src/main.rs

@@ -3,20 +3,20 @@ use std::io::stdin;
 
 use macroquad::prelude::*;
 
-const DOT_RADIUS: f32 = 1.0;
+const DOT_RADIUS: f32 = 2.0;
+const TAIL_LEN: usize = 250;
 
 #[derive(Clone,Copy)]
 struct Dot {
     x: f32,
     y: f32,
 }
-
 impl Dot {
     fn new(x: f32, y: f32) -> Self {
         Self {x,y}
     }
-    fn draw(&self) {
+    fn draw(&self, color: Color) {
-        draw_circle(self.x, self.y,DOT_RADIUS, GREEN);
+        draw_circle(self.x, self.y,DOT_RADIUS, color);
     }
 }
 
@@ -48,36 +48,35 @@ impl DebugWindow {
     }
 }
 
-
 enum Axis {
     One,
     Two
 }
-
 struct Tail {
-    points: [Dot; 500],
+    points: [Dot; TAIL_LEN],
     head: usize,
     axis: Axis,
+    /// What the tail treats as 0
     x_offset: f32,
+    /// What the tail treats as 0
     y_offset: f32,
+    /// How fast X scrolls when using a since axis tail
     px_per_s: f32,
 }
 impl Tail {
     fn new(axis: Axis) -> Self {
-        
         let (x_offset, y_offset) = match axis {
             Axis::One => (0., screen_height() /2.),
             Axis::Two => (screen_width() /2., screen_height() /2.),
         };
-        
         Self {
             // start all the dots off screen
-            points: [Dot::new(-1.,-1.); 500],
+            points: [Dot::new(-1.,-1.); TAIL_LEN],
             head: 0,
             axis,
             x_offset,
             y_offset,
-            px_per_s: 500.,
+            px_per_s: 1000.,
         }
     }
     fn place_next(&mut self, delta_time: f32, x_displace: f32, y_displace: f32) {
@@ -107,8 +106,19 @@ impl Tail {
         self.points[self.head] = dot;
     }
     fn draw(&self) {
-        // TODO fadding alpha?
+        self.points.into_iter().enumerate().for_each(|(index, dot) |{
-        self.points.iter().for_each(|d| d.draw());
+            let virtual_index = if index > self.head {
+                index-self.head
+            } else {
+                index + (self.points.len() - self.head)
+            };
+            
+            let faded = virtual_index as f32 / self.points.len() as f32;
+            let faded_inverse = 1. - faded;
+
+            // dots fade
+            dot.draw(Color { r: faded_inverse, g: faded, b: 0.2, a: faded+0.1});
+        });
     }
     fn dots(&self) -> usize {
         self.points.len()
@@ -120,7 +130,7 @@ async fn main() {
     // Dot params 
     let mut y_displacement = 0.;
     let mut x_displacement = 0.;
-    let mut tail = Tail::new(Axis::Two);
+    let mut tail = Tail::new(Axis::One);
 
     // Selection box
     let mut inital_x_pos = 0.;
@@ -128,7 +138,6 @@ async fn main() {
     
     // Tooling
     let mut show_debug = true;
-    let mut px_per_s: f32 = 1000.;
 
     let stdin = stdin();
     let handle= stdin.lock();
@@ -164,12 +173,6 @@ async fn main() {
         if is_key_pressed(KeyCode::F3) {
             show_debug = !show_debug;
         }
-        if is_key_pressed(KeyCode::Up) {
-            px_per_s += 5.;
-        }
-        if is_key_pressed(KeyCode::Down) {
-            px_per_s -= 5.;
-        }
         // selection box
         if is_mouse_button_pressed(MouseButton::Left) {
             (inital_x_pos, inital_y_pos) = mouse_position();
@@ -188,7 +191,6 @@ async fn main() {
             debug.add_line(format!("FPS {}, Latency {:.2}ms", get_fps(), delta_time * 1000.0));
             debug.add_line(format!("Dots {}", tail.dots()));
             debug.add_line(format!("Cursor Pos {:?}", mouse_position()));
-            debug.add_line(format!("px/s {}", px_per_s));
             debug.draw();
         }