wip: started implementing terrain system

Cargo.lock

@@ -2061,6 +2061,7 @@ dependencies = [
  "bevy",
  "bevy-inspector-egui",
  "bevy_rapier2d",
+ "lazy_static",
 ]
 
 [[package]]

Cargo.toml

@@ -9,6 +9,7 @@ edition = "2021"
 bevy = { version = "0.9.0", features = ["dynamic"] }
 bevy-inspector-egui = "0.14.0"
 bevy_rapier2d = { path = "../bevy_rapier/bevy_rapier2d" }
+lazy_static = "1.4.0"
 
 # Enable a small amount of optimization in debug mode
 [profile.dev]

src/game.rs

@@ -16,12 +16,12 @@ pub fn init() {
         .add_plugin(WorldInspectorPlugin::new())
         .add_plugin(KinematicPlugin)
         .add_plugin(GameCameraPlugin)
-        .add_plugin(PlayerPlugin)
-        .add_startup_system(setup)
+        // .add_plugin(PlayerPlugin)
+        // .add_startup_system(setup_debug_ground)
         .run();
 }
 
-fn setup(mut commands: Commands) {
+fn setup_debug_ground(mut commands: Commands) {
     // Static ground
     commands
         .spawn(())

src/game/camera.rs

@@ -37,10 +37,10 @@ fn camera_setup(mut commands: Commands) {
     commands.spawn((
         Name::new("Camera"),
         Camera2dBundle {
-            projection: OrthographicProjection {
-                scaling_mode: ScalingMode::FixedHorizontal(320.0),
-                ..default()
-            },
+            // projection: OrthographicProjection {
+            //     scaling_mode: ScalingMode::FixedHorizontal(320.0),
+            //     ..default()
+            // },
             ..default()
         },
     ));

src/game/kinematic.rs

@@ -27,7 +27,6 @@ pub struct KinematicBundle {
     pub events: ActiveEvents,
     pub collisions: ActiveCollisionTypes,
     pub properties: KinematicProperties,
-    #[bundle]
     pub transform: TransformBundle,
 }
 
@@ -71,10 +70,7 @@ impl KinematicState {
     }
 
     pub fn can_jump(&self) -> bool {
-        if self.on_ground && !self.did_jump {
-            return true;
-        }
-        false
+        self.on_ground && !self.did_jump
     }
 }
 

src/game/player.rs

@@ -43,7 +43,7 @@ pub fn player_system(
     };
 
     kinematic_input.movement = movement;
-    kinematic_input.want_jump = input.pressed(KeyCode::Space)
+    kinematic_input.want_jump = input.just_pressed(KeyCode::Space)
 }
 
 fn input_to_axis(negative: bool, positive: bool) -> f32 {

src/main.rs

@@ -1,4 +1,5 @@
 pub mod game;
+pub mod terrain2d;
 pub mod util;
 
 fn main() {

src/mst/world.rs

@@ -1,51 +0,0 @@
-use box2d_rs::{
-    b2_body::BodyPtr,
-    b2_math::B2vec2,
-    b2_world::{B2world, B2worldPtr},
-    b2rs_common::UserDataType,
-};
-use unsafe_send_sync::UnsafeSendSync;
-
-pub type UnsafeBox2D = UnsafeSendSync<Box2D>;
-pub type UnsafeBody = UnsafeSendSync<BodyPtr<UserData>>;
-
-#[derive(Clone, Copy, Default)]
-pub struct UserData;
-impl UserDataType for UserData {
-    type Body = Option<u32>;
-    type Fixture = u32;
-    type Joint = ();
-}
-
-pub struct Box2D {
-    pub gravity: B2vec2,
-    pub world_ptr: B2worldPtr<UserData>,
-}
-
-impl Box2D {
-    pub const METERS_TO_TEXELS: f32 = 4.0;
-    pub const TEXELS_TO_METERS: f32 = 1.0 / Self::METERS_TO_TEXELS;
-    pub const INIT_POS: B2vec2 = B2vec2 {
-        x: -1000.0,
-        y: -1000.0,
-    };
-
-    fn new() -> Box2D {
-        let gravity: B2vec2 = B2vec2 { x: 0.0, y: 100.0 };
-        // let gravity: B2vec2 = B2vec2 { x: 0.0, y: 1.0 };
-        // let gravity: B2vec2 = B2vec2 { x: 0.0, y: 0.0 };
-        let world_ptr: B2worldPtr<UserData> = B2world::new(gravity);
-
-        Box2D { gravity, world_ptr }
-    }
-
-    pub fn new_unsafe() -> UnsafeBox2D {
-        UnsafeBox2D::new(Self::new())
-    }
-}
-
-impl Default for Box2D {
-    fn default() -> Self {
-        Self::new()
-    }
-}

src/terrain2d.rs

@@ -0,0 +1,155 @@
+use std::collections::{
+    hash_map::{Iter, IterMut},
+    HashMap,
+};
+
+use bevy::prelude::*;
+
+mod chunk2d;
+mod texel2d;
+
+pub use chunk2d::*;
+pub use texel2d::*;
+
+use crate::util::{math::*, Vector2I};
+
+pub struct Terrain2DPlugin;
+
+impl Plugin for Terrain2DPlugin {
+    fn build(&self, app: &mut App) {
+        app.insert_resource(Terrain2D::new())
+            .add_system(emit_terrain_events);
+    }
+}
+
+fn emit_terrain_events(
+    mut terrain: ResMut<Terrain2D>,
+    mut terrain_events: EventWriter<TerrainEvent>,
+) {
+    for event in terrain.events.drain(..) {
+        terrain_events.send(event)
+    }
+    for (chunk_index, mut chunk) in terrain.chunk_iter_mut() {
+        if let Some(rect) = &chunk.dirty_rect {
+            terrain_events.send(TerrainEvent::TexelsUpdated(*chunk_index, *rect));
+            chunk.dirty_rect = None;
+        }
+    }
+}
+
+pub enum TerrainEvent {
+    ChunkAdded(ChunkIndex),
+    ChunkRemoved(ChunkIndex),
+    TexelsUpdated(ChunkIndex, ChunkRect),
+}
+
+#[derive(Default, Resource)]
+pub struct Terrain2D {
+    chunk_map: HashMap<ChunkIndex, Chunk>,
+    events: Vec<TerrainEvent>,
+}
+
+impl Terrain2D {
+    pub fn new() -> Terrain2D {
+        Terrain2D {
+            chunk_map: HashMap::new(),
+            events: Vec::new(),
+        }
+    }
+
+    pub fn add_chunk(&mut self, index: ChunkIndex, chunk: Chunk) {
+        self.chunk_map.insert(index, chunk);
+        self.events.push(TerrainEvent::ChunkAdded(index))
+    }
+
+    pub fn remove_chunk(&mut self, index: ChunkIndex) {
+        self.events.push(TerrainEvent::ChunkRemoved(index));
+        self.chunk_map.remove(&index);
+    }
+
+    pub fn chunk_iter(&self) -> Iter<ChunkIndex, Chunk> {
+        self.chunk_map.iter()
+    }
+
+    pub fn chunk_iter_mut(&mut self) -> IterMut<ChunkIndex, Chunk> {
+        self.chunk_map.iter_mut()
+    }
+
+    pub fn index_to_chunk(&self, index: &ChunkIndex) -> Option<&Chunk> {
+        self.chunk_map.get(index)
+    }
+
+    pub fn index_to_chunk_mut(&mut self, index: &ChunkIndex) -> Option<&mut Chunk> {
+        self.chunk_map.get_mut(index)
+    }
+
+    pub fn global_to_chunk(&self, global: &Vector2I) -> Option<&Chunk> {
+        self.index_to_chunk(&global_to_chunk_index(global))
+    }
+
+    pub fn global_to_chunk_mut(&mut self, global: &Vector2I) -> Option<&mut Chunk> {
+        self.index_to_chunk_mut(&global_to_chunk_index(global))
+    }
+
+    pub fn global_to_texel(&self, global: &Vector2I) -> Option<Texel> {
+        match self.global_to_chunk(global) {
+            Some(chunk) => chunk.get_texel(&global_to_local(global)),
+            None => None,
+        }
+    }
+
+    pub fn global_to_texel_mut(&mut self, global: &Vector2I) -> Option<Texel> {
+        match self.global_to_chunk(global) {
+            Some(chunk) => chunk.get_texel(&global_to_local(global)),
+            None => None,
+        }
+    }
+
+    pub fn set_texel(&mut self, global: &Vector2I, id: TexelID) {
+        let index = global_to_chunk_index(global);
+        match self.index_to_chunk_mut(&index) {
+            Some(chunk) => chunk.set_texel(&global_to_local(global), id),
+            None => {
+                let mut chunk = Chunk::new();
+                chunk.set_texel(&global_to_local(global), id);
+                self.add_chunk(index, chunk);
+            }
+        }
+    }
+}
+
+pub fn local_to_texel_index(position: &Vector2I) -> Option<usize> {
+    match position.x >= 0
+        && position.y >= 0
+        && position.x < Chunk::SIZE.x
+        && position.y < Chunk::SIZE.y
+    {
+        true => Some(position.y as usize * Chunk::SIZE_X + position.x as usize),
+        false => None,
+    }
+}
+
+pub fn texel_index_to_local(i: usize) -> Vector2I {
+    Vector2I {
+        x: i as i32 % Chunk::SIZE.x,
+        y: i as i32 / Chunk::SIZE.y,
+    }
+}
+
+pub fn global_to_local(position: &Vector2I) -> Vector2I {
+    Vector2I {
+        x: wrapping_remainder(position.x, Chunk::SIZE.x),
+        y: wrapping_remainder(position.y, Chunk::SIZE.y),
+    }
+}
+
+pub fn global_to_chunk_index(position: &Vector2I) -> ChunkIndex {
+    Vector2I {
+        x: wrapping_quotient(position.x, Chunk::SIZE.x),
+        y: wrapping_quotient(position.y, Chunk::SIZE.y),
+    }
+}
+
+pub fn chunk_index_to_global(chunk_pos: &ChunkIndex) -> Vector2I {
+    *chunk_pos * Chunk::SIZE
+}

src/terrain2d/chunk2d.rs

@@ -0,0 +1,94 @@
+use super::{local_to_texel_index, Texel, TexelID, NEIGHBOUR_INDEX_MAP};
+use crate::util::Vector2I;
+
+pub type ChunkIndex = Vector2I;
+
+#[derive(Clone, Copy)]
+pub struct ChunkRect {
+    pub min: Vector2I,
+    pub max: Vector2I,
+}
+
+pub struct Chunk {
+    pub texels: [Texel; (Self::SIZE_X * Self::SIZE_Y) as usize],
+    // TODO: handle multiple dirty rects
+    pub dirty_rect: Option<ChunkRect>,
+}
+
+impl Chunk {
+    pub const SIZE_X: usize = 64;
+    pub const SIZE_Y: usize = 64;
+    pub const SIZE: Vector2I = Vector2I {
+        x: Self::SIZE_X as i32,
+        y: Self::SIZE_Y as i32,
+    };
+
+    pub fn new() -> Chunk {
+        Chunk {
+            texels: Self::new_texel_array(),
+            dirty_rect: None,
+        }
+    }
+
+    pub fn new_texel_array() -> [Texel; Self::SIZE_X * Self::SIZE_Y] {
+        [Texel::default(); Self::SIZE_X * Self::SIZE_Y]
+    }
+
+    pub fn mark_all_dirty(&mut self) {
+        self.dirty_rect = Some(ChunkRect {
+            min: Vector2I::ZERO,
+            max: Self::SIZE,
+        });
+    }
+
+    pub fn mark_dirty(&mut self, position: &Vector2I) {
+        match &self.dirty_rect {
+            Some(rect) => {
+                self.dirty_rect = Some(ChunkRect {
+                    min: Vector2I::min(&rect.min, position),
+                    max: Vector2I::max(&rect.max, position),
+                })
+            }
+            None => {
+                self.dirty_rect = Some(ChunkRect {
+                    min: *position,
+                    max: *position,
+                })
+            }
+        }
+    }
+
+    pub fn get_texel(&self, position: &Vector2I) -> Option<Texel> {
+        local_to_texel_index(position).map(|i| self.texels[i])
+    }
+
+    pub fn get_texel_option_mut(&mut self, position: &Vector2I) -> Option<&mut Texel> {
+        local_to_texel_index(position).map(|i| &mut self.texels[i])
+    }
+
+    pub fn set_texel(&mut self, position: &Vector2I, id: TexelID) {
+        let i = local_to_texel_index(position).expect("Texel index out of range");
+        if self.texels[i].id != id {
+            self.mark_dirty(position);
+        }
+        let update_neighbours = self.texels[i].is_empty()
+            != (Texel {
+                id,
+                ..self.texels[i]
+            })
+            .is_empty();
+        self.texels[i].id = id;
+        // Update neighbour mask
+        if update_neighbours {
+            for offset in Texel::NEIGHBOUR_OFFSET_VECTORS {
+                // Flip neighbour's bit
+                match self.get_texel_option_mut(&(*position + offset)) {
+                    Some(mut neighbour) => {
+                        neighbour.neighbour_mask ^= 1 << NEIGHBOUR_INDEX_MAP[&-offset];
+                    }
+                    None => (),
+                }
+            }
+        }
+    }
+}

src/terrain2d/texel2d.rs

@@ -0,0 +1,38 @@
+use lazy_static::lazy_static;
+use std::collections::HashMap;
+
+pub use u8 as TexelID;
+pub use u8 as NeighbourMask;
+
+use crate::util::Vector2I;
+
+#[derive(Clone, Copy, Default)]
+pub struct Texel {
+    pub id: TexelID,
+    /// bitmask of empty/non-empty neighbours, see NEIGHBOUR_OFFSET_VECTORS for the order
+    pub neighbour_mask: NeighbourMask,
+}
+
+lazy_static! {
+    pub static ref NEIGHBOUR_INDEX_MAP: HashMap<Vector2I, u8> = {
+        let mut map = HashMap::new();
+        for i in 0..Texel::NEIGHBOUR_OFFSET_VECTORS.len() {
+            map.insert(Texel::NEIGHBOUR_OFFSET_VECTORS[i], i as u8);
+        }
+        map
+    };
+}
+
+impl Texel {
+    pub const EMPTY: TexelID = 0;
+    pub const NEIGHBOUR_OFFSET_VECTORS: [Vector2I; 4] = [
+        Vector2I { x: 0, y: 1 },
+        Vector2I { x: 1, y: 0 },
+        Vector2I { x: 0, y: -1 },
+        Vector2I { x: -1, y: 0 },
+    ];
+
+    pub fn is_empty(&self) -> bool {
+        self.id == 0
+    }
+}

src/util.rs

@@ -1,5 +1,12 @@
 use bevy::prelude::*;
 
+pub mod math;
+mod vector2;
+mod vector2_i32;
+
+pub use vector2::*;
+pub use vector2_i32::*;
+
 pub fn lerp(a: f32, b: f32, t: f32) -> f32 {
     a * (1.0 - t) + b * t
 }

src/util/math.rs

@@ -0,0 +1,25 @@
+pub fn lerp(a: f32, b: f32, t: f32) -> f32 {
+    a * (1.0 - t) + b * t
+}
+
+/// Calculate quotient, but take into account negative values so that they continue the cycle seamlessly.
+/// e.g. (0, 4) -> 0, (-4, 4) -> -1, (-5, 4) -> -2
+pub fn wrapping_quotient(dividend: i32, divisor: i32) -> i32 {
+    let res = (if dividend < 0 { dividend + 1 } else { dividend }) / divisor;
+    if dividend < 0 {
+        res - 1
+    } else {
+        res
+    }
+}
+
+/// Calculate remainder, but take into account negative values so that they continue the cycle seamlessly.
+/// e.g. (0, 4) -> 0, (-4, 4) -> 0, (-5, 4) -> 3
+pub fn wrapping_remainder(dividend: i32, divisor: i32) -> i32 {
+    let res = dividend % divisor;
+    if dividend < 0 {
+        (divisor + res) % divisor
+    } else {
+        res
+    }
+}

src/util/vector2.rs

@@ -0,0 +1,122 @@
+use core::{fmt, ops};
+
+pub trait VectorComponent:
+    Sized
+    + Copy
+    + Ord
+    + fmt::Display
+    + ops::Add<Output = Self>
+    + ops::Neg<Output = Self>
+    + ops::Sub<Output = Self>
+    + ops::Mul<Output = Self>
+    + ops::Div<Output = Self>
+{
+}
+
+impl<T> VectorComponent for T where
+    T: Sized
+        + Copy
+        + Ord
+        + fmt::Display
+        + ops::Neg<Output = T>
+        + ops::Add<Output = T>
+        + ops::Sub<Output = T>
+        + ops::Mul<Output = T>
+        + ops::Div<Output = T>
+{
+}
+
+#[derive(PartialEq, Eq, Hash, Clone, Copy, Default, Debug)]
+pub struct Vector2<T: VectorComponent> {
+    pub x: T,
+    pub y: T,
+}
+
+impl<T: VectorComponent> Vector2<T> {
+    pub fn min(&self, other: &Vector2<T>) -> Vector2<T> {
+        Vector2 {
+            x: Ord::min(self.x, other.x),
+            y: Ord::min(self.y, other.y),
+        }
+    }
+
+    pub fn max(&self, other: &Vector2<T>) -> Vector2<T> {
+        Vector2 {
+            x: Ord::max(self.x, other.x),
+            y: Ord::max(self.y, other.y),
+        }
+    }
+}
+
+impl<T: VectorComponent> fmt::Display for Vector2<T> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "({}, {})", self.x, self.y)
+    }
+}
+
+impl<T: VectorComponent> ops::Add<Vector2<T>> for Vector2<T> {
+    type Output = Vector2<T>;
+    fn add(self, rhs: Vector2<T>) -> Self::Output {
+        Vector2 {
+            x: self.x + rhs.x,
+            y: self.y + rhs.y,
+        }
+    }
+}
+
+impl<T: VectorComponent> ops::Neg for Vector2<T> {
+    type Output = Vector2<T>;
+    fn neg(self) -> Self::Output {
+        Vector2 {
+            x: -self.x,
+            y: -self.y,
+        }
+    }
+}
+
+impl<T: VectorComponent> ops::Sub<Vector2<T>> for Vector2<T> {
+    type Output = Vector2<T>;
+    fn sub(self, rhs: Vector2<T>) -> Self::Output {
+        self + (-rhs)
+    }
+}
+
+impl<T: VectorComponent> ops::Mul<Vector2<T>> for Vector2<T> {
+    type Output = Vector2<T>;
+    fn mul(self, rhs: Vector2<T>) -> Self::Output {
+        Vector2 {
+            x: self.x * rhs.x,
+            y: self.y * rhs.y,
+        }
+    }
+}
+
+impl<T: VectorComponent> ops::Mul<T> for Vector2<T> {
+    type Output = Vector2<T>;
+    fn mul(self, rhs: T) -> Self::Output {
+        Vector2 {
+            x: self.x * rhs,
+            y: self.y * rhs,
+        }
+    }
+}
+
+impl<T: VectorComponent> ops::Div<Vector2<T>> for Vector2<T> {
+    type Output = Vector2<T>;
+    fn div(self, rhs: Vector2<T>) -> Self::Output {
+        Vector2 {
+            x: self.x / rhs.x,
+            y: self.y / rhs.y,
+        }
+    }
+}
+
+impl<T: VectorComponent> ops::Div<T> for Vector2<T> {
+    type Output = Vector2<T>;
+    fn div(self, rhs: T) -> Self::Output {
+        Vector2 {
+            x: self.x / rhs,
+            y: self.y / rhs,
+        }
+    }
+}

src/util/vector2_i32.rs

@@ -0,0 +1,27 @@
+use bevy::prelude::Vec2;
+
+use super::Vector2;
+
+pub type Vector2I = Vector2<i32>;
+
+impl Vector2I {
+    pub const ZERO: Vector2I = Vector2I { x: 0, y: 0 };
+    pub const ONE: Vector2I = Vector2I { x: 1, y: 1 };
+    pub const UP: Vector2I = Vector2I { x: 0, y: 1 };
+    pub const DOWN: Vector2I = Vector2I { x: 0, y: -1 };
+    pub const LEFT: Vector2I = Vector2I { x: -1, y: 0 };
+    pub const RIGHT: Vector2I = Vector2I { x: 1, y: 0 };
+
+    pub fn angle(&self) -> f32 {
+        (self.y as f32).atan2(self.x as f32)
+    }
+}
+
+impl From<Vector2I> for Vec2 {
+    fn from(vec: Vector2I) -> Self {
+        Vec2 {
+            x: vec.x as f32,
+            y: vec.y as f32,
+        }
+    }
+}