heightmaps

azalea-client/src/packet_handling.rs

@@ -9,6 +9,7 @@ use azalea_entity::{
     Dead, EntityBundle, EntityKind, EntityUpdateSet, LastSentPosition, LoadedBy, LookDirection,
     Physics, PlayerBundle, Position, RelativeEntityUpdate,
 };
+use azalea_nbt::NbtCompound;
 use azalea_protocol::{
     connect::{ReadConnection, WriteConnection},
     packets::game::{
@@ -578,9 +579,20 @@ pub fn process_packet_events(ecs: &mut World) {
                     }
                 }
 
+                let heightmaps = p
+                    .chunk_data
+                    .heightmaps
+                    .as_compound()
+                    .and_then(|c| c.get(""))
+                    .and_then(|c| c.as_compound());
+                // necessary to make the unwrap_or work
+                let empty_nbt_compound = NbtCompound::default();
+                let heightmaps = heightmaps.unwrap_or(&empty_nbt_compound);
+
                 if let Err(e) = partial_world.chunks.replace_with_packet_data(
                     &pos,
                     &mut Cursor::new(&p.chunk_data.data),
+                    heightmaps,
                     &mut world.chunks,
                 ) {
                     error!("Couldn't set chunk data: {}", e);
@@ -632,6 +644,7 @@ pub fn process_packet_events(ecs: &mut World) {
             ClientboundGamePacket::SetEntityData(p) => {
                 debug!("Got set entity data packet {:?}", p);
 
+                #[allow(clippy::type_complexity)]
                 let mut system_state: SystemState<(
                     Commands,
                     Query<(&EntityIdIndex, &LocalPlayer)>,

azalea-core/src/math.rs

@@ -9,17 +9,17 @@ pub static SIN: LazyLock<[f32; 65536]> = LazyLock::new(|| {
 });
 
 /// A sine function that uses a lookup table.
-pub fn sin(var0: f32) -> f32 {
-    let var0 = var0 * 10430.378;
-    let var0 = var0 as usize;
-    SIN[var0 & 65535]
+pub fn sin(x: f32) -> f32 {
+    let x = x * 10430.378;
+    let x = x as usize;
+    SIN[x & 65535]
 }
 
 /// A cosine function that uses a lookup table.
-pub fn cos(var0: f32) -> f32 {
-    let var0 = var0 * 10430.378 + 16384.0;
-    let var0 = var0 as usize;
-    SIN[var0 & 65535]
+pub fn cos(x: f32) -> f32 {
+    let x = x * 10430.378 + 16384.0;
+    let x = x as usize;
+    SIN[x & 65535]
 }
 
 // TODO: make this generic
@@ -56,6 +56,10 @@ pub fn lerp<T: num_traits::Float>(amount: T, a: T, b: T) -> T {
     a + amount * (b - a)
 }
 
+pub fn ceil_log2(x: u32) -> u32 {
+    u32::BITS - x.leading_zeros()
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

azalea-core/src/position.rs

@@ -346,6 +346,17 @@ impl From<Vec3> for ChunkPos {
     }
 }
 
+impl From<&Vec3> for ChunkBlockPos {
+    fn from(pos: &Vec3) -> Self {
+        ChunkBlockPos::from(&BlockPos::from(pos))
+    }
+}
+impl From<Vec3> for ChunkBlockPos {
+    fn from(pos: Vec3) -> Self {
+        ChunkBlockPos::from(&pos)
+    }
+}
+
 const PACKED_X_LENGTH: u64 = 1 + 25; // minecraft does something a bit more complicated to get this 25
 const PACKED_Z_LENGTH: u64 = PACKED_X_LENGTH;
 const PACKED_Y_LENGTH: u64 = 64 - PACKED_X_LENGTH - PACKED_Z_LENGTH;

azalea-protocol/src/packets/game/clientbound_level_chunk_with_light_packet.rs

@@ -27,3 +27,34 @@ pub struct BlockEntity {
     pub kind: azalea_registry::BlockEntityKind,
     pub data: Nbt,
 }
+
+// Compound(NbtCompound {
+//     inner: [("", Compound(NbtCompound {
+//         inner: [
+//         ("MOTION_BLOCKING", LongArray([2310355422147575936,
+// 2292305770412047999, 2310355422147575423, 2292305770412310656,
+// 2310355422013095551, 2292305839266005120, 2310320168921529983,
+// 2310355422147575936, 2292305770412048512, 2310355422147575935,
+// 2292305839266005120, 2310355422147313279, 2292305770546528384,
+// 2310355353293618815, 2292305839266005120, 2292305770412047999,
+// 2310355422147575936, 2292305770412047999, 2310355422147575423,
+// 2292305770412048512, 2292305770412047999, 2292305770412047999,
+// 2292305770412047999, 2292305770412047999, 2292305770412047999,
+// 2292305770412047999, 2292305770412047999, 2292305770412047999,
+// 2292305770412047999, 2292305770412047999, 2292305770412047999,
+// 2292305770412047999, 2292305770412047999, 2292305770412047999,
+// 2292305770412047999, 2292305770412047999, 17079008895])),
+//         ("WORLD_SURFACE", LongArray([2310355422147575936,
+// 2292340954784136831, 2310355422147575423, 2292305770412310656,
+// 2310355422013095551, 2292305839266005120, 2310320168921529983,
+// 2310355422147575936, 2292305770412048512, 2310355422147575935,
+// 2292305839266005120, 2310355422147313279, 2292305770546528384,
+// 2310355353293618815, 2292305839266005120, 2292305770412047999,
+// 2310355422147575936, 2292305770412047999, 2310355422147575423,
+// 2292305770412048512, 2292305770412047999, 2292305770412047999,
+// 2292305770412047999, 2292305770412047999, 2292305770412047999,
+// 2292305770412047999, 2292305770412047999, 2292305770412047999,
+// 2292305770412047999, 2292305770412047999, 2292305770412047999,
+// 2292305770412047999, 2292305770412047999, 2292305770412047999,
+// 2292305770412047999, 2292305770412047999, 17079008895]))]     }))]
+// })

azalea-world/src/bit_storage.rs

@@ -106,7 +106,7 @@ impl BitStorage {
             // 0 bit storage
             if data.is_empty() {
                 return Ok(BitStorage {
-                    data: Vec::with_capacity(0),
+                    data: Vec::new(),
                     bits,
                     size,
                     ..Default::default()

azalea-world/src/chunk_storage.rs

@@ -1,10 +1,14 @@
+use crate::heightmap::Heightmap;
+use crate::heightmap::HeightmapKind;
 use crate::palette::PalettedContainer;
 use crate::palette::PalettedContainerKind;
 use azalea_block::BlockState;
 use azalea_buf::{BufReadError, McBufReadable, McBufWritable};
 use azalea_core::{BlockPos, ChunkBlockPos, ChunkPos, ChunkSectionBlockPos};
+use azalea_nbt::NbtCompound;
 use log::{debug, trace, warn};
 use parking_lot::RwLock;
+use std::str::FromStr;
 use std::{
     collections::HashMap,
     fmt::Debug,
@@ -43,6 +47,10 @@ pub struct ChunkStorage {
 #[derive(Debug)]
 pub struct Chunk {
     pub sections: Vec<Section>,
+    /// Heightmaps are used for identifying the surface blocks in a chunk.
+    /// Usually for clients only `WorldSurface` and `MotionBlocking` are
+    /// present.
+    pub heightmaps: HashMap<HeightmapKind, Heightmap>,
 }
 
 /// A section of a chunk, i.e. a 16*16*16 block area.
@@ -73,6 +81,7 @@ impl Default for Chunk {
     fn default() -> Self {
         Chunk {
             sections: vec![Section::default(); (384 / 16) as usize],
+            heightmaps: HashMap::new(),
         }
     }
 }
@@ -119,6 +128,7 @@ impl PartialChunkStorage {
         &mut self,
         pos: &ChunkPos,
         data: &mut Cursor<&[u8]>,
+        heightmaps: &NbtCompound,
         chunk_storage: &mut ChunkStorage,
     ) -> Result<(), BufReadError> {
         debug!("Replacing chunk at {:?}", pos);
@@ -127,7 +137,12 @@ impl PartialChunkStorage {
             return Ok(());
         }
 
-        let chunk = Chunk::read_with_dimension_height(data, chunk_storage.height)?;
+        let chunk = Chunk::read_with_dimension_height(
+            data,
+            chunk_storage.height,
+            chunk_storage.min_y,
+            heightmaps,
+        )?;
 
         trace!("Loaded chunk {:?}", pos);
         self.set(pos, Some(chunk), chunk_storage);
@@ -229,6 +244,8 @@ impl Chunk {
     pub fn read_with_dimension_height(
         buf: &mut Cursor<&[u8]>,
         dimension_height: u32,
+        min_y: i32,
+        heightmaps_nbt: &NbtCompound,
     ) -> Result<Self, BufReadError> {
         let section_count = dimension_height / SECTION_HEIGHT;
         let mut sections = Vec::with_capacity(section_count as usize);
@@ -236,23 +253,30 @@ impl Chunk {
             let section = Section::read_from(buf)?;
             sections.push(section);
         }
-        Ok(Chunk { sections })
+
+        let mut heightmaps = HashMap::new();
+        for (name, heightmap) in heightmaps_nbt.iter() {
+            let Ok(kind) = HeightmapKind::from_str(name) else {
+                warn!("Unknown heightmap kind: {name}");
+                continue;
+            };
+            let Some(data) = heightmap.as_long_array() else {
+                warn!("Heightmap {name} is not a long array");
+                continue;
+            };
+            let data: Vec<u64> = data.iter().map(|x| *x as u64).collect();
+            let heightmap = Heightmap::new(kind, dimension_height, min_y, data);
+            heightmaps.insert(kind, heightmap);
+        }
+
+        Ok(Chunk {
+            sections,
+            heightmaps,
+        })
     }
 
     pub fn get(&self, pos: &ChunkBlockPos, min_y: i32) -> Option<BlockState> {
-        if pos.y < min_y {
-            // y position is out of bounds
-            return None;
-        }
-        let section_index = section_index(pos.y, min_y) as usize;
-        if section_index >= self.sections.len() {
-            // y position is out of bounds
-            return None;
-        };
-        // TODO: make sure the section exists
-        let section = &self.sections[section_index];
-        let chunk_section_pos = ChunkSectionBlockPos::from(pos);
-        Some(section.get(chunk_section_pos))
+        get_block_state_from_sections(&self.sections, pos, min_y)
     }
 
     pub fn get_and_set(
@@ -265,7 +289,13 @@ impl Chunk {
         // TODO: make sure the section exists
         let section = &mut self.sections[section_index as usize];
         let chunk_section_pos = ChunkSectionBlockPos::from(pos);
-        section.get_and_set(chunk_section_pos, state)
+        let previous_state = section.get_and_set(chunk_section_pos, state);
+
+        for heightmap in self.heightmaps.values_mut() {
+            heightmap.update(pos, state, &self.sections);
+        }
+
+        previous_state
     }
 
     pub fn set(&mut self, pos: &ChunkBlockPos, state: BlockState, min_y: i32) {
@@ -274,7 +304,33 @@ impl Chunk {
         let section = &mut self.sections[section_index as usize];
         let chunk_section_pos = ChunkSectionBlockPos::from(pos);
         section.set(chunk_section_pos, state);
+
+        for heightmap in self.heightmaps.values_mut() {
+            heightmap.update(pos, state, &self.sections);
         }
+    }
+}
+
+/// Get the block state at the given position from a list of sections. Returns
+/// `None` if the position is out of bounds.
+pub fn get_block_state_from_sections(
+    sections: &[Section],
+    pos: &ChunkBlockPos,
+    min_y: i32,
+) -> Option<BlockState> {
+    if pos.y < min_y {
+        // y position is out of bounds
+        return None;
+    }
+    let section_index = section_index(pos.y, min_y) as usize;
+    if section_index >= sections.len() {
+        // y position is out of bounds
+        return None;
+    };
+    // TODO: make sure the section exists
+    let section = &sections[section_index];
+    let chunk_section_pos = ChunkSectionBlockPos::from(pos);
+    Some(section.get(chunk_section_pos))
 }
 
 impl McBufWritable for Chunk {

azalea-world/src/heightmap.rs

@@ -0,0 +1,151 @@
+use std::{fmt::Display, str::FromStr};
+
+use azalea_block::BlockState;
+use azalea_core::{math, ChunkBlockPos};
+use azalea_registry::tags::blocks::LEAVES;
+
+use crate::{chunk_storage::get_block_state_from_sections, BitStorage, Section};
+
+// (wg stands for worldgen)
+
+#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
+pub enum HeightmapKind {
+    WorldSurfaceWg,
+    WorldSurface,
+    OceanFloorWg,
+    OceanFloor,
+    MotionBlocking,
+    MotionBlockingNoLeaves,
+}
+
+#[derive(Clone, Debug)]
+pub struct Heightmap {
+    pub data: BitStorage,
+    pub min_y: i32,
+    pub kind: HeightmapKind,
+}
+
+fn blocks_motion(block_state: BlockState) -> bool {
+    // TODO
+    !block_state.is_air()
+}
+
+fn motion_blocking(block_state: BlockState) -> bool {
+    // TODO
+    !block_state.is_air() || block_state.waterlogged()
+}
+
+impl HeightmapKind {
+    pub fn is_opaque(self, block_state: BlockState) -> bool {
+        let block = Box::<dyn azalea_block::Block>::from(block_state);
+        let registry_block = block.as_registry_block();
+        match self {
+            HeightmapKind::WorldSurfaceWg => !block_state.is_air(),
+            HeightmapKind::WorldSurface => !block_state.is_air(),
+            HeightmapKind::OceanFloorWg => blocks_motion(block_state),
+            HeightmapKind::OceanFloor => blocks_motion(block_state),
+            HeightmapKind::MotionBlocking => motion_blocking(block_state),
+            HeightmapKind::MotionBlockingNoLeaves => {
+                motion_blocking(block_state) && !LEAVES.contains(&registry_block)
+            }
+        }
+    }
+}
+
+impl Heightmap {
+    pub fn new(kind: HeightmapKind, dimension_height: u32, min_y: i32, data: Vec<u64>) -> Self {
+        let bits = math::ceil_log2(dimension_height + 1);
+        let data = BitStorage::new(bits as usize, 16 * 16, Some(data)).unwrap();
+        Self { kind, data, min_y }
+    }
+
+    pub fn get_index(x: u8, z: u8) -> usize {
+        (x as usize) + (z as usize) * 16
+    }
+
+    pub fn get_first_available_at_index(&self, index: usize) -> i32 {
+        self.data.get(index) as i32 + self.min_y
+    }
+
+    pub fn get_first_available(&self, x: u8, z: u8) -> i32 {
+        self.get_first_available_at_index(Self::get_index(x, z))
+    }
+
+    pub fn get_highest_taken(&self, x: u8, z: u8) -> i32 {
+        self.get_first_available(x, z) - 1
+    }
+
+    pub fn set_height(&mut self, x: u8, z: u8, height: i32) {
+        self.data
+            .set(Self::get_index(x, z), (height - self.min_y) as u64);
+    }
+
+    /// Updates the heightmap with the given block state at the given position.
+    pub fn update(
+        &mut self,
+        pos: &ChunkBlockPos,
+        block_state: BlockState,
+        sections: &[Section],
+    ) -> bool {
+        let first_available_y = self.get_first_available(pos.x, pos.z);
+        if pos.y <= first_available_y - 2 {
+            return false;
+        }
+        if self.kind.is_opaque(block_state) {
+            // increase y
+            if pos.y >= first_available_y {
+                self.set_height(pos.x, pos.z, pos.y + 1);
+                return true;
+            }
+        } else if first_available_y - 1 == pos.y {
+            // decrease y
+            for y in (self.min_y..pos.y).rev() {
+                if self.kind.is_opaque(
+                    get_block_state_from_sections(
+                        sections,
+                        &ChunkBlockPos::new(pos.x, y, pos.z),
+                        self.min_y,
+                    )
+                    .unwrap_or_default(),
+                ) {
+                    self.set_height(pos.x, pos.z, y + 1);
+                    return true;
+                }
+            }
+
+            self.set_height(pos.x, pos.z, self.min_y);
+            return true;
+        }
+
+        false
+    }
+}
+
+impl FromStr for HeightmapKind {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "WORLD_SURFACE_WG" => Ok(HeightmapKind::WorldSurfaceWg),
+            "WORLD_SURFACE" => Ok(HeightmapKind::WorldSurface),
+            "OCEAN_FLOOR_WG" => Ok(HeightmapKind::OceanFloorWg),
+            "OCEAN_FLOOR" => Ok(HeightmapKind::OceanFloor),
+            "MOTION_BLOCKING" => Ok(HeightmapKind::MotionBlocking),
+            "MOTION_BLOCKING_NO_LEAVES" => Ok(HeightmapKind::MotionBlockingNoLeaves),
+            _ => Err(()),
+        }
+    }
+}
+
+impl Display for HeightmapKind {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            HeightmapKind::WorldSurfaceWg => write!(f, "WORLD_SURFACE_WG"),
+            HeightmapKind::WorldSurface => write!(f, "WORLD_SURFACE"),
+            HeightmapKind::OceanFloorWg => write!(f, "OCEAN_FLOOR_WG"),
+            HeightmapKind::OceanFloor => write!(f, "OCEAN_FLOOR"),
+            HeightmapKind::MotionBlocking => write!(f, "MOTION_BLOCKING"),
+            HeightmapKind::MotionBlockingNoLeaves => write!(f, "MOTION_BLOCKING_NO_LEAVES"),
+        }
+    }
+}

azalea-world/src/lib.rs

@@ -5,6 +5,7 @@
 mod bit_storage;
 mod chunk_storage;
 mod container;
+pub mod heightmap;
 pub mod iterators;
 pub mod palette;
 mod world;

azalea/examples/testbot.rs

@@ -3,17 +3,18 @@
 #![feature(type_alias_impl_trait)]
 
 use azalea::ecs::query::With;
-use azalea::entity::metadata::Player;
-use azalea::entity::{EyeHeight, Position};
+use azalea::entity::{metadata::Player, EyeHeight, Position};
 use azalea::interact::HitResultComponent;
 use azalea::inventory::ItemSlot;
 use azalea::pathfinder::goals::BlockPosGoal;
 use azalea::protocol::packets::game::ClientboundGamePacket;
-use azalea::{prelude::*, swarm::prelude::*, BlockPos, GameProfileComponent, WalkDirection};
-use azalea::{Account, Client, Event};
-use azalea_client::SprintDirection;
-use azalea_core::Vec3;
-use azalea_world::{InstanceName, MinecraftEntityId};
+use azalea::world::{heightmap::HeightmapKind, InstanceName, MinecraftEntityId};
+use azalea::SprintDirection;
+use azalea::{prelude::*, swarm::prelude::*};
+use azalea::{
+    Account, BlockPos, ChunkPos, Client, Event, GameProfileComponent, Vec3, WalkDirection,
+};
+use azalea_core::ChunkBlockPos;
 use std::time::Duration;
 
 #[derive(Default, Clone, Component)]
@@ -288,6 +289,26 @@ async fn handle(mut bot: Client, event: Event, _state: State) -> anyhow::Result<
                         bot.chat("no entities found");
                     }
                 }
+                "heightmap" => {
+                    let position = bot.position();
+                    let chunk_pos = ChunkPos::from(position);
+                    let chunk_block_pos = ChunkBlockPos::from(position);
+                    let chunk = bot.world().read().chunks.get(&chunk_pos);
+                    if let Some(chunk) = chunk {
+                        let heightmaps = &chunk.read().heightmaps;
+                        let Some(world_surface_heightmap) =
+                            heightmaps.get(&HeightmapKind::WorldSurface)
+                        else {
+                            bot.chat("no world surface heightmap");
+                            return Ok(());
+                        };
+                        let highest_y = world_surface_heightmap
+                            .get_highest_taken(chunk_block_pos.x, chunk_block_pos.z);
+                        bot.chat(&format!("highest_y: {highest_y}",));
+                    } else {
+                        bot.chat("no chunk found");
+                    }
+                }
                 _ => {}
             }
         }

azalea/src/lib.rs

@@ -20,7 +20,7 @@ pub use azalea_block as blocks;
 pub use azalea_brigadier as brigadier;
 pub use azalea_chat::FormattedText;
 pub use azalea_client::*;
-pub use azalea_core::{BlockPos, Vec3};
+pub use azalea_core::{BlockPos, ChunkPos, Vec3};
 pub use azalea_entity as entity;
 pub use azalea_protocol as protocol;
 pub use azalea_registry::{Block, EntityKind, Item};