use av1 for encoding

Cargo.lock

@@ -8,12 +8,33 @@ version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "512761e0bb2578dd7380c6baaa0f4ce03e84f95e960231d1dec8bf4d7d6e2627"
 
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "aligned-vec"
 version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4aa90d7ce82d4be67b64039a3d588d38dbcc6736577de4a847025ce5b0c468d1"
 
+[[package]]
+name = "anes"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4b46cbb362ab8752921c97e041f5e366ee6297bd428a31275b9fcf1e380f7299"
+
+[[package]]
+name = "anstyle"
+version = "1.0.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "55cc3b69f167a1ef2e161439aa98aed94e6028e5f9a59be9a6ffb47aef1651f9"
+
 [[package]]
 name = "anyhow"
 version = "1.0.97"
@@ -120,6 +141,12 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8f1fe948ff07f4bd06c30984e69f5b4899c516a3ef74f34df92a2df2ab535495"
 
+[[package]]
+name = "cast"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37b2a672a2cb129a2e41c10b1224bb368f9f37a2b16b612598138befd7b37eb5"
+
 [[package]]
 name = "cc"
 version = "1.2.17"
@@ -147,6 +174,58 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "ciborium"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42e69ffd6f0917f5c029256a24d0161db17cea3997d185db0d35926308770f0e"
+dependencies = [
+ "ciborium-io",
+ "ciborium-ll",
+ "serde",
+]
+
+[[package]]
+name = "ciborium-io"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "05afea1e0a06c9be33d539b876f1ce3692f4afea2cb41f740e7743225ed1c757"
+
+[[package]]
+name = "ciborium-ll"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "57663b653d948a338bfb3eeba9bb2fd5fcfaecb9e199e87e1eda4d9e8b240fd9"
+dependencies = [
+ "ciborium-io",
+ "half",
+]
+
+[[package]]
+name = "clap"
+version = "4.5.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e958897981290da2a852763fe9cdb89cd36977a5d729023127095fa94d95e2ff"
+dependencies = [
+ "clap_builder",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.5.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "83b0f35019843db2160b5bb19ae09b4e6411ac33fc6a712003c33e03090e2489"
+dependencies = [
+ "anstyle",
+ "clap_lex",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f46ad14479a25103f283c0f10005961cf086d8dc42205bb44c46ac563475dca6"
+
 [[package]]
 name = "color_quant"
 version = "1.1.0"
@@ -175,6 +254,42 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "criterion"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2b12d017a929603d80db1831cd3a24082f8137ce19c69e6447f54f5fc8d692f"
+dependencies = [
+ "anes",
+ "cast",
+ "ciborium",
+ "clap",
+ "criterion-plot",
+ "is-terminal",
+ "itertools 0.10.5",
+ "num-traits",
+ "once_cell",
+ "oorandom",
+ "plotters",
+ "rayon",
+ "regex",
+ "serde",
+ "serde_derive",
+ "serde_json",
+ "tinytemplate",
+ "walkdir",
+]
+
+[[package]]
+name = "criterion-plot"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6b50826342786a51a89e2da3a28f1c32b06e387201bc2d19791f622c673706b1"
+dependencies = [
+ "cast",
+ "itertools 0.10.5",
+]
+
 [[package]]
 name = "crossbeam-deque"
 version = "0.8.6"
@@ -319,6 +434,12 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
+[[package]]
+name = "hermit-abi"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fbd780fe5cc30f81464441920d82ac8740e2e46b29a6fad543ddd075229ce37e"
+
 [[package]]
 name = "image"
 version = "0.25.6"
@@ -393,6 +514,26 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "is-terminal"
+version = "0.4.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e04d7f318608d35d4b61ddd75cbdaee86b023ebe2bd5a66ee0915f0bf93095a9"
+dependencies = [
+ "hermit-abi",
+ "libc",
+ "windows-sys",
+]
+
+[[package]]
+name = "itertools"
+version = "0.10.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0fd2260e829bddf4cb6ea802289de2f86d6a7a690192fbe91b3f46e0f2c8473"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "itertools"
 version = "0.12.1"
@@ -411,6 +552,12 @@ dependencies = [
  "either",
 ]
 
+[[package]]
+name = "itoa"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4a5f13b858c8d314ee3e8f639011f7ccefe71f97f96e50151fb991f267928e2c"
+
 [[package]]
 name = "jobserver"
 version = "0.1.32"
@@ -592,9 +739,15 @@ checksum = "830b246a0e5f20af87141b25c173cd1b609bd7779a4617d6ec582abaf90870f3"
 
 [[package]]
 name = "once_cell"
-version = "1.21.2"
+version = "1.21.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c2806eaa3524762875e21c3dcd057bc4b7bfa01ce4da8d46be1cd43649e1cc6b"
+checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
+
+[[package]]
+name = "oorandom"
+version = "11.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d6790f58c7ff633d8771f42965289203411a5e5c68388703c06e14f24770b41e"
 
 [[package]]
 name = "paste"
@@ -606,6 +759,7 @@ checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
 name = "physarum"
 version = "0.1.0"
 dependencies = [
+ "criterion",
  "fastapprox",
  "image",
  "indicatif",
@@ -621,6 +775,34 @@ version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
 
+[[package]]
+name = "plotters"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5aeb6f403d7a4911efb1e33402027fc44f29b5bf6def3effcc22d7bb75f2b747"
+dependencies = [
+ "num-traits",
+ "plotters-backend",
+ "plotters-svg",
+ "wasm-bindgen",
+ "web-sys",
+]
+
+[[package]]
+name = "plotters-backend"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df42e13c12958a16b3f7f4386b9ab1f3e7933914ecea48da7139435263a4172a"
+
+[[package]]
+name = "plotters-svg"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51bae2ac328883f7acdfea3d66a7c35751187f870bc81f94563733a154d7a670"
+dependencies = [
+ "plotters-backend",
+]
+
 [[package]]
 name = "png"
 version = "0.17.16"
@@ -847,6 +1029,35 @@ dependencies = [
  "crossbeam-utils",
 ]
 
+[[package]]
+name = "regex"
+version = "1.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b544ef1b4eac5dc2db33ea63606ae9ffcfac26c1416a2806ae0bf5f56b201191"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "809e8dc61f6de73b46c85f4c96486310fe304c434cfa43669d7b40f711150908"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
+
 [[package]]
 name = "rgb"
 version = "0.8.50"
@@ -859,6 +1070,21 @@ version = "1.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "eded382c5f5f786b989652c49544c4877d9f015cc22e145a5ea8ea66c2921cd2"
 
+[[package]]
+name = "ryu"
+version = "1.0.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "28d3b2b1366ec20994f1fd18c3c594f05c5dd4bc44d8bb0c1c632c8d6829481f"
+
+[[package]]
+name = "same-file"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93fc1dc3aaa9bfed95e02e6eadabb4baf7e3078b0bd1b4d7b6b0b68378900502"
+dependencies = [
+ "winapi-util",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.219"
@@ -879,6 +1105,18 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "serde_json"
+version = "1.0.140"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "20068b6e96dc6c9bd23e01df8827e6c7e1f2fddd43c21810382803c136b99373"
+dependencies = [
+ "itoa",
+ "memchr",
+ "ryu",
+ "serde",
+]
+
 [[package]]
 name = "serde_spanned"
 version = "0.6.8"
@@ -976,6 +1214,16 @@ dependencies = [
  "weezl",
 ]
 
+[[package]]
+name = "tinytemplate"
+version = "1.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "be4d6b5f19ff7664e8c98d03e2139cb510db9b0a60b55f8e8709b689d939b6bc"
+dependencies = [
+ "serde",
+ "serde_json",
+]
+
 [[package]]
 name = "toml"
 version = "0.8.20"
@@ -1039,6 +1287,16 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "852e951cb7832cb45cb1169900d19760cfa39b82bc0ea9c0e5a14ae88411c98b"
 
+[[package]]
+name = "walkdir"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29790946404f91d9c5d06f9874efddea1dc06c5efe94541a7d6863108e3a5e4b"
+dependencies = [
+ "same-file",
+ "winapi-util",
+]
+
 [[package]]
 name = "wasi"
 version = "0.11.0+wasi-snapshot-preview1"
@@ -1112,6 +1370,16 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "web-sys"
+version = "0.3.77"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "33b6dd2ef9186f1f2072e409e99cd22a975331a6b3591b12c764e0e55c60d5d2"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "web-time"
 version = "1.1.0"
@@ -1128,6 +1396,15 @@ version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "53a85b86a771b1c87058196170769dd264f66c0782acf1ae6cc51bfd64b39082"
 
+[[package]]
+name = "winapi-util"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf221c93e13a30d793f7645a0e7762c55d169dbb0a49671918a2319d289b10bb"
+dependencies = [
+ "windows-sys",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.59.0"

Cargo.toml

@@ -13,6 +13,13 @@ rand_distr = "0.5"
 rayon = "1.10"
 fastapprox = "0.3"
 
+[dev-dependencies]
+criterion = { version = "0.5", features = ["html_reports"] }
+
+[[bench]]
+name = "benchmark"
+harness = false
+
 [profile.release]
 codegen-units = 1
 opt-level = 3

benches/benchmark.rs

@@ -0,0 +1,107 @@
+use criterion::{criterion_group, criterion_main, BatchSize, BenchmarkId, Criterion};
+use physarum::{
+    agent::Agent,
+    grid::{combine, Grid},
+    model,
+};
+use rand::{rngs::StdRng, SeedableRng};
+
+// Benchmark agent movement and deposition
+fn agent_benchmark(c: &mut Criterion) {
+    let mut group = c.benchmark_group("Agent Tick");
+    let n_agents = [1_000, 10_000, 100_000];
+
+    for &n in &n_agents {
+        group.bench_with_input(BenchmarkId::from_parameter(n), &n, |b, &n| {
+            let mut rng = StdRng::seed_from_u64(42);
+            let agents = (0..n).map(|_| Agent::new(256, 256, &mut rng)).collect();
+            let mut grid = Grid::new(256, 256, &mut rng, agents);
+
+            b.iter(|| {
+                grid.tick();
+            });
+        });
+    }
+    group.finish();
+}
+
+// Benchmark grid diffusion (blur)
+fn diffusion_benchmark(c: &mut Criterion) {
+    let mut group = c.benchmark_group("Grid Diffusion");
+    let sizes = [(256, 256), (512, 512)];
+    let radii = [1, 3];
+
+    for &(w, h) in &sizes {
+        for &r in &radii {
+            group.bench_with_input(
+                BenchmarkId::new("diffuse", format!("{}x{}_r{}", w, h, r)),
+                &(w, h, r),
+                |b, &(w, h, r)| {
+                    b.iter_batched(
+                        || {
+                            let mut rng = StdRng::seed_from_u64(42);
+                            Grid::new(w, h, &mut rng, vec![])
+                        },
+                        |mut grid| grid.diffuse(r),
+                        BatchSize::SmallInput,
+                    );
+                },
+            );
+        }
+    }
+    group.finish();
+}
+
+// Benchmark grid combining
+fn combine_benchmark(c: &mut Criterion) {
+    let mut group = c.benchmark_group("Combine Grids");
+    let populations = [2, 4];
+
+    for &np in &populations {
+        group.bench_with_input(BenchmarkId::from_parameter(np), &np, |b, &np| {
+            b.iter_batched(
+                || {
+                    let mut rng = StdRng::seed_from_u64(42);
+                    let grids = (0..np)
+                        .map(|_| Grid::new(256, 256, &mut rng, vec![]))
+                        .collect::<Vec<_>>();
+                    let attraction_table = vec![vec![1.0; np]; np];
+                    (grids, attraction_table)
+                },
+                |(mut grids, table)| combine(&mut grids, &table),
+                BatchSize::SmallInput,
+            );
+        });
+    }
+    group.finish();
+}
+
+// Benchmark full model step
+fn model_step_benchmark(c: &mut Criterion) {
+    let mut group = c.benchmark_group("Model Step");
+    let params = [(256, 256, 2), (512, 512, 4)];
+
+    for &(w, h, np) in &params {
+        group.bench_with_input(
+            BenchmarkId::new("step", format!("{}x{}_p{}", w, h, np)),
+            &(w, h, np),
+            |b, &(w, h, np)| {
+                b.iter_batched(
+                    || model::Model::new(w, h, 1 << 16, np, 1),
+                    |mut model| model.step(),
+                    BatchSize::SmallInput,
+                );
+            },
+        );
+    }
+    group.finish();
+}
+
+criterion_group!(
+    benches,
+    agent_benchmark,
+    diffusion_benchmark,
+    combine_benchmark,
+    model_step_benchmark
+);
+criterion_main!(benches);

src/agent.rs

@@ -1,3 +1,4 @@
+use crate::grid::PopulationConfig;
 use crate::{buffer::Buf, util::wrap};
 use fastapprox::faster::{cos, sin};
 use rand::prelude::IndexedRandom;
@@ -31,26 +32,17 @@ impl Agent {
     }
 
     /// Tick an agent
-    pub fn tick(
+    pub fn tick(&mut self, buf: &Buf, pop_config: PopulationConfig, width: usize, height: usize) {
-        &mut self,
+        let xc = self.x + cos(self.heading) * pop_config.sensor_distance;
-        buf: &Buf,
+        let yc = self.y + sin(self.heading) * pop_config.sensor_distance;
-        sensor_distance: f32,
-        sensor_angle: f32,
-        rotation_angle: f32,
-        step_distance: f32,
-        width: usize,
-        height: usize,
-    ) {
-        let xc = self.x + cos(self.heading) * sensor_distance;
-        let yc = self.y + sin(self.heading) * sensor_distance;
 
-        let agent_add_sens = self.heading + sensor_angle;
+        let agent_add_sens = self.heading + pop_config.sensor_angle;
-        let agent_sub_sens = self.heading - sensor_angle;
+        let agent_sub_sens = self.heading - pop_config.sensor_angle;
 
-        let xl = self.x + cos(agent_sub_sens) * sensor_distance;
+        let xl = self.x + cos(agent_sub_sens) * pop_config.sensor_distance;
-        let yl = self.y + sin(agent_sub_sens) * sensor_distance;
+        let yl = self.y + sin(agent_sub_sens) * pop_config.sensor_distance;
-        let xr = self.x + cos(agent_add_sens) * sensor_distance;
+        let xr = self.x + cos(agent_add_sens) * pop_config.sensor_distance;
-        let yr = self.y + sin(agent_add_sens) * sensor_distance;
+        let yr = self.y + sin(agent_add_sens) * pop_config.sensor_distance;
 
         // We sense from the buffer because this is where we previously combined data from all the grid.
         let center = buf.get_buf(xc, yc);
@@ -72,10 +64,16 @@ impl Agent {
             0.0
         };
 
-        let delta_angle = rotation_angle * direction;
+        let delta_angle = pop_config.rotation_angle * direction;
 
         self.heading = wrap(self.heading + delta_angle, TAU);
-        self.x = wrap(self.x + step_distance * cos(self.heading), width as f32);
+        self.x = wrap(
-        self.y = wrap(self.y + step_distance * sin(self.heading), height as f32);
+            self.x + pop_config.step_distance * cos(self.heading),
+            width as f32,
+        );
+        self.y = wrap(
+            self.y + pop_config.step_distance * sin(self.heading),
+            height as f32,
+        );
     }
 }

src/blur.rs

@@ -30,18 +30,17 @@ impl Blur {
 
     /// Approximate 1D Gaussian filter of standard deviation sigma with N box filter passes. Each element in the output array contains the radius of the box filter for the corresponding pass.
     fn boxes_for_gaussian<const N: usize>(sigma: f32) -> [usize; N] {
-        let w_ideal = (12.0 * sigma * sigma / N as f32 + 1.0).sqrt();
+        let sigma_sq = sigma.powi(2);
+        let w_ideal = (12.0 * sigma_sq / N as f32 + 1.0).sqrt();
         let mut w = w_ideal as usize;
         w -= 1 - (w & 1);
-        let mut m = 0.25 * (N * (w + 3)) as f32;
+        let m = (0.25 * (N * (w + 3)) as f32 - 3.0 * sigma_sq / (w + 1) as f32).round() as usize;
-        m -= 3.0 * sigma * sigma / (w + 1) as f32;
-        let m = m.round() as usize;
 
-        let mut result = [0; N];
+        (0..N)
-        for (i, value) in result.iter_mut().enumerate() {
+            .map(|i| (w + 1 - 2 * (i < m) as usize) / 2)
-            *value = (if i < m { w - 1 } else { w + 1 }) / 2;
+            .collect::<Vec<_>>()
-        }
+            .try_into()
-        result
+            .unwrap()
     }
 
     /// Perform one pass of the 2D box filter of the given radius. The result will be written to the src slice, while the buf slice is used as a scratch space.
@@ -67,7 +66,7 @@ impl Blur {
             .for_each(|(src_row, dst_row)| {
                 // First we build a value for the beginning of each row. We assume periodic boundary conditions, so we need to push the left index to the opposite side of the row.
                 let width_sub_radius = width - radius;
-                let mut value = src_row[width - radius - 1];
+                let mut value = src_row[width_sub_radius - 1];
                 for j in 0..radius {
                     value += src_row[width_sub_radius + j] + src_row[j];
                 }

src/grid.rs

@@ -7,10 +7,10 @@ use std::fmt::{Display, Formatter};
 /// A population configuration.
 #[derive(Debug, Clone, Copy)]
 pub struct PopulationConfig {
-    sensor_distance: f32,
+    pub sensor_distance: f32,
-    step_distance: f32,
+    pub step_distance: f32,
-    sensor_angle: f32,
+    pub sensor_angle: f32,
-    rotation_angle: f32,
+    pub rotation_angle: f32,
 
     deposition_amount: f32,
 }
@@ -90,25 +90,8 @@ impl Grid {
     }
 
     pub fn tick(&mut self) {
-        let (width, height) = (self.width, self.height);
-        let PopulationConfig {
-            sensor_distance,
-            sensor_angle,
-            rotation_angle,
-            step_distance,
-            ..
-        } = self.config;
-
         self.agents.par_iter_mut().for_each(|agent| {
-            agent.tick(
+            agent.tick(&self.buf, self.config, self.width, self.height);
-                &self.buf,
-                sensor_distance,
-                sensor_angle,
-                rotation_angle,
-                step_distance,
-                width,
-                height,
-            );
         });
         self.deposit_all();
     }
@@ -131,11 +114,14 @@ where
     // We mutate grid buffers and read grid data. We use unsafe because we need shared/unique borrows on different fields of the same Grid struct.
     bufs.iter().enumerate().for_each(|(i, buf)| {
         let buf_ptr = *buf as *const Vec<f32> as *mut Vec<f32>;
-        unsafe { buf_ptr.as_mut() }.unwrap().fill(0.0);
+        // SAFETY! we can take these are raw pointers because we are
+        // getting it from a `&mut [Grid]`
+        let buf_ptr_mut = unsafe { buf_ptr.as_mut().unwrap_unchecked() };
+
+        buf_ptr_mut.fill(0.0);
         datas.iter().enumerate().for_each(|(j, other)| {
             let multiplier = attraction_table[i].as_ref()[j];
-            unsafe { buf_ptr.as_mut() }
+            buf_ptr_mut
-                .unwrap()
                 .iter_mut()
                 .zip(*other)
                 .for_each(|(to, from)| *to += from * multiplier)

src/lib.rs

@@ -1,7 +1,7 @@
-mod agent;
+pub mod agent;
 mod blur;
 mod buffer;
-mod grid;
+pub mod grid;
 pub mod imgdata; // for storing image data
 pub mod model;
 mod palette;

src/main.rs

@@ -29,9 +29,7 @@ fn main() {
             "-i",
             "-",
             "-c:v",
-            "libx264",
+            "libsvtav1",
-            "-preset",
-            "fast",
             "output.mp4",
         ])
         .stdin(std::process::Stdio::piped())

src/model.rs

@@ -57,28 +57,32 @@ impl Model {
 
         let attraction_distr =
             Normal::new(Self::ATTRACTION_FACTOR_MEAN, Self::ATTRACTION_FACTOR_STD).unwrap();
-        let repulstion_distr =
+        let repulsion_distr =
             Normal::new(Self::REPULSION_FACTOR_MEAN, Self::REPULSION_FACTOR_STD).unwrap();
 
         let mut attraction_table = Vec::with_capacity(n_populations);
         for i in 0..n_populations {
             attraction_table.push(Vec::with_capacity(n_populations));
             for j in 0..n_populations {
-                attraction_table[i].push(if i == j {
+                attraction_table[i].push(
-                    attraction_distr.sample(&mut rng)
+                    if i == j {
-                } else {
+                        &attraction_distr
-                    repulstion_distr.sample(&mut rng)
+                    } else {
-                });
+                        &repulsion_distr
+                    }
+                    .sample(&mut rng),
+                );
             }
         }
 
-        let mut grids: Vec<Grid> = Vec::new();
+        let grids = (0..n_populations)
-        for _ in 0..n_populations {
+            .map(|_| {
-            let agents = (0..particles_per_grid)
+                let agents = (0..particles_per_grid)
-                .map(|_| Agent::new(width, height, &mut rng))
+                    .map(|_| Agent::new(width, height, &mut rng))
-                .collect();
+                    .collect();
-            grids.push(Grid::new(width, height, &mut rng, agents));
+                Grid::new(width, height, &mut rng, agents)
-        }
+            })
+            .collect();
 
         Model {
             population_grids: grids,

src/util.rs

@@ -17,10 +17,95 @@ pub const fn index(width: usize, height: usize, x: f32, y: f32) -> usize {
 mod test {
     use super::*;
 
-    #[test]
+    mod wrap {
-    fn wrap_test() {
+        use super::*;
-        assert_eq!(wrap(1.1, 1.0), 0.100000024); // floating point weirdness
+        #[test]
-        assert_eq!(wrap(0.5, 1.0), 0.5);
+        fn over() {
-        assert_eq!(wrap(-1.0, 2.0), 1.0);
+            assert_eq!(wrap(1.1, 1.0), 0.100000024); // floating point weirdness
+        }
+
+        #[test]
+        fn middle() {
+            assert_eq!(wrap(0.5, 1.0), 0.5);
+        }
+
+        #[test]
+        fn under() {
+            assert_eq!(wrap(-1.0, 2.0), 1.0);
+        }
+    }
+
+    mod index {
+        use super::*;
+
+        #[test]
+        fn basic_positive_coordinates() {
+            let width = 4;
+            let height = 4;
+            assert_eq!(index(width, height, 1.5, 2.5), 9);
+        }
+
+        #[test]
+        fn negative_x_coordinate() {
+            let width = 8;
+            let height = 8;
+            assert_eq!(index(width, height, -3.2, 5.6), 44);
+        }
+
+        #[test]
+        fn exact_boundary_values() {
+            let width = 16;
+            let height = 16;
+            assert_eq!(index(width, height, 16.0, 0.0), 0);
+        }
+
+        #[test]
+        fn large_coordinates() {
+            let width = 2;
+            let height = 2;
+            assert_eq!(index(width, height, 1000.0, 2000.0), 0);
+        }
+
+        #[test]
+        fn negative_x_and_y() {
+            let width = 4;
+            let height = 4;
+            assert_eq!(index(width, height, -1.5, -0.5), 14);
+        }
+
+        #[test]
+        fn fractional_truncation() {
+            let width = 4;
+            let height = 4;
+            assert_eq!(index(width, height, 3.9, 3.999), 15);
+        }
+
+        #[test]
+        fn zero_coordinates() {
+            let width = 4;
+            let height = 4;
+            assert_eq!(index(width, height, 0.0, 0.0), 0);
+        }
+
+        #[test]
+        fn x_equals_width() {
+            let width = 8;
+            let height = 8;
+            assert_eq!(index(width, height, 8.0, 0.0), 0);
+        }
+
+        #[test]
+        fn y_negative_beyond_height() {
+            let width = 4;
+            let height = 4;
+            assert_eq!(index(width, height, 0.0, -4.5), 0);
+        }
+
+        #[test]
+        fn width_and_height_one() {
+            let width = 1;
+            let height = 1;
+            assert_eq!(index(width, height, 123.4, -56.7), 0);
+        }
     }
 }