From 995b5b7c548592893457f1acdcac3538f4aafced Mon Sep 17 00:00:00 2001
From: Colin <colin@uninsane.org>
Date: Mon, 7 Sep 2020 21:34:33 -0700
Subject: [PATCH] Render current as a vector field

hmm...
---
 src/driver.rs |  2 +-
 src/render.rs | 16 ++++++++++++----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/driver.rs b/src/driver.rs
index 7c3b223..a195eef 100644
--- a/src/driver.rs
+++ b/src/driver.rs
@@ -49,7 +49,7 @@ impl Driver {
         for inset in 0..thickness {
             let depth = thickness - inset;
             // TODO: tune a scalar multiplier on this value
-            let conductivity = 0.1 * (depth*depth) as f64;
+            let conductivity = 0.02 * (depth*depth) as f64;
             for x in inset..self.state.width() - inset {
                 // left
                 *self.state.get_mut(x, inset).mat_mut() = mat::Static::conductor(conductivity).into();
diff --git a/src/render.rs b/src/render.rs
index 9fa34f4..37e4b8d 100644
--- a/src/render.rs
+++ b/src/render.rs
@@ -89,7 +89,7 @@ impl<'a> RenderSteps<'a> {
             }
         }
     }
-    fn render_vector_field<F: Fn(&Cell<mat::Static>) -> Point>(&mut self, color: Rgb<u8>, measure: F) {
+    fn render_vector_field<F: Fn(&Cell<mat::Static>) -> Point>(&mut self, color: Rgb<u8>, typical: f64, measure: F) {
         let w = self.sim.width();
         let h = self.sim.height();
         let vec_spacing = 10;
@@ -97,8 +97,8 @@ impl<'a> RenderSteps<'a> {
             for x in 0..w {
                 if x % vec_spacing == 0 && y % vec_spacing == 0 {
                     let vec = self.field_vector(x, y, vec_spacing, &measure);
-                    let norm_vec = scale_vector(vec, 100.0);
-                    let alpha = scale_unsigned(vec.mag_sq(), 500.0);
+                    let norm_vec = scale_vector(vec, typical);
+                    let alpha = 0.7*scale_unsigned(vec.mag_sq(), typical * 5.0);
                     let vec = norm_vec * (vec_spacing as f64);
                     let center = Point::new(x as _, y as _) + Point::new(vec_spacing as _, vec_spacing as _)*0.5;
                     self.im.draw_field_arrow(center, vec, color, alpha as f32);
@@ -107,7 +107,15 @@ impl<'a> RenderSteps<'a> {
         }
     }
     fn render_e_field(&mut self) {
-        self.render_vector_field(Rgb([0xff, 0xff, 0xff]), |cell| cell.e());
+        self.render_vector_field(Rgb([0xff, 0xff, 0xff]), 100.0, |cell| cell.e());
+        // current
+        self.render_vector_field(Rgb([0x00, 0xa0, 0x30]), 0.001, |cell| {
+            if cell.mat().conductivity() >= 1.0e3 {
+                cell.e()*cell.mat().conductivity()
+            } else {
+                Default::default()
+            }
+        });
     }
     fn render_measurements(&mut self) {
         for (meas_no, m) in self.meas.iter().enumerate() {