fix(track): at a crossing at a wide angle the floor of the flangeway between a running rail and its guard rail is laid only where real crossings have it, as the cast floor of each corner up to 0.3 m past the rail of the other track and as separate spacer blocks every 0.5 m along the rest of the guard, and the floor takes its texture across its width at the scale of the head instead of one stretched column; the wheels of the other track roll over a guard rail across their whole tread instead of only over the head of their rail; and when the tracks cross at nearly a right angle the treads of the other track are laid as plain spans along the rail instead of lines running almost straight across it, which left fins standing up at every edge of a tread

world/RailLayout.h

@@ -30,6 +30,10 @@ double constexpr middle_angle { 0.35 };
 double constexpr wide_angle { 0.785 };
 double constexpr guard_reach { 1.0 };
 double constexpr guard_flare { 0.6 };
+double constexpr casting_reach { 0.3 };
+double constexpr square_slope { 3.0 };
+double constexpr spacer_length { 0.12 };
+double constexpr spacer_pitch { 0.5 };
 
 // where the inner rails of the two paths of a switch cross, found from their gauge lines behind the blades
 struct switch_frog {
@@ -122,6 +126,7 @@ struct guard_rail {
     glm::dvec2 tomiter { 0.0 };
     bool through { true };
     std::vector<rail_tread> treads;
+    knots::line castings;
 };
 struct rail_band {
     double at { 0.0 };