Improve clarity of start and finish

Author: tovrstra

CHANGELOG.md

@@ -8,6 +8,11 @@ and this project adheres to [Effort-based Versioning](https://jacobtomlinson.dev
 
 (no changes yet)
 
+### Changed
+
+- Improved README.
+- Improved clarity of first and last target.
+
 ## [1.0.0] - 2025-10-11
 
 Initial release, just to get things started.

README.md

@@ -21,6 +21,9 @@ and visualizes the slides [`boxcar_blitz.toml`](boxcar_blitz.toml) and [`brutal_
 
 Your eyes may need some time to adapt to the correct depth perception: black ridges are high-altitude separations between the colored valleys.
 
+Note that the starting point and the finish are denoted as green and red circles respectively.
+All other circles are waypoints that must be reached on the way down.
+
 ## Concept
 
 The idea is for students to use the surface implemented in `soapboxslide` to simulate the dynamics of a particle (or a connected set of particles) sliding down.

slides.jpg

@@ -400,22 +400,19 @@ def plot(
             )
             ax.plot(self.waypoints[:, 0], self.waypoints[:, 1], "ko", ms=10, zorder=3)
         if add_targets:
-            colors = {0: "g", len(self.waypoints) - 1: "r"}
+            target_colors = {0: "g", len(self.waypoints) - 1: "r"}
             for i, waypoint in enumerate(self.waypoints):
-                color = colors.get(i, "w")
-                alpha = 0.7 if color == "w" else 1.0
-                ax.add_patch(
-                    plt.Circle(
-                        waypoint,
-                        self.target_radius,
-                        color="none",
-                        ec=color,
-                        lw=2,
-                        ls=":",
-                        zorder=4,
-                        alpha=alpha,
-                    )
+                circle = plt.Circle(
+                    waypoint,
+                    self.target_radius,
+                    color=target_colors.get(i, "none"),
+                    ec="w",
+                    lw=2,
+                    ls=":",
+                    zorder=4,
+                    alpha=0.5,
                 )
+                ax.add_patch(circle)
         ax.set_xlim(0, self.width)
         ax.set_ylim(0, self.height)
         ax.set_xlabel("x [m]")