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, 59 Temple Place, Suite 330, Boston, MA 02111-1307, 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); }
59 static list_of_culledCloud inViewClouds;
61 // visibility distance for clouds in meters
62 float SGCloudField::CloudVis = 25000.0f;
63 bool SGCloudField::enable3D = false;
64 // fieldSize must be > CloudVis or we can destroy the impostor cache
65 // a cloud must only be seen once or the impostor will be generated for each of his positions
66 double SGCloudField::fieldSize = 50000.0;
67 float SGCloudField::density = 100.0;
68 double SGCloudField::timer_dt = 0.0;
69 sgVec3 SGCloudField::view_vec, SGCloudField::view_X, SGCloudField::view_Y;
71 static int last_cache_size = 1*1024;
72 static int cacheResolution = 64;
73 static sgVec3 last_sunlight={0.0f, 0.0f, 0.0f};
75 int SGCloudField::get_CacheResolution(void) {
76 return cacheResolution;
79 void SGCloudField::set_CacheResolution(int resolutionPixels) {
80 if(cacheResolution == resolutionPixels)
82 cacheResolution = resolutionPixels;
84 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
87 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
91 int SGCloudField::get_CacheSize(void) {
92 return SGNewCloud::cldCache->queryCacheSize();
95 void SGCloudField::set_CacheSize(int sizeKb) {
96 // apply in rendering option dialog
97 if(last_cache_size == sizeKb)
102 last_cache_size = sizeKb;
104 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
107 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
110 void SGCloudField::set_CloudVis(float distance) {
111 if( distance <= fieldSize )
112 SGCloudField::CloudVis = distance;
114 void SGCloudField::set_density(float density) {
115 SGCloudField::density = density;
117 void SGCloudField::set_enable3dClouds(bool enable) {
118 if(enable3D == enable)
122 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
125 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
127 SGNewCloud::cldCache->setCacheSize(0);
131 // reposition the cloud layer at the specified origin and orientation
132 void SGCloudField::reposition( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double dt, float direction, float speed) {
136 sgMakeTransMat4( T1, p );
138 sgSetVec3( axis, 0.0, 0.0, 1.0 );
139 sgMakeRotMat4( LON, lon * SGD_RADIANS_TO_DEGREES, axis );
141 sgSetVec3( axis, 0.0, 1.0, 0.0 );
142 sgMakeRotMat4( LAT, 90.0 - lat * SGD_RADIANS_TO_DEGREES, axis );
146 sgCopyMat4( TRANSFORM, T1 );
147 sgPreMultMat4( TRANSFORM, LON );
148 sgPreMultMat4( TRANSFORM, LAT );
151 sgSetCoord( &layerpos, TRANSFORM );
153 sgMakeCoordMat4( transform, &layerpos );
158 // simulate clouds movement from wind
159 double sp_dist = speed*dt;
161 double bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
162 double by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
163 relative_position[SG_X] += bx;
164 relative_position[SG_Y] += by;
167 if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
168 Point3D start( last_lon, last_lat, 0.0 );
169 Point3D dest( lon, lat, 0.0 );
170 double course = 0.0, dist = 0.0;
172 calc_gc_course_dist( dest, start, &course, &dist );
173 // if start and dest are too close together,
174 // calc_gc_course_dist() can return a course of "nan". If
175 // this happens, lets just use the last known good course.
176 // This is a hack, and it would probably be better to make
177 // calc_gc_course_dist() more robust.
178 if ( isnan(course) ) {
179 course = last_course;
181 last_course = course;
184 // calculate cloud movement due to external forces
185 double ax = 0.0, ay = 0.0;
188 ax = cos(course) * dist;
189 ay = sin(course) * dist;
200 // correct the frustum with the right far plane
201 ssgContext *context = ssgGetCurrentContext();
202 frustum = *context->getFrustum();
205 sgEnviro.getFOV( w, h );
206 frustum.setFOV( w, h );
207 frustum.setNearFar(1.0, CloudVis);
211 SGCloudField::SGCloudField() :
218 sgSetVec3( relative_position, 0,0,0);
219 theField.reserve(200);
220 inViewClouds.reserve(200);
221 sg_srandom_time_10();
224 SGCloudField::~SGCloudField() {
225 list_of_Cloud::iterator iCloud;
226 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
227 delete iCloud->aCloud;
233 void SGCloudField::clear(void) {
234 list_of_Cloud::iterator iCloud;
235 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
236 delete iCloud->aCloud;
239 // force a recompute of density on first redraw
241 // true to come back in set density after layer is built
245 // use a table or else we see poping when moving the slider...
246 static int densTable[][10] = {
247 {0,0,0,0,0,0,0,0,0,0},
248 {1,0,0,0,0,0,0,0,0,0},
249 {1,0,0,0,1,0,0,0,0,0},
250 {1,0,0,0,1,0,0,1,0,0}, // 30%
251 {1,0,1,0,1,0,0,1,0,0},
252 {1,0,1,0,1,0,1,1,0,0}, // 50%
253 {1,0,1,0,1,0,1,1,0,1},
254 {1,0,1,1,1,0,1,1,0,1}, // 70%
255 {1,1,1,1,1,0,1,1,0,1},
256 {1,1,1,1,1,0,1,1,1,1}, // 90%
257 {1,1,1,1,1,1,1,1,1,1}
260 // set the visible flag depending on density
261 void SGCloudField::applyDensity(void) {
262 int row = (int) (density / 10.0);
266 list_of_Cloud::iterator iCloud;
267 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
270 if( densTable[row][col] ) {
271 iCloud->visible = true;
272 fieldBox.extend( *iCloud->aCloud->getCenter() );
274 iCloud->visible = false;
276 last_density = density;
277 draw_in_3d = ( theField.size() != 0);
279 sgSubVec3( center, fieldBox.getMax(), fieldBox.getMin() );
280 sgScaleVec3( center, 0.5f );
282 field_sphere.setCenter( center );
283 field_sphere.setRadius( fieldSize * 0.5f * 1.414f );
286 // add one cloud, data is not copied, ownership given
287 void SGCloudField::addCloud( sgVec3 pos, SGNewCloud *cloud) {
291 cloud->SetPos( pos );
292 sgCopyVec3( cl.pos, *cloud->getCenter() );
293 theField.push_back( cl );
297 static float Rnd(float n) {
298 return n * (-0.5f + sg_random());
302 // build a field of cloud of size 25x25 km, its a grid of 11x11 clouds
303 void SGCloudField::buildTestLayer(void) {
305 const float s = 2250.0f;
307 for( int z = -5 ; z <= 5 ; z++) {
308 for( int x = -5 ; x <= 5 ; x++ ) {
309 SGNewCloud *cloud = new SGNewCloud(SGNewCloud::CLFamilly_cu);
311 sgVec3 pos = {(x+Rnd(0.7)) * s, 750.0f, (z+Rnd(0.7)) * s};
312 addCloud(pos, cloud);
318 // cull all clouds of a tiled field
319 void SGCloudField::cullClouds(sgVec3 eyePos, sgMat4 mat) {
320 list_of_Cloud::iterator iCloud;
322 sgSphere tile_sphere;
323 tile_sphere.setRadius( field_sphere.getRadius() );
325 sgSubVec3( tile_center, field_sphere.getCenter(), eyePos );
326 tile_sphere.setCenter( tile_center );
327 tile_sphere.orthoXform(mat);
328 if( frustum.contains( & tile_sphere ) == SG_OUTSIDE )
331 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
334 if( ! iCloud->visible )
336 sgSubVec3( dist, iCloud->pos, eyePos );
337 sphere.setCenter(dist[0], dist[2], dist[1] + eyePos[1]);
338 float radius = iCloud->aCloud->getRadius();
339 sphere.setRadius(radius);
340 sphere.orthoXform(mat);
341 if( frustum.contains( & sphere ) != SG_OUTSIDE ) {
342 float squareDist = dist[0]*dist[0] + dist[1]*dist[1] + dist[2]*dist[2];
344 tmp.aCloud = iCloud->aCloud;
345 sgCopyVec3( tmp.eyePos, eyePos );
346 // save distance for later sort, opposite distance because we want back to front
347 tmp.dist = - squareDist;
348 tmp.heading = -SG_PI/2.0 - atan2( dist[0], dist[2] ); // + SG_PI;
349 tmp.alt = iCloud->pos[1];
350 inViewClouds.push_back(tmp);
351 if( squareDist - radius*radius < 100*100 )
352 sgEnviro.set_view_in_cloud(true);
359 // Render a cloud field
360 // because no field can have an infinite size (and we don't want to reach his border)
361 // we draw this field and adjacent fields.
362 // adjacent fields are not real, its the same field displaced by some offset
363 void SGCloudField::Render(void) {
370 if( last_density != density ) {
371 last_density = density;
378 if( ! SGNewCloud::cldCache->isRttAvailable() )
381 inViewClouds.clear();
386 sgMat4 modelview, tmp, invtrans;
388 // try to find the sun position
389 sgTransposeNegateMat4( invtrans, transform );
391 ssgGetLight( 0 )->getPosition( lightVec );
392 sgXformVec3( lightVec, invtrans );
394 sgSetVec3( SGNewCloud::modelSunDir, lightVec[0], lightVec[2], lightVec[1]);
395 // try to find the lighting data (not accurate)
396 sgVec4 diffuse, ambient;
397 ssgGetLight( 0 )->getColour( GL_DIFFUSE, diffuse );
398 ssgGetLight( 0 )->getColour( GL_AMBIENT, ambient );
399 // sgScaleVec3 ( SGNewCloud::sunlight, diffuse , 1.0f);
400 sgScaleVec3 ( SGNewCloud::ambLight, ambient , 1.1f);
401 // trying something else : clouds are more yellow/red at dawn/dusk
402 // and added a bit of blue ambient
403 float *sun_color = thesky->get_sun_color();
404 sgScaleVec3 ( SGNewCloud::sunlight, sun_color , 0.4f);
405 SGNewCloud::ambLight[2] += 0.1f;
408 sgSubVec3(delta_light, last_sunlight, SGNewCloud::sunlight);
409 if( (fabs(delta_light[0]) + fabs(delta_light[1]) + fabs(delta_light[2])) > 0.05f ) {
410 sgCopyVec3( last_sunlight, SGNewCloud::sunlight );
411 // force the redraw of all the impostors
412 SGNewCloud::cldCache->invalidateCache();
415 // voodoo things on the matrix stack
416 ssgGetModelviewMatrix( modelview );
417 sgCopyMat4( tmp, transform );
418 sgPostMultMat4( tmp, modelview );
420 // cloud fields are tiled on the flat earth
421 // compute the position in the tile
422 relx = fmod( deltax + relative_position[SG_X], fieldSize );
423 rely = fmod( deltay + relative_position[SG_Y], fieldSize );
425 relx = fmod( relx + fieldSize, fieldSize );
426 rely = fmod( rely + fieldSize, fieldSize );
427 sgSetVec3( eyePos, relx, alt, rely);
429 sgSetVec3( view_X, tmp[0][0], tmp[1][0], tmp[2][0] );
430 sgSetVec3( view_Y, tmp[0][1], tmp[1][1], tmp[2][1] );
431 sgSetVec3( view_vec, tmp[0][2], tmp[1][2], tmp[2][2] );
433 ssgLoadModelviewMatrix( tmp );
448 for(int x = -1 ; x <= 1 ; x++)
449 for(int y = -1 ; y <= 1 ; y++ ) {
451 // pretend we are not where we are
452 sgSetVec3(fieldPos, eyePos[0] + x*fieldSize, eyePos[1], eyePos[2] + y*fieldSize);
453 cullClouds(fieldPos, tmp);
455 // sort all visible clouds back to front (because of transparency)
456 std::sort( inViewClouds.begin(), inViewClouds.end() );
459 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
460 glEnable(GL_ALPHA_TEST);
461 glAlphaFunc(GL_GREATER, 0.0f);
462 glDisable(GL_CULL_FACE);
463 glEnable(GL_DEPTH_TEST);
464 glDepthMask( GL_FALSE );
467 glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA );
468 glEnable( GL_TEXTURE_2D );
470 glDisable(GL_LIGHTING);
472 // test data: field = 11x11 cloud, 9 fields
473 // depending on position and view direction, perhaps 40 to 60 clouds not culled
474 list_of_culledCloud::iterator iCloud;
475 for( iCloud = inViewClouds.begin() ; iCloud != inViewClouds.end() ; iCloud++ ) {
476 // iCloud->aCloud->drawContainers();
477 iCloud->aCloud->Render(iCloud->eyePos);
478 sgEnviro.callback_cloud(iCloud->heading, iCloud->alt,
479 iCloud->aCloud->getRadius(), iCloud->aCloud->getFamilly(), - iCloud->dist, iCloud->aCloud->getId());
482 glBindTexture(GL_TEXTURE_2D, 0);
483 glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
485 glEnable(GL_CULL_FACE);
486 glEnable(GL_DEPTH_TEST);
488 ssgLoadModelviewMatrix( modelview );