1 // a layer of 3d clouds
3 // Written by Harald JOHNSEN, started April 2005.
5 // Copyright (C) 2005 Harald JOHNSEN - hjohnsen@evc.net
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
24 # include <simgear_config.h>
27 #include <simgear/compiler.h>
31 #include <simgear/math/sg_random.h>
32 #include <simgear/math/sg_geodesy.hxx>
33 #include <simgear/math/polar3d.hxx>
35 #include STL_ALGORITHM
40 #include <simgear/environment/visual_enviro.hxx>
42 #include "newcloud.hxx"
43 #include "cloudfield.hxx"
45 #if defined(__MINGW32__)
46 #define isnan(x) _isnan(x)
49 #if defined (__FreeBSD__)
50 # if __FreeBSD_version < 500000
52 inline int isnan(double r) { return !(r <= 0 || r >= 0); }
58 #if defined (__CYGWIN__)
64 static list_of_culledCloud inViewClouds;
66 // visibility distance for clouds in meters
67 float SGCloudField::CloudVis = 25000.0f;
68 bool SGCloudField::enable3D = false;
69 // fieldSize must be > CloudVis or we can destroy the impostor cache
70 // a cloud must only be seen once or the impostor will be generated for each of his positions
71 double SGCloudField::fieldSize = 50000.0;
72 float SGCloudField::density = 100.0;
73 double SGCloudField::timer_dt = 0.0;
74 sgVec3 SGCloudField::view_vec, SGCloudField::view_X, SGCloudField::view_Y;
76 static int last_cache_size = 1*1024;
77 static int cacheResolution = 64;
78 static sgVec3 last_sunlight={0.0f, 0.0f, 0.0f};
80 int SGCloudField::get_CacheResolution(void) {
81 return cacheResolution;
84 void SGCloudField::set_CacheResolution(int resolutionPixels) {
85 if(cacheResolution == resolutionPixels)
87 cacheResolution = resolutionPixels;
89 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
92 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
96 int SGCloudField::get_CacheSize(void) {
97 return SGNewCloud::cldCache->queryCacheSize();
100 void SGCloudField::set_CacheSize(int sizeKb) {
101 // apply in rendering option dialog
102 if(last_cache_size == sizeKb)
107 last_cache_size = sizeKb;
109 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
112 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
115 void SGCloudField::set_CloudVis(float distance) {
116 if( distance <= fieldSize )
117 SGCloudField::CloudVis = distance;
119 void SGCloudField::set_density(float density) {
120 SGCloudField::density = density;
122 void SGCloudField::set_enable3dClouds(bool enable) {
123 if(enable3D == enable)
127 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
130 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
132 SGNewCloud::cldCache->setCacheSize(0);
136 // reposition the cloud layer at the specified origin and orientation
137 void SGCloudField::reposition( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double dt, float direction, float speed) {
141 sgMakeTransMat4( T1, p );
143 sgSetVec3( axis, 0.0, 0.0, 1.0 );
144 sgMakeRotMat4( LON, lon * SGD_RADIANS_TO_DEGREES, axis );
146 sgSetVec3( axis, 0.0, 1.0, 0.0 );
147 sgMakeRotMat4( LAT, 90.0 - lat * SGD_RADIANS_TO_DEGREES, axis );
151 sgCopyMat4( TRANSFORM, T1 );
152 sgPreMultMat4( TRANSFORM, LON );
153 sgPreMultMat4( TRANSFORM, LAT );
156 sgSetCoord( &layerpos, TRANSFORM );
158 sgMakeCoordMat4( transform, &layerpos );
163 // simulate clouds movement from wind
164 double sp_dist = speed*dt;
166 double bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
167 double by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
168 relative_position[SG_X] += bx;
169 relative_position[SG_Y] += by;
172 if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
173 Point3D start( last_lon, last_lat, 0.0 );
174 Point3D dest( lon, lat, 0.0 );
175 double course = 0.0, dist = 0.0;
177 calc_gc_course_dist( dest, start, &course, &dist );
178 // if start and dest are too close together,
179 // calc_gc_course_dist() can return a course of "nan". If
180 // this happens, lets just use the last known good course.
181 // This is a hack, and it would probably be better to make
182 // calc_gc_course_dist() more robust.
183 if ( isnan(course) ) {
184 course = last_course;
186 last_course = course;
189 // calculate cloud movement due to external forces
190 double ax = 0.0, ay = 0.0;
193 ax = cos(course) * dist;
194 ay = sin(course) * dist;
205 // correct the frustum with the right far plane
206 ssgContext *context = ssgGetCurrentContext();
207 frustum = *context->getFrustum();
210 sgEnviro.getFOV( w, h );
211 frustum.setFOV( w, h );
212 frustum.setNearFar(1.0, CloudVis);
216 SGCloudField::SGCloudField() :
223 sgSetVec3( relative_position, 0,0,0);
224 theField.reserve(200);
225 inViewClouds.reserve(200);
226 sg_srandom_time_10();
229 SGCloudField::~SGCloudField() {
230 list_of_Cloud::iterator iCloud;
231 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
232 delete iCloud->aCloud;
238 void SGCloudField::clear(void) {
239 list_of_Cloud::iterator iCloud;
240 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
241 delete iCloud->aCloud;
244 // force a recompute of density on first redraw
246 // true to come back in set density after layer is built
250 // use a table or else we see poping when moving the slider...
251 static int densTable[][10] = {
252 {0,0,0,0,0,0,0,0,0,0},
253 {1,0,0,0,0,0,0,0,0,0},
254 {1,0,0,0,1,0,0,0,0,0},
255 {1,0,0,0,1,0,0,1,0,0}, // 30%
256 {1,0,1,0,1,0,0,1,0,0},
257 {1,0,1,0,1,0,1,1,0,0}, // 50%
258 {1,0,1,0,1,0,1,1,0,1},
259 {1,0,1,1,1,0,1,1,0,1}, // 70%
260 {1,1,1,1,1,0,1,1,0,1},
261 {1,1,1,1,1,0,1,1,1,1}, // 90%
262 {1,1,1,1,1,1,1,1,1,1}
265 // set the visible flag depending on density
266 void SGCloudField::applyDensity(void) {
267 int row = (int) (density / 10.0);
271 list_of_Cloud::iterator iCloud;
272 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
275 if( densTable[row][col] ) {
276 iCloud->visible = true;
277 fieldBox.extend( *iCloud->aCloud->getCenter() );
279 iCloud->visible = false;
281 last_density = density;
282 draw_in_3d = ( theField.size() != 0);
284 sgSubVec3( center, fieldBox.getMax(), fieldBox.getMin() );
285 sgScaleVec3( center, 0.5f );
287 field_sphere.setCenter( center );
288 field_sphere.setRadius( fieldSize * 0.5f * 1.414f );
291 // add one cloud, data is not copied, ownership given
292 void SGCloudField::addCloud( sgVec3 pos, SGNewCloud *cloud) {
296 cloud->SetPos( pos );
297 sgCopyVec3( cl.pos, *cloud->getCenter() );
298 theField.push_back( cl );
302 static float Rnd(float n) {
303 return n * (-0.5f + sg_random());
307 // build a field of cloud of size 25x25 km, its a grid of 11x11 clouds
308 void SGCloudField::buildTestLayer(void) {
310 const float s = 2250.0f;
312 for( int z = -5 ; z <= 5 ; z++) {
313 for( int x = -5 ; x <= 5 ; x++ ) {
314 SGNewCloud *cloud = new SGNewCloud(SGNewCloud::CLFamilly_cu);
316 sgVec3 pos = {(x+Rnd(0.7)) * s, 750.0f, (z+Rnd(0.7)) * s};
317 addCloud(pos, cloud);
323 // cull all clouds of a tiled field
324 void SGCloudField::cullClouds(sgVec3 eyePos, sgMat4 mat) {
325 list_of_Cloud::iterator iCloud;
327 sgSphere tile_sphere;
328 tile_sphere.setRadius( field_sphere.getRadius() );
330 sgSubVec3( tile_center, field_sphere.getCenter(), eyePos );
331 tile_sphere.setCenter( tile_center );
332 tile_sphere.orthoXform(mat);
333 if( frustum.contains( & tile_sphere ) == SG_OUTSIDE )
336 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
339 if( ! iCloud->visible )
341 sgSubVec3( dist, iCloud->pos, eyePos );
342 sphere.setCenter(dist[0], dist[2], dist[1] + eyePos[1]);
343 float radius = iCloud->aCloud->getRadius();
344 sphere.setRadius(radius);
345 sphere.orthoXform(mat);
346 if( frustum.contains( & sphere ) != SG_OUTSIDE ) {
347 float squareDist = dist[0]*dist[0] + dist[1]*dist[1] + dist[2]*dist[2];
349 tmp.aCloud = iCloud->aCloud;
350 sgCopyVec3( tmp.eyePos, eyePos );
351 // save distance for later sort, opposite distance because we want back to front
352 tmp.dist = - squareDist;
353 tmp.heading = -SG_PI/2.0 - atan2( dist[0], dist[2] ); // + SG_PI;
354 tmp.alt = iCloud->pos[1];
355 inViewClouds.push_back(tmp);
356 if( squareDist - radius*radius < 100*100 )
357 sgEnviro.set_view_in_cloud(true);
364 // Render a cloud field
365 // because no field can have an infinite size (and we don't want to reach his border)
366 // we draw this field and adjacent fields.
367 // adjacent fields are not real, its the same field displaced by some offset
368 void SGCloudField::Render(void) {
375 if( last_density != density ) {
376 last_density = density;
383 if( ! SGNewCloud::cldCache->isRttAvailable() )
386 inViewClouds.clear();
391 sgMat4 modelview, tmp, invtrans;
393 // try to find the sun position
394 sgTransposeNegateMat4( invtrans, transform );
396 ssgGetLight( 0 )->getPosition( lightVec );
397 sgXformVec3( lightVec, invtrans );
399 sgSetVec3( SGNewCloud::modelSunDir, lightVec[0], lightVec[2], lightVec[1]);
400 // try to find the lighting data (not accurate)
401 sgVec4 diffuse, ambient;
402 ssgGetLight( 0 )->getColour( GL_DIFFUSE, diffuse );
403 ssgGetLight( 0 )->getColour( GL_AMBIENT, ambient );
404 // sgScaleVec3 ( SGNewCloud::sunlight, diffuse , 1.0f);
405 sgScaleVec3 ( SGNewCloud::ambLight, ambient , 1.1f);
406 // trying something else : clouds are more yellow/red at dawn/dusk
407 // and added a bit of blue ambient
408 float *sun_color = thesky->get_sun_color();
409 sgScaleVec3 ( SGNewCloud::sunlight, sun_color , 0.4f);
410 SGNewCloud::ambLight[2] += 0.1f;
413 sgSubVec3(delta_light, last_sunlight, SGNewCloud::sunlight);
414 if( (fabs(delta_light[0]) + fabs(delta_light[1]) + fabs(delta_light[2])) > 0.05f ) {
415 sgCopyVec3( last_sunlight, SGNewCloud::sunlight );
416 // force the redraw of all the impostors
417 SGNewCloud::cldCache->invalidateCache();
420 // voodoo things on the matrix stack
421 ssgGetModelviewMatrix( modelview );
422 sgCopyMat4( tmp, transform );
423 sgPostMultMat4( tmp, modelview );
425 // cloud fields are tiled on the flat earth
426 // compute the position in the tile
427 relx = fmod( deltax + relative_position[SG_X], fieldSize );
428 rely = fmod( deltay + relative_position[SG_Y], fieldSize );
430 relx = fmod( relx + fieldSize, fieldSize );
431 rely = fmod( rely + fieldSize, fieldSize );
432 sgSetVec3( eyePos, relx, alt, rely);
434 sgSetVec3( view_X, tmp[0][0], tmp[1][0], tmp[2][0] );
435 sgSetVec3( view_Y, tmp[0][1], tmp[1][1], tmp[2][1] );
436 sgSetVec3( view_vec, tmp[0][2], tmp[1][2], tmp[2][2] );
438 ssgLoadModelviewMatrix( tmp );
453 for(int x = -1 ; x <= 1 ; x++)
454 for(int y = -1 ; y <= 1 ; y++ ) {
456 // pretend we are not where we are
457 sgSetVec3(fieldPos, eyePos[0] + x*fieldSize, eyePos[1], eyePos[2] + y*fieldSize);
458 cullClouds(fieldPos, tmp);
460 // sort all visible clouds back to front (because of transparency)
461 std::sort( inViewClouds.begin(), inViewClouds.end() );
464 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
465 glEnable(GL_ALPHA_TEST);
466 glAlphaFunc(GL_GREATER, 0.0f);
467 glDisable(GL_CULL_FACE);
468 glEnable(GL_DEPTH_TEST);
469 glDepthMask( GL_FALSE );
472 glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA );
473 glEnable( GL_TEXTURE_2D );
475 glDisable(GL_LIGHTING);
477 // test data: field = 11x11 cloud, 9 fields
478 // depending on position and view direction, perhaps 40 to 60 clouds not culled
479 list_of_culledCloud::iterator iCloud;
480 for( iCloud = inViewClouds.begin() ; iCloud != inViewClouds.end() ; iCloud++ ) {
481 // iCloud->aCloud->drawContainers();
482 iCloud->aCloud->Render(iCloud->eyePos);
483 sgEnviro.callback_cloud(iCloud->heading, iCloud->alt,
484 iCloud->aCloud->getRadius(), iCloud->aCloud->getFamilly(), - iCloud->dist, iCloud->aCloud->getId());
487 glBindTexture(GL_TEXTURE_2D, 0);
488 glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
490 glEnable(GL_CULL_FACE);
491 glEnable(GL_DEPTH_TEST);
493 ssgLoadModelviewMatrix( modelview );