From c5ec6927b38bc29febd2811a743d3916aa7836b3 Mon Sep 17 00:00:00 2001
From: "Cutis L. Olson" <curt@stinson.flightgear.org>
Date: Fri, 23 Jul 2010 09:01:49 -0500
Subject: [PATCH] Add a method to set particle wind using from heading (deg)
 and speed (kt)

---
 simgear/scene/model/particles.cxx | 6 ++++--
 simgear/scene/model/particles.hxx | 7 +++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/simgear/scene/model/particles.cxx b/simgear/scene/model/particles.cxx
index 08037900..acac7dfc 100644
--- a/simgear/scene/model/particles.cxx
+++ b/simgear/scene/model/particles.cxx
@@ -62,11 +62,13 @@ void GlobalParticleCallback::operator()(osg::Node* node, osg::NodeVisitor* nv)
     osg::Matrix om(toOsg(q));
     osg::Vec3 v(0,0,9.81);
     gravity = om.preMult(v);
+    // NOTE: THIS WIND COMPUTATION DOESN'T SEEM TO AFFECT PARTICLES
     const osg::Vec3& zUpWind = Particles::getWindVector();
-    osg::Vec3 w(zUpWind.y(), zUpWind.x(), - zUpWind.z());
+    osg::Vec3 w(zUpWind.y(), zUpWind.x(), -zUpWind.z());
     wind = om.preMult(w);
 
-    //SG_LOG(SG_GENERAL, SG_ALERT, "wind vector:"<<w[0]<<","<<w[1]<<","<<w[2]<<"\n");
+    // SG_LOG(SG_GENERAL, SG_ALERT,
+    //        "wind vector:" << w[0] << "," <<w[1] << "," << w[2]);
 }
 
 
diff --git a/simgear/scene/model/particles.hxx b/simgear/scene/model/particles.hxx
index 6dda343d..78c10821 100644
--- a/simgear/scene/model/particles.hxx
+++ b/simgear/scene/model/particles.hxx
@@ -257,6 +257,13 @@ public:
      * magnitude is the velocity in meters per second.
      */
     static void setWindVector(const osg::Vec3& wind) { _wind = wind; }
+    static void setWindFrom(const double from_deg, const double speed_kt) {
+	double map_rad = -from_deg * SG_DEGREES_TO_RADIANS;
+	double speed_mps = speed_kt * SG_KT_TO_MPS;
+	_wind[0] = cos(map_rad) * speed_mps;
+	_wind[1] = sin(map_rad) * speed_mps;
+	_wind[2] = 0.0;
+    }
     static const osg::Vec3& getWindVector() { return _wind; }
 protected:
     float shooterExtraRange;
-- 
2.39.5