fix center lines for two-ways

TODO.md

@@ -46,12 +46,12 @@
 
 - multiple lanes
 	- display + mouseover parking lane and sidewalk
-		- make the center lines in geom layer work (use debug mode to verify)
 		- something broke curved roads
 		- make extra lanes for oneways work
 			- have to switch from Centered to DrivingDirection somehow
 			- either translate points up-front and be normal or fix geom layer (for turns and intersections)
 
+	- dont allow cars on non-driving lanes :)
 	- model cars parking
 		- maybe render numbers on the cars to distinguish them
 		- document the FSM (on lane driving, waiting, turning, parking, etc)

docs/backlog.md

@@ -20,6 +20,7 @@
 	- and maybe to recalculate fixedish things if they change?
 
 - more advanced road modeling, like https://wiki.openstreetmap.org/wiki/Proposed_features/Street_area
+- yellow center lines eat into the width of one lane arbitrarily
 
 ## Conga line idea
 

editor/src/plugins/selection.rs

@@ -174,6 +174,8 @@ impl SelectionState {
                         draw_map.get_t(turn.id).draw_full(g, render::TURN_COLOR);
                     },
                 }
+                // TODO tmp
+                draw_map.get_r(id).draw_debug(g, geom_map.get_r(id));
             }
             SelectionState::TooltipRoad(id) => {
                 canvas.draw_mouse_tooltip(g, &draw_map.get_r(id).tooltip_lines(map, geom_map));

editor/src/render/mod.rs

@@ -25,8 +25,8 @@ const BIG_ARROW_TIP_LENGTH: f64 = 1.0;
 const TURN_ICON_ARROW_TIP_LENGTH: f64 = BIG_ARROW_TIP_LENGTH * 0.8;
 const TURN_ICON_ARROW_LENGTH: f64 = 2.0;
 
-pub const DEBUG_COLOR: Color = canvas::PURPLE;
-pub const BRIGHT_DEBUG_COLOR: Color = [1.0, 0.1, 0.55, 1.0];
+pub const DEBUG_COLOR: Color = canvas::RED;
+pub const BRIGHT_DEBUG_COLOR: Color = [0.8, 0.1, 0.1, 1.0];
 pub const ROAD_COLOR: Color = canvas::BLACK;
 pub const PARKING_COLOR: Color = canvas::PURPLE;
 pub const SIDEWALK_COLOR: Color = canvas::GREEN;

geom/src/road.rs

@@ -41,6 +41,7 @@ impl GeomRoad {
         pts[num_pts - 1] = Pt2D::from(new_last_pt);
 
         // TODO handle offset
+        let offset = road.offset as f64;
         let lane_center_shift = if road.one_way_road {
             0.0
         } else if road.use_yellow_center_lines {
@@ -48,9 +49,9 @@ impl GeomRoad {
             // shouldn't match either lane. Needs to be its own thing, or adjust the bbox.
             (LANE_THICKNESS / 2.0) + (BIG_ARROW_THICKNESS / 2.0)
         } else {
-            (LANE_THICKNESS / 2.0)
+            LANE_THICKNESS * (offset + 0.5)
         };
-        // TODO when drawing cars along these lines, do we have the line overlap problem?
+        // TODO when drawing cars along these lines, do we have the line overlap problem? yes.
         let lane_center_lines: Vec<(Pt2D, Pt2D)> = pts.windows(2)
             .map(|pair| {
                 geometry::shift_line_perpendicularly_in_driving_direction(