From 1a702b7fd4e5746823d991ce489bedffab4d808f Mon Sep 17 00:00:00 2001
From: Jarrod Doyle <thejarroddoyle@gmail.com>
Date: Sun, 4 Feb 2024 10:38:54 +0000
Subject: [PATCH] Use ndarray for chunk cells

---
 Cargo.lock                  | 51 +++++++++++++++++++++++++++++++++++++
 Cargo.toml                  |  4 ++-
 src/falling_sand/mod.rs     | 13 +++++-----
 src/falling_sand/systems.rs |  2 +-
 4 files changed, 61 insertions(+), 9 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 2f44800..82c3639 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2051,7 +2051,9 @@ version = "0.1.0"
 dependencies = [
  "bevy",
  "criterion",
+ "ndarray",
  "rand",
+ "rayon",
 ]
 
 [[package]]
@@ -2406,6 +2408,16 @@ dependencies = [
  "regex-automata 0.1.10",
 ]
 
+[[package]]
+name = "matrixmultiply"
+version = "0.3.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7574c1cf36da4798ab73da5b215bbf444f50718207754cb522201d78d1cd0ff2"
+dependencies = [
+ "autocfg",
+ "rawpointer",
+]
+
 [[package]]
 name = "memchr"
 version = "2.7.1"
@@ -2496,6 +2508,20 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "ndarray"
+version = "0.15.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "adb12d4e967ec485a5f71c6311fe28158e9d6f4bc4a447b474184d0f91a8fa32"
+dependencies = [
+ "matrixmultiply",
+ "num-complex",
+ "num-integer",
+ "num-traits",
+ "rawpointer",
+ "rayon",
+]
+
 [[package]]
 name = "ndk"
 version = "0.7.0"
@@ -2582,6 +2608,15 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "num-complex"
+version = "0.4.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ba157ca0885411de85d6ca030ba7e2a83a28636056c7c699b07c8b6f7383214"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "num-derive"
 version = "0.3.3"
@@ -2593,6 +2628,16 @@ dependencies = [
  "syn 1.0.109",
 ]
 
+[[package]]
+name = "num-integer"
+version = "0.1.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "225d3389fb3509a24c93f5c29eb6bde2586b98d9f016636dff58d7c6f7569cd9"
+dependencies = [
+ "autocfg",
+ "num-traits",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.17"
@@ -2984,6 +3029,12 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f2ff9a1f06a88b01621b7ae906ef0211290d1c8a168a15542486a8f61c0833b9"
 
+[[package]]
+name = "rawpointer"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "60a357793950651c4ed0f3f52338f53b2f809f32d83a07f72909fa13e4c6c1e3"
+
 [[package]]
 name = "rayon"
 version = "1.8.1"
diff --git a/Cargo.toml b/Cargo.toml
index 3c106c0..e91198b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,11 +8,13 @@ edition = "2021"
 [dependencies]
 bevy = "0.12.1"
 criterion = "0.5.1"
+ndarray = { version = "0.15.6", features = ["rayon"] }
 rand = "0.8.5"
+rayon = "1.8.1"
 
 [profile.dev.package."*"]
 opt-level = 3
 
 [[bench]]
 name = "rule_generation"
-harness = false
\ No newline at end of file
+harness = false
diff --git a/src/falling_sand/mod.rs b/src/falling_sand/mod.rs
index 2d83d59..1cd2369 100644
--- a/src/falling_sand/mod.rs
+++ b/src/falling_sand/mod.rs
@@ -15,6 +15,7 @@ use bevy::{
     sprite::SpriteBundle,
     transform::components::Transform,
 };
+use ndarray::Array2;
 use rand::Rng;
 
 use crate::util::DirtyRect;
@@ -75,7 +76,7 @@ pub struct Chunk {
     step: usize,
     width: usize,
     height: usize,
-    cells: Vec<Element>,
+    cells: Array2<Element>,
     dirty_rect: DirtyRect,
 }
 
@@ -85,7 +86,7 @@ impl Chunk {
             step: 0,
             width,
             height,
-            cells: vec![Element::Air; width * height],
+            cells: Array2::from_elem((width, height), Element::Air),
             dirty_rect: DirtyRect::default(),
         };
 
@@ -103,7 +104,7 @@ impl Chunk {
             return;
         }
 
-        self.cells[x + y * self.width] = element;
+        self.cells[(x, y)] = element;
         self.dirty_rect.add_point(x, y);
     }
 
@@ -112,9 +113,7 @@ impl Chunk {
             return;
         }
 
-        let i0 = x0 + y0 * self.width;
-        let i1 = x1 + y1 * self.width;
-        self.cells.swap(i0, i1);
+        self.cells.swap((x0, y0), (x1, y1));
         self.dirty_rect.add_point(x0, y0);
         self.dirty_rect.add_point(x1, y1);
     }
@@ -124,6 +123,6 @@ impl Chunk {
             return None;
         }
 
-        Some(self.cells[x + y * self.width])
+        Some(self.cells[(x, y)])
     }
 }
diff --git a/src/falling_sand/systems.rs b/src/falling_sand/systems.rs
index 530fdfb..9e3f419 100644
--- a/src/falling_sand/systems.rs
+++ b/src/falling_sand/systems.rs
@@ -79,7 +79,7 @@ pub fn update_chunk_texture(
             for y in chunk.dirty_rect.range_y() {
                 for x in chunk.dirty_rect.range_x() {
                     let mut colour = (0, 0, 0);
-                    if let Some(element) = chunk.cells.get(x + y * chunk.width) {
+                    if let Some(element) = chunk.get_cell(x, y) {
                         match element {
                             Element::Air => colour = (25, 24, 26),
                             Element::Sand => colour = (255, 216, 102),