Harald JOHNSEN:

This is another update for the cloud code, a lot of lines but this time I have started to add the doxygen doc.

Misc
====

- corrected a bug when RTT is not available, the current rendering context was
  altered
- if RTT is not available then 3d clouds are not drawn at all
- impostors lighting is now recomputed when the sun changes position
- distant objects are no more seen in front of clouds
- blending of distant clouds is a bit better now
- litle optimization of code (uses a less cpu time)
- use layer wind speed and direction (no more hardcoded wind)
- fov is no more hardcoded

Changes
=======

- clouds (cu only) are dissipating/reforming (experimental)
- compute a turbulence factor that depends on surrounding clouds and type of
  clouds (experimental)
- clouds shapes are defined in cloudlayers.xml
- type of clouds present in a layer is also defined in cloudlayers.xml
- cloud layers are generated from metar and other misc. data (in progress)
- added a rain effect around the viewer (enabled in the rendering dialog and
  when the metar property says so)
- added a lightning effect (enabled in the rendering dialog) : cb clouds spawn
  new lightnings
- added a dialog to select from different weather source : metar/property,
  a 'fair weather' environment and a 'thunderstorm' environment.

simgear/environment/visual_enviro.cxx

@@ -20,32 +20,145 @@
 //
 //
 
+#ifdef HAVE_CONFIG_H
+#  include <simgear_config.h>
+#endif
+
+#include <plib/sg.h>
+#include <simgear/constants.h>
+#include <simgear/math/sg_random.h>
+#include <simgear/math/sg_geodesy.hxx>
+#include <simgear/math/point3d.hxx>
+#include <simgear/math/polar3d.hxx>
+#include <simgear/sound/soundmgr_openal.hxx>
 #include <simgear/scene/sky/cloudfield.hxx>
 #include <simgear/scene/sky/newcloud.hxx>
 #include "visual_enviro.hxx"
 
+#include <vector>
+
+SG_USING_STD(vector);
+
+
+typedef struct {
+	Point3D		pt;
+	int			depth;
+	int			prev;
+} lt_tree_seg;
+
+#define MAX_RAIN_SLICE	200
+static float rainpos[MAX_RAIN_SLICE];
+#define MAX_LT_TREE_SEG	400
+
+/**
+ * A class to render lightnings.
+ */
+class SGLightning {
+public:
+    /**
+     * Build a new lightning.
+     * The lightning has a limited life time. It will also play a thunder sounder once.
+     * @param lon lon longitude in degree
+     * @param lat lat latitude in degree
+     * @param alt asl of top of lightning
+     */
+	SGLightning(double lon, double lat, double alt);
+	~SGLightning();
+	void lt_Render(void);
+	void lt_build(void);
+	void lt_build_tree_branch(int tree_nr, Point3D &start, float energy, int nbseg, float segsize);
+
+	// contains all the segments of the lightning
+	lt_tree_seg lt_tree[MAX_LT_TREE_SEG];
+	// segment count
+	int		nb_tree;
+	// position of lightning
+	double	lon, lat, alt;
+	int		sequence_count;
+	// time to live
+	double	age;
+};
+
+typedef vector<SGLightning *> list_of_lightning;
+static list_of_lightning lightnings;
+
 SGEnviro sgEnviro;
 
 SGEnviro::SGEnviro(void) :
 	view_in_cloud(false),
-	precipitation_enable_state(false),
+	turbulence_enable_state(false),
+	precipitation_enable_state(true),
+	lightning_enable_state(false),
+	soundMgr(NULL),
+	snd_active(false),
+	snd_dist(0.0),
+	last_cloud_turbulence(0.0),
+	cloud_turbulence(0.0),
+	elapsed_time(0.0),
+	dt(0.0),
+	min_time_before_lt(0.0),
+	fov_width(55.0),
+	fov_height(55.0),
 	precipitation_density(100.0)
 
 {
+	for(int i = 0; i < MAX_RAIN_SLICE ; i++)
+		rainpos[i] = sg_random();
+
 }
 
 SGEnviro::~SGEnviro(void) {
+	list_of_lightning::iterator iLightning;
+	for( iLightning = lightnings.begin() ; iLightning != lightnings.end() ; iLightning++ ) {
+		delete (*iLightning);
+	}
+	lightnings.clear();
 }
 
-void SGEnviro::startOfFrame(void) {
+void SGEnviro::startOfFrame( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double delta_time) {
 	view_in_cloud = false;
+	// ask the impostor cache to do some cleanup
 	if(SGNewCloud::cldCache)
 		SGNewCloud::cldCache->startNewFrame();
+	last_cloud_turbulence = cloud_turbulence;
+	cloud_turbulence = 0.0;
+	elapsed_time += delta_time;
+	min_time_before_lt -= delta_time;
+	dt = delta_time;
+
+	sgMat4 T1, LON, LAT;
+    sgVec3 axis;
+
+    sgMakeTransMat4( T1, p );
+
+    sgSetVec3( axis, 0.0, 0.0, 1.0 );
+    sgMakeRotMat4( LON, lon, axis );
+
+    sgSetVec3( axis, 0.0, 1.0, 0.0 );
+    sgMakeRotMat4( LAT, 90.0 - lat, axis );
+
+    sgMat4 TRANSFORM;
+
+    sgCopyMat4( TRANSFORM, T1 );
+    sgPreMultMat4( TRANSFORM, LON );
+    sgPreMultMat4( TRANSFORM, LAT );
+
+    sgCoord pos;
+    sgSetCoord( &pos, TRANSFORM );
+
+	sgMakeCoordMat4( transform, &pos );
+    last_lon = lon;
+    last_lat = lat;
+	last_alt = alt;
 }
 
 void SGEnviro::endOfFrame(void) {
 }
 
+double SGEnviro::get_cloud_turbulence(void) const {
+	return last_cloud_turbulence;
+}
+
 // this can be queried to add some turbulence for example
 bool SGEnviro::is_view_in_cloud(void) const {
 	return view_in_cloud;
@@ -71,6 +184,10 @@ bool SGEnviro::get_clouds_enable_state(void) const {
 	return SGCloudField::get_enable3dClouds();
 }
 
+bool SGEnviro::get_turbulence_enable_state(void) const {
+	return turbulence_enable_state;
+}
+
 void SGEnviro::set_CacheResolution(int resolutionPixels) {
 	SGCloudField::set_CacheResolution(resolutionPixels);
 }
@@ -87,7 +204,9 @@ void SGEnviro::set_clouds_density(float density) {
 void SGEnviro::set_clouds_enable_state(bool enable) {
 	SGCloudField::set_enable3dClouds(enable);
 }
-
+void SGEnviro::set_turbulence_enable_state(bool enable) {
+	turbulence_enable_state = enable;
+}
 // rain/snow
 float SGEnviro::get_precipitation_density(void) const {
 	return precipitation_density;
@@ -105,9 +224,453 @@ void SGEnviro::set_precipitation_enable_state(bool enable) {
 
 // others
 bool SGEnviro::get_lightning_enable_state(void) const {
-	return false;
+	return lightning_enable_state;
 }
 
 void SGEnviro::set_lightning_enable_state(bool enable) {
+	lightning_enable_state = enable;
+	if( ! enable ) {
+		// TODO:cleanup
+	}
 }
 
+void SGEnviro::setLight(sgVec4 adj_fog_color) {
+	sgCopyVec4( fog_color, adj_fog_color );
+	if( false ) {
+	//    ssgGetLight( 0 ) -> setColour( GL_DIFFUSE, l->scene_diffuse() );
+	}
+}
+
+void SGEnviro::callback_cloud(float heading, float alt, float radius, int familly, float dist) {
+	// send data to wx radar
+	// compute turbulence
+	// draw precipitation
+	// draw lightning
+	// compute illumination
+
+	// http://www.pilotfriend.com/flight_training/weather/THUNDERSTORM%20HAZARDS1.htm
+	double turbulence = 0.0;
+	if( dist < radius * radius * 2.25f ) {
+		switch(familly) {
+			case SGNewCloud::CLFamilly_st:
+				turbulence = 0.2;
+				break;
+			case SGNewCloud::CLFamilly_ci:
+			case SGNewCloud::CLFamilly_cs:
+			case SGNewCloud::CLFamilly_cc:
+			case SGNewCloud::CLFamilly_ac:
+			case SGNewCloud::CLFamilly_as:
+				turbulence = 0.1;
+				break;
+			case SGNewCloud::CLFamilly_sc:
+				turbulence = 0.3;
+				break;
+			case SGNewCloud::CLFamilly_ns:
+				turbulence = 0.4;
+				break;
+			case SGNewCloud::CLFamilly_cu:
+				turbulence = 0.5;
+				break;
+			case SGNewCloud::CLFamilly_cb:
+				turbulence = 0.6;
+				break;
+		}
+		// full turbulence inside cloud, half in the vicinity
+		if( dist > radius * radius )
+			turbulence *= 0.5;
+		if( turbulence > cloud_turbulence )
+			cloud_turbulence = turbulence;
+		// we can do 'local' precipitations too
+	}
+
+	// convert to LWC for radar (experimental)
+	// http://www-das.uwyo.edu/~geerts/cwx/notes/chap08/moist_cloud.html
+	double LWC = 0.0;
+	switch(familly) {
+		case SGNewCloud::CLFamilly_st:
+			LWC = 0.29;
+			break;
+		case SGNewCloud::CLFamilly_cu:
+			LWC = 0.27;
+			break;
+		case SGNewCloud::CLFamilly_cb:
+			LWC = 2.0;
+			break;
+		case SGNewCloud::CLFamilly_sc:
+			LWC = 0.44;
+			break;
+		case SGNewCloud::CLFamilly_ci:
+			LWC = 0.03;
+			break;
+		// no data
+		case SGNewCloud::CLFamilly_cs:
+		case SGNewCloud::CLFamilly_cc:
+		case SGNewCloud::CLFamilly_ac:
+		case SGNewCloud::CLFamilly_as:
+			LWC = 0.03;
+			break;
+		case SGNewCloud::CLFamilly_ns:
+			LWC = 0.29*2.0;
+			break;
+	}
+	// TODO:send data to radar antenna
+	// NB:data valid only from cockpit view
+
+	// spawn a new lightning
+	if(min_time_before_lt <= 0.0 && (familly == SGNewCloud::CLFamilly_cb) &&
+		dist < 15000.0 * 15000.0 && sg_random() > 0.9f) {
+		double lat, lon;
+		Point3D orig, dest;
+		orig.setlat(last_lat * SG_DEGREES_TO_RADIANS );
+		orig.setlon(last_lon * SG_DEGREES_TO_RADIANS );
+		orig.setelev(0.0);
+		dist = sgSqrt(dist);
+		dest = calc_gc_lon_lat(orig, heading, dist);
+		lon = dest.lon() * SG_RADIANS_TO_DEGREES;
+		lat = dest.lat() * SG_RADIANS_TO_DEGREES;
+		addLightning( lon, lat, alt );
+
+		// reset timer
+		min_time_before_lt = 5.0 + sg_random() * 30;
+		// DEBUG only
+//		min_time_before_lt = 1.0;
+	}
+}
+
+// precipitation rendering code
+void SGEnviro::DrawCone2(float baseRadius, float height, int slices, bool down, double rain_norm, double speed) {
+
+	sgVec3 light;
+	sgVec3 min_light = {0.35, 0.35, 0.35};
+	sgAddVec3( light, fog_color, min_light );
+	float da = SG_PI * 2.0f / (float) slices;
+	// low number = faster
+	float speedf = 2.5f - speed / 200.0;
+	if( speedf < 1.0f )
+		speedf = 1.0f;
+	float lenf = 0.03f + speed / 2000.0;
+	if( lenf > 0.10f )
+		lenf = 0.10f;
+    float t = fmod((float) elapsed_time, speedf) / speedf;
+//	t = 0.1f;
+	if( !down )
+		t = 1.0f - t;
+	float angle = 0.0f;
+	glColor4f(1.0f, 0.7f, 0.7f, 0.9f);
+	glBegin(GL_LINES);
+	int rainpos_indice = 0;
+	for( int i = 0 ; i < slices ; i++ ) {
+		float x = cos(angle) * baseRadius;
+		float y = sin(angle) * baseRadius;
+		angle += da;
+		sgVec3 dir = {x, -height, y};
+
+		// rain drops at 2 different speed to simulate depth
+		float t1 = (i & 1 ? t : t + t) + rainpos[rainpos_indice];
+		if(t1 > 1.0f)	t1 -= 1.0f;
+		if(t1 > 1.0f)	t1 -= 1.0f;
+
+		// distant raindrops are more transparent
+		float c = (i & 1 ? t1 * 0.5f : t1 * 0.9f);
+		glColor4f(c * light[0], c * light[1], c * light[2], c);
+		sgVec3 p1, p2;
+		sgScaleVec3(p1, dir, t1);
+		// distant raindrops are shorter
+		float t2 = t1 + (i & 1 ? lenf : lenf+lenf);
+		sgScaleVec3(p2, dir, t2);
+
+		glVertex3f(p1[0], p1[1] + height, p1[2]);
+		glVertex3f(p2[0], p2[1] + height, p2[2]);
+		if( ++rainpos_indice >= MAX_RAIN_SLICE )
+			rainpos_indice = 0;
+	}
+	glEnd();
+}
+
+// TODO:check alt vs layer
+void SGEnviro::drawRain(double pitch, double roll, double speed, double rain_norm) {
+
+	glBindTexture(GL_TEXTURE_2D, 0);
+
+	glDisable(GL_DEPTH_TEST);
+	glShadeModel(GL_SMOOTH);
+	glEnable(GL_BLEND);
+	glBlendFunc( GL_DST_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
+	glDisable( GL_FOG );
+	glDisable(GL_LIGHTING);
+
+	int slice_count = (40.0 + rain_norm*150.0)* precipitation_density / 100.0;
+
+	float angle = speed;
+	if( angle > 90.0 )
+		angle = 90.0;
+
+	glPushMatrix();
+		// TODO:find the real view orientation, not the AC one
+		// the cone rotate with speed
+		angle = -pitch - angle;
+		glRotatef(angle, 1.0, 0.0, 0.0);
+		glRotatef(roll, 0.0, 1.0, 0.0);
+
+		// up cone
+		DrawCone2(15.0, 30.0, slice_count, true, rain_norm, speed);
+		// down cone (usually not visible)
+		if(angle > 0.0)
+			DrawCone2(15.0, -30.0, slice_count, false, rain_norm, speed);
+
+	glPopMatrix();
+
+	glEnable(GL_LIGHTING);
+	glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
+	glEnable( GL_FOG );
+	glEnable(GL_DEPTH_TEST);
+
+}
+
+void SGEnviro::set_soundMgr(SGSoundMgr *mgr) {
+	soundMgr = mgr;
+}
+
+void SGEnviro::drawPrecipitation(double rain_norm, double snow_norm, double hail_norm, double pitch, double roll, double speed) {
+	// TODO:check alt with right layer (wich layer ?)
+	if( precipitation_enable_state && rain_norm > 0.0)
+		drawRain(pitch, roll, speed, rain_norm);
+}
+
+
+SGLightning::SGLightning(double _lon, double _lat, double _alt) :
+	lon(_lon),
+	lat(_lat),
+	alt(_alt),
+	age(1.0 + sg_random() * 4.0),
+	nb_tree(0)
+{
+//	sequence_count = 1 + sg_random() * 5.0;
+	lt_build();
+}
+
+SGLightning::~SGLightning() {
+}
+
+// lightning rendering code
+void SGLightning::lt_build_tree_branch(int tree_nr, Point3D &start, float energy, int nbseg, float segsize) {
+
+	sgVec3 dir, newdir;
+	int nseg = 0;
+	Point3D pt = start;
+	if( nbseg == 50 )
+		sgSetVec3( dir, 0.0, -1.0, 0.0 );
+	else {
+		sgSetVec3( dir, sg_random() - 0.5f, sg_random() - 0.5f, sg_random() - 0.5f);
+		sgNormaliseVec3(dir);
+	}
+	if( nb_tree >= MAX_LT_TREE_SEG )
+		return;
+
+	lt_tree[nb_tree].depth = tree_nr;
+	nseg = 0;
+	lt_tree[nb_tree].pt = pt;
+	lt_tree[nb_tree].prev = -1;
+	nb_tree ++;
+
+	// TODO:check agl
+	while(nseg < nbseg && pt.y() > 0.0) {
+        int prev = nb_tree - 1;
+        nseg++;
+		// add a branch
+        if( energy * sg_random() > 0.8f )
+			lt_build_tree_branch(tree_nr + 1, pt, energy * 0.9f, nbseg == 50 ? 10 : nbseg * 0.4f, segsize * 0.7f);
+
+		if( nb_tree >= MAX_LT_TREE_SEG )
+			return;
+		sgSetVec3(newdir, (sg_random() - 0.5f), (sg_random() - 0.5f) - (nbseg == 50 ? 0.5f : 0.0), (sg_random() - 0.5f));
+		sgNormaliseVec3(newdir);
+		sgAddVec3( dir, newdir);
+		sgNormaliseVec3(dir);
+		sgVec3 scaleDir;
+		sgScaleVec3( scaleDir, dir, segsize * energy * 0.5f );
+		pt[PX] += scaleDir[0];
+		pt[PY] += scaleDir[1];
+		pt[PZ] += scaleDir[2];
+
+		lt_tree[nb_tree].depth = tree_nr;
+		lt_tree[nb_tree].pt = pt;
+		lt_tree[nb_tree].prev = prev;
+		nb_tree ++;
+	}
+}
+
+void SGLightning::lt_build(void) {
+    Point3D top;
+    nb_tree = 0;
+    top[PX] = 0 ;
+    top[PY] = alt;
+    top[PZ] = 0;
+    lt_build_tree_branch(0, top, 1.0, 50, top[PY] / 8.0);
+	if( ! sgEnviro.soundMgr )
+		return;
+	Point3D start( sgEnviro.last_lon*SG_DEGREES_TO_RADIANS, sgEnviro.last_lat*SG_DEGREES_TO_RADIANS, 0.0 );
+	Point3D dest( lon*SG_DEGREES_TO_RADIANS, lat*SG_DEGREES_TO_RADIANS, 0.0 );
+	double course = 0.0, dist = 0.0;
+	calc_gc_course_dist( dest, start, &course, &dist );
+	if( dist < 10000.0 && ! sgEnviro.snd_playing && (dist < sgEnviro.snd_dist || ! sgEnviro.snd_active) ) {
+		sgEnviro.snd_timer = 0.0;
+		sgEnviro.snd_wait  = dist / 340;
+		sgEnviro.snd_dist  = dist;
+		sgEnviro.snd_pos_lat = lat;
+		sgEnviro.snd_pos_lon = lon;
+		sgEnviro.snd_active = true;
+		sgEnviro.snd_playing = false;
+	}
+}
+
+
+void SGLightning::lt_Render(void) {
+	float flash = 0.5;
+	if( fmod(sgEnviro.elapsed_time*100.0, 100.0) > 50.0 )
+		flash = sg_random() * 0.75f + 0.25f;
+    float h = lt_tree[0].pt[PY];
+	sgVec4 col={0.62f, 0.83f, 1.0f, 1.0f};
+	sgVec4 c;
+
+#define DRAW_SEG() \
+			{glBegin(GL_LINES); \
+				glColor4fv(c); \
+                glVertex3f(lt_tree[n].pt[PX], lt_tree[n].pt[PZ], lt_tree[n].pt[PY]); \
+                glVertex3f(lt_tree[lt_tree[n].prev].pt[PX], lt_tree[lt_tree[n].prev].pt[PZ], lt_tree[lt_tree[n].prev].pt[PY]); \
+			glEnd();}
+
+	glDepthMask( GL_FALSE );
+	glEnable(GL_BLEND);
+	glBlendFunc( GL_DST_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
+	glBindTexture(GL_TEXTURE_2D, 0);
+
+	glDisable(GL_LIGHTING);
+	glDisable( GL_FOG );
+	glPushMatrix();
+	sgMat4 modelview, tmp;
+    ssgGetModelviewMatrix( modelview );
+	sgCopyMat4( tmp, sgEnviro.transform );
+    sgPostMultMat4( tmp, modelview );
+    ssgLoadModelviewMatrix( tmp );
+
+    Point3D start( sgEnviro.last_lon*SG_DEGREES_TO_RADIANS, sgEnviro.last_lat*SG_DEGREES_TO_RADIANS, 0.0 );
+    Point3D dest( lon*SG_DEGREES_TO_RADIANS, lat*SG_DEGREES_TO_RADIANS, 0.0 );
+    double course = 0.0, dist = 0.0;
+    calc_gc_course_dist( dest, start, &course, &dist );
+    double ax = 0.0, ay = 0.0;
+    ax = cos(course) * dist;
+    ay = sin(course) * dist;
+
+	glTranslatef( ax, ay, -sgEnviro.last_alt );
+//	glTranslatef( ax, ay, 0 );
+
+	for( int n = 0 ; n < nb_tree ; n++ ) {
+        if( lt_tree[n].prev < 0 )
+			continue;
+
+        float t1 = sgLerp(0.5, 1.0, lt_tree[n].pt[PY] / h);
+		t1 *= flash;
+		if( lt_tree[n].depth >= 2 ) {
+            glLineWidth(3);
+			sgScaleVec4(c, col, t1 * 0.6f);
+			DRAW_SEG();
+		} else {
+			if( lt_tree[n].depth == 0 ) {
+                glLineWidth(12);
+				sgScaleVec4(c, col, t1 * 0.5f);
+				DRAW_SEG();
+
+                glLineWidth(6);
+				sgScaleVec4(c, col, t1);
+				DRAW_SEG();
+			} else {
+                glLineWidth(6);
+				sgScaleVec4(c, col, t1 * 0.7f);
+				DRAW_SEG();
+			}
+
+            if( lt_tree[n].depth == 0 ) 
+                glLineWidth(3);
+			else
+                glLineWidth(2);
+
+            sgSetVec4(c, t1, t1, t1, t1);
+			DRAW_SEG();
+		}
+
+	}
+    glLineWidth(1);
+	glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
+	glPopMatrix();
+	glDepthMask( GL_TRUE );	
+	glEnable( GL_FOG );
+	glEnable(GL_LIGHTING);
+}
+
+void SGEnviro::addLightning(double lon, double lat, double alt) {
+	if( lightnings.size() > 10)
+		return;
+	SGLightning *lt= new SGLightning(lon, lat, alt);
+	lightnings.push_back(lt);
+}
+
+void SGEnviro::drawLightning(void) {
+	list_of_lightning::iterator iLightning;
+	// play 'thunder' for lightning
+	if( snd_active )
+		if( !snd_playing ) {
+			// wait until sound has reached us
+			snd_timer += dt;
+			if( snd_timer >= snd_wait ) {
+				snd_playing = true;
+				// compute relative position of lightning
+				Point3D start( sgEnviro.last_lon*SG_DEGREES_TO_RADIANS, sgEnviro.last_lat*SG_DEGREES_TO_RADIANS, 0.0 );
+				Point3D dest( snd_pos_lon*SG_DEGREES_TO_RADIANS, snd_pos_lat*SG_DEGREES_TO_RADIANS, 0.0 );
+				double course = 0.0, dist = 0.0;
+				calc_gc_course_dist( dest, start, &course, &dist );
+				double ax = 0.0, ay = 0.0;
+				ax = cos(course) * dist;
+				ay = sin(course) * dist;
+				SGSoundSample *snd = soundMgr->find("thunder");
+				if( snd ) {
+					ALfloat pos[3]={ax, ay, -sgEnviro.last_alt };
+					snd->set_source_pos(pos);
+					snd->play_once();
+				}
+			}
+		} else {
+			if( !soundMgr->is_playing("thunder") ) {
+				snd_active = false;
+				snd_playing = false;
+			}
+		}
+
+	if( ! lightning_enable_state )
+		return;
+
+	for( iLightning = lightnings.begin() ; iLightning != lightnings.end() ; iLightning++ ) {
+		if( dt )
+			if( sg_random() > 0.95f )
+				(*iLightning)->lt_build();
+		(*iLightning)->lt_Render();
+		(*iLightning)->age -= dt;
+		if( (*iLightning)->age < 0.0 ) {
+			delete (*iLightning);
+			lightnings.erase( iLightning );
+			break;
+		}
+	}
+
+}
+
+
+void SGEnviro::setFOV( float w, float h ) {
+	fov_width = w;
+	fov_height = h;
+}
+
+void SGEnviro::getFOV( float &w, float &h ) {
+	w = fov_width;
+	h = fov_height;
+}

simgear/environment/visual_enviro.hxx

@@ -22,23 +22,89 @@
 #ifndef _VISUAL_ENVIRO_HXX
 #define _VISUAL_ENVIRO_HXX
 
-class SGEnviro {
+#include <simgear/compiler.h>
+#include STL_STRING
 
+SG_USING_STD(string);
+
+class SGLightning;
+class SGSoundMgr;
+
+/**
+ * Visual environment helper class.
+ */
+class SGEnviro {
+friend SGLightning;
 private:
+	void DrawCone2(float baseRadius, float height, int slices, bool down, double rain_norm, double speed);
+	void lt_update(void);
+
 	bool view_in_cloud;
 	bool precipitation_enable_state;
 	float precipitation_density;
+	bool turbulence_enable_state;
+	double last_cloud_turbulence, cloud_turbulence;
+	bool lightning_enable_state;
+	double elapsed_time, dt;
+	sgVec4	fog_color;
+	sgMat4 transform;
+	double last_lon, last_lat, last_alt;
+	SGSoundMgr	*soundMgr;
+	bool		snd_active, snd_playing;
+	double		snd_timer, snd_wait, snd_pos_lat, snd_pos_lon, snd_dist;
+	double		min_time_before_lt;
+
+	float fov_width, fov_height;
 
 public:
 	SGEnviro();
 	~SGEnviro();
 
-	void startOfFrame(void);
+    /**
+     * Forward a few states used for renderings.
+     */
+	void startOfFrame( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double delta_time);
+
 	void endOfFrame(void);
 
+    /**
+     * Whenever a cloud is drawn we check his 'impact' on the environment.
+     * @param heading direction of cloud in radians
+     * @param alt asl of cloud in meters
+     * @param radius radius of cloud in meters
+     * @param familly cloud familly
+     * @param dist  squared dist to cloud in meters
+     */
+	void callback_cloud(float heading, float alt, float radius, int familly, float dist);
+
+	void drawRain(double pitch, double roll, double speed, double rain_norm);
+    /**
+     * Draw rain or snow precipitation around the viewer.
+     * @param rain_norm rain normalized intensity given by metar class
+     * @param snow_norm snow normalized intensity given by metar class
+     * @param hail_norm hail normalized intensity given by metar class
+     * @param pitch pitch rotation of viewer
+     * @param roll roll rotation of viewer
+     * @param speed moving speed of viewer in kt
+     */
+	void drawPrecipitation(double rain_norm, double snow_norm, double hail_norm,
+							double pitch, double roll, double speed);
+
+    /**
+     * Draw the lightnings spawned by cumulo nimbus.
+     */
+	void drawLightning(void);
+
+    /**
+     * Forward the fog color used by the rain rendering.
+     * @param adj_fog_color color of the fog
+     */
+	void setLight(sgVec4 adj_fog_color);
+
 	// this can be queried to add some turbulence for example
 	bool is_view_in_cloud(void) const;
 	void set_view_in_cloud(bool incloud);
+	double get_cloud_turbulence(void) const;
 
 	// Clouds
 	// return the size of the memory pool used by texture impostors
@@ -47,23 +113,76 @@ public:
 	float get_clouds_visibility(void) const;
 	float get_clouds_density(void) const;
 	bool get_clouds_enable_state(void) const;
+	bool get_turbulence_enable_state(void) const;
 
+    /**
+     * Set the size of the impostor texture cache for 3D clouds.
+     * @param sizeKb size of the texture pool in Kb
+     */
 	void set_clouds_CacheSize(int sizeKb);
+    /**
+     * Set the resolution of the impostor texture for 3D clouds.
+     * @param resolutionPixels size of each texture in pixels (64|128|256)
+     */
 	void set_CacheResolution(int resolutionPixels);
+    /**
+     * Set the maximum range used when drawing clouds.
+	 * Clouds are blended from totaly transparent at max range to totaly opaque around the viewer
+     * @param distance in meters
+     */
 	void set_clouds_visibility(float distance);
+    /**
+     * Set the proportion of clouds that will be rendered to limit drop in FPS.
+     * @param density 0..100 no clouds drawn when density == 0, all are drawn when density == 100
+     */
 	void set_clouds_density(float density);
+    /**
+     * Enable or disable the use of 3D clouds.
+     * @param enable when false we draw the 2D layers
+     */
 	void set_clouds_enable_state(bool enable);
+    /**
+     * Enable or disable the use of proximity cloud turbulence.
+     * @param enable when true the turbulence is computed based on type of cloud around the AC
+     */
+	void set_turbulence_enable_state(bool enable);
 
 	// rain/snow
 	float get_precipitation_density(void) const;
 	bool get_precipitation_enable_state(void) const;
 
 	void set_precipitation_density(float density);
+    /**
+     * Enable or disable the rendering of precipitation around the viewer.
+     * @param enable when true we will draw precipitation depending on metar data
+     */
 	void set_precipitation_enable_state(bool enable);
 
 	// others
 	bool get_lightning_enable_state(void) const;
+    /**
+     * Enable or disable the rendering of lightning and the thunder sound.
+     * @param enable when true we will draw lightning spwaned by cumulonimbus
+     */
 	void set_lightning_enable_state(bool enable);
+
+    /**
+     * Spawn a new lighning at specified lon/lat.
+     * @param lon position of the new lightning
+     * @param lat position of the new lightning
+     * @param alt asl of the starting point of the lightning in meters
+     */
+	void addLightning(double lon, double lat, double alt);
+
+    /**
+     * Forward the sound manager instance to be able to play samples.
+     * @param mgr a running sound manager
+     */
+	void set_soundMgr(SGSoundMgr *mgr);
+
+	void setFOV( float w, float h );
+	void getFOV( float &w, float &h );
+
 };
 
 extern SGEnviro sgEnviro;

simgear/scene/sky/bbcache.cxx

@@ -47,6 +47,7 @@ void SGBbCache::freeTextureMemory(void) {
 
 	if( bbListCount ) {
 		for(int i = 0 ; i < bbListCount ; i++) {
+			bbList[i].cldID = 0;
 			if(bbList[i].texID)
 				glDeleteTextures(1, & bbList[i].texID);
 		}
@@ -78,11 +79,12 @@ bool SGBbCache::allocTextureMemory(int cacheCount, int textureDimension) {
 	cacheSizeKb = (textureDimension * textureDimension * 4);
 	cacheSizeKb *= cacheCount;
 	cacheSizeKb /= 1024;
-	if(rt) {
+	if(rtAvailable) {
-		rt->BeginCapture();
+		if( rt->BeginCapture() ) {
 			glViewport(0, 0, textureDimension, textureDimension);
 			rt->EndCapture();
 		}
+	}
 	return true;
 }
 
@@ -113,9 +115,9 @@ void SGBbCache::init(int cacheCount) {
 	rt->Reset("rgba tex2D ctt");
 //	rt->Reset("rgba tex2D");
 	if( rt->Initialize(256, 256, true) ) {
-		rtAvailable = true;
 		if (rt->BeginCapture())
 		{
+			rtAvailable = true;
 			glViewport(0, 0, 256, 256);
 			glMatrixMode(GL_PROJECTION);
 			glLoadIdentity();
@@ -219,6 +221,7 @@ int SGBbCache::alloc(int cldId) {
 			bbList[i].angleX = -999;
 			bbList[i].angleY = -999;
 			bbList[i].frameUsed = 0;
+			bbList[i].needRedraw = true;
 			return i;
 		}
 	}
@@ -279,6 +282,7 @@ void SGBbCache::setTextureData(int bbId) {
 //    bbList[bbId].angleY = angleY;
     bbList[bbId].frame = frameNumber;
 	bbList[bbId].frameUsed = frameNumber;
+	bbList[bbId].needRedraw = false;
     builtBBCount ++;
 	builtBBframe ++;
 }
@@ -305,11 +309,14 @@ bool SGBbCache::isBbValid( int cldId, int bbId, float angleY, float angleX) {
 	if( builtBBframe >= maxImpostorRegenFrame )
 		return true;
 
-    if( fabs(angleY - bbList[bbId].angleY) >= 4.0 )
+	if( bbList[bbId].needRedraw )
 		return false;
 
-    if( fabs(angleX - bbList[bbId].angleX) >= 4.0 )
+//    if( fabs(angleY - bbList[bbId].angleY) >= 4.0 )
-        return false;
+//        return false;
+
+//    if( fabs(angleX - bbList[bbId].angleX) >= 4.0 )
+//        return false;
 
 	bbList[bbId].frameUsed = frameNumber;
 	return true;
@@ -328,7 +335,7 @@ void SGBbCache::setReference( int cldId, int bbId, float angleY, float angleX) {
 void SGBbCache::startNewFrame(void) {
 	builtBBframe = 0;
 	// TOTO:find reasonable value
-	int minFrameNumber = frameNumber - 500;
+	int minFrameNumber = frameNumber - 100;
 	frameNumber++;
 	// cleanup of unused enties
 	for( int bbId = 0 ; bbId < bbListCount ; bbId++)
@@ -337,3 +344,21 @@ void SGBbCache::startNewFrame(void) {
 			bbList[bbId].cldID = 0;
 		}
 }
+
+// force all impostors to be rebuilt, this will enventually be done over several frames
+void SGBbCache::invalidateCache(void) {
+
+	for( int bbId = 0 ; bbId < bbListCount ; bbId++)
+//		bbList[bbId].cldID = 0;
+		bbList[bbId].needRedraw = true;
+}
+
+// flag the impostor for a lazy update
+void SGBbCache::invalidate(int cldId, int bbId) {
+	if( bbId < 0 || bbId >= bbListCount )
+		return;
+	if( bbList[bbId].cldID != cldId )
+		return;
+	bbList[bbId].needRedraw = true;
+}
+

simgear/scene/sky/bbcache.hxx

@@ -29,20 +29,36 @@
 #include <simgear/screen/extensions.hxx>
 #include <simgear/screen/RenderTexture.h>
 
+/**
+ * Billboard helper class.
+ */
 class SGBbCache {
 private:
 
-	typedef struct {
+	/**
+	* storage class for impostors state.
+	*/
+	class bbInfo {
+	public:
+		/// the texture used by this impostor
 		GLuint 	texID;
+		/// the cloud owning this impostor
 		int		cldID;
 		float	angleX, angleY;
 		// creation frame number for debug only
 		int		frame;
-		// last time this entry was used
+		/// last time this entry was used
 		int		frameUsed;
-	} bbInfo;
+		/// dirty flag for lazy rebuild of impostor
+		bool	needRedraw;
+	};
 
 	void freeTextureMemory(void);
+    /**
+     * Allocate and initialize the texture pool.
+     * @param count the number of texture to build
+     * @param textureDimension size in pixel of each texture
+     */
 	bool allocTextureMemory(int count, int textureDimension);
 
 	// a list of impostors
@@ -64,53 +80,126 @@ public:
 	SGBbCache(void);
 	~SGBbCache(void);
 
-	// call this first to initialize everything, cacheCount is the number of texture to allocate
+    /**
+     * Call this first to initialize the cache.
+     * @param cacheCount the number of texture to allocate
+     */
 	void init(int cacheCount);
 
-	// free one cache slot, usualy when the cached object is destroyed
+    /**
+     * Free one cache slot, usualy when the cached object is destroyed.
+     * @param bbId the impostor slot
+     * @param cldId the cloud identifier
+     */
 	void free(int bbId, int cldId);
 
-	// allocate a new texture, return an index in the cache
+    /**
+     * Allocate a new impostor.
+     * @param cldId the cloud identifier
+     * @return an impostor slot
+     */
 	int alloc(int cldId);
 
-	// give the texture name to use
+    /**
+     * Query the texture name associated with this cloud.
+     * @param bbId the impostor slot
+     * @param cldId the cloud identifier
+     * @return a texture name
+     */
 	GLuint QueryTexID(int cldId, int bbId);
 
-	// save the rendered texture from the current context to a new texture
+    /**
+     * Save the rendered texture from the current context to a new texture.
+     * @param bbId the impostor slot
+     */
 	void setTextureData(int bbId);
 
-	// start the rendering of a billboard in the RTT context
+    /**
+     * Start the rendering of a billboard in the RTT context.
+     */
 	void beginCapture(void);
 
-	// adjust the projection matrix of the RTT context to the size of the object
+    /**
+     * Adjust the projection matrix of the RTT context to the size of the object.
+     * @param radius radius in meters of the object to draw
+     * @param dist_center distance between viewer and object
+     */
 	void setRadius(float radius, float dist_center);
 
-	// forget the RTT and go back to the previous rendering context
+    /**
+     * Forget the RTT and go back to the previous rendering context.
+     */
 	void endCapture(void);
 
-	// for debugging only, give the number of frames since the inpostor was built
+    /**
+     * For debugging only, give the number of frames since the impostor was built.
+     * @param bbId the impostor slot
+     */
 	int queryImpostorAge(int bbId);
 
-	// can we still use this impostor ?
+    /**
+     * Can we still use this impostor ? Check versus view angles and load.
+     * @param bbId the impostor slot
+     * @param cloudId the cloud identifier
+     * @param angleY rotation needed to face the impostor
+     * @param angleX rotation needed to face the impostor
+     */
 	bool isBbValid( int cloudId, int bbId, float angleY, float angleX);
 
-	// save view angles of this billboard
+    /**
+     * Save view angles of this billboard.
+     * @param bbId the impostor slot
+     * @param cloudId the cloud identifier
+     * @param angleY rotation needed to face the impostor
+     * @param angleX rotation needed to face the impostor
+     */
 	void setReference( int cloudId, int bbId, float angleY, float angleX);
 
-	// prepare the cache for the rendering of a new frame
+    /**
+     * Prepare the cache for the rendering of a new frame.
+     * Do some garbage collect of unused impostors
+     */
 	void startNewFrame(void);
 
-	// alloc the impostors texture memory given the size of the memory pool
+    /**
-	// if sizeKb == 0 then the memory pool is freed and impostors are disabled
+     * Alloc the impostors texture memory given the size of the memory pool.
+	 * If sizeKb == 0 then the memory pool is freed and impostors are disabled
+     * @param sizeKb size of the texture pool in K
+     */
 	bool setCacheSize(int sizeKb);
 
-	// alloc the impostors texture memory given the count and size of texture
+    /**
-	// if count == 0 then the memory pool is freed and impostors are disabled
+     * Alloc the impostors texture memory given the count and size of texture.
+	 * If count == 0 then the memory pool is freed and impostors are disabled
+     * @param count number of texture to allocate
+     * @param textureDimension size of each texture in pixels
+     */
 	bool setCacheSize(int count, int textureDimension);
 
-	// return the size of the memory pool used by texture impostors
+	bool isRttAvailable(void) { return rtAvailable; }
+
+    /**
+     * Force all impostors to be rebuilt.
+     */
+	void invalidateCache(void);
+
+    /**
+     * Flag the impostor for a lazy update.
+     * @param bbId the impostor slot
+     * @param cldId the cloud identifier
+     */
+	void invalidate(int cldId, int bbId);
+
+    /**
+     * Return the size of the memory pool used by texture impostors.
+     * @return size of the memory pool in Kb
+     */
 	int queryCacheSize(void);
 
+    /**
+     * Maximum number of impostor to regen each frame.
+     * If we can't update all of them we will do that in the next frame
+     */
 	int maxImpostorRegenFrame;
 };
 

simgear/scene/sky/cloud.cxx

@@ -843,7 +843,7 @@ bool SGCloudLayer::reposition( sgVec3 p, sgVec3 up, double lon, double lat,
         last_lat = lat;
     }
 
-	layer3D->reposition( p, up, lon, lat, alt, dt);
+	layer3D->reposition( p, up, lon, lat, alt, dt, direction, speed);
     return true;
 }
 
@@ -851,7 +851,7 @@ bool SGCloudLayer::reposition( sgVec3 p, sgVec3 up, double lon, double lat,
 void SGCloudLayer::draw( bool top ) {
     if ( layer_coverage != SG_CLOUD_CLEAR ) {
 
-		if ( SGCloudField::enable3D )
+		if ( SGCloudField::enable3D && layer3D->is3D())
 			layer3D->Render();
 		else
         if ( bump_mapping && enable_bump_mapping ) {

simgear/scene/sky/cloud.hxx

@@ -184,6 +184,9 @@ public:
 
     static bool enable_bump_mapping;
 
+	/** return the 3D layer cloud associated with this 2D layer */
+	SGCloudField *get_layer3D(void) { return layer3D; }
+
 private:
 
     struct CloudVertex {

simgear/scene/sky/cloudfield.cxx

@@ -45,13 +45,17 @@ static list_of_culledCloud inViewClouds;
 
 // visibility distance for clouds in meters
 float SGCloudField::CloudVis = 25000.0f;
-bool SGCloudField::enable3D = true;
+bool SGCloudField::enable3D = false;
 // fieldSize must be > CloudVis or we can destroy the impostor cache
 // a cloud must only be seen once or the impostor will be generated for each of his positions
-double SGCloudField::fieldSize = 27000.0;
+double SGCloudField::fieldSize = 50000.0;
 float SGCloudField::density = 100.0;
+double SGCloudField::timer_dt = 0.0;
+sgVec3 SGCloudField::view_vec;
+
 static int last_cache_size = 1*1024;
 static int cacheResolution = 64;
+static sgVec3 last_sunlight={0.0f, 0.0f, 0.0f};
 
 int SGCloudField::get_CacheResolution(void) {
 	return cacheResolution;
@@ -85,7 +89,6 @@ void SGCloudField::set_CacheSize(int sizeKb) {
 		int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
 		if(count == 0)
 			count = 1;
-//		SGNewCloud::cldCache->setCacheSize(sizeKb);
 		SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
 	}
 }
@@ -101,14 +104,17 @@ void SGCloudField::set_enable3dClouds(bool enable) {
 		return;
 	enable3D = enable;
 	if(enable) {
-		SGNewCloud::cldCache->setCacheSize(last_cache_size);
+		int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
+		if(count == 0)
+			count = 1;
+		SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
 	} else {
 		SGNewCloud::cldCache->setCacheSize(0);
 	}
 }
 
 // reposition the cloud layer at the specified origin and orientation
-void SGCloudField::reposition( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double dt) {
+void SGCloudField::reposition( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double dt, float direction, float speed) {
     sgMat4 T1, LON, LAT;
     sgVec3 axis;
 
@@ -135,8 +141,6 @@ void SGCloudField::reposition( sgVec3 p, sgVec3 up, double lon, double lat, doub
 	this->alt = alt;
 
 	// simulate clouds movement from wind
-	double speed = 10.0f;
-	double direction = 45.0;
     double sp_dist = speed*dt;
     if (sp_dist > 0) {
         double bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
@@ -181,11 +185,16 @@ void SGCloudField::reposition( sgVec3 p, sgVec3 up, double lon, double lat, doub
 	// correct the frustum with the right far plane
 	ssgContext *context = ssgGetCurrentContext();
 	frustum = *context->getFrustum();
-	frustum.setFOV(55.0,0);
+
+	float w, h;
+	sgEnviro.getFOV( w, h );
+	frustum.setFOV( w, h );
 	frustum.setNearFar(1.0, CloudVis);
+	timer_dt = dt;
 }
 
 SGCloudField::SGCloudField() :
+	draw_in_3d(true),
 	last_density(0.0),
 	deltax(0.0),
 	deltay(0.0),
@@ -206,6 +215,18 @@ SGCloudField::~SGCloudField() {
 }
 
 
+void SGCloudField::clear(void) {
+	list_of_Cloud::iterator iCloud;
+	for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
+		delete iCloud->aCloud;
+	}
+	theField.clear();
+	// force a recompute of density on first redraw
+	last_density = 0.0;
+	// true to come back in set density after layer is built
+	draw_in_3d = true;
+}
+
 // use a table or else we see poping when moving the slider...
 static int densTable[][10] = {
 	{0,0,0,0,0,0,0,0,0,0},
@@ -235,15 +256,16 @@ void SGCloudField::applyDensity(void) {
 			iCloud->visible = false;
 	}
 	last_density = density;
+	draw_in_3d = ( theField.size() != 0);
 }
 
 // add one cloud, data is not copied, ownership given
 void SGCloudField::addCloud( sgVec3 pos, SGNewCloud *cloud) {
 	Cloud cl;
-	sgCopyVec3( cl.pos, pos );
 	cl.aCloud = cloud;
 	cl.visible = true;
 	cloud->SetPos( pos );
+	sgCopyVec3( cl.pos, *cloud->getCenter() );
 	theField.push_back( cl );
 }
 
@@ -260,7 +282,7 @@ void SGCloudField::buildTestLayer(void) {
 
 	for( int z = -5 ; z <= 5 ; z++) {
 		for( int x = -5 ; x <= 5 ; x++ ) {
-            SGNewCloud *cloud = new SGNewCloud;
+			SGNewCloud *cloud = new SGNewCloud(SGNewCloud::CLFamilly_cu);
 			cloud->new_cu();
 			sgVec3 pos = {(x+Rnd(0.7)) * s, 750.0f, (z+Rnd(0.7)) * s};
             addCloud(pos, cloud);
@@ -291,6 +313,8 @@ void SGCloudField::cullClouds(sgVec3 eyePos, sgMat4 mat) {
 			sgCopyVec3( tmp.eyePos, eyePos ); 
 			// save distance for later sort, opposite distance because we want back to front
 			tmp.dist   =  - squareDist;
+			tmp.heading = -SG_PI/2.0 - atan2( dist[0], dist[2] ); // + SG_PI;
+			tmp.alt		= iCloud->pos[1];
 			inViewClouds.push_back(tmp);
 			if( squareDist - radius*radius < 100*100 )
 				sgEnviro.set_view_in_cloud(true);
@@ -316,9 +340,11 @@ void SGCloudField::Render(void) {
 		applyDensity();
 	}
 
-	// ask the impostor cache to do some cleanup
+	if( ! draw_in_3d )
-	// TODO:don't do that for every field
+		return;
-	SGNewCloud::cldCache->startNewFrame();
+
+	if( ! SGNewCloud::cldCache->isRttAvailable() )
+		return;
 
 	inViewClouds.clear();
 
@@ -332,14 +358,22 @@ void SGCloudField::Render(void) {
     sgVec3 lightVec;
     ssgGetLight( 0 )->getPosition( lightVec );
     sgXformVec3( lightVec, invtrans );
-	sgCopyVec3( SGNewCloud::modelSunDir, lightVec );
+
 	sgSetVec3(  SGNewCloud::modelSunDir, lightVec[0], lightVec[2], lightVec[1]);
-	// try to find the lighting data (buggy)
+	// try to find the lighting data (not accurate)
 	sgVec4 diffuse, ambient;
 	ssgGetLight( 0 )->getColour( GL_DIFFUSE, diffuse );
 	ssgGetLight( 0 )->getColour( GL_AMBIENT, ambient );
-	sgScaleVec3 ( SGNewCloud::sunlight, diffuse , 0.70f);
+	sgScaleVec3 ( SGNewCloud::sunlight, diffuse , 1.0f);
-	sgScaleVec3 ( SGNewCloud::ambLight, ambient , 0.60f);
+	sgScaleVec3 ( SGNewCloud::ambLight, ambient , 1.0f);
+
+	sgVec3 delta_light;
+	sgSubVec3(delta_light, last_sunlight, SGNewCloud::sunlight);
+	if( (fabs(delta_light[0]) + fabs(delta_light[1]) + fabs(delta_light[2])) > 0.05f ) {
+		sgCopyVec3( last_sunlight, SGNewCloud::sunlight );
+		// force the redraw of all the impostors
+		SGNewCloud::cldCache->invalidateCache();
+	}
 
 	// voodoo things on the matrix stack
     ssgGetModelviewMatrix( modelview );
@@ -348,10 +382,13 @@ void SGCloudField::Render(void) {
 
 	// cloud fields are tiled on the flat earth
 	// compute the position in the tile
-	relx = -fmod( deltax + relative_position[SG_X] + tmp[3][0], fieldSize );
+	relx = fmod( deltax + relative_position[SG_X] + tmp[3][0], fieldSize );
-	rely = -fmod( deltay + relative_position[SG_Y] + tmp[3][1], fieldSize );
+	rely = fmod( deltay + relative_position[SG_Y] + tmp[3][1], fieldSize );
 
-	sgSetVec3( eyePos, -relx, alt, -rely);
+	relx = fmod( relx + fieldSize, fieldSize );
+	rely = fmod( rely + fieldSize, fieldSize );
+	sgSetVec3( eyePos, relx, alt, rely);
+	sgCopyVec3( view_vec, tmp[1] );
 
 	tmp[3][2] = 0;
 	tmp[3][0] = 0;
@@ -400,6 +437,8 @@ void SGCloudField::Render(void) {
 	for( iCloud = inViewClouds.begin() ; iCloud != inViewClouds.end() ; iCloud++ ) {
 //		iCloud->aCloud->drawContainers();
 		iCloud->aCloud->Render(iCloud->eyePos);
+		sgEnviro.callback_cloud(iCloud->heading, iCloud->alt, 
+			iCloud->aCloud->getRadius(), iCloud->aCloud->getFamilly(), - iCloud->dist);
 	}
 
 	glBindTexture(GL_TEXTURE_2D, 0);

simgear/scene/sky/cloudfield.hxx

@@ -37,12 +37,17 @@ public:
 	SGNewCloud	*aCloud;
 	sgVec3		eyePos;
 	float		dist;
+	float		heading;
+	float		alt;
 	bool operator<(const culledCloud &b) const {
-		return this->dist < b.dist;
+		return (this->dist < b.dist);
 	}
 };
 typedef vector<culledCloud> list_of_culledCloud;
 
+/**
+ * A layer of 3D clouds.
+ */
 class SGCloudField {
 
 private:
@@ -51,12 +56,6 @@ private:
 		SGNewCloud	*aCloud;
 		sgVec3		pos;
 		bool		visible;
-//		float		dist;
-//		bool		culled;
-
-//		bool operator<(const Cloud &b) {
-//			return this->dist < b.dist;
-//		}
 	};
 
 
@@ -79,12 +78,15 @@ private:
     double last_lon, last_lat, last_course;
 
 	float	last_density;
+	bool	draw_in_3d;
 
 public:
 
 	SGCloudField();
 	~SGCloudField();
 
+	void clear(void);
+
 	// add one cloud, data is not copied, ownership given
 	void addCloud( sgVec3 pos, SGNewCloud *cloud);
 
@@ -95,13 +97,17 @@ public:
 	void Render(void);
 
 	// reposition the cloud layer at the specified origin and orientation
-	void reposition( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double dt);
+	void reposition( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double dt, float direction, float speed);
+
+	bool is3D(void) { return draw_in_3d; }
 
 	// visibility distance for clouds in meters
 	static float CloudVis;
 
-	static float density;
+	static sgVec3 view_vec;
 
+	static float density;
+	static double timer_dt;
 	static double fieldSize;
 	static bool enable3D;
 

simgear/scene/sky/newcloud.cxx

@@ -47,6 +47,8 @@ static ssgTexture *cloudTextures[SGNewCloud::CLTexture_max];
 bool SGNewCloud::useAnisotropic = true;
 SGBbCache *SGNewCloud::cldCache = 0;
 static bool texturesLoaded = false;
+static float minx, maxx, miny, maxy, minz, maxz;
+
 float SGNewCloud::nearRadius = 3500.0f;
 bool SGNewCloud::lowQuality = false;
 sgVec3 SGNewCloud::sunlight = {0.5f, 0.5f, 0.5f};
@@ -54,25 +56,60 @@ sgVec3 SGNewCloud::ambLight = {0.5f, 0.5f, 0.5f};
 sgVec3 SGNewCloud::modelSunDir = {0,1,0};
 
 
-// constructor
+void SGNewCloud::init(void) {
-SGNewCloud::SGNewCloud() :
+	bbId = -1;
-	bbId(-1),
+	fadeActive = false;
-//	rank(-1),
+	duration = 100.0f;
-	minx(999), miny(999), minz(999), maxx(-999), maxy(-999), maxz(-999)
+	fadetimer = 100.0f;
-
+	pauseLength = 0.0f;
-{
+	last_step = -1.0f;
+	familly = CLFamilly_nn;
 	cloudId = (int) this;
 	sgSetVec3(center, 0.0f, 0.0f, 0.0f);
 	sgSetVec3(cloudpos, 0.0f, 0.0f, 0.0f);
+	radius = 0.0f;
+	delta_base = 0.0f;
 	list_spriteContainer.reserve(8);
 	list_spriteDef.reserve(40);
-//	if( ! texturesLoaded ) {}
+
 	if( cldCache == 0 ) {
 		cldCache = new SGBbCache;
 		cldCache->init( 64 );
 	}
 }
 
+// constructor
+SGNewCloud::SGNewCloud(CLFamilly_type classification)
+{
+	init();
+	familly = classification;
+}
+
+SGNewCloud::SGNewCloud(string classification)
+{
+	init();
+	if( classification == "cu" )
+		familly = CLFamilly_cu;
+	else if( classification == "cb" )
+		familly = CLFamilly_cb;
+	else if( classification == "st" )
+		familly = CLFamilly_st;
+	else if( classification == "ns" )
+		familly = CLFamilly_ns;
+	else if( classification == "sc" )
+		familly = CLFamilly_sc;
+	else if( classification == "as" )
+		familly = CLFamilly_as;
+	else if( classification == "ac" )
+		familly = CLFamilly_ac;
+	else if( classification == "ci" )
+		familly = CLFamilly_ci;
+	else if( classification == "cc" )
+		familly = CLFamilly_cc;
+	else if( classification == "cs" )
+		familly = CLFamilly_cs;
+}
+
 SGNewCloud::~SGNewCloud() {
 	list_spriteDef.clear();
 	list_spriteContainer.clear();
@@ -101,12 +138,26 @@ void SGNewCloud::loadTextures(const string &tex_path) {
 }
 
 void SGNewCloud::startFade(bool direction, float duration, float pauseLength) {
+      if(duration <= 0.0) {
+              fadeActive = false;
+              return;
+      }
+      this->direction = direction;
+      fadetimer = 0.0;
+      this->duration = duration;
+      this->pauseLength = pauseLength;
+      last_step = -1.0;
+      fadeActive = true;
 }
 void SGNewCloud::setFade(float howMuch) {
+      duration = 100.0;
+      fadetimer = howMuch;
+      fadeActive = false;
+      last_step = -1.0;
 }
 
 
-static float rayleighCoeffAngular(float cosAngle) {
+static inline float rayleighCoeffAngular(float cosAngle) {
 	return 3.0f / 4.0f * (1.0f + cosAngle * cosAngle);
 }
 
@@ -128,10 +179,10 @@ static void PolarToCart3d(sgVec3 p, sgVec3 cart) {
 // compute the light for a cloud sprite corner
 // from the normal and the sun, scaled by the Rayleigh factor
 // and finaly added to the ambient light
-static void lightFunction(sgVec3 normal, sgVec4 light, float pf) {
+static inline void lightFunction(sgVec3 normal, sgVec4 light, float pf) {
 	float cosAngle = sgScalarProductVec3( normal, SGNewCloud::modelSunDir);
-	float vl = (1.0f - 0.1f + cosAngle / 10.0f) * pf;
+	float vl = (1.0f - 0.5f + cosAngle * 0.5f) * pf;
-	sgScaleVec3( light, SGNewCloud::sunlight, vl );
+	sgScaleVec3( light, SGNewCloud::sunlight, 0.25f + 0.75f * vl );
 	sgAddVec3( light, SGNewCloud::ambLight );
 	// we need to clamp or else the light will bug when adding transparency
 	if( light[0] > 1.0 )	light[0] = 1.0;
@@ -142,11 +193,10 @@ static void lightFunction(sgVec3 normal, sgVec4 light, float pf) {
 
 // compute the light for a cloud sprite
 // we use ambient light and orientation versus sun position
-// TODO:check sun pos and check code
 void SGNewCloud::computeSimpleLight(sgVec3 FakeEyePos) {
 	// constant Rayleigh factor if we are not doing Anisotropic lighting
 	float pf = 1.0f;
-	const float ang = 45.0f * SG_PI / 180.0f;
+
 	list_of_spriteDef::iterator iSprite;
 	for( iSprite = list_spriteDef.begin() ; iSprite != list_spriteDef.end() ; iSprite++ ) {
 		if( useAnisotropic ) {
@@ -156,44 +206,11 @@ void SGNewCloud::computeSimpleLight(sgVec3 FakeEyePos) {
             float cosAngle = sgScalarProductVec3(eyeDir, modelSunDir);
             pf = rayleighCoeffAngular(cosAngle);
 		}
-		// compute the vector going from the container box center to the sprite
+		lightFunction(iSprite->n0, iSprite->l0, pf);
-		// TODO : this is a constant except for cloudpos, compute the normal in setpos function
+		lightFunction(iSprite->n1, iSprite->l1, pf);
-		sgVec3 normal;
+		lightFunction(iSprite->n2, iSprite->l2, pf);
-		spriteContainer *thisSpriteContainer = &list_spriteContainer[iSprite->box];
+		lightFunction(iSprite->n3, iSprite->l3, pf);
-        sgSubVec3(normal, iSprite->pos, thisSpriteContainer->pos);
-        sgSubVec3(normal, thisSpriteContainer->center);
-        sgSubVec3(normal, cloudpos);
-        sgNormaliseVec3(normal);
-		if( lowQuality ) {
-			// juste use the traditional normal to compute some lightning
-			sgVec4 centerColor;
-			lightFunction(normal, centerColor, pf);
-			sgCopyVec4(iSprite->l0, centerColor);
-			sgCopyVec4(iSprite->l1, centerColor);
-			sgCopyVec4(iSprite->l2, centerColor);
-			sgCopyVec4(iSprite->l3, centerColor);
 
-		} else {
-			// use exotic lightning function, this will give more 'relief' to the clouds
-			// compute a normal for each vextex this will simulate a smooth shading for a round shape
-			sgVec3 polar, cart, pt;
-			// I suspect this code to be bugged...
-            CartToPolar3d(normal, polar);
-
-			// offset the normal vector by some angle for each vertex
-            sgSetVec3(pt, polar[0] - ang, polar[1] - ang, polar[2]);
-            PolarToCart3d(pt, cart);
-            lightFunction(cart, iSprite->l0, pf);
-            sgSetVec3(pt, polar[0] + ang, polar[1] - ang, polar[2]);
-            PolarToCart3d(pt, cart);
-            lightFunction(cart, iSprite->l1, pf);
-            sgSetVec3(pt, polar[0] + ang, polar[1] + ang, polar[2]);
-            PolarToCart3d(pt, cart);
-            lightFunction(cart, iSprite->l2, pf);
-            sgSetVec3(pt, polar[0] - ang, polar[1] + ang, polar[2]);
-            PolarToCart3d(pt, cart);
-            lightFunction(cart, iSprite->l3, pf);
-		}
 	}
 }
 
@@ -206,13 +223,16 @@ void SGNewCloud::addContainer (float x, float y, float z, float r, CLbox_type ty
 	cont.cont_type = type;
 	sgSetVec3( cont.center, 0.0f, 0.0f, 0.0f);
 	list_spriteContainer.push_back( cont );
+	// don't place cloud below his base
+	if( y - r*0.50 < delta_base )
+		delta_base = y - r*0.50;
 }
 
 // add a sprite inside a box
 void SGNewCloud::addSprite(float x, float y, float z, float r, CLbox_type type, int box) {
 	spriteDef newSpriteDef;
 	int rank = list_spriteDef.size();
-	sgSetVec3( newSpriteDef.pos, x, y, z);
+	sgSetVec3( newSpriteDef.pos, x, y - delta_base, z);
 	newSpriteDef.box = box;
 	newSpriteDef.sprite_type = type;
 	newSpriteDef.rank = rank;
@@ -223,7 +243,7 @@ void SGNewCloud::addSprite(float x, float y, float z, float r, CLbox_type type,
 	sgSubVec3( deltaPos, newSpriteDef.pos, thisBox->pos );
 	sgAddVec3( thisBox->center, deltaPos );
 
-	r = r * 0.6f;	// 0.5 * 1.xxx
+	r = r * 0.65f;	// 0.5 * 1.xxx
     if( x - r < minx )
 		minx = x - r;
     if( y - r < miny )
@@ -248,19 +268,21 @@ static float Rnd(float n) {
 void SGNewCloud::genSprites( void ) {
 	float x, y, z, r;
     int N, sc;
+	minx = miny = minz = 99999.0;
+	maxx = maxy = maxz = -99999.0;
+
     N = list_spriteContainer.size();
 	for(int i = 0 ; i < N ; i++ ) {
 		spriteContainer *thisBox = & list_spriteContainer[i];
 		// the type defines how the sprites can be positioned inside the box, their size, etc
 		switch(thisBox->cont_type) {
 			case CLbox_sc:
-				for( sc = 0 ; sc <= 4 ; sc ++ ) {
+				sc = 1;
 				r = thisBox->r + Rnd(0.2f);
-					x = thisBox->pos[SG_X] + Rnd(thisBox->r);
+				x = thisBox->pos[SG_X] + Rnd(thisBox->r * 0.75f);
-					y = thisBox->pos[SG_Y] + Rnd(thisBox->r * 0.2f);
+				y = thisBox->pos[SG_Y] + Rnd(thisBox->r * 0.75f);
-					z = thisBox->pos[SG_Z] + Rnd(thisBox->r);
+				z = thisBox->pos[SG_Z] + Rnd(thisBox->r * 0.75f);
 				addSprite(x, y, z, r, thisBox->cont_type, i);
-				}
 				break;
 			case CLbox_stratus:
 				sc = 1;
@@ -302,10 +324,46 @@ void SGNewCloud::genSprites( void ) {
     radius /= 2.0f;
     sgSetVec3( center, (maxx + minx) / 2.0f, (maxy + miny) / 2.0f, (maxz + minz) / 2.0f );
 
-/*    fadingrank = 0
+	const float ang = 45.0f * SG_PI / 180.0f;
-'    fadingrank = UBound(tbSpriteDef()) * 10
+
-    fadingdir = 0*/
+	// compute normals
-	// TODO : compute initial sprite normals for lighting function
+	list_of_spriteDef::iterator iSprite;
+	for( iSprite = list_spriteDef.begin() ; iSprite != list_spriteDef.end() ; iSprite++ ) {
+		sgVec3 normal;
+		spriteContainer *thisSpriteContainer = &list_spriteContainer[iSprite->box];
+		if( familly == CLFamilly_sc || familly == CLFamilly_cu || familly == CLFamilly_cb) {
+			sgSubVec3(normal, iSprite->pos, center);
+		} else {
+			sgSubVec3(normal, iSprite->pos, thisSpriteContainer->pos);
+			sgSubVec3(normal, thisSpriteContainer->center);
+			sgSubVec3(normal, cloudpos);
+		}
+		if( normal[0] == 0.0f && normal[1] == 0.0f && normal[2] == 0.0f )
+			sgSetVec3( normal, 0.0f, 1.0f, 0.0f );
+        sgNormaliseVec3(normal);
+		// use exotic lightning function, this will give more 'relief' to the clouds
+		// compute a normal for each vextex this will simulate a smooth shading for a round shape
+		sgVec3 polar, pt;
+		// I suspect this code to be bugged...
+        CartToPolar3d(normal, polar);
+		sgCopyVec3(iSprite->normal, normal);
+
+		// offset the normal vector by some angle for each vertex
+        sgSetVec3(pt, polar[0] - ang, polar[1] - ang, polar[2]);
+        PolarToCart3d(pt, iSprite->n0);
+        sgSetVec3(pt, polar[0] + ang, polar[1] - ang, polar[2]);
+        PolarToCart3d(pt, iSprite->n1);
+        sgSetVec3(pt, polar[0] + ang, polar[1] + ang, polar[2]);
+        PolarToCart3d(pt, iSprite->n2);
+        sgSetVec3(pt, polar[0] - ang, polar[1] + ang, polar[2]);
+        PolarToCart3d(pt, iSprite->n3);
+	}
+
+	// experimental : clouds are dissipating with time
+	if( familly == CLFamilly_cu ) {
+		startFade(true, 300.0f, 30.0f);
+		fadetimer = sg_random() * 300.0f;
+	}
 }
 
 
@@ -364,7 +422,6 @@ void SGNewCloud::SetPos(sgVec3 newPos) {
 	}
 	sgAddVec3( center, deltaPos );
     sgSetVec3( cloudpos, newPos[SG_X], newPos[SG_Y], newPos[SG_Z]);
-	// TODO : recompute sprite normal so we don't have to redo that each frame
 }
 
 
@@ -393,18 +450,30 @@ void SGNewCloud::sortSprite( sgVec3 eye ) {
 // render the cloud on screen or on the RTT texture to build the impostor
 void SGNewCloud::Render3Dcloud( bool drawBB, sgVec3 FakeEyePos, sgVec3 deltaPos, float dist_center ) {
 
-/*    int clrank		 = fadingrank / 10;
+	float step = ( list_spriteDef.size() * (direction ? fadetimer : duration-fadetimer)) / duration;
-	int clfadeinrank = fadingrank - clrank * 10;*/
+	int clrank = (int) step;
-	float CloudVisFade = 1.0 / (1.5 * SGCloudField::get_CloudVis());
+	float clfadeinrank = (step - clrank);
+	last_step = step;
+
+	float CloudVisFade = 1.0 / (0.7f * SGCloudField::get_CloudVis());
+	// blend clouds with sky based on distance to limit the contrast of distant cloud
+	float t = 1.0f - dist_center * CloudVisFade;
+//	if ( t < 0.0f ) 
+//		return;
 
     computeSimpleLight( FakeEyePos );
 
     // view point sort, we sort because of transparency
 	sortSprite( FakeEyePos );
 
+	float dark = (familly == CLFamilly_cb ? 0.9f : 1.0f);
+
 	GLint previousTexture = -1, thisTexture;
 	list_of_spriteDef::iterator iSprite;
 	for( iSprite = list_spriteDef.begin() ; iSprite != list_spriteDef.end() ; iSprite++ ) {
+		// skip this sprite if faded
+		if(iSprite->rank > clrank)
+			continue;
 		// choose texture to use depending on sprite type
 		switch(iSprite->sprite_type) {
 			case CLbox_stratus:
@@ -421,11 +490,6 @@ void SGNewCloud::Render3Dcloud( bool drawBB, sgVec3 FakeEyePos, sgVec3 deltaPos,
 		}
 
 			sgVec3 translate;
-			if( drawBB ) {
-				sgCopyVec3( translate, iSprite->pos);
-				sgSubVec3( translate, iSprite->pos, deltaPos );
-			}
-			else
 			sgSubVec3( translate, iSprite->pos, deltaPos);
 
 
@@ -433,24 +497,33 @@ void SGNewCloud::Render3Dcloud( bool drawBB, sgVec3 FakeEyePos, sgVec3 deltaPos,
 			float flipx = (float) ( iSprite->rank & 1 );
 			float flipy = (float) ( (iSprite->rank >> 1) & 1 );
 			// cu texture have a flat bottom so we can't do a vertical flip
-			if( iSprite->sprite_type == CLbox_cumulus || iSprite->sprite_type == CLbox_stratus )
+			if( iSprite->sprite_type == CLbox_cumulus )
 				flipy = 0.0f;
-			if( iSprite->sprite_type == CLbox_stratus )
+//			if( iSprite->sprite_type == CLbox_stratus )
-				flipx = 0.0f;
+//				flipx = 0.0f;
 			// adjust colors depending on cloud type
 			// TODO : rewrite that later, still experimental
 			switch(iSprite->sprite_type) {
 				case CLbox_cumulus:
 					// dark bottom
-                    sgScaleVec3(iSprite->l0, 0.6f);
+                    sgScaleVec3(iSprite->l0, 0.8f * dark);
-                    sgScaleVec3(iSprite->l1, 0.6f);
+                    sgScaleVec3(iSprite->l1, 0.8f * dark);
+					sgScaleVec3(iSprite->l2, dark);
+					sgScaleVec3(iSprite->l3, dark);
 					break;
 				case CLbox_stratus:
 					// usually dark grey
+					if( familly == CLFamilly_st ) {
 						sgScaleVec3(iSprite->l0, 0.8f);
 						sgScaleVec3(iSprite->l1, 0.8f);
 						sgScaleVec3(iSprite->l2, 0.8f);
 						sgScaleVec3(iSprite->l3, 0.8f);
+					} else {
+						sgScaleVec3(iSprite->l0, 0.7f);
+						sgScaleVec3(iSprite->l1, 0.7f);
+						sgScaleVec3(iSprite->l2, 0.7f);
+						sgScaleVec3(iSprite->l3, 0.7f);
+					}
 					break;
 				default:
 					// darker bottom than top
@@ -466,27 +539,40 @@ void SGNewCloud::Render3Dcloud( bool drawBB, sgVec3 FakeEyePos, sgVec3 deltaPos,
 			sgCopyVec4 ( l2, iSprite->l2 );
 			sgCopyVec4 ( l3, iSprite->l3 );
 			if( ! drawBB ) {
-				// blend clouds with sky based on distance to limit the contrast of distant cloud
-				float t = 1.0f - dist_center * CloudVisFade;
-				if ( t < 0.0f ) 
-					t = 0.0f;	// no, it should have been culled
 				// now clouds at the far plane are half blended
 				sgScaleVec4( l0, t );
 				sgScaleVec4( l1, t );
 				sgScaleVec4( l2, t );
 				sgScaleVec4( l3, t );
 			}
+			if( iSprite->rank == clrank ) {
+				sgScaleVec4( l0, clfadeinrank );
+				sgScaleVec4( l1, clfadeinrank );
+				sgScaleVec4( l2, clfadeinrank );
+				sgScaleVec4( l3, clfadeinrank );
+			}
 			// compute the rotations so that the quad is facing the camera
 			sgVec3 pos;
 			sgSetVec3( pos, translate[SG_X], translate[SG_Z], translate[SG_Y] );
 			sgCopyVec3( translate, pos );
 			sgNormaliseVec3( translate );
+#if 0
+			// change view angle when near a sprite
+			sgVec3 trans={translate[0], translate[2], translate[1]};
+			float angle = sgScalarProductVec3( SGCloudField::view_vec, trans );
+			if( fabs(angle) < 0.85f ) {
+				// view not ok from under
+				sgSetVec3( translate, -SGCloudField::view_vec[0],-SGCloudField::view_vec[2],-SGCloudField::view_vec[1] );
+//				sgSetVec3( l0,1,0,0 );
+//				sgSetVec3( l1,1,0,0 );
+//				sgSetVec3( l2,1,0,0 );
+//				sgSetVec3( l3,1,0,0 );
+			}
+#endif
 			sgVec3 x, y, up = {0.0f, 0.0f, 1.0f};
 			sgVectorProductVec3(x, translate, up);
-			sgNormaliseVec3(x);
-			sgScaleVec3(x, r);
 			sgVectorProductVec3(y, x, translate);
-			sgNormaliseVec3(y);
+			sgScaleVec3(x, r);
 			sgScaleVec3(y, r);
  
 			sgVec3 left, right;
@@ -558,33 +644,61 @@ void SGNewCloud::CalcAngles(sgVec3 refpos, sgVec3 FakeEyePos, float *angleY, flo
 }
 
 // draw a cloud but this time we use the impostor texture
-void SGNewCloud::RenderBB(sgVec3 deltaPos, float angleY, float angleX, float dist_center) {
+void SGNewCloud::RenderBB(sgVec3 deltaPos, bool first_time, float dist_center) {
-	// TODO:glrotate is not needed
+
-    glPushMatrix();
+		sgVec3 translate;
-        glTranslatef(center[SG_X] - deltaPos[SG_X], center[SG_Z] - deltaPos[SG_Z], center[SG_Y] - deltaPos[SG_Y]);
+		sgSubVec3( translate, center, deltaPos);
-        glRotatef(angleY, 0.0f, 0.0f, 1.0f);
-        glRotatef(angleX, 1.0f, 0.0f, 0.0f);
 
 		// blend clouds with sky based on distance to limit the contrast of distant cloud
-		float CloudVisFade = (1.5 * SGCloudField::get_CloudVis());
+		float CloudVisFade = (1.0f * SGCloudField::get_CloudVis());
 
-		float t = 1.0f - dist_center / CloudVisFade;
+		float t = 1.0f - (dist_center - 1.0*radius) / CloudVisFade;
-		// err the alpha value is not good for impostor, debug that
-		t *= 1.65;
 		if ( t < 0.0f ) 
-			t = 0.0f;
+			return;
-  
+		if( t > 1.0f )
+			t = 1.0f;
+		if( t > 0.50f )
+			t *= 1.1f;
         glColor4f(t, t, t, t);
         float r = radius;
+		// compute the rotations so that the quad is facing the camera
+		sgVec3 pos;
+		sgSetVec3( pos, translate[SG_X], translate[SG_Z], translate[SG_Y] );
+		sgCopyVec3( translate, pos );
+		sgNormaliseVec3( translate );
+		sgVec3 x, y, up = {0.0f, 0.0f, 1.0f};
+		sgVectorProductVec3(x, translate, up);
+		sgVectorProductVec3(y, x, translate);
+		if(first_time) {
+			sgCopyVec3( rotX, x );
+			sgCopyVec3( rotY, y );
+		} else if(fabs(sgScalarProductVec3(rotX, x)) < 0.93f || fabs(sgScalarProductVec3(rotY, y)) < 0.93f ) {
+			// ask for a redraw of this impostor if the view angle changed too much
+			sgCopyVec3( rotX, x );
+			sgCopyVec3( rotY, y );
+			cldCache->invalidate(cloudId, bbId);
+		}
+		sgScaleVec3(x, r);
+		sgScaleVec3(y, r);
+
+		sgVec3 left, right;
+		sgCopyVec3( left, pos );
+		sgSubVec3 (left, y);
+		sgAddVec3 (right, left, x);
+		sgSubVec3 (left, x);
+
 		glBegin(GL_QUADS);
-			glTexCoord2f(0.0f, 1.0f);
-			glVertex2f(-r, r);
-			glTexCoord2f(1.0f, 1.0f);
-			glVertex2f(r, r);
-			glTexCoord2f(1.0f, 0.0f);
-			glVertex2f(r, -r);
 			glTexCoord2f(0.0f, 0.0f);
-			glVertex2f(-r, -r);
+            glVertex3fv(left);
+			glTexCoord2f(1.0f, 0.0f);
+            glVertex3fv(right);
+			sgScaleVec3( y, 2.0 );
+			sgAddVec3( left, y);
+			sgAddVec3( right, y);
+			glTexCoord2f(1.0f, 1.0f);
+            glVertex3fv(right);
+			glTexCoord2f(0.0f, 1.0f);
+            glVertex3fv(left);
 		glEnd();
 
 #if 0	// debug only
@@ -607,8 +721,6 @@ void SGNewCloud::RenderBB(sgVec3 deltaPos, float angleY, float angleX, float dis
 
 #endif
 
-	glPopMatrix();
-
 }
 
 // determine if it is a good idea to use an impostor to render the cloud
@@ -631,19 +743,26 @@ bool SGNewCloud::isBillboardable(float dist) {
 void SGNewCloud::Render(sgVec3 FakeEyePos) {
 	sgVec3 dist;
 
-
 	sgVec3 deltaPos;
 	sgCopyVec3( deltaPos, FakeEyePos);
     sgSubVec3( dist, center, FakeEyePos);
     float dist_center = sgLengthVec3(dist);
 
-
+	if( fadeActive ) {
+		fadetimer += SGCloudField::timer_dt;
+		if( fadetimer > duration + pauseLength ) {
+			// fade out after fade in, and vice versa
+			direction = ! direction;
+			fadetimer = 0.0;
+		}
+	}
 
 	if( !isBillboardable(dist_center) ) {
 		// not a good candidate for impostors, draw a real cloud
 		Render3Dcloud(false, FakeEyePos, deltaPos, dist_center);
 	} else {
 		GLuint texID = 0;
+			bool first_time = false;
 			// lets use our impostor
 			if( bbId >= 0)
 				texID = cldCache->QueryTexID(cloudId, bbId);
@@ -653,14 +772,20 @@ void SGNewCloud::Render(sgVec3 FakeEyePos) {
                 // allocate a new Impostor
                 bbId = cldCache->alloc(cloudId);
 				texID = cldCache->QueryTexID(cloudId, bbId);
+				first_time = true;
 			}
 			if( texID == 0 ) {
                 // no more free texture in the pool
                 Render3Dcloud(false, FakeEyePos, deltaPos, dist_center);
 			} else {
-                float angleX, angleY;
+                float angleX=0.0f, angleY=0.0f;
-                CalcAngles(center, FakeEyePos, &angleY, &angleX);
+
-				if( ! cldCache->isBbValid( cloudId, bbId, angleY, angleX) ) {
+				// force a redraw of the impostor if the cloud shape has changed enought
+				float step = ( list_spriteDef.size() * (direction ? fadetimer : duration-fadetimer)) / duration;
+				if( fabs(step - last_step) > 0.5f )
+					cldCache->invalidate(cloudId, bbId);
+
+				if( ! cldCache->isBbValid( cloudId, bbId, angleY, angleX)) {
                     // we must build or rebuild this billboard
 					// start render to texture
                     cldCache->beginCapture();
@@ -679,7 +804,7 @@ void SGNewCloud::Render(sgVec3 FakeEyePos) {
 				}
                 // draw the newly built BB or an old one
                 glBindTexture(GL_TEXTURE_2D, texID);
-                RenderBB(deltaPos, angleY, angleX, dist_center);
+                RenderBB(deltaPos, first_time, dist_center);
 			}
 	}
 

simgear/scene/sky/newcloud.hxx

@@ -33,10 +33,27 @@
 SG_USING_STD(string);
 SG_USING_STD(vector);
 
+/**
+ * 3D cloud class.
+ */
 class SGNewCloud {
 
 public:
-	SGNewCloud();
+	enum CLFamilly_type {
+		CLFamilly_cu = 0,
+		CLFamilly_cb,
+		CLFamilly_st,
+		CLFamilly_ns,
+		CLFamilly_sc,
+		CLFamilly_as,
+		CLFamilly_ac,
+		CLFamilly_ci,
+		CLFamilly_cc,
+		CLFamilly_cs,
+		CLFamilly_nn
+	};
+	SGNewCloud(CLFamilly_type classification=CLFamilly_nn);
+	SGNewCloud(string classification);
 	~SGNewCloud();
 
 	enum CLbox_type {
@@ -51,6 +68,7 @@ public:
 		CLTexture_stratus = 2,
 		CLTexture_max
 	};
+
 private:
 
 	class spriteDef {
@@ -59,11 +77,12 @@ private:
 		float		r;
 		CLbox_type	sprite_type;
 		sgVec4		l0, l1, l2, l3;
+		sgVec3		normal, n0, n1, n2, n3;
 		int			rank;
 		int			box;
 		float		dist;		// distance used during sort
 		bool operator<(const spriteDef &b) const {
-			return this->dist < b.dist;
+			return (this->dist < b.dist);
 		}
 	};
 
@@ -78,6 +97,8 @@ private:
 	typedef vector<spriteDef>		list_of_spriteDef;
 	typedef vector<spriteContainer>	list_of_spriteContainer;
 
+	void init(void);
+
 	void computeSimpleLight(sgVec3 eyePos);
 	void addSprite(float x, float y, float z, float r, CLbox_type type, int box);
 
@@ -91,23 +112,26 @@ private:
 	void CalcAngles(sgVec3 refpos, sgVec3 eyePos, float *angleY, float *angleX);
 
 	// draw a cloud but this time we use the impostor texture
-	void RenderBB(sgVec3 deltaPos, float angleY, float angleX, float dist_center);
+	void RenderBB(sgVec3 deltaPos, bool first_time, float dist_center);
 
 	// determine if it is a good idea to use an impostor to render the cloud
 	bool isBillboardable(float dist);
 
 	int		cloudId, bbId;
+	sgVec3	rotX, rotY;
+
 //	int		rank;
 	sgVec3	cloudpos, center;
+	float	delta_base;
 	list_of_spriteDef		list_spriteDef;
 	list_of_spriteContainer	list_spriteContainer;
-	float minx, maxx, miny, maxy, minz, maxz;
 	float radius;
+	CLFamilly_type familly;
 
 	// fading data
 	bool direction, fadeActive;
-	float duration, pauseLength;
+	float duration, pauseLength, fadetimer;
-	// need timer here
+	float last_step;
 
 public:
 	// add a new box to the cloud
@@ -133,6 +157,9 @@ public:
 	void setFade(float howMuch);
 
 	inline float getRadius() { return radius; }
+	inline sgVec3 *getCenter() { return &center; }
+
+	inline CLFamilly_type getFamilly(void) { return familly; }
 
 	// load all textures used to draw cloud sprites
 	static void loadTextures( const string &tex_path );

simgear/scene/sky/sky.cxx

@@ -29,7 +29,7 @@
 #include <simgear/math/sg_random.h>
 
 #include "sky.hxx"
-
+#include "cloudfield.hxx"
 
 // Constructor
 SGSky::SGSky( void ) {
@@ -187,6 +187,8 @@ void SGSky::preDraw( float alt, float fog_exp2_density ) {
             // in cloud layer
 
             // bail now and don't draw any clouds
+			if( cloud_layers[i]->get_layer3D()->is3D() && SGCloudField::enable3D )
+				continue;
             in_cloud = i;
         } else {
             // above cloud layer
@@ -286,7 +288,8 @@ void SGSky::modify_vis( float alt, float time_factor ) {
 	    ratio = 1.0;
 	}
 
-        if ( cloud_layers[i]->getCoverage() == SGCloudLayer::SG_CLOUD_CLEAR ) {
+        if ( cloud_layers[i]->getCoverage() == SGCloudLayer::SG_CLOUD_CLEAR ||
+			cloud_layers[i]->get_layer3D()->is3D() && SGCloudField::enable3D) {
             // do nothing, clear layers aren't drawn, don't affect
             // visibility andn dont' need to be faded in or out.
         } else if ( (cloud_layers[i]->getCoverage() == 

simgear/screen/Makefile.am

@@ -12,7 +12,7 @@ IMAGE_SERVER_INCL =
 IMAGE_SERVER_SRCS = 
 endif
 
-noinst_HEADERS = colours.h RenderTexture.h
+noinst_HEADERS = colours.h GLBitmaps.h
 
 include_HEADERS = \
 	colors.hxx \
@@ -20,11 +20,12 @@ include_HEADERS = \
 	$(IMAGE_SERVER_INCL) \
 	screen-dump.hxx \
 	extensions.hxx \
+	RenderTexture.h \
 	tr.h
 
 libsgscreen_a_SOURCES = \
 	texture.cxx \
-	GLBitmaps.cxx GLBitmaps.h \
+	GLBitmaps.cxx \
 	$(IMAGE_SERVER_SRCS) \
 	screen-dump.cxx \
 	tr.cxx \