parallelize render_scalar_field

Cargo.toml

@@ -20,8 +20,10 @@ lazy_static = "1.4"
 log = "0.4"
 natord = "1.0"
 ndarray = { version = "0.13", features = ["rayon", "serde"] }
+num = "0.3"
 piecewise-linear = "0.1"
 plotly = { version = "0.6", features = ["kaleido", "plotly_ndarray"], path = "../plotly/plotly" }
+rayon = "1.5"
 serde = "1.0"
 structopt = "0.3"
 threadpool = "1.8"

examples/wrapped_torus.rs

@@ -5,7 +5,7 @@ use coremem::stim::{CurlStimulus, Sinusoid1, TimeVarying1 as _};
 fn main() {
     coremem::init_logging();
     let feat_size = 10e-6; // feature size
-    let duration = 2e-9;
+    let duration = 3e-9;
     let width = 2200e-6;
     let depth = 1800e-6;
     let buffer = 200e-6;
@@ -13,8 +13,8 @@ fn main() {
     let ferro_minor = 40e-6;
     let wire_minor = 20e-6;
     let wire_major = 100e-6;
-    let peak_current = 1e4;
-    let current_duration = 0.5e-9; // half-wavelength of the sine wave
+    let peak_current = 5e4;
+    let current_duration = 1.0e-9; // half-wavelength of the sine wave
     let current_break = 0.5e-9; // time between 'set' pulse and 'clear' pulse
     let conductivity = 1.0e9;
 

src/geom/mod.rs

@@ -184,7 +184,7 @@ impl Polygon2d {
 }
 
 #[typetag::serde(tag = "type")]
-pub trait Region: Send + DynClone {
+pub trait Region: Send + Sync + DynClone {
     fn contains(&self, p: Meters) -> bool;
 }
 dyn_clone::clone_trait_object!(Region);

src/meas.rs

@@ -9,7 +9,7 @@ use std::iter::Sum;
 // TODO: remove this Clone and Send requirement? Have Measurements be shared by-reference across
 // threads? i.e. Sync, and no Clone
 #[typetag::serde(tag = "type")]
-pub trait AbstractMeasurement: Send + DynClone {
+pub trait AbstractMeasurement: Send + Sync + DynClone {
     fn eval(&self, state: &dyn GenericSim) -> String;
 }
 dyn_clone::clone_trait_object!(AbstractMeasurement);

src/render.rs

@@ -7,9 +7,11 @@ use crossterm::{cursor, QueueableCommand as _};
 use crossterm::style::{style, Color, PrintStyledContent};
 use font8x8::{BASIC_FONTS, GREEK_FONTS, UnicodeFonts as _};
 use log::trace;
+use num::integer::Integer;
 use plotly;
 use image::{RgbImage, Rgb};
 use imageproc::{pixelops, drawing};
+use rayon::prelude::*;
 use serde::{Serialize, Deserialize};
 use std::fs::File;
 use std::io::{BufWriter, Write as _};
@@ -158,9 +160,8 @@ impl<'a> RenderSteps<'a> {
         let w = self.im.width();
         let h = self.im.height();
         let vec_spacing = 10;
-        for y in 0..h {
-            for x in 0..w {
-                if x % vec_spacing == 0 && y % vec_spacing == 0 {
+        for y in (0..h).into_iter().step_by(vec_spacing as _) {
+            for x in (0..w).into_iter().step_by(vec_spacing as _) {
                 let vec = self.field_vector(x, y, vec_spacing, &measure);
                 let norm_vec = scale_vector(vec, typical);
                 let alpha = 0.7*scale_unsigned(vec.mag_sq(), typical * 5.0);
@@ -170,12 +171,18 @@ impl<'a> RenderSteps<'a> {
             }
         }
     }
-    }
-    fn render_scalar_field<F: Fn(&Cell<mat::Static>) -> Flt>(&mut self, typical: Flt, signed: bool, slot: u32, measure: F) {
-        let w = self.im.width();
-        let h = self.im.height();
-        for y in 0..h {
-            for x in 0..w {
+    fn render_scalar_field<F: Fn(&Cell<mat::Static>) -> Flt + Sync>(&mut self, typical: Flt, signed: bool, slot: u32, measure: F) {
+        // XXX: get_at_px borrows self, so we need to clone the image to operate on it mutably.
+        let mut im = self.im.clone();
+        let w = im.width();
+        let h = im.height();
+        let samples = im.as_flat_samples_mut();
+        assert_eq!(samples.layout.channel_stride, 1);
+        assert_eq!(samples.layout.width_stride, 3);
+        assert_eq!(samples.layout.height_stride, 3*w as usize);
+        let pixel_buf: &mut [[u8; 3]] = unsafe { std::mem::transmute(samples.samples) };
+        pixel_buf[..(w*h) as usize].par_iter_mut().enumerate().for_each(|(idx, px)| {
+            let (y, x) = (idx as u32).div_rem(&w);
             let cell = self.get_at_px(x, y);
             let value = measure(&cell);
             let scaled = if signed {
@@ -183,11 +190,9 @@ impl<'a> RenderSteps<'a> {
             } else {
                 scale_unsigned_to_u8(value, typical)
             };
-                let mut p = *self.im.get_pixel(x, y);
-                p.0[slot as usize] = scaled;
-                self.im.put_pixel(x, y, p);
-            }
-        }
+            px[slot as usize] = scaled;
+        });
+        self.im = im;
     }
     fn render_measurements(&mut self) {
         for (meas_no, m) in self.meas.iter().enumerate() {