From 4e9778bffcdf1f5e77ef6fe9bafdc0c756d4dc95 Mon Sep 17 00:00:00 2001
From: mindv0rtex <mindv0rtex@users.noreply.github.com>
Date: Fri, 26 Feb 2021 14:46:43 -0500
Subject: [PATCH] Make horizontal blur parallel.

---
 src/blur.rs  | 31 +++++++++++++++++--------------
 src/main.rs  |  2 ++
 src/model.rs | 13 +++++++++----
 3 files changed, 28 insertions(+), 18 deletions(-)

diff --git a/src/blur.rs b/src/blur.rs
index 72e8261..5dcf603 100644
--- a/src/blur.rs
+++ b/src/blur.rs
@@ -1,4 +1,5 @@
 use itertools::multizip;
+use rayon::prelude::*;
 
 #[derive(Debug)]
 pub struct Blur {
@@ -56,21 +57,23 @@ impl Blur {
         let weight = 1.0 / (2 * radius + 1) as f32;
         let width = self.width;
 
-        for (src_row, dst_row) in src.chunks_exact(width).zip(dst.chunks_exact_mut(width)) {
-            // 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 mut value = src_row[width - radius - 1];
-            for j in 0..radius {
-                value += src_row[width - radius + j] + src_row[j];
-            }
+        src.par_chunks_exact(width)
+            .zip(dst.par_chunks_exact_mut(width))
+            .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 mut value = src_row[width - radius - 1];
+                for j in 0..radius {
+                    value += src_row[width - radius + j] + src_row[j];
+                }
 
-            for i in 0..width {
-                let left = (i + width - radius - 1) & (width - 1);
-                let right = (i + radius) & (width - 1);
-                value += src_row[right] - src_row[left];
-                dst_row[i] = value * weight;
-            }
-        }
+                for i in 0..width {
+                    let left = (i + width - radius - 1) & (width - 1);
+                    let right = (i + radius) & (width - 1);
+                    value += src_row[right] - src_row[left];
+                    dst_row[i] = value * weight;
+                }
+            })
     }
 
     /// Perform one pass of the 1D box filter of the given radius along y axis. Applies the decay
diff --git a/src/main.rs b/src/main.rs
index 702765c..3143b55 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,4 +5,6 @@ fn main() {
     println!("{:#?}", model);
     model.step();
     println!("{:#?}", model);
+    model.step();
+    println!("{:#?}", model);
 }
diff --git a/src/model.rs b/src/model.rs
index 927f650..6c84cc6 100644
--- a/src/model.rs
+++ b/src/model.rs
@@ -134,10 +134,13 @@ impl Model {
     /// Perform a single simulation step.
     pub fn step(&mut self) {
         // To avoid borrow-checker errors inside the parallel loop.
-        let sensor_distance = self.config.sensor_distance;
-        let sensor_angle = self.config.sensor_angle;
-        let rotation_angle = self.config.rotation_angle;
-        let step_distance = self.config.step_distance;
+        let PopulationConfig {
+            sensor_distance,
+            sensor_angle,
+            rotation_angle,
+            step_distance,
+            ..
+        } = self.config;
         let (width, height) = (self.width, self.height);
         let grid = &self.grid;
 
@@ -161,5 +164,7 @@ impl Model {
         });
 
         // Deposit + Diffuse + Decay
+
+        self.iteration += 1;
     }
 }