut(Option<EntityId>, Aabb<f64>) -> TraverseStep<T>,
-    {
-        self.bvh.traverse(|e, bb| f(e.cloned(), bb))
+        debug_assert!(
+            direction.is_normalized(),
+            "the ray direction must be normalized"
+        );
+
+        let root = self.bvh.traverse()?;
+        let (near, far) = ray_box_intersect(origin, direction, root.bb())?;
+
+        let mut hit = None;
+        raycast_rec(root, &mut hit, near, far, origin, direction, &mut f);
+        hit
+    }
+
+    /// Returns an iterator over all entities and their hitboxes in
+    /// an unspecified order.
+    pub fn iter(
+        &self,
+    ) -> impl ExactSizeIterator<Item = (EntityId, Aabb<f64>)> + FusedIterator + Clone + '_ {
+        self.bvh.iter().map(|(&id, bb)| (id, bb))
+    }
+
+    /// Returns a parallel iterator over all entities and their
+    /// hitboxes in an unspecified order.
+    pub fn par_iter(
+        &self,
+    ) -> impl IndexedParallelIterator<Item = (EntityId, Aabb<f64>)> + Clone + '_ {
+        self.bvh.par_iter().map(|(&id, bb)| (id, bb))
     }
 
     pub(crate) fn update(&mut self, entities: &Entities, id: WorldId) {
@@ -162,8 +236,8 @@ impl SpatialIndex {
 }
 
 /// Represents an intersection between a ray and an entity's axis-aligned
-/// bounding box.
-#[derive(Clone, Copy, PartialEq)]
+/// bounding box (hitbox).
+#[derive(Clone, Copy, PartialEq, Debug)]
 pub struct RaycastHit {
     /// The [`EntityId`] of the entity that was hit by the ray.
     pub entity: EntityId,
@@ -177,75 +251,3 @@ pub struct RaycastHit {
     /// represents the point at which the ray exits the bounding box.
     pub far: f64,
 }
-
-fn ray_box_intersection(ro: Vec3<f64>, rd: Vec3<f64>, bb: Aabb<f64>) -> Option<(f64, f64)> {
-    let mut near = -f64::INFINITY;
-    let mut far = f64::INFINITY;
-
-    for i in 0..3 {
-        // Rust's definition of min and max properly handle the NaNs that these
-        // computations might produce.
-        let t0 = (bb.min[i] - ro[i]) / rd[i];
-        let t1 = (bb.max[i] - ro[i]) / rd[i];
-
-        near = near.max(t0.min(t1));
-        far = far.min(t0.max(t1));
-    }
-
-    if near <= far && far >= 0.0 {
-        Some((near.max(0.0), far))
-    } else {
-        None
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn ray_box_edge_cases() {
-        let bb = Aabb {
-            min: Vec3::new(0.0, 0.0, 0.0),
-            max: Vec3::new(1.0, 1.0, 1.0),
-        };
-
-        let ros = [
-            // On a corner
-            Vec3::new(0.0, 0.0, 0.0),
-            // Outside
-            Vec3::new(-0.5, 0.5, -0.5),
-            // In the center
-            Vec3::new(0.5, 0.5, 0.5),
-            // On an edge
-            Vec3::new(0.0, 0.5, 0.0),
-            // On a face
-            Vec3::new(0.0, 0.5, 0.5),
-            // Outside slabs
-            Vec3::new(-2.0, -2.0, -2.0),
-        ];
-
-        let rds = [
-            Vec3::new(1.0, 0.0, 0.0),
-            Vec3::new(-1.0, 0.0, 0.0),
-            Vec3::new(0.0, 1.0, 0.0),
-            Vec3::new(0.0, -1.0, 0.0),
-            Vec3::new(0.0, 0.0, 1.0),
-            Vec3::new(0.0, 0.0, -1.0),
-        ];
-
-        assert!(rds.iter().all(|d| d.is_normalized()));
-
-        for ro in ros {
-            for rd in rds {
-                if let Some((near, far)) = ray_box_intersection(ro, rd, bb) {
-                    assert!(near.is_finite());
-                    assert!(far.is_finite());
-                    assert!(near <= far);
-                    assert!(near >= 0.0);
-                    assert!(far >= 0.0);
-                }
-            }
-        }
-    }
-}

src/text.rs

@@ -397,6 +397,12 @@ impl<T: Into<Text>> std::ops::AddAssign<T> for Text {
     }
 }
 
+impl From<char> for Text {
+    fn from(c: char) -> Self {
+        Text::text(String::from(c))
+    }
+}
+
 impl From<String> for Text {
     fn from(s: String) -> Self {
         Text::text(s)

src/util.rs

@@ -62,7 +62,7 @@ where
         ),
         max: Vec3::new(
             bottom.x + size.x / 2.0.as_(),
-            bottom.y,
+            bottom.y + size.y,
             bottom.z + size.z / 2.0.as_(),
         ),
     };
@@ -75,19 +75,118 @@ where
 /// Takes a normalized direction vector and returns a `(yaw, pitch)` tuple in
 /// degrees.
 ///
-// /// This function is the inverse of [`from_yaw_and_pitch`].
-pub fn to_yaw_and_pitch(d: Vec3<f64>) -> (f32, f32) {
+/// This function is the inverse of [`from_yaw_and_pitch`] except for the case
+/// where the direction is straight up or down.
+pub fn to_yaw_and_pitch(d: Vec3<f64>) -> (f64, f64) {
     debug_assert!(d.is_normalized(), "the given vector should be normalized");
 
-    let yaw = f32::atan2(d.z as f32, d.x as f32).to_degrees() - 90.0;
-    let pitch = -(d.y as f32).asin().to_degrees();
+    let yaw = f64::atan2(d.z, d.x).to_degrees() - 90.0;
+    let pitch = -(d.y).asin().to_degrees();
     (yaw, pitch)
 }
 
-// /// Takes yaw and pitch angles (in degrees) and returns a normalized
-// direction /// vector.
-// ///
-// /// This function is the inverse of [`to_yaw_and_pitch`].
-// pub fn from_yaw_and_pitch(yaw: f32, pitch: f32) -> Vec3<f64> {
-//     todo!()
-// }
+/// Takes yaw and pitch angles (in degrees) and returns a normalized
+/// direction vector.
+///
+/// This function is the inverse of [`to_yaw_and_pitch`].
+pub fn from_yaw_and_pitch(yaw: f64, pitch: f64) -> Vec3<f64> {
+    let yaw = (yaw + 90.0).to_radians();
+    let pitch = (-pitch).to_radians();
+
+    let xz_len = pitch.cos();
+    Vec3::new(yaw.cos() * xz_len, pitch.sin(), yaw.sin() * xz_len)
+}
+
+/// Calculates the intersection between an axis-aligned bounding box and a ray
+/// defined by its origin `ro` and direction `rd`.
+///
+/// If an intersection occurs, `Some((near, far))` is returned. `near` and `far`
+/// are the distance from the origin to the closest and furthest intersection
+/// points respectively. If the intersection occurs inside the bounding box,
+/// then `near` is zero.
+pub fn ray_box_intersect(ro: Vec3<f64>, rd: Vec3<f64>, bb: Aabb<f64>) -> Option<(f64, f64)> {
+    let mut near = -f64::INFINITY;
+    let mut far = f64::INFINITY;
+
+    for i in 0..3 {
+        // Rust's definition of min and max properly handle the NaNs that these
+        // computations might produce.
+        let t0 = (bb.min[i] - ro[i]) / rd[i];
+        let t1 = (bb.max[i] - ro[i]) / rd[i];
+
+        near = near.max(t0.min(t1));
+        far = far.min(t0.max(t1));
+    }
+
+    if near <= far && far >= 0.0 {
+        Some((near.max(0.0), far))
+    } else {
+        None
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use approx::assert_relative_eq;
+    use rand::random;
+
+    use super::*;
+
+    #[test]
+    fn yaw_pitch_round_trip() {
+        for _ in 0..=100 {
+            let d = (Vec3::new(random(), random(), random()) * 2.0 - 1.0).normalized();
+
+            let (yaw, pitch) = to_yaw_and_pitch(d);
+            let d_new = from_yaw_and_pitch(yaw, pitch);
+
+            assert_relative_eq!(d, d_new, epsilon = f64::EPSILON * 100.0);
+        }
+    }
+
+    #[test]
+    fn ray_box_edge_cases() {
+        let bb = Aabb {
+            min: Vec3::new(0.0, 0.0, 0.0),
+            max: Vec3::new(1.0, 1.0, 1.0),
+        };
+
+        let ros = [
+            // On a corner
+            Vec3::new(0.0, 0.0, 0.0),
+            // Outside
+            Vec3::new(-0.5, 0.5, -0.5),
+            // In the center
+            Vec3::new(0.5, 0.5, 0.5),
+            // On an edge
+            Vec3::new(0.0, 0.5, 0.0),
+            // On a face
+            Vec3::new(0.0, 0.5, 0.5),
+            // Outside slabs
+            Vec3::new(-2.0, -2.0, -2.0),
+        ];
+
+        let rds = [
+            Vec3::new(1.0, 0.0, 0.0),
+            Vec3::new(-1.0, 0.0, 0.0),
+            Vec3::new(0.0, 1.0, 0.0),
+            Vec3::new(0.0, -1.0, 0.0),
+            Vec3::new(0.0, 0.0, 1.0),
+            Vec3::new(0.0, 0.0, -1.0),
+        ];
+
+        assert!(rds.iter().all(|d| d.is_normalized()));
+
+        for ro in ros {
+            for rd in rds {
+                if let Some((near, far)) = ray_box_intersect(ro, rd, bb) {
+                    assert!(near.is_finite());
+                    assert!(far.is_finite());
+                    assert!(near <= far);
+                    assert!(near >= 0.0);
+                    assert!(far >= 0.0);
+                }
+            }
+        }
+    }
+}