feat: simulation boundaries

src/game/camera.rs

@@ -77,7 +77,6 @@ fn camera_system(
         None => return,
     };
 
-    // let offset = Vec3::new(WORLD_WIDTH as f32 / 2.0, 0.0, 999.9);
     for (mut camera_transform, projection) in camera_query.iter_mut() {
         let left_limit = 0.0;
         let right_limit = WORLD_WIDTH as f32;
@@ -101,6 +100,7 @@ fn camera_system(
                 );
             }
         }
+        // horizontal boundaries
         let camera_x = camera_transform.translation.x;
         camera_transform.translation += Vec3::new(
             (left_limit - (projection.left * projection.scale + camera_x)).max(0.0),

src/game/debug/terrain.rs

@@ -7,7 +7,7 @@ pub struct TerrainDebugPlugin;
 impl Plugin for TerrainDebugPlugin {
     fn build(&self, app: &mut App) {
         app.insert_resource(TerrainBrush2D::default())
-            // .add_system_to_stage(TerrainStages::EventHandler, dirty_rect_visualizer)
+            .add_system_to_stage(TerrainStages::EventHandler, dirty_rect_visualizer)
             .add_system(debug_painter);
     }
 }

src/terrain2d.rs

@@ -17,7 +17,10 @@ pub use terrain_gen2d::*;
 pub use texel2d::*;
 pub use texel_behaviour2d::*;
 
-use crate::util::{frame_counter::FrameCounter, math::*, Vector2I};
+use crate::{
+    game::camera::WORLD_WIDTH,
+    util::{frame_counter::FrameCounter, math::*, Vector2I},
+};
 
 pub struct Terrain2DPlugin;
 
@@ -42,7 +45,7 @@ impl Plugin for Terrain2DPlugin {
         );
 
         app.register_type::<TerrainChunk2D>()
-            .insert_resource(Terrain2D::new())
+            .insert_resource(Terrain2D::new(Some(WORLD_WIDTH * 2), Some(0), Some(0), Some(WORLD_WIDTH)))
             .add_event::<TerrainEvent2D>()
             .add_system_to_stage(TerrainStages::Simulation, terrain_simulation)
             .add_system_to_stage(TerrainStages::EventHandler, emit_terrain_events)
@@ -191,13 +194,26 @@ pub enum TerrainEvent2D {
 pub struct Terrain2D {
     chunk_map: HashMap<Chunk2DIndex, Chunk2D>,
     events: Vec<TerrainEvent2D>,
+    pub top_boundary: Option<i32>,
+    pub bottom_boundary: Option<i32>,
+    pub left_boundary: Option<i32>,
+    pub right_boundary: Option<i32>,
 }
 
 impl Terrain2D {
-    pub fn new() -> Terrain2D {
+    pub fn new(
+        top_boundary: Option<i32>,
+        bottom_boundary: Option<i32>,
+        left_boundary: Option<i32>,
+        right_boundary: Option<i32>,
+    ) -> Terrain2D {
         Terrain2D {
             chunk_map: HashMap::new(),
             events: Vec::new(),
+            top_boundary,
+            bottom_boundary,
+            left_boundary,
+            right_boundary,
         }
     }
 
@@ -256,6 +272,30 @@ impl Terrain2D {
         }
     }
 
+    pub fn is_within_boundaries(&self, global: &Vector2I) -> bool {
+        if let Some(top) = self.top_boundary {
+            if global.y > top {
+                return false;
+            }
+        }
+        if let Some(bottom) = self.bottom_boundary {
+            if global.y < bottom {
+                return false;
+            }
+        }
+        if let Some(left) = self.left_boundary {
+            if global.x < left {
+                return false;
+            }
+        }
+        if let Some(right) = self.right_boundary {
+            if global.x > right {
+                return false;
+            }
+        }
+        return true;
+    }
+
     pub fn get_texel(&self, global: &Vector2I) -> Option<Texel2D> {
         self.global_to_chunk(global)
             .map_or(None, |chunk| chunk.get_texel(&global_to_local(global)))
@@ -268,11 +308,18 @@ impl Terrain2D {
         let texel = self.get_texel(global);
         (
             texel,
-            texel.map_or(None, |t| TexelBehaviour2D::from_id(&t.id)),
+            if self.is_within_boundaries(global) {
+                texel.map_or(None, |t| TexelBehaviour2D::from_id(&t.id))
+            } else {
+                Some(TexelBehaviour2D::OUT_OF_BOUNDS)
+            },
         )
     }
 
     pub fn set_texel(&mut self, global: &Vector2I, id: TexelID, simulation_frame: Option<u8>) {
+        if !self.is_within_boundaries(global) {
+            return
+        }
         let index = global_to_chunk_index(global);
         let changed = match self.index_to_chunk_mut(&index) {
             Some(chunk) => chunk.set_texel(&global_to_local(global), id, simulation_frame),

src/terrain2d/texel_behaviour2d.rs

@@ -3,7 +3,7 @@ use crate::util::Vector2I;
 use super::TexelID;
 use bevy::prelude::*;
 use lazy_static::lazy_static;
-use std::collections::HashMap;
+use std::{collections::HashMap, borrow::Cow};
 
 lazy_static! {
     static ref ID_MAP: HashMap<TexelID, TexelBehaviour2D> = {
@@ -12,7 +12,7 @@ lazy_static! {
         result.insert(
             1,
             TexelBehaviour2D {
-                name: String::from("loose sand"),
+                name: Cow::Borrowed("loose sand"),
                 color: Color::rgb(0.61, 0.49, 0.38),
                 gravity: Some(TexelGravity::Down(100)),
                 has_collision: true,
@@ -23,7 +23,7 @@ lazy_static! {
         result.insert(
             2,
             TexelBehaviour2D {
-                name: String::from("loose stone"),
+                name: Cow::Borrowed("loose stone"),
                 color: Color::rgb(0.21, 0.19, 0.17),
                 gravity: Some(TexelGravity::Down(100)),
                 has_collision: true,
@@ -34,7 +34,7 @@ lazy_static! {
         result.insert(
             3,
             TexelBehaviour2D {
-                name: String::from("loose sturdy stone"),
+                name: Cow::Borrowed("loose sturdy stone"),
                 color: Color::rgb(0.11, 0.11, 0.11),
                 gravity: Some(TexelGravity::Down(100)),
                 has_collision: true,
@@ -45,7 +45,7 @@ lazy_static! {
         result.insert(
             4,
             TexelBehaviour2D {
-                name: String::from("water"),
+                name: Cow::Borrowed("water"),
                 color: Color::rgba(0.0, 0.0, 1.0, 0.5),
                 form: TexelForm::Liquid,
                 gravity: Some(TexelGravity::Down(10)),
@@ -56,7 +56,7 @@ lazy_static! {
         result.insert(
             5,
             TexelBehaviour2D {
-                name: String::from("oil"),
+                name: Cow::Borrowed("oil"),
                 color: Color::rgba(0.0, 1.0, 0.0, 0.5),
                 form: TexelForm::Gas,
                 gravity: Some(TexelGravity::Up(50)),
@@ -67,7 +67,7 @@ lazy_static! {
         result.insert(
             6,
             TexelBehaviour2D {
-                name: String::from("gas"),
+                name: Cow::Borrowed("gas"),
                 color: Color::rgba(0.5, 0.5, 0.25, 0.5),
                 form: TexelForm::Liquid,
                 gravity: Some(TexelGravity::Down(5)),
@@ -78,7 +78,7 @@ lazy_static! {
         result.insert(
             11,
             TexelBehaviour2D {
-                name: String::from("sand"),
+                name: Cow::Borrowed("sand"),
                 color: Color::rgb(0.61, 0.49, 0.38),
                 has_collision: true,
                 ..default()
@@ -88,7 +88,7 @@ lazy_static! {
         result.insert(
             12,
             TexelBehaviour2D {
-                name: String::from("stone"),
+                name: Cow::Borrowed("stone"),
                 color: Color::rgb(0.21, 0.19, 0.17),
                 has_collision: true,
                 ..default()
@@ -98,22 +98,13 @@ lazy_static! {
         result.insert(
             13,
             TexelBehaviour2D {
-                name: String::from("sturdy stone"),
+                name: Cow::Borrowed("sturdy stone"),
                 color: Color::rgb(0.11, 0.11, 0.11),
                 has_collision: true,
                 ..default()
             },
         );
 
-        result.insert(
-            u8::MAX,
-            TexelBehaviour2D {
-                color: Color::BLACK,
-                has_collision: true,
-                ..default()
-            },
-        );
-
         result
     };
 }
@@ -146,7 +137,7 @@ impl From<TexelGravity> for Vector2I {
 
 #[derive(Clone)]
 pub struct TexelBehaviour2D {
-    pub name: String,
+    pub name: Cow<'static, str>,
     pub color: Color,
     pub form: TexelForm,
     pub has_collision: bool,
@@ -157,7 +148,7 @@ pub struct TexelBehaviour2D {
 impl Default for TexelBehaviour2D {
     fn default() -> Self {
         TexelBehaviour2D {
-            name: "Unnamed material".to_string(),
+            name: Cow::Borrowed("Unnamed material"),
             color: Color::PINK,
             form: TexelForm::Solid,
             has_collision: false,
@@ -169,6 +160,15 @@ impl Default for TexelBehaviour2D {
 
 // TODO: change form-based functions like is_solid to behaviour based (e.g. has_collision)
 impl TexelBehaviour2D {
+    pub const OUT_OF_BOUNDS: Self = TexelBehaviour2D {
+        name: Cow::Borrowed(":)"),
+        color: Color::BLACK,
+        has_collision: true,
+        form: TexelForm::Solid,
+        gravity: None,
+        toughness: None,
+    };
+
     pub fn from_id(id: &TexelID) -> Option<Self> {
         ID_MAP.get(id).cloned()
     }
@@ -181,12 +181,12 @@ impl TexelBehaviour2D {
         ID_MAP.get(id).map_or(false, |b| b.has_collision)
     }
 
+    /// Can this type of material displace another?
     pub fn can_displace(from: &TexelBehaviour2D, to: &Option<TexelBehaviour2D>) -> bool {
         let to = if let Some(to) = to { to } else { return true };
 
         match (from.form, to.form) {
-            (_, TexelForm::Solid) => false,
+            (_, to_form) => {
-            (_, _) => {
                 if let (Some(from_grav), Some(to_grav)) = (from.gravity, to.gravity) {
                     match (from_grav, to_grav) {
                         (TexelGravity::Down(from_grav), TexelGravity::Down(to_grav)) => {
@@ -198,7 +198,8 @@ impl TexelBehaviour2D {
                         (_, _) => true,
                     }
                 } else {
-                    true
+                    // Solids can also be displaced, but only if the other material has gravity
+                    to_form != TexelForm::Solid
                 }
             }
         }