simgear/scene/sky/cloud.cxx

   1 // cloud.cxx -- model a single cloud layer
   2 //
   3 // Written by Curtis Olson, started June 2000.
   4 //
   5 // Copyright (C) 2000  Curtis L. Olson  - http://www.flightgear.org/~curt
   6 //
   7 // This library is free software; you can redistribute it and/or
   8 // modify it under the terms of the GNU Library General Public
   9 // License as published by the Free Software Foundation; either
  10 // version 2 of the License, or (at your option) any later version.
  11 //
  12 // This library 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.
  16 //
  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.
  20 //
  21 // $Id$
  22
  23 #ifdef HAVE_CONFIG_H
  24 #  include <simgear_config.h>
  25 #endif
  26
  27 #include <simgear/compiler.h>
  28
  29 #include <sstream>
  30
  31 #include <math.h>
  32
  33 #include <osg/AlphaFunc>
  34 #include <osg/BlendFunc>
  35 #include <osg/Geode>
  36 #include <osg/Geometry>
  37 #include <osg/Material>
  38 #include <osg/ShadeModel>
  39 #include <osg/TexEnv>
  40 #include <osg/TexEnvCombine>
  41 #include <osg/Texture2D>
  42 #include <osg/TextureCubeMap>
  43 #include <osg/TexMat>
  44 #include <osg/Fog>
  45
  46 #include <simgear/math/sg_random.h>
  47 #include <simgear/misc/PathOptions.hxx>
  48 #include <simgear/debug/logstream.hxx>
  49 #include <simgear/scene/model/model.hxx>
  50 #include <simgear/scene/util/RenderConstants.hxx>
  51 #include <simgear/scene/util/StateAttributeFactory.hxx>
  52 #include <simgear/math/polar3d.hxx>
  53
  54 #include "newcloud.hxx"
  55 #include "cloudfield.hxx"
  56 #include "cloud.hxx"
  57
  58 using namespace simgear;
  59 #if defined(__MINGW32__)
  60 #define isnan(x) _isnan(x)
  61 #endif
  62
  63 // #if defined (__FreeBSD__)
  64 // #  if __FreeBSD_version < 500000
  65 //      extern "C" {
  66 //        inline int isnan(double r) { return !(r <= 0 || r >= 0); }
  67 //      }
  68 // #  endif
  69 // #endif
  70
  71 #if defined (__CYGWIN__)
  72 #include <ieeefp.h>
  73 #endif
  74
  75 static osg::ref_ptr<osg::StateSet> layer_states[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  76 static osg::ref_ptr<osg::StateSet> layer_states2[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  77 static osg::ref_ptr<osg::TextureCubeMap> cubeMap;
  78 static bool state_initialized = false;
  79 static bool bump_mapping = false;
  80
  81 bool SGCloudLayer::enable_bump_mapping = false;
  82
  83 // make an StateSet for a cloud layer given the named texture
  84 static osg::StateSet*
  85 SGMakeState(const SGPath &path, const char* colorTexture,
  86             const char* normalTexture)
  87 {
  88     osg::StateSet *stateSet = new osg::StateSet;
  89
  90     osg::ref_ptr<osgDB::ReaderWriter::Options> options
  91         = makeOptionsFromPath(path);
  92     stateSet->setTextureAttribute(0, SGLoadTexture2D(colorTexture,
  93                                                      options.get()));
  94     stateSet->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
  95     StateAttributeFactory* attribFactory = StateAttributeFactory::instance();
  96     stateSet->setAttributeAndModes(attribFactory->getSmoothShadeModel());
  97     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
  98     stateSet->setMode(GL_CULL_FACE, osg::StateAttribute::OFF);
  99     stateSet->setAttributeAndModes(attribFactory->getStandardAlphaFunc());
 100     stateSet->setAttributeAndModes(attribFactory->getStandardBlendFunc());
 101
 102 //     osg::Material* material = new osg::Material;
 103 //     material->setColorMode(osg::Material::AMBIENT_AND_DIFFUSE);
 104 //     material->setEmission(osg::Material::FRONT_AND_BACK,
 105 //                           osg::Vec4(0.05, 0.05, 0.05, 0));
 106 //     material->setSpecular(osg::Material::FRONT_AND_BACK,
 107 //                           osg::Vec4(0, 0, 0, 1));
 108 //     stateSet->setAttribute(material);
 109
 110     stateSet->setMode(GL_FOG, osg::StateAttribute::OFF);
 111
 112     // OSGFIXME: invented by me ...
 113 //     stateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
 114 //     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::ON);
 115
 116 //     stateSet->setMode(GL_LIGHT0, osg::StateAttribute::OFF);
 117
 118     // If the normal texture is given prepare a bumpmapping enabled state
 119 //     if (normalTexture) {
 120 //       SGPath normalPath(path);
 121 //       normalPath.append(normalTexture);
 122 //       stateSet->setTextureAttribute(2, SGLoadTexture2D(normalPath));
 123 //       stateSet->setTextureMode(2, GL_TEXTURE_2D, osg::StateAttribute::ON);
 124 //     }
 125
 126     return stateSet;
 127 }
 128
 129 // Constructor
 130 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
 131     cloud_root(new osg::Switch),
 132     layer_root(new osg::Switch),
 133     group_top(new osg::Group),
 134     group_bottom(new osg::Group),
 135     layer_transform(new osg::MatrixTransform),
 136     cloud_alpha(1.0),
 137     texture_path(tex_path),
 138     layer_span(0.0),
 139     layer_asl(0.0),
 140     layer_thickness(0.0),
 141     layer_transition(0.0),
 142     layer_coverage(SG_CLOUD_CLEAR),
 143     scale(4000.0),
 144     speed(0.0),
 145     direction(0.0),
 146     last_lon(0.0),
 147     last_lat(0.0)
 148 {
 149     // XXX
 150     // Render bottoms before the rest of transparent objects (rendered
 151     // in bin 10), tops after. The negative numbers on the bottoms
 152     // RenderBins and the positive numbers on the tops enforce this
 153     // order.
 154   cloud_root->addChild(layer_root.get(), true);
 155   layer_root->addChild(group_bottom.get());
 156   layer_root->addChild(group_top.get());
 157   osg::StateSet *rootSet = layer_root->getOrCreateStateSet();
 158   rootSet->setRenderBinDetails(CLOUDS_BIN, "DepthSortedBin");
 159   rootSet->setTextureAttribute(0, new osg::TexMat);
 160   // Combiner for fog color and cloud alpha
 161   osg::TexEnvCombine* combine0 = new osg::TexEnvCombine;
 162   osg::TexEnvCombine* combine1 = new osg::TexEnvCombine;
 163   combine0->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 164   combine0->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 165   combine0->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 166   combine0->setSource1_RGB(osg::TexEnvCombine::TEXTURE0);
 167   combine0->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 168   combine0->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 169   combine0->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 170   combine0->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 171   combine0->setSource1_Alpha(osg::TexEnvCombine::TEXTURE0);
 172   combine0->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 173
 174   combine1->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 175   combine1->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 176   combine1->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 177   combine1->setSource1_RGB(osg::TexEnvCombine::CONSTANT);
 178   combine1->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 179   combine1->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 180   combine1->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 181   combine1->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 182   combine1->setSource1_Alpha(osg::TexEnvCombine::CONSTANT);
 183   combine1->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 184   combine1->setDataVariance(osg::Object::DYNAMIC);
 185   rootSet->setTextureAttributeAndModes(0, combine0);
 186   rootSet->setTextureAttributeAndModes(1, combine1);
 187   rootSet->setTextureMode(1, GL_TEXTURE_2D, osg::StateAttribute::ON);
 188   rootSet->setTextureAttributeAndModes(1, StateAttributeFactory::instance()
 189                                        ->getWhiteTexture(),
 190                                        osg::StateAttribute::ON);
 191   rootSet->setDataVariance(osg::Object::DYNAMIC);
 192
 193   base = osg::Vec2(sg_random(), sg_random());
 194
 195   group_top->addChild(layer_transform.get());
 196   group_bottom->addChild(layer_transform.get());
 197
 198   layer3D = new SGCloudField();
 199   cloud_root->addChild(layer3D->getNode(), false);
 200
 201   rebuild();
 202 }
 203
 204 // Destructor
 205 SGCloudLayer::~SGCloudLayer()
 206 {
 207   delete layer3D;
 208 }
 209
 210 float
 211 SGCloudLayer::getSpan_m () const
 212 {
 213     return layer_span;
 214 }
 215
 216 void
 217 SGCloudLayer::setSpan_m (float span_m)
 218 {
 219     if (span_m != layer_span) {
 220         layer_span = span_m;
 221         rebuild();
 222     }
 223 }
 224
 225 float
 226 SGCloudLayer::getElevation_m () const
 227 {
 228     return layer_asl;
 229 }
 230
 231 void
 232 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 233 {
 234     layer_asl = elevation_m;
 235
 236     if (set_span) {
 237         if (elevation_m > 4000)
 238             setSpan_m(  elevation_m * 10 );
 239         else
 240             setSpan_m( 40000 );
 241     }
 242 }
 243
 244 float
 245 SGCloudLayer::getThickness_m () const
 246 {
 247     return layer_thickness;
 248 }
 249
 250 void
 251 SGCloudLayer::setThickness_m (float thickness_m)
 252 {
 253     layer_thickness = thickness_m;
 254 }
 255
 256 float
 257 SGCloudLayer::getTransition_m () const
 258 {
 259     return layer_transition;
 260 }
 261
 262 void
 263 SGCloudLayer::setTransition_m (float transition_m)
 264 {
 265     layer_transition = transition_m;
 266 }
 267
 268 SGCloudLayer::Coverage
 269 SGCloudLayer::getCoverage () const
 270 {
 271     return layer_coverage;
 272 }
 273
 274 void
 275 SGCloudLayer::setCoverage (Coverage coverage)
 276 {
 277     if (coverage != layer_coverage) {
 278         layer_coverage = coverage;
 279         rebuild();
 280     }
 281 }
 282
 283 void
 284 SGCloudLayer::setTextureOffset(const osg::Vec2& offset)
 285 {
 286     osg::StateAttribute* attr = layer_root->getStateSet()
 287         ->getTextureAttribute(0, osg::StateAttribute::TEXMAT);
 288     osg::TexMat* texMat = dynamic_cast<osg::TexMat*>(attr);
 289     if (!texMat)
 290         return;
 291     texMat->setMatrix(osg::Matrix::translate(offset[0], offset[1], 0.0));
 292 }
 293
 294 // build the cloud object
 295 void
 296 SGCloudLayer::rebuild()
 297 {
 298     // Initialize states and sizes if necessary.
 299     if ( !state_initialized ) {
 300         state_initialized = true;
 301
 302         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 303
 304         osg::Texture::Extensions* extensions;
 305         extensions = osg::Texture::getExtensions(0, true);
 306         // OSGFIXME
 307         bump_mapping = extensions->isMultiTexturingSupported() &&
 308           (2 <= extensions->numTextureUnits()) &&
 309           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_combine") &&
 310           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_dot3");
 311
 312         osg::TextureCubeMap::Extensions* extensions2;
 313         extensions2 = osg::TextureCubeMap::getExtensions(0, true);
 314         bump_mapping = bump_mapping && extensions2->isCubeMapSupported();
 315
 316         // This bump mapping code was inspired by the tutorial available at
 317         // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 318         // and a NVidia white paper
 319         //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 320         // The normal map textures were generated by the normal map Gimp plugin :
 321         //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 322         //
 323         cubeMap = new osg::TextureCubeMap;
 324         cubeMap->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
 325         cubeMap->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
 326         cubeMap->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
 327         cubeMap->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE);
 328         cubeMap->setWrap(osg::Texture::WRAP_R, osg::Texture::CLAMP_TO_EDGE);
 329
 330         const int size = 32;
 331         const float half_size = 16.0f;
 332         const float offset = 0.5f;
 333         osg::Vec3 zero_normal(0.5, 0.5, 0.5);
 334
 335         osg::Image* image = new osg::Image;
 336         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 337         unsigned char *ptr = image->data(0, 0);
 338         for (int j = 0; j < size; j++ ) {
 339           for (int i = 0; i < size; i++ ) {
 340             osg::Vec3 tmp(half_size, -( j + offset - half_size ),
 341                           -( i + offset - half_size ) );
 342             tmp.normalize();
 343             tmp = tmp*0.5 - zero_normal;
 344
 345             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 346             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 347             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 348           }
 349         }
 350         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_X, image);
 351
 352         image = new osg::Image;
 353         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 354         ptr = image->data(0, 0);
 355         for (int j = 0; j < size; j++ ) {
 356           for (int i = 0; i < size; i++ ) {
 357             osg::Vec3 tmp(-half_size, -( j + offset - half_size ),
 358                           ( i + offset - half_size ) );
 359             tmp.normalize();
 360             tmp = tmp*0.5 - zero_normal;
 361
 362             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 363             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 364             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 365           }
 366         }
 367         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_X, image);
 368
 369         image = new osg::Image;
 370         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 371         ptr = image->data(0, 0);
 372         for (int j = 0; j < size; j++ ) {
 373           for (int i = 0; i < size; i++ ) {
 374             osg::Vec3 tmp(( i + offset - half_size ), half_size,
 375                           ( j + offset - half_size ) );
 376             tmp.normalize();
 377             tmp = tmp*0.5 - zero_normal;
 378
 379             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 380             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 381             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 382           }
 383         }
 384         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Y, image);
 385
 386         image = new osg::Image;
 387         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 388         ptr = image->data(0, 0);
 389         for (int j = 0; j < size; j++ ) {
 390           for (int i = 0; i < size; i++ ) {
 391             osg::Vec3 tmp(( i + offset - half_size ), -half_size,
 392                           -( j + offset - half_size ) );
 393             tmp.normalize();
 394             tmp = tmp*0.5 - zero_normal;
 395
 396             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 397             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 398             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 399           }
 400         }
 401         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Y, image);
 402
 403         image = new osg::Image;
 404         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 405         ptr = image->data(0, 0);
 406         for (int j = 0; j < size; j++ ) {
 407           for (int i = 0; i < size; i++ ) {
 408             osg::Vec3 tmp(( i + offset - half_size ),
 409                           -( j + offset - half_size ), half_size );
 410             tmp.normalize();
 411             tmp = tmp*0.5 - zero_normal;
 412
 413             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 414             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 415             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 416           }
 417         }
 418         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Z, image);
 419
 420         image = new osg::Image;
 421         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 422         ptr = image->data(0, 0);
 423         for (int j = 0; j < size; j++ ) {
 424           for (int i = 0; i < size; i++ ) {
 425             osg::Vec3 tmp(-( i + offset - half_size ),
 426                           -( j + offset - half_size ), -half_size );
 427             tmp.normalize();
 428             tmp = tmp*0.5 - zero_normal;
 429             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 430             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 431             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 432           }
 433         }
 434         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Z, image);
 435
 436         osg::StateSet* state;
 437         state = SGMakeState(texture_path, "overcast.png", "overcast_n.png");
 438         layer_states[SG_CLOUD_OVERCAST] = state;
 439         state = SGMakeState(texture_path, "overcast_top.png", "overcast_top_n.png");
 440         layer_states2[SG_CLOUD_OVERCAST] = state;
 441
 442         state = SGMakeState(texture_path, "broken.png", "broken_n.png");
 443         layer_states[SG_CLOUD_BROKEN] = state;
 444         layer_states2[SG_CLOUD_BROKEN] = state;
 445
 446         state = SGMakeState(texture_path, "scattered.png", "scattered_n.png");
 447         layer_states[SG_CLOUD_SCATTERED] = state;
 448         layer_states2[SG_CLOUD_SCATTERED] = state;
 449
 450         state = SGMakeState(texture_path, "few.png", "few_n.png");
 451         layer_states[SG_CLOUD_FEW] = state;
 452         layer_states2[SG_CLOUD_FEW] = state;
 453
 454         state = SGMakeState(texture_path, "cirrus.png", "cirrus_n.png");
 455         layer_states[SG_CLOUD_CIRRUS] = state;
 456         layer_states2[SG_CLOUD_CIRRUS] = state;
 457
 458         layer_states[SG_CLOUD_CLEAR] = 0;
 459         layer_states2[SG_CLOUD_CLEAR] = 0;
 460     }
 461
 462     scale = 4000.0;
 463     last_lon = last_lat = -999.0f;
 464
 465     setTextureOffset(base);
 466     // build the cloud layer
 467     const float layer_scale = layer_span / scale;
 468     const float mpi = SG_PI/4;
 469
 470     // caclculate the difference between a flat-earth model and
 471     // a round earth model given the span and altutude ASL of
 472     // the cloud layer. This is the difference in altitude between
 473     // the top of the inverted bowl and the edge of the bowl.
 474     // const float alt_diff = layer_asl * 0.8;
 475     const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 476     const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 477     const float border_to_core = layer_to_core * cos(layer_angle);
 478     const float alt_diff = layer_to_core - border_to_core;
 479
 480     for (int i = 0; i < 4; i++) {
 481       if ( layer[i] != NULL ) {
 482         layer_transform->removeChild(layer[i].get()); // automatic delete
 483       }
 484
 485       vl[i] = new osg::Vec3Array;
 486       cl[i] = new osg::Vec4Array;
 487       tl[i] = new osg::Vec2Array;
 488
 489
 490       osg::Vec3 vertex(layer_span*(i-2)/2, -layer_span,
 491                        alt_diff * (sin(i*mpi) - 2));
 492       osg::Vec2 tc(layer_scale * i/4, 0.0f);
 493       osg::Vec4 color(1.0f, 1.0f, 1.0f, (i == 0) ? 0.0f : 0.15f);
 494
 495       cl[i]->push_back(color);
 496       vl[i]->push_back(vertex);
 497       tl[i]->push_back(tc);
 498
 499       for (int j = 0; j < 4; j++) {
 500         vertex = osg::Vec3(layer_span*(i-1)/2, layer_span*(j-2)/2,
 501                            alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2));
 502         tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale * j/4);
 503         color = osg::Vec4(1.0f, 1.0f, 1.0f,
 504                           ( (j == 0) || (i == 3)) ?
 505                           ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 506
 507         cl[i]->push_back(color);
 508         vl[i]->push_back(vertex);
 509         tl[i]->push_back(tc);
 510
 511         vertex = osg::Vec3(layer_span*(i-2)/2, layer_span*(j-1)/2,
 512                            alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 513         tc = osg::Vec2(layer_scale * i/4, layer_scale * (j+1)/4 );
 514         color = osg::Vec4(1.0f, 1.0f, 1.0f,
 515                           ((j == 3) || (i == 0)) ?
 516                           ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 517         cl[i]->push_back(color);
 518         vl[i]->push_back(vertex);
 519         tl[i]->push_back(tc);
 520       }
 521
 522       vertex = osg::Vec3(layer_span*(i-1)/2, layer_span,
 523                          alt_diff * (sin((i+1)*mpi) - 2));
 524
 525       tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale);
 526
 527       color = osg::Vec4(1.0f, 1.0f, 1.0f, (i == 3) ? 0.0f : 0.15f );
 528
 529       cl[i]->push_back( color );
 530       vl[i]->push_back( vertex );
 531       tl[i]->push_back( tc );
 532
 533       osg::Geometry* geometry = new osg::Geometry;
 534       geometry->setUseDisplayList(false);
 535       geometry->setVertexArray(vl[i].get());
 536       geometry->setNormalBinding(osg::Geometry::BIND_OFF);
 537       geometry->setColorArray(cl[i].get());
 538       geometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
 539       geometry->setTexCoordArray(0, tl[i].get());
 540       geometry->addPrimitiveSet(new osg::DrawArrays(GL_TRIANGLE_STRIP, 0, vl[i]->size()));
 541       layer[i] = new osg::Geode;
 542
 543       std::stringstream sstr;
 544       sstr << "Cloud Layer (" << i << ")";
 545       geometry->setName(sstr.str());
 546       layer[i]->setName(sstr.str());
 547       layer[i]->addDrawable(geometry);
 548       layer_transform->addChild(layer[i].get());
 549     }
 550
 551     //OSGFIXME: true
 552     if ( layer_states[layer_coverage].valid() ) {
 553       osg::CopyOp copyOp;    // shallow copy
 554       // render bin will be set in reposition
 555       osg::StateSet* stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 556       stateSet->setDataVariance(osg::Object::DYNAMIC);
 557       group_top->setStateSet(stateSet);
 558       stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 559       stateSet->setDataVariance(osg::Object::DYNAMIC);
 560       group_bottom->setStateSet(stateSet);
 561     }
 562 }
 563
 564 // repaint the cloud layer colors
 565 bool SGCloudLayer::repaint( const SGVec3f& fog_color ) {
 566     osg::Vec4f combineColor(fog_color.osg(), cloud_alpha);
 567     osg::TexEnvCombine* combiner
 568         = dynamic_cast<osg::TexEnvCombine*>(layer_root->getStateSet()
 569                                             ->getTextureAttribute(1, osg::StateAttribute::TEXENV));
 570     combiner->setConstantColor(combineColor);
 571
 572     // Set the fog color for the 3D clouds too.
 573     //cloud3dfog->setColor(combineColor);
 574     return true;
 575 }
 576
 577 // reposition the cloud layer at the specified origin and orientation
 578 // lon specifies a rotation about the Z axis
 579 // lat specifies a rotation about the new Y axis
 580 // spin specifies a rotation about the new Z axis (and orients the
 581 // sunrise/set effects
 582 bool SGCloudLayer::reposition( const SGVec3f& p, const SGVec3f& up, double lon, double lat,
 583                                double alt, double dt )
 584 {
 585     // combine p and asl (meters) to get translation offset
 586     osg::Vec3 asl_offset(up.osg());
 587     asl_offset.normalize();
 588     if ( alt <= layer_asl ) {
 589         asl_offset *= layer_asl;
 590     } else {
 591         asl_offset *= layer_asl + layer_thickness;
 592     }
 593
 594     // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 595     //      << "," << asl_offset[2] << endl;
 596     asl_offset += p.osg();
 597     // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 598     //      << "," << asl_offset[2] << endl;
 599
 600     osg::Matrix T, LON, LAT;
 601     // Translate to zero elevation
 602     // Point3D zero_elev = current_view.get_cur_zero_elev();
 603     T.makeTranslate( asl_offset );
 604
 605     // printf("  Translated to %.2f %.2f %.2f\n",
 606     //        zero_elev.x, zero_elev.y, zero_elev.z );
 607
 608     // Rotate to proper orientation
 609     // printf("  lon = %.2f  lat = %.2f\n",
 610     //        lon * SGD_RADIANS_TO_DEGREES,
 611     //        lat * SGD_RADIANS_TO_DEGREES);
 612     LON.makeRotate(lon, osg::Vec3(0, 0, 1));
 613
 614     // xglRotatef( 90.0 - f->get_Latitude() * SGD_RADIANS_TO_DEGREES,
 615     //             0.0, 1.0, 0.0 );
 616     LAT.makeRotate(90.0 * SGD_DEGREES_TO_RADIANS - lat, osg::Vec3(0, 1, 0));
 617
 618     layer_transform->setMatrix( LAT*LON*T );
 619
 620     // The layers need to be drawn in order because they are
 621     // translucent, but OSG transparency sorting doesn't work because
 622     // the cloud polys are huge. However, the ordering is simple: the
 623     // bottom polys should be drawn from high altitude to low, and the
 624     // top polygons from low to high. The altitude can be used
 625     // directly to order the polygons!
 626     group_bottom->getStateSet()->setRenderBinDetails(-(int)layer_asl,
 627                                                      "RenderBin");
 628     group_top->getStateSet()->setRenderBinDetails((int)layer_asl,
 629                                                   "RenderBin");
 630     if ( alt <= layer_asl ) {
 631       layer_root->setSingleChildOn(0);
 632     } else if ( alt >= layer_asl + layer_thickness ) {
 633       layer_root->setSingleChildOn(1);
 634     } else {
 635       layer_root->setAllChildrenOff();
 636     }
 637
 638
 639     // now calculate update texture coordinates
 640     if ( last_lon < -900 ) {
 641         last_lon = lon;
 642         last_lat = lat;
 643     }
 644
 645     double sp_dist = speed*dt;
 646
 647     if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
 648         Point3D start( last_lon, last_lat, 0.0 );
 649         Point3D dest( lon, lat, 0.0 );
 650         double course = 0.0, dist = 0.0;
 651
 652         calc_gc_course_dist( dest, start, &course, &dist );
 653         // cout << "course = " << course << ", dist = " << dist << endl;
 654
 655         // if start and dest are too close together,
 656         // calc_gc_course_dist() can return a course of "nan".  If
 657         // this happens, lets just use the last known good course.
 658         // This is a hack, and it would probably be better to make
 659         // calc_gc_course_dist() more robust.
 660         if ( isnan(course) ) {
 661             course = last_course;
 662         } else {
 663             last_course = course;
 664         }
 665
 666         // calculate cloud movement due to external forces
 667         double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 668
 669         if (dist > 0.0) {
 670             ax = cos(course) * dist;
 671             ay = sin(course) * dist;
 672         }
 673
 674         if (sp_dist > 0) {
 675             bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 676             by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 677         }
 678
 679
 680         double xoff = (ax + bx) / (2 * scale);
 681         double yoff = (ay + by) / (2 * scale);
 682
 683         const float layer_scale = layer_span / scale;
 684
 685         // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 686         base[0] += xoff;
 687
 688         // the while loops can lead to *long* pauses if base[0] comes
 689         // with a bogus value.
 690         // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 691         // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 692         if ( base[0] > -10.0 && base[0] < 10.0 ) {
 693             base[0] -= (int)base[0];
 694         } else {
 695             SG_LOG(SG_ASTRO, SG_DEBUG,
 696                 "Error: base = " << base[0] << "," << base[1] <<
 697                 " course = " << course << " dist = " << dist );
 698             base[0] = 0.0;
 699         }
 700
 701         base[1] += yoff;
 702         // the while loops can lead to *long* pauses if base[0] comes
 703         // with a bogus value.
 704         // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 705         // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 706         if ( base[1] > -10.0 && base[1] < 10.0 ) {
 707             base[1] -= (int)base[1];
 708         } else {
 709             SG_LOG(SG_ASTRO, SG_DEBUG,
 710                     "Error: base = " << base[0] << "," << base[1] <<
 711                     " course = " << course << " dist = " << dist );
 712             base[1] = 0.0;
 713         }
 714
 715         // cout << "base = " << base[0] << "," << base[1] << endl;
 716
 717         setTextureOffset(base);
 718         last_lon = lon;
 719         last_lat = lat;
 720     }
 721
 722     layer3D->reposition( p, up, lon, lat, dt);
 723     return true;
 724 }
 725
 726 void SGCloudLayer::set_enable3dClouds(bool enable) {
 727
 728     if (layer3D->defined3D && enable) {
 729         cloud_root->setChildValue(layer3D->getNode(), true);
 730         cloud_root->setChildValue(layer_root.get(),   false);
 731     } else {
 732         cloud_root->setChildValue(layer3D->getNode(), false);
 733         cloud_root->setChildValue(layer_root.get(),   true);
 734     }
 735 }
 736
 737 void SGCloudLayer::applyDensity() {
 738     layer3D->applyDensity();
 739 }