]> git.mxchange.org Git - simgear.git/blobdiff - simgear/sky/sky.cxx
Updating cloud code.
[simgear.git] / simgear / sky / sky.cxx
index eb86def9f5aa838d2b47cabd63eb35819102d326..d37cc9d88c99686cdbad9a885bb9540d843e12dc 100644 (file)
 
 #include <plib/ssg.h>          // plib include
 
+#include <simgear/constants.h>
+#include <simgear/math/fg_random.h>
+
 #include "sky.hxx"
 
 
 // Constructor
 SGSky::SGSky( void ) {
+    effective_visibility = visibility = 10000.0;
+
+    // near cloud visibility state variables
+    in_puff = false;
+    puff_length = 0;
+    puff_progression = 0;
+    ramp_up = 0.15;
+    ramp_down = 0.15;
 }
 
 
@@ -43,35 +54,45 @@ SGSky::~SGSky( void ) {
 
 // initialize the sky and connect the components to the scene graph at
 // the provided branch
-ssgBranch * SGSky::build(  double sun_size, double moon_size,
-                          int nplanets, sgdVec3 *planet_data,
-                          double planet_dist,
-                          int nstars, sgdVec3 *star_data, double star_dist )
+void SGSky::build(  double sun_size, double moon_size,
+                   int nplanets, sgdVec3 *planet_data,
+                   double planet_dist,
+                   int nstars, sgdVec3 *star_data, double star_dist )
 {
-    sky_selector = new ssgSelector;
-    sky_transform = new ssgTransform;
+    pre_root = new ssgRoot;
+    post_root = new ssgRoot;
+
+    pre_selector = new ssgSelector;
+    post_selector = new ssgSelector;
+
+    pre_transform = new ssgTransform;
+    post_transform = new ssgTransform;
 
     dome = new SGSkyDome;
-    sky_transform -> addKid( dome->build() );
+    pre_transform -> addKid( dome->build() );
 
     planets = new SGStars;
-    sky_transform -> addKid( planets->build(nplanets, planet_data,
+    pre_transform -> addKid( planets->build(nplanets, planet_data,
                                            planet_dist)
                             );
 
     stars = new SGStars;
-    sky_transform -> addKid( stars->build(nstars, star_data, star_dist) );
+    pre_transform -> addKid( stars->build(nstars, star_data, star_dist) );
     
     moon = new SGMoon;
-    sky_transform -> addKid( moon->build(tex_path, moon_size) );
+    pre_transform -> addKid( moon->build(tex_path, moon_size) );
 
     oursun = new SGSun;
-    sky_transform -> addKid( oursun->build(tex_path, sun_size) );
+    pre_transform -> addKid( oursun->build(tex_path, sun_size) );
+
+    pre_selector->addKid( pre_transform );
+    pre_selector->clrTraversalMaskBits( SSGTRAV_HOT );
 
-    sky_selector->addKid( sky_transform );
-    sky_selector->clrTraversalMaskBits( SSGTRAV_HOT );
+    post_selector->addKid( post_transform );
+    post_selector->clrTraversalMaskBits( SSGTRAV_HOT );
 
-    return sky_selector;
+    pre_root->addKid( pre_selector );
+    post_root->addKid( post_selector );
 }
 
 
@@ -87,11 +108,21 @@ bool SGSky::repaint( sgVec4 sky_color, sgVec4 fog_color,
                     int nplanets, sgdVec3 *planet_data,
                     int nstars, sgdVec3 *star_data )
 {
-    dome->repaint( sky_color, fog_color, sun_angle );
-    oursun->repaint( sun_angle );
-    moon->repaint( moon_angle );
-    planets->repaint( sun_angle, nplanets, planet_data );
-    stars->repaint( sun_angle, nstars, star_data );
+    if ( effective_visibility > 1000.0 ) {
+       enable();
+       dome->repaint( sky_color, fog_color, sun_angle );
+       oursun->repaint( sun_angle );
+       moon->repaint( moon_angle );
+       planets->repaint( sun_angle, nplanets, planet_data );
+       stars->repaint( sun_angle, nstars, star_data );
+
+       for ( int i = 0; i < (int)cloud_layers.size(); ++i ) {
+           cloud_layers[i]->repaint( fog_color );
+       }
+    } else {
+       // turn off sky
+       disable();
+    }
 
     return true;
 }
@@ -104,8 +135,8 @@ bool SGSky::repaint( sgVec4 sky_color, sgVec4 fog_color,
 // spin specifies a rotation about the new Z axis (this allows
 // additional orientation for the sunrise/set effects and is used by
 // the skydome and perhaps clouds.
-bool SGSky::reposition( sgVec3 view_pos, sgVec3 zero_elev, 
-                       double lon, double lat, double spin,
+bool SGSky::reposition( sgVec3 view_pos, sgVec3 zero_elev, sgVec3 view_up,
+                       double lon, double lat, double alt, double spin,
                        double gst, 
                        double sun_ra, double sun_dec, double sun_dist,
                        double moon_ra, double moon_dec, double moon_dist )
@@ -117,5 +148,174 @@ bool SGSky::reposition( sgVec3 view_pos, sgVec3 zero_elev,
     planets->reposition( view_pos, angle );
     stars->reposition( view_pos, angle );
 
+    for ( int i = 0; i < (int)cloud_layers.size(); ++i ) {
+       cloud_layers[i]->reposition( zero_elev, view_up, lon, lat, alt );
+    }
+
     return true;
 }
+
+
+// draw background portions of the sky
+void SGSky::draw_background() {
+    ssgCullAndDraw( pre_root );
+}
+
+
+// draw scenery elements of the sky
+void SGSky::draw_scene( float alt ) {
+
+    if ( effective_visibility < 4000.0 ) {
+       // bail and don't draw clouds
+       return;
+    }
+
+    // determine rendering order
+    int pos = 0;
+    while ( pos < (int)cloud_layers.size() && 
+           alt > cloud_layers[pos]->get_asl())
+    {
+       ++pos;
+    }
+
+    if ( pos == 0 ) {
+       // we are below all the cloud layers, draw top to bottom
+       for ( int i = cloud_layers.size() - 1; i >= 0; --i ) {
+           cloud_layers[i]->draw();
+       }
+    } else if ( pos >= (int)cloud_layers.size() ) {
+       // we are above all the cloud layers, draw bottom to top
+       for ( int i = 0; i < (int)cloud_layers.size(); ++i ) {
+           cloud_layers[i]->draw();
+       }
+    } else {
+       // we are between cloud layers, draw lower layers bottom to
+       // top and upper layers top to bottom
+       for ( int i = 0; i < pos; ++i ) {
+           cloud_layers[i]->draw();
+       }
+       for ( int i = cloud_layers.size() - 1; i >= pos; --i ) {
+           cloud_layers[i]->draw();
+       }
+    }
+}
+
+void SGSky::add_cloud_layer( double asl, double thickness, double transition ) {
+    SGCloudLayer *layer = new SGCloudLayer;
+    layer->build(tex_path, 40000.0f, asl, thickness, transition);
+
+    layer_list_iterator current = cloud_layers.begin();
+    layer_list_iterator last = cloud_layers.end();
+    while ( current != last && (*current)->get_asl() < asl ) {
+       ++current;
+    }
+
+    if ( current != last ) {
+       cloud_layers.insert( current, layer );
+    } else {
+       cloud_layers.push_back( layer );
+    }
+
+    for ( int i = 0; i < (int)cloud_layers.size(); ++i ) {
+       cout << "layer " << i << " = " << cloud_layers[i]->get_asl() << endl;
+    }
+    cout << endl;
+}
+
+
+// modify the current visibility based on cloud layers, thickness,
+// transition range, and simulated "puffs".
+void SGSky::modify_vis( float alt, float time_factor ) {
+    float effvis = visibility;
+
+    for ( int i = 0; i < (int)cloud_layers.size(); ++i ) {
+       float asl = cloud_layers[i]->get_asl();
+       float thickness = cloud_layers[i]->get_thickness();
+       float transition = cloud_layers[i]->get_transition();
+
+       double ratio = 1.0;
+
+       if ( alt < asl - transition ) {
+           // below cloud layer
+           ratio = 1.0;
+       } else if ( alt < asl ) {
+           // in lower transition
+           ratio = (asl - alt) / transition;
+       } else if ( alt < asl + thickness ) {
+           // in cloud layer
+           ratio = 0.0;
+       } else if ( alt < asl + thickness + transition ) {
+           // in upper transition
+           ratio = (alt - (asl + thickness)) / transition;
+       } else {
+           // above cloud layer
+           ratio = 1.0;
+       }
+
+       // accumulate effects from multiple cloud layers
+       effvis *= ratio;
+
+       if ( ratio < 1.0 ) {
+           if ( ! in_puff ) {
+               // calc chance of entering cloud puff
+               double rnd = fg_random();
+               double chance = rnd * rnd * rnd;
+               if ( chance > 0.95 /* * (diff - 25) / 50.0 */ ) {
+                   in_puff = true;
+                   do {
+                       puff_length = fg_random() * 2.0; // up to 2 seconds
+                   } while ( puff_length <= 0.0 );
+                   puff_progression = 0.0;
+               }
+           }
+
+           if ( in_puff ) {
+               // modify actual_visibility based on puff envelope
+           
+               if ( puff_progression <= ramp_up ) {
+                   double x = FG_PI_2 * puff_progression / ramp_up;
+                   double factor = 1.0 - sin( x );
+                   effvis = effvis * factor;
+               } else if ( puff_progression >= ramp_up + puff_length ) {
+                   double x = FG_PI_2 * 
+                       (puff_progression - (ramp_up + puff_length)) /
+                       ramp_down;
+                   double factor = sin( x );
+                   effvis = effvis * factor;
+               } else {
+                   effvis = 0.0;
+               }
+
+               /* cout << "len = " << puff_length
+                  << "  x = " << x 
+                  << "  factor = " << factor
+                  << "  actual_visibility = " << actual_visibility 
+                  << endl; */
+
+               // time_factor = ( global_multi_loop * 
+               //                 current_options.get_speed_up() ) /
+               //                (double)current_options.get_model_hz();
+
+               puff_progression += time_factor;
+
+               /* cout << "gml = " << global_multi_loop 
+                  << "  speed up = " << current_options.get_speed_up()
+                  << "  hz = " << current_options.get_model_hz() << endl;
+                  */ 
+
+               if ( puff_progression > puff_length + ramp_up + ramp_down) {
+                   in_puff = false; 
+               }
+           }
+
+           // never let visibility drop below zero
+           if ( effvis <= 0 ) {
+               effvis = 0.1;
+           }
+       }
+    } // for
+
+    effective_visibility = effvis;
+}
+