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"
47 static list_of_culledCloud inViewClouds;
49 // visibility distance for clouds in meters
50 float SGCloudField::CloudVis = 25000.0f;
51 bool SGCloudField::enable3D = false;
52 // fieldSize must be > CloudVis or we can destroy the impostor cache
53 // a cloud must only be seen once or the impostor will be generated for each of his positions
54 double SGCloudField::fieldSize = 50000.0;
55 float SGCloudField::density = 100.0;
56 double SGCloudField::timer_dt = 0.0;
57 sgVec3 SGCloudField::view_vec, SGCloudField::view_X, SGCloudField::view_Y;
59 static int last_cache_size = 1*1024;
60 static int cacheResolution = 64;
61 static sgVec3 last_sunlight={0.0f, 0.0f, 0.0f};
63 int SGCloudField::get_CacheResolution(void) {
64 return cacheResolution;
67 void SGCloudField::set_CacheResolution(int resolutionPixels) {
68 if(cacheResolution == resolutionPixels)
70 cacheResolution = resolutionPixels;
72 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
75 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
79 int SGCloudField::get_CacheSize(void) {
80 return SGNewCloud::cldCache->queryCacheSize();
83 void SGCloudField::set_CacheSize(int sizeKb) {
84 // apply in rendering option dialog
85 if(last_cache_size == sizeKb)
90 last_cache_size = sizeKb;
92 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
95 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
98 void SGCloudField::set_CloudVis(float distance) {
99 if( distance <= fieldSize )
100 SGCloudField::CloudVis = distance;
102 void SGCloudField::set_density(float density) {
103 SGCloudField::density = density;
105 void SGCloudField::set_enable3dClouds(bool enable) {
106 if(enable3D == enable)
110 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
113 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
115 SGNewCloud::cldCache->setCacheSize(0);
119 // reposition the cloud layer at the specified origin and orientation
120 void SGCloudField::reposition( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double dt, float direction, float speed) {
124 sgMakeTransMat4( T1, p );
126 sgSetVec3( axis, 0.0, 0.0, 1.0 );
127 sgMakeRotMat4( LON, lon * SGD_RADIANS_TO_DEGREES, axis );
129 sgSetVec3( axis, 0.0, 1.0, 0.0 );
130 sgMakeRotMat4( LAT, 90.0 - lat * SGD_RADIANS_TO_DEGREES, axis );
134 sgCopyMat4( TRANSFORM, T1 );
135 sgPreMultMat4( TRANSFORM, LON );
136 sgPreMultMat4( TRANSFORM, LAT );
139 sgSetCoord( &layerpos, TRANSFORM );
141 sgMakeCoordMat4( transform, &layerpos );
146 // simulate clouds movement from wind
147 double sp_dist = speed*dt;
149 double bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
150 double by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
151 relative_position[SG_X] += bx;
152 relative_position[SG_Y] += by;
155 if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
156 Point3D start( last_lon, last_lat, 0.0 );
157 Point3D dest( lon, lat, 0.0 );
158 double course = 0.0, dist = 0.0;
160 calc_gc_course_dist( dest, start, &course, &dist );
161 // if start and dest are too close together,
162 // calc_gc_course_dist() can return a course of "nan". If
163 // this happens, lets just use the last known good course.
164 // This is a hack, and it would probably be better to make
165 // calc_gc_course_dist() more robust.
166 if ( isnan(course) ) {
167 course = last_course;
169 last_course = course;
172 // calculate cloud movement due to external forces
173 double ax = 0.0, ay = 0.0;
176 ax = cos(course) * dist;
177 ay = sin(course) * dist;
188 // correct the frustum with the right far plane
189 ssgContext *context = ssgGetCurrentContext();
190 frustum = *context->getFrustum();
193 sgEnviro.getFOV( w, h );
194 frustum.setFOV( w, h );
195 frustum.setNearFar(1.0, CloudVis);
199 SGCloudField::SGCloudField() :
206 sgSetVec3( relative_position, 0,0,0);
207 theField.reserve(200);
208 inViewClouds.reserve(200);
209 sg_srandom_time_10();
212 SGCloudField::~SGCloudField() {
213 list_of_Cloud::iterator iCloud;
214 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
215 delete iCloud->aCloud;
221 void SGCloudField::clear(void) {
222 list_of_Cloud::iterator iCloud;
223 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
224 delete iCloud->aCloud;
227 // force a recompute of density on first redraw
229 // true to come back in set density after layer is built
233 // use a table or else we see poping when moving the slider...
234 static int densTable[][10] = {
235 {0,0,0,0,0,0,0,0,0,0},
236 {1,0,0,0,0,0,0,0,0,0},
237 {1,0,0,0,1,0,0,0,0,0},
238 {1,0,0,0,1,0,0,1,0,0}, // 30%
239 {1,0,1,0,1,0,0,1,0,0},
240 {1,0,1,0,1,0,1,1,0,0}, // 50%
241 {1,0,1,0,1,0,1,1,0,1},
242 {1,0,1,1,1,0,1,1,0,1}, // 70%
243 {1,1,1,1,1,0,1,1,0,1},
244 {1,1,1,1,1,0,1,1,1,1}, // 90%
245 {1,1,1,1,1,1,1,1,1,1}
248 // set the visible flag depending on density
249 void SGCloudField::applyDensity(void) {
250 int row = (int) (density / 10.0);
252 list_of_Cloud::iterator iCloud;
253 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
256 if( densTable[row][col] ) {
257 iCloud->visible = true;
259 iCloud->visible = false;
261 last_density = density;
262 draw_in_3d = ( theField.size() != 0);
265 // add one cloud, data is not copied, ownership given
266 void SGCloudField::addCloud( sgVec3 pos, SGNewCloud *cloud) {
270 cloud->SetPos( pos );
271 sgCopyVec3( cl.pos, *cloud->getCenter() );
272 theField.push_back( cl );
276 static float Rnd(float n) {
277 return n * (-0.5f + sg_random());
281 // build a field of cloud of size 25x25 km, its a grid of 11x11 clouds
282 void SGCloudField::buildTestLayer(void) {
284 const float s = 2250.0f;
286 for( int z = -5 ; z <= 5 ; z++) {
287 for( int x = -5 ; x <= 5 ; x++ ) {
288 SGNewCloud *cloud = new SGNewCloud(SGNewCloud::CLFamilly_cu);
290 sgVec3 pos = {(x+Rnd(0.7)) * s, 750.0f, (z+Rnd(0.7)) * s};
291 addCloud(pos, cloud);
297 // cull all clouds of a tiled field
298 void SGCloudField::cullClouds(sgVec3 eyePos, sgMat4 mat) {
299 list_of_Cloud::iterator iCloud;
301 // TODO:cull the field before culling the clouds in the field (should eliminate 3 fields)
302 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
305 if( ! iCloud->visible )
307 sgSubVec3( dist, iCloud->pos, eyePos );
308 sphere.setCenter(dist[0], dist[2], dist[1] + eyePos[1]);
309 float radius = iCloud->aCloud->getRadius();
310 sphere.setRadius(radius);
311 sphere.orthoXform(mat);
312 if( frustum.contains( & sphere ) != SG_OUTSIDE ) {
313 float squareDist = dist[0]*dist[0] + dist[1]*dist[1] + dist[2]*dist[2];
315 tmp.aCloud = iCloud->aCloud;
316 sgCopyVec3( tmp.eyePos, eyePos );
317 // save distance for later sort, opposite distance because we want back to front
318 tmp.dist = - squareDist;
319 tmp.heading = -SG_PI/2.0 - atan2( dist[0], dist[2] ); // + SG_PI;
320 tmp.alt = iCloud->pos[1];
321 inViewClouds.push_back(tmp);
322 if( squareDist - radius*radius < 100*100 )
323 sgEnviro.set_view_in_cloud(true);
330 // Render a cloud field
331 // because no field can have an infinite size (and we don't want to reach his border)
332 // we draw this field and adjacent fields.
333 // adjacent fields are not real, its the same field displaced by some offset
334 void SGCloudField::Render(void) {
341 if( last_density != density ) {
342 last_density = density;
349 if( ! SGNewCloud::cldCache->isRttAvailable() )
352 inViewClouds.clear();
357 sgMat4 modelview, tmp, invtrans;
359 // try to find the sun position
360 sgTransposeNegateMat4( invtrans, transform );
362 ssgGetLight( 0 )->getPosition( lightVec );
363 sgXformVec3( lightVec, invtrans );
365 sgSetVec3( SGNewCloud::modelSunDir, lightVec[0], lightVec[2], lightVec[1]);
366 // try to find the lighting data (not accurate)
367 sgVec4 diffuse, ambient;
368 ssgGetLight( 0 )->getColour( GL_DIFFUSE, diffuse );
369 ssgGetLight( 0 )->getColour( GL_AMBIENT, ambient );
370 // sgScaleVec3 ( SGNewCloud::sunlight, diffuse , 1.0f);
371 sgScaleVec3 ( SGNewCloud::ambLight, ambient , 1.1f);
372 // trying something else : clouds are more yellow/red at dawn/dusk
373 // and added a bit of blue ambient
374 float *sun_color = thesky->get_sun_color();
375 sgScaleVec3 ( SGNewCloud::sunlight, sun_color , 0.4f);
376 SGNewCloud::ambLight[2] += 0.1f;
379 sgSubVec3(delta_light, last_sunlight, SGNewCloud::sunlight);
380 if( (fabs(delta_light[0]) + fabs(delta_light[1]) + fabs(delta_light[2])) > 0.05f ) {
381 sgCopyVec3( last_sunlight, SGNewCloud::sunlight );
382 // force the redraw of all the impostors
383 SGNewCloud::cldCache->invalidateCache();
386 // voodoo things on the matrix stack
387 ssgGetModelviewMatrix( modelview );
388 sgCopyMat4( tmp, transform );
389 sgPostMultMat4( tmp, modelview );
391 // cloud fields are tiled on the flat earth
392 // compute the position in the tile
393 relx = fmod( deltax + relative_position[SG_X], fieldSize );
394 rely = fmod( deltay + relative_position[SG_Y], fieldSize );
396 relx = fmod( relx + fieldSize, fieldSize );
397 rely = fmod( rely + fieldSize, fieldSize );
398 sgSetVec3( eyePos, relx, alt, rely);
400 sgSetVec3( view_X, tmp[0][0], tmp[1][0], tmp[2][0] );
401 sgSetVec3( view_Y, tmp[0][1], tmp[1][1], tmp[2][1] );
402 sgSetVec3( view_vec, tmp[0][2], tmp[1][2], tmp[2][2] );
404 ssgLoadModelviewMatrix( tmp );
419 for(int x = -1 ; x <= 1 ; x++)
420 for(int y = -1 ; y <= 1 ; y++ ) {
422 // pretend we are not where we are
423 sgSetVec3(fieldPos, eyePos[0] + x*fieldSize, eyePos[1], eyePos[2] + y*fieldSize);
424 cullClouds(fieldPos, tmp);
426 // sort all visible clouds back to front (because of transparency)
427 std::sort( inViewClouds.begin(), inViewClouds.end() );
430 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
431 glEnable(GL_ALPHA_TEST);
432 glAlphaFunc(GL_GREATER, 0.0f);
433 glDisable(GL_CULL_FACE);
434 glEnable(GL_DEPTH_TEST);
435 glDepthMask( GL_FALSE );
438 glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA );
439 glEnable( GL_TEXTURE_2D );
441 glDisable(GL_LIGHTING);
443 // test data: field = 11x11 cloud, 9 fields
444 // depending on position and view direction, perhaps 40 to 60 clouds not culled
445 list_of_culledCloud::iterator iCloud;
446 for( iCloud = inViewClouds.begin() ; iCloud != inViewClouds.end() ; iCloud++ ) {
447 // iCloud->aCloud->drawContainers();
448 iCloud->aCloud->Render(iCloud->eyePos);
449 sgEnviro.callback_cloud(iCloud->heading, iCloud->alt,
450 iCloud->aCloud->getRadius(), iCloud->aCloud->getFamilly(), - iCloud->dist, iCloud->aCloud->getId());
453 glBindTexture(GL_TEXTURE_2D, 0);
454 glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
456 glEnable(GL_CULL_FACE);
457 glEnable(GL_DEPTH_TEST);
459 ssgLoadModelviewMatrix( modelview );