Add a color terminal renderer

src/render.rs

@@ -1,3 +1,5 @@
+use ansi_term::Color::RGB;
+use crate::consts;
 use crate::SimState;
 
 pub struct NumericTermRenderer;
@@ -15,3 +17,23 @@ impl NumericTermRenderer {
         print!("\n");
     }
 }
+
+pub struct ColorTermRenderer;
+
+fn clamp(v: f32, range: f32) -> f32 {
+    v.min(range).max(-range)
+}
+
+impl ColorTermRenderer {
+    pub fn render(&self, state: &SimState) {
+        let square = "█";
+        for cell in state.cells() {
+            let b_value = clamp(cell.by() * consts::C * 128.0, 255.0);
+            let b_color = RGB(0, b_value.max(0.0) as _, b_value.abs() as _);
+            let e_value = clamp(cell.ez() * 128.0, 255.0);
+            let e_color = RGB(e_value.abs() as _, e_value.max(0.0) as _, 0);
+            print!("{}{}", e_color.paint(square), b_color.paint(square));
+        }
+        print!("\n");
+    }
+}