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>
30 #include <simgear/math/sg_random.h>
31 #include <simgear/math/sg_geodesy.hxx>
32 #include <simgear/math/polar3d.hxx>
34 #include STL_ALGORITHM
39 #include <simgear/environment/visual_enviro.hxx>
41 #include "newcloud.hxx"
42 #include "cloudfield.hxx"
44 #if defined(__MINGW32__)
45 #define isnan(x) _isnan(x)
48 #if defined (__FreeBSD__)
49 # if __FreeBSD_version < 500000
51 inline int isnan(double r) { return !(r <= 0 || r >= 0); }
57 #if defined (__CYGWIN__)
63 static list_of_culledCloud inViewClouds;
65 // visibility distance for clouds in meters
66 float SGCloudField::CloudVis = 25000.0f;
67 bool SGCloudField::enable3D = false;
68 // fieldSize must be > CloudVis or we can destroy the impostor cache
69 // a cloud must only be seen once or the impostor will be generated for each of his positions
70 double SGCloudField::fieldSize = 50000.0;
71 float SGCloudField::density = 100.0;
72 double SGCloudField::timer_dt = 0.0;
73 sgVec3 SGCloudField::view_vec, SGCloudField::view_X, SGCloudField::view_Y;
75 static int last_cache_size = 1*1024;
76 static int cacheResolution = 64;
77 static sgVec3 last_sunlight={0.0f, 0.0f, 0.0f};
79 int SGCloudField::get_CacheResolution(void) {
81 return cacheResolution;
86 void SGCloudField::set_CacheResolution(int resolutionPixels) {
88 if(cacheResolution == resolutionPixels)
90 cacheResolution = resolutionPixels;
92 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
95 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
100 int SGCloudField::get_CacheSize(void) {
102 return SGNewCloud::cldCache->queryCacheSize();
107 void SGCloudField::set_CacheSize(int sizeKb) {
109 // apply in rendering option dialog
110 if(last_cache_size == sizeKb)
115 last_cache_size = sizeKb;
117 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
120 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
124 void SGCloudField::set_CloudVis(float distance) {
126 if( distance <= fieldSize )
127 SGCloudField::CloudVis = distance;
130 void SGCloudField::set_density(float density) {
132 SGCloudField::density = density;
135 void SGCloudField::set_enable3dClouds(bool enable) {
137 if(enable3D == enable)
141 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
144 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
146 SGNewCloud::cldCache->setCacheSize(0);
151 // reposition the cloud layer at the specified origin and orientation
152 void SGCloudField::reposition( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double dt, float direction, float speed) {
157 sgMakeTransMat4( T1, p );
159 sgSetVec3( axis, 0.0, 0.0, 1.0 );
160 sgMakeRotMat4( LON, lon * SGD_RADIANS_TO_DEGREES, axis );
162 sgSetVec3( axis, 0.0, 1.0, 0.0 );
163 sgMakeRotMat4( LAT, 90.0 - lat * SGD_RADIANS_TO_DEGREES, axis );
167 sgCopyMat4( TRANSFORM, T1 );
168 sgPreMultMat4( TRANSFORM, LON );
169 sgPreMultMat4( TRANSFORM, LAT );
172 sgSetCoord( &layerpos, TRANSFORM );
174 sgMakeCoordMat4( transform, &layerpos );
179 // simulate clouds movement from wind
180 double sp_dist = speed*dt;
182 double bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
183 double by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
184 relative_position[SG_X] += bx;
185 relative_position[SG_Y] += by;
188 if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
189 Point3D start( last_lon, last_lat, 0.0 );
190 Point3D dest( lon, lat, 0.0 );
191 double course = 0.0, dist = 0.0;
193 calc_gc_course_dist( dest, start, &course, &dist );
194 // if start and dest are too close together,
195 // calc_gc_course_dist() can return a course of "nan". If
196 // this happens, lets just use the last known good course.
197 // This is a hack, and it would probably be better to make
198 // calc_gc_course_dist() more robust.
199 if ( isnan(course) ) {
200 course = last_course;
202 last_course = course;
205 // calculate cloud movement due to external forces
206 double ax = 0.0, ay = 0.0;
209 ax = cos(course) * dist;
210 ay = sin(course) * dist;
221 // correct the frustum with the right far plane
222 ssgContext *context = ssgGetCurrentContext();
223 frustum = *context->getFrustum();
226 sgEnviro.getFOV( w, h );
227 frustum.setFOV( w, h );
228 frustum.setNearFar(1.0, CloudVis);
233 SGCloudField::SGCloudField() :
241 sgSetVec3( relative_position, 0,0,0);
242 theField.reserve(200);
243 inViewClouds.reserve(200);
244 sg_srandom_time_10();
250 SGCloudField::~SGCloudField() {
252 list_of_Cloud::iterator iCloud;
253 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
254 delete iCloud->aCloud;
261 void SGCloudField::clear(void) {
263 list_of_Cloud::iterator iCloud;
264 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
265 delete iCloud->aCloud;
268 // force a recompute of density on first redraw
270 // true to come back in set density after layer is built
275 // use a table or else we see poping when moving the slider...
276 static int densTable[][10] = {
277 {0,0,0,0,0,0,0,0,0,0},
278 {1,0,0,0,0,0,0,0,0,0},
279 {1,0,0,0,1,0,0,0,0,0},
280 {1,0,0,0,1,0,0,1,0,0}, // 30%
281 {1,0,1,0,1,0,0,1,0,0},
282 {1,0,1,0,1,0,1,1,0,0}, // 50%
283 {1,0,1,0,1,0,1,1,0,1},
284 {1,0,1,1,1,0,1,1,0,1}, // 70%
285 {1,1,1,1,1,0,1,1,0,1},
286 {1,1,1,1,1,0,1,1,1,1}, // 90%
287 {1,1,1,1,1,1,1,1,1,1}
290 // set the visible flag depending on density
291 void SGCloudField::applyDensity(void) {
293 int row = (int) (density / 10.0);
297 list_of_Cloud::iterator iCloud;
298 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
301 if( densTable[row][col] ) {
302 iCloud->visible = true;
303 fieldBox.extend( *iCloud->aCloud->getCenter() );
305 iCloud->visible = false;
307 last_density = density;
308 draw_in_3d = ( theField.size() != 0);
310 sgSubVec3( center, fieldBox.getMax(), fieldBox.getMin() );
311 sgScaleVec3( center, 0.5f );
313 field_sphere.setCenter( center );
314 field_sphere.setRadius( fieldSize * 0.5f * 1.414f );
318 // add one cloud, data is not copied, ownership given
319 void SGCloudField::addCloud( sgVec3 pos, SGNewCloud *cloud) {
324 cloud->SetPos( pos );
325 sgCopyVec3( cl.pos, *cloud->getCenter() );
326 theField.push_back( cl );
331 static float Rnd(float n) {
332 return n * (-0.5f + sg_random());
336 // build a field of cloud of size 25x25 km, its a grid of 11x11 clouds
337 void SGCloudField::buildTestLayer(void) {
339 const float s = 2250.0f;
341 for( int z = -5 ; z <= 5 ; z++) {
342 for( int x = -5 ; x <= 5 ; x++ ) {
343 SGNewCloud *cloud = new SGNewCloud(SGNewCloud::CLFamilly_cu);
345 sgVec3 pos = {(x+Rnd(0.7)) * s, 750.0f, (z+Rnd(0.7)) * s};
346 addCloud(pos, cloud);
353 // cull all clouds of a tiled field
354 void SGCloudField::cullClouds(sgVec3 eyePos, sgMat4 mat) {
356 list_of_Cloud::iterator iCloud;
358 sgSphere tile_sphere;
359 tile_sphere.setRadius( field_sphere.getRadius() );
361 sgSubVec3( tile_center, field_sphere.getCenter(), eyePos );
362 tile_sphere.setCenter( tile_center );
363 tile_sphere.orthoXform(mat);
364 if( frustum.contains( & tile_sphere ) == SG_OUTSIDE )
367 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
370 if( ! iCloud->visible )
372 sgSubVec3( dist, iCloud->pos, eyePos );
373 sphere.setCenter(dist[0], dist[2], dist[1] + eyePos[1]);
374 float radius = iCloud->aCloud->getRadius();
375 sphere.setRadius(radius);
376 sphere.orthoXform(mat);
377 if( frustum.contains( & sphere ) != SG_OUTSIDE ) {
378 float squareDist = dist[0]*dist[0] + dist[1]*dist[1] + dist[2]*dist[2];
380 tmp.aCloud = iCloud->aCloud;
381 sgCopyVec3( tmp.eyePos, eyePos );
382 // save distance for later sort, opposite distance because we want back to front
383 tmp.dist = - squareDist;
384 tmp.heading = -SG_PI/2.0 - atan2( dist[0], dist[2] ); // + SG_PI;
385 tmp.alt = iCloud->pos[1];
386 inViewClouds.push_back(tmp);
387 if( squareDist - radius*radius < 100*100 )
388 sgEnviro.set_view_in_cloud(true);
395 // Render a cloud field
396 // because no field can have an infinite size (and we don't want to reach his border)
397 // we draw this field and adjacent fields.
398 // adjacent fields are not real, its the same field displaced by some offset
399 void SGCloudField::Render(void) {
407 if( last_density != density ) {
408 last_density = density;
415 if( ! SGNewCloud::cldCache->isRttAvailable() )
418 inViewClouds.clear();
423 sgMat4 modelview, tmp, invtrans;
425 // try to find the sun position
426 sgTransposeNegateMat4( invtrans, transform );
428 ssgGetLight( 0 )->getPosition( lightVec );
429 sgXformVec3( lightVec, invtrans );
431 sgSetVec3( SGNewCloud::modelSunDir, lightVec[0], lightVec[2], lightVec[1]);
432 // try to find the lighting data (not accurate)
433 sgVec4 diffuse, ambient;
434 ssgGetLight( 0 )->getColour( GL_DIFFUSE, diffuse );
435 ssgGetLight( 0 )->getColour( GL_AMBIENT, ambient );
436 // sgScaleVec3 ( SGNewCloud::sunlight, diffuse , 1.0f);
437 sgScaleVec3 ( SGNewCloud::ambLight, ambient , 1.1f);
438 // trying something else : clouds are more yellow/red at dawn/dusk
439 // and added a bit of blue ambient
440 float *sun_color = thesky->get_sun_color();
441 sgScaleVec3 ( SGNewCloud::sunlight, sun_color , 0.4f);
442 SGNewCloud::ambLight[2] += 0.1f;
445 sgSubVec3(delta_light, last_sunlight, SGNewCloud::sunlight);
446 if( (fabs(delta_light[0]) + fabs(delta_light[1]) + fabs(delta_light[2])) > 0.05f ) {
447 sgCopyVec3( last_sunlight, SGNewCloud::sunlight );
448 // force the redraw of all the impostors
449 SGNewCloud::cldCache->invalidateCache();
452 // voodoo things on the matrix stack
453 ssgGetModelviewMatrix( modelview );
454 sgCopyMat4( tmp, transform );
455 sgPostMultMat4( tmp, modelview );
457 // cloud fields are tiled on the flat earth
458 // compute the position in the tile
459 relx = fmod( deltax + relative_position[SG_X], fieldSize );
460 rely = fmod( deltay + relative_position[SG_Y], fieldSize );
462 relx = fmod( relx + fieldSize, fieldSize );
463 rely = fmod( rely + fieldSize, fieldSize );
464 sgSetVec3( eyePos, relx, alt, rely);
466 sgSetVec3( view_X, tmp[0][0], tmp[1][0], tmp[2][0] );
467 sgSetVec3( view_Y, tmp[0][1], tmp[1][1], tmp[2][1] );
468 sgSetVec3( view_vec, tmp[0][2], tmp[1][2], tmp[2][2] );
470 ssgLoadModelviewMatrix( tmp );
485 for(int x = -1 ; x <= 1 ; x++)
486 for(int y = -1 ; y <= 1 ; y++ ) {
488 // pretend we are not where we are
489 sgSetVec3(fieldPos, eyePos[0] + x*fieldSize, eyePos[1], eyePos[2] + y*fieldSize);
490 cullClouds(fieldPos, tmp);
492 // sort all visible clouds back to front (because of transparency)
493 std::sort( inViewClouds.begin(), inViewClouds.end() );
496 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
497 glEnable(GL_ALPHA_TEST);
498 glAlphaFunc(GL_GREATER, 0.0f);
499 glDisable(GL_CULL_FACE);
500 glEnable(GL_DEPTH_TEST);
501 glDepthMask( GL_FALSE );
504 glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA );
505 glEnable( GL_TEXTURE_2D );
507 glDisable(GL_LIGHTING);
509 // test data: field = 11x11 cloud, 9 fields
510 // depending on position and view direction, perhaps 40 to 60 clouds not culled
511 list_of_culledCloud::iterator iCloud;
512 for( iCloud = inViewClouds.begin() ; iCloud != inViewClouds.end() ; iCloud++ ) {
513 // iCloud->aCloud->drawContainers();
514 iCloud->aCloud->Render(iCloud->eyePos);
515 sgEnviro.callback_cloud(iCloud->heading, iCloud->alt,
516 iCloud->aCloud->getRadius(), iCloud->aCloud->getFamilly(), - iCloud->dist, iCloud->aCloud->getId());
519 glBindTexture(GL_TEXTURE_2D, 0);
520 glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
522 glEnable(GL_CULL_FACE);
523 glEnable(GL_DEPTH_TEST);
525 ssgLoadModelviewMatrix( modelview );