Bug in grid indexing.

src/main.rs

@@ -1,9 +1,27 @@
+use indicatif::{ProgressBar, ProgressStyle};
 use physarum::model;
 
 fn main() {
-    let mut model = model::Model::new(128, 128, 4096, 1);
-    println!("{:#?}", model);
-    model.step();
-    model.step();
-    model.save_to_image();
+    let n_iterations = 400;
+    let pb = ProgressBar::new(n_iterations);
+    pb.set_style(
+        ProgressStyle::default_bar()
+            .template(
+                "{spinner:.green} [{elapsed_precise}] [{bar:40.cyan/blue}] {pos}/{len} ({eta})",
+            )
+            .progress_chars("#>-"),
+    );
+
+    let (width, height) = (1024, 1024);
+    let n_particles = 1 << 22;
+    let diffusivity = 1;
+    let mut model = model::Model::new(width, height, n_particles, diffusivity);
+    println!("Model configuration: {:#?}", model.config);
+
+    for i in 0..n_iterations {
+        model.step();
+        pb.set_position(i);
+    }
+    pb.finish_with_message("Finished!");
+    model.save_to_image("out.png");
 }