basic particle system implementation

simulationenvironment.h

@@ -36,8 +36,25 @@ public:
     void compute_season( int const Yearday ) const;
     // calculates current weather
     void compute_weather() const;
+    // data access
+    glm::vec3 const &
+        wind() const {
+            return m_wind.vector; }
 
 private:
+// types
+    struct basic_wind {
+        // internal state data
+        float azimuth;
+        float azimuth_change;
+        float velocity;
+        float velocity_change;
+        float change_time;
+        // output
+        glm::vec3 vector;
+    };
+// methods
+    void update_wind();
 // members
     CSkyDome m_skydome;
     cStars m_stars;
@@ -45,8 +62,8 @@ private:
     cMoon m_moon;
     TSky m_clouds;
     basic_precipitation m_precipitation;
-
     sound_source m_precipitationsound { sound_placement::external, -1 };
+    basic_wind m_wind;
 };
 
 namespace simulation {