Slightly better way to get car world location #14

Cargo.toml

@@ -18,4 +18,7 @@ path = "./lib/kay_macros/"
 path = "./lib/descartes/"
 
 [dependencies.monet]
-path = "./lib/monet/"
+path = "./lib/monet/"
+
+[profile.release]
+debug = true

src/game/lanes_and_cars/lane_rendering.rs

@@ -1,8 +1,9 @@
-use descartes::{Band, FiniteCurve, WithUniqueOrthogonal, Norm};
+use descartes::{Band, FiniteCurve, WithUniqueOrthogonal, Norm, Path};
 use kay::{Actor, CVec, Individual, Recipient, RecipientAsSwarm, ActorSystem, Swarm, Fate};
 use monet::{Instance, Thing, Vertex};
 use core::geometry::band_to_thing;
 use super::{Lane, TransferLane, InteractionKind};
+use itertools::Itertools;
 
 #[path = "./resources/car.rs"]
 mod car;
@@ -78,15 +79,21 @@ use ::monet::UpdateThing;
 impl Recipient<RenderToScene> for Lane {
     fn receive(&mut self, msg: &RenderToScene) -> Fate {match *msg {
         RenderToScene{renderer_id, scene_id} => {
-            let car_instances = self.cars.iter().map(|car| {
-                let position2d = self.path.along(*car.position);
-                let direction = self.path.direction_along(*car.position);
-                Instance{
-                    instance_position: [position2d.x, position2d.y, 0.0],
-                    instance_direction: [direction.x, direction.y],
-                    instance_color: [0.5, 0.5, 0.5]
+            let mut cars_iter = self.cars.iter();
+            let mut current_offset = 0.0;
+            let mut car_instances = CVec::with_capacity(self.cars.len());
+            for segment in self.path.segments().iter() {
+                for car in cars_iter.take_while_ref(|car| *car.position - current_offset < segment.length()) {
+                    let position2d = segment.along(*car.position - current_offset);
+                    let direction = segment.direction_along(*car.position - current_offset);
+                    car_instances.push(Instance{
+                        instance_position: [position2d.x, position2d.y, 0.0],
+                        instance_direction: [direction.x, direction.y],
+                        instance_color: [0.5, 0.5, 0.5]
+                    })
                 }
-            }).collect::<CVec<_>>();
+                current_offset += segment.length;
+            }
 
             renderer_id << AddSeveralInstances{
                 scene_id: scene_id,

src/game/lanes_and_cars/planning/road_stroke_canvas.rs

@@ -54,15 +54,17 @@ impl Recipient<Event3d> for RoadStrokeCanvas {
             Fate::Live
         },
         Event3d::KeyDown(VirtualKeyCode::C) => {
-            Swarm::<Lane>::all() << ::game::lanes_and_cars::Add::Car(LaneCar{
-                trip: ID::invalid(),
-                as_obstacle: Obstacle{
-                    position: OrderedFloat(0.0),
-                    velocity: 0.0,
-                    max_velocity: 20.0
-                },
-                acceleration: 0.0
-            });
+            for _i in 0..100 {
+                Swarm::<Lane>::all() << ::game::lanes_and_cars::Add::Car(LaneCar{
+                    trip: ID::invalid(),
+                    as_obstacle: Obstacle{
+                        position: OrderedFloat(0.0),
+                        velocity: 0.0,
+                        max_velocity: 20.0
+                    },
+                    acceleration: 0.0
+                });
+            }
             Fate::Live
         },
         Event3d::KeyDown(VirtualKeyCode::G) => {