From c147c5eb55f415bd4840af3bef97f7e072768486 Mon Sep 17 00:00:00 2001
From: Stuart Buchanan <stuart_d_buchanan@yahoo.co.uk>
Date: Thu, 4 Mar 2021 21:00:12 +0000
Subject: [PATCH] WS30 - Move expensive conversion to loading thread

---
 simgear/scene/tgdb/LineFeatureBin.cxx |  9 ++++++---
 simgear/scene/tgdb/LineFeatureBin.hxx |  5 ++---
 simgear/scene/tgdb/VPBTechnique.cxx   | 12 ++----------
 3 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/simgear/scene/tgdb/LineFeatureBin.cxx b/simgear/scene/tgdb/LineFeatureBin.cxx
index ddf9fbe3..769bb49b 100644
--- a/simgear/scene/tgdb/LineFeatureBin.cxx
+++ b/simgear/scene/tgdb/LineFeatureBin.cxx
@@ -28,6 +28,8 @@
 
 #include <simgear/debug/logstream.hxx>
 #include <simgear/io/iostreams/sgstream.hxx>
+#include <simgear/math/SGGeod.hxx>
+#include <simgear/scene/util/OsgMath.hxx>
 
 #include "LineFeatureBin.hxx"
 
@@ -72,7 +74,7 @@ LineFeatureBin::LineFeatureBin(const SGPath& absoluteFileName, const std::string
         float w = 0.0f;
         int attributes = 0;
         float a=0, b=0, c=0, d=0;
-        std::list<SGGeod> nodes;
+        std::list<osg::Vec3d> nodes;
 
         in >> w >> attributes >> a >> b >> c >> d;
 
@@ -89,8 +91,9 @@ LineFeatureBin::LineFeatureBin(const SGPath& absoluteFileName, const std::string
                 break;
             }
 
-            const SGGeod node = SGGeod::fromDeg(lon, lat);
-            nodes.push_back(node);
+            SGVec3d tmp;
+            SGGeodesy::SGGeodToCart(SGGeod::fromDeg(lon, lat), tmp);
+            nodes.push_back(toOsg(tmp));
         }
 
         if (nodes.size() > 1) {
diff --git a/simgear/scene/tgdb/LineFeatureBin.hxx b/simgear/scene/tgdb/LineFeatureBin.hxx
index 13b7cde6..88b0312d 100644
--- a/simgear/scene/tgdb/LineFeatureBin.hxx
+++ b/simgear/scene/tgdb/LineFeatureBin.hxx
@@ -30,7 +30,6 @@
 #include <osg/Matrix>
 
 #include <simgear/misc/sg_path.hxx>
-#include <simgear/math/SGGeod.hxx>
 
 namespace simgear
 {
@@ -42,14 +41,14 @@ public:
     ~LineFeatureBin() = default;
 
     struct LineFeature {
-        const std::list<SGGeod> _nodes;
+        const std::list<osg::Vec3d> _nodes;
         const float _width;
         const int _attributes;
         const float _a;
         const float _b;
         const float _c;
         const float _d;
-        LineFeature(const std::list<SGGeod> nodes, const float w, const int attributes, const float a, const float b, const float c, const float d) : 
+        LineFeature(const std::list<osg::Vec3d> nodes, const float w, const int attributes, const float a, const float b, const float c, const float d) :
           _nodes(nodes), _width(w), _attributes(attributes), _a(a), _b(b), _c(c), _d(d)
         {
         }
diff --git a/simgear/scene/tgdb/VPBTechnique.cxx b/simgear/scene/tgdb/VPBTechnique.cxx
index f76af7c0..d8078261 100644
--- a/simgear/scene/tgdb/VPBTechnique.cxx
+++ b/simgear/scene/tgdb/VPBTechnique.cxx
@@ -1861,15 +1861,11 @@ void VPBTechnique::generateLineFeature(BufferData& buffer, Locator* masterLocato
         return; 
     }
 
-    SGVec3d tmp;
     osg::Vec3d ma, mb;
     std::list<osg::Vec3d> roadPoints;
 
     auto road_iter = road._nodes.begin();
-
-    // This is expensive.
-    SGGeodesy::SGGeodToCart(SGGeod(*road_iter), tmp);
-    ma = toOsg(tmp) - modelCenter;
+    ma = *road_iter - modelCenter;
 
     osg::Vec3d intersect = getMeshIntersection(buffer, masterLocator, ma);
 
@@ -1879,10 +1875,7 @@ void VPBTechnique::generateLineFeature(BufferData& buffer, Locator* masterLocato
     road_iter++;
 
     for (; road_iter != road._nodes.end(); road_iter++) {
-
-        // This is expensive.
-        SGGeodesy::SGGeodToCart(SGGeod(*road_iter), tmp);
-        mb = toOsg(tmp) - modelCenter;
+        mb = *road_iter - modelCenter;
 
         intersect = getMeshIntersection(buffer, masterLocator, mb);
         if (intersect != mb) roadPoints.push_back(intersect);
@@ -1960,7 +1953,6 @@ void VPBTechnique::generateLineFeature(BufferData& buffer, Locator* masterLocato
 // Find the intersection of a given SGGeod with the terrain mesh
 osg::Vec3d VPBTechnique::getMeshIntersection(BufferData& buffer, Locator* masterLocator, osg::Vec3d pt) 
 {
-    SGVec3d tmp;
     osg::Vec3d local, origin, top;
 
     // Get a vertical line segment.