refactor(track): the rail code is split by concern into gauge lines, crossings and check rails, rail materials, rail profile measuring, planning the cuts and laying the geometry, instead of one TrackRails.cpp; rail_offset reuses nearest_distance and lateral; TTrack::rail_dimensions measures the profile through track_rails::measure_rail

world/GaugeLine.cpp

@@ -0,0 +1,65 @@
+/*
+This Source Code Form is subject to the
+terms of the Mozilla Public License, v.
+2.0. If a copy of the MPL was not
+distributed with this file, You can
+obtain one at
+http://mozilla.org/MPL/2.0/.
+*/
+
+#include "stdafx.h"
+
+#include "world/GaugeLine.h"
+
+namespace track_rails {
+
+gauge_line make_gauge_line( TSegment const &Segment, double const Offset, double const From ) {
+
+    gauge_line line;
+    line.segment = &Segment;
+    line.offset = Offset;
+    line.from = From;
+    auto const length { Segment.GetLength() };
+    auto const add = [&]( double const Distance ) {
+        glm::dvec3 point, tangent;
+        line.at( Distance, point, tangent );
+        line.points.push_back( point );
+        line.distances.push_back( Distance ); };
+    auto const count { std::max( { 1, Segment.RaSegCount(), static_cast<int>( std::ceil( ( length - From ) / 5.0 ) ) } ) };
+    for( int i = 0; i <= count; ++i ) {
+        add( From + ( length - From ) * i / count );
+    }
+    line.low = line.high = plan( line.points.front() );
+    for( auto const &point : line.points ) {
+        line.low = glm::min( line.low, plan( point ) );
+        line.high = glm::max( line.high, plan( point ) );
+    }
+    return line;
+}
+
+double lateral( gauge_line const &Line, int const Side, glm::dvec3 const &Point, double &Distance ) {
+
+    glm::dvec3 point, tangent;
+    for( int step = 0; step < 8; ++step ) {
+        Line.at( Distance, point, tangent );
+        Distance += glm::dot( plan( Point - point ), glm::normalize( plan( tangent ) ) );
+    }
+    Line.at( Distance, point, tangent );
+    return -glm::dot( plan( Point - point ), plan( Line.normal( Distance, Side ) ) );
+}
+
+double nearest_distance( gauge_line const &Line, glm::dvec3 const &Point ) {
+
+    auto result { Line.distances.front() };
+    auto nearest { std::numeric_limits<double>::max() };
+    for( std::size_t i = 0; i < Line.points.size(); ++i ) {
+        auto const gap { glm::length( plan( Line.points[ i ] - Point ) ) };
+        if( gap < nearest ) {
+            nearest = gap;
+            result = Line.distances[ i ];
+        }
+    }
+    return result;
+}
+
+} // namespace track_rails