From f243048c450ef39439c3352b3cb3f427ec04f7d5 Mon Sep 17 00:00:00 2001
From: Dustin Carlino <dabreegster@gmail.com>
Date: Sat, 10 Nov 2018 16:39:47 -0800
Subject: [PATCH] drawing border nodes differently

---
 docs/design/maps.md               |  2 ++
 editor/src/render/intersection.rs |  6 ++++++
 map_model/src/intersection.rs     | 12 +++++++++++-
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/docs/design/maps.md b/docs/design/maps.md
index 34aa31bc6d..3a35292e81 100644
--- a/docs/design/maps.md
+++ b/docs/design/maps.md
@@ -282,3 +282,5 @@ can begin or end.
 	- manually marking them?
 - draw the FSM for cars/peds
 	- trips starting/ending at border nodes short-circuit some steps
+
+What about border nodes where the sidewalk can cross over, but the driving lane leads nowhere?
diff --git a/editor/src/render/intersection.rs b/editor/src/render/intersection.rs
index 15d4b98dd4..42d941efa3 100644
--- a/editor/src/render/intersection.rs
+++ b/editor/src/render/intersection.rs
@@ -19,6 +19,7 @@ pub struct DrawIntersection {
     sidewalk_corners: Vec<Polygon>,
     center: Pt2D,
     has_traffic_signal: bool,
+    is_border: bool,
     should_draw_stop_sign: bool,
 }
 
@@ -36,6 +37,7 @@ impl DrawIntersection {
             crosswalks: calculate_crosswalks(inter.id, map),
             sidewalk_corners: calculate_corners(inter.id, map),
             has_traffic_signal: inter.has_traffic_signal,
+            is_border: inter.is_border(map),
             should_draw_stop_sign: !inter.has_traffic_signal && !inter.is_degenerate(),
         }
     }
@@ -85,6 +87,10 @@ impl Renderable for DrawIntersection {
 
     fn draw(&self, g: &mut GfxCtx, opts: RenderOptions, ctx: Ctx) {
         let color = opts.color.unwrap_or_else(|| {
+            if self.is_border {
+                return ctx.cs.get("border intersection", Color::rgb(50, 205, 50));
+            }
+
             let changed = if let Some(s) = ctx.control_map.traffic_signals.get(&self.id) {
                 s.is_changed()
             } else if let Some(s) = ctx.control_map.stop_signs.get(&self.id) {
diff --git a/map_model/src/intersection.rs b/map_model/src/intersection.rs
index a1f9e04d0f..756ee776e3 100644
--- a/map_model/src/intersection.rs
+++ b/map_model/src/intersection.rs
@@ -5,7 +5,7 @@ use dimensioned::si;
 use geom::Pt2D;
 use std::collections::BTreeSet;
 use std::fmt;
-use {LaneID, RoadID, TurnID};
+use {LaneID, Map, RoadID, TurnID};
 
 // TODO reconsider pub usize. maybe outside world shouldnt know.
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, PartialOrd, Ord, Serialize, Deserialize)]
@@ -51,6 +51,16 @@ impl Intersection {
         self.roads.len() == 2
     }
 
+    pub fn is_border(&self, map: &Map) -> bool {
+        // Bias for driving
+        if !self.is_dead_end() {
+            return false;
+        }
+        let has_driving_in = self.incoming_lanes.iter().find(|l| map.get_l(**l).is_driving()).is_some();
+        let has_driving_out = self.outgoing_lanes.iter().find(|l| map.get_l(**l).is_driving()).is_some();
+        has_driving_in != has_driving_out
+    }
+
     pub fn dump_debug(&self) {
         println!("{}", abstutil::to_json(self));
     }