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
  22 #ifdef HAVE_CONFIG_H
  23 #  include <simgear_config.h>
  24 #endif
  25
  26 #include <simgear/compiler.h>
  27
  28 #include <sstream>
  29
  30 #include <math.h>
  31
  32 #include <simgear/structure/OSGVersion.hxx>
  33 #include <osg/AlphaFunc>
  34 #include <osg/BlendFunc>
  35 #include <osg/CullFace>
  36 #include <osg/Geode>
  37 #include <osg/Geometry>
  38 #include <osg/Material>
  39 #include <osg/ShadeModel>
  40 #include <osg/TexEnv>
  41 #include <osg/TexEnvCombine>
  42 #include <osg/Texture2D>
  43 #include <osg/TextureCubeMap>
  44 #include <osg/TexMat>
  45 #include <osg/Fog>
  46
  47 #include <simgear/math/sg_random.h>
  48 #include <simgear/scene/util/SGReaderWriterOptions.hxx>
  49 #include <simgear/debug/logstream.hxx>
  50 #include <simgear/scene/model/model.hxx>
  51 #include <simgear/scene/util/RenderConstants.hxx>
  52 #include <simgear/scene/util/OsgMath.hxx>
  53 #include <simgear/scene/util/StateAttributeFactory.hxx>
  54 #include <simgear/screen/extensions.hxx>
  55
  56 #include "newcloud.hxx"
  57 #include "cloudfield.hxx"
  58 #include "cloud.hxx"
  59
  60 using namespace simgear;
  61 using namespace osg;
  62
  63 static osg::ref_ptr<osg::StateSet> layer_states[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  64 static osg::ref_ptr<osg::StateSet> layer_states2[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  65 static osg::ref_ptr<osg::TextureCubeMap> cubeMap;
  66 static bool state_initialized = false;
  67
  68 const std::string SGCloudLayer::SG_CLOUD_OVERCAST_STRING = "overcast";
  69 const std::string SGCloudLayer::SG_CLOUD_BROKEN_STRING = "broken";
  70 const std::string SGCloudLayer::SG_CLOUD_SCATTERED_STRING = "scattered";
  71 const std::string SGCloudLayer::SG_CLOUD_FEW_STRING = "few";
  72 const std::string SGCloudLayer::SG_CLOUD_CIRRUS_STRING = "cirrus";
  73 const std::string SGCloudLayer::SG_CLOUD_CLEAR_STRING = "clear";
  74
  75 // make an StateSet for a cloud layer given the named texture
  76 static osg::StateSet*
  77 SGMakeState(const SGPath &path, const char* colorTexture,
  78             const char* normalTexture)
  79 {
  80     osg::StateSet *stateSet = new osg::StateSet;
  81
  82     osg::ref_ptr<SGReaderWriterOptions> options;
  83     options = SGReaderWriterOptions::fromPath(path.str());
  84     stateSet->setTextureAttribute(0, SGLoadTexture2D(colorTexture,
  85                                                      options.get()));
  86     stateSet->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
  87     StateAttributeFactory* attribFactory = StateAttributeFactory::instance();
  88     stateSet->setAttributeAndModes(attribFactory->getSmoothShadeModel());
  89     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
  90     stateSet->setAttributeAndModes(attribFactory->getStandardAlphaFunc());
  91     stateSet->setAttributeAndModes(attribFactory->getStandardBlendFunc());
  92
  93 //     osg::Material* material = new osg::Material;
  94 //     material->setColorMode(osg::Material::AMBIENT_AND_DIFFUSE);
  95 //     material->setEmission(osg::Material::FRONT_AND_BACK,
  96 //                           osg::Vec4(0.05, 0.05, 0.05, 0));
  97 //     material->setSpecular(osg::Material::FRONT_AND_BACK,
  98 //                           osg::Vec4(0, 0, 0, 1));
  99 //     stateSet->setAttribute(material);
 100
 101     stateSet->setMode(GL_FOG, osg::StateAttribute::OFF);
 102
 103     // OSGFIXME: invented by me ...
 104 //     stateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
 105 //     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::ON);
 106
 107 //     stateSet->setMode(GL_LIGHT0, osg::StateAttribute::OFF);
 108
 109     // If the normal texture is given prepare a bumpmapping enabled state
 110 //     if (normalTexture) {
 111 //       SGPath normalPath(path);
 112 //       normalPath.append(normalTexture);
 113 //       stateSet->setTextureAttribute(2, SGLoadTexture2D(normalPath));
 114 //       stateSet->setTextureMode(2, GL_TEXTURE_2D, osg::StateAttribute::ON);
 115 //     }
 116
 117     return stateSet;
 118 }
 119
 120 // Constructor
 121 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
 122     cloud_root(new osg::Switch),
 123     layer_root(new osg::Switch),
 124     group_top(new osg::Group),
 125     group_bottom(new osg::Group),
 126     layer_transform(new osg::MatrixTransform),
 127     cloud_alpha(1.0),
 128     texture_path(tex_path),
 129     layer_span(0.0),
 130     layer_asl(0.0),
 131     layer_thickness(0.0),
 132     layer_transition(0.0),
 133     layer_visibility(25.0),
 134     layer_coverage(SG_CLOUD_CLEAR),
 135     scale(4000.0),
 136     speed(0.0),
 137     direction(0.0),
 138     last_course(0.0),
 139     max_alpha(1.0)
 140 {
 141     // XXX
 142     // Render bottoms before the rest of transparent objects (rendered
 143     // in bin 10), tops after. The negative numbers on the bottoms
 144     // RenderBins and the positive numbers on the tops enforce this
 145     // order.
 146   cloud_root->addChild(layer_root.get(), true);
 147   layer_root->addChild(group_bottom.get());
 148   layer_root->addChild(group_top.get());
 149   osg::StateSet *rootSet = layer_root->getOrCreateStateSet();
 150   rootSet->setRenderBinDetails(CLOUDS_BIN, "DepthSortedBin");
 151   rootSet->setTextureAttribute(0, new osg::TexMat);
 152   rootSet->setMode(GL_CULL_FACE, osg::StateAttribute::ON);
 153   // Combiner for fog color and cloud alpha
 154   osg::TexEnvCombine* combine0 = new osg::TexEnvCombine;
 155   osg::TexEnvCombine* combine1 = new osg::TexEnvCombine;
 156   combine0->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 157   combine0->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 158   combine0->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 159   combine0->setSource1_RGB(osg::TexEnvCombine::TEXTURE0);
 160   combine0->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 161   combine0->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 162   combine0->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 163   combine0->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 164   combine0->setSource1_Alpha(osg::TexEnvCombine::TEXTURE0);
 165   combine0->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 166
 167   combine1->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 168   combine1->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 169   combine1->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 170   combine1->setSource1_RGB(osg::TexEnvCombine::CONSTANT);
 171   combine1->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 172   combine1->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 173   combine1->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 174   combine1->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 175   combine1->setSource1_Alpha(osg::TexEnvCombine::CONSTANT);
 176   combine1->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 177   combine1->setDataVariance(osg::Object::DYNAMIC);
 178   rootSet->setTextureAttributeAndModes(0, combine0);
 179   rootSet->setTextureAttributeAndModes(1, combine1);
 180   rootSet->setTextureMode(1, GL_TEXTURE_2D, osg::StateAttribute::ON);
 181   rootSet->setTextureAttributeAndModes(1, StateAttributeFactory::instance()
 182                                        ->getWhiteTexture(),
 183                                        osg::StateAttribute::ON);
 184   rootSet->setDataVariance(osg::Object::DYNAMIC);
 185
 186   // Ensure repeatability of the random seed within 10 minutes,
 187   // to keep multi-computer systems in sync.
 188   sg_srandom_time_10();
 189   base = osg::Vec2(sg_random(), sg_random());
 190   group_top->addChild(layer_transform.get());
 191   group_bottom->addChild(layer_transform.get());
 192
 193   layer3D = new SGCloudField();
 194   cloud_root->addChild(layer3D->getNode(), false);
 195
 196   rebuild();
 197 }
 198
 199 // Destructor
 200 SGCloudLayer::~SGCloudLayer()
 201 {
 202   delete layer3D;
 203 }
 204
 205 float
 206 SGCloudLayer::getSpan_m () const
 207 {
 208     return layer_span;
 209 }
 210
 211 void
 212 SGCloudLayer::setSpan_m (float span_m)
 213 {
 214     if (span_m != layer_span) {
 215         layer_span = span_m;
 216         rebuild();
 217     }
 218 }
 219
 220 float
 221 SGCloudLayer::getElevation_m () const
 222 {
 223     return layer_asl;
 224 }
 225
 226 void
 227 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 228 {
 229     layer_asl = elevation_m;
 230
 231     if (set_span) {
 232         if (elevation_m > 4000)
 233             setSpan_m(  elevation_m * 10 );
 234         else
 235             setSpan_m( 40000 );
 236     }
 237 }
 238
 239 float
 240 SGCloudLayer::getThickness_m () const
 241 {
 242     return layer_thickness;
 243 }
 244
 245 void
 246 SGCloudLayer::setThickness_m (float thickness_m)
 247 {
 248     layer_thickness = thickness_m;
 249 }
 250
 251 float
 252 SGCloudLayer::getVisibility_m() const
 253 {
 254     return layer_visibility;
 255 }
 256
 257 void
 258 SGCloudLayer::setVisibility_m (float visibility_m)
 259 {
 260     layer_visibility = visibility_m;
 261 }
 262
 263 float
 264 SGCloudLayer::getTransition_m () const
 265 {
 266     return layer_transition;
 267 }
 268
 269 void
 270 SGCloudLayer::setTransition_m (float transition_m)
 271 {
 272     layer_transition = transition_m;
 273 }
 274
 275 SGCloudLayer::Coverage
 276 SGCloudLayer::getCoverage () const
 277 {
 278     return layer_coverage;
 279 }
 280
 281 void
 282 SGCloudLayer::setCoverage (Coverage coverage)
 283 {
 284     if (coverage != layer_coverage) {
 285         layer_coverage = coverage;
 286         rebuild();
 287     }
 288 }
 289
 290 const std::string &
 291 SGCloudLayer::getCoverageString( Coverage coverage )
 292 {
 293         switch( coverage ) {
 294                 case SG_CLOUD_OVERCAST:
 295                         return SG_CLOUD_OVERCAST_STRING;
 296                 case SG_CLOUD_BROKEN:
 297                         return SG_CLOUD_BROKEN_STRING;
 298                 case SG_CLOUD_SCATTERED:
 299                         return SG_CLOUD_SCATTERED_STRING;
 300                 case SG_CLOUD_FEW:
 301                         return SG_CLOUD_FEW_STRING;
 302                 case SG_CLOUD_CIRRUS:
 303                         return SG_CLOUD_CIRRUS_STRING;
 304                 case SG_CLOUD_CLEAR:
 305                 default:
 306                         return SG_CLOUD_CLEAR_STRING;
 307         }
 308 }
 309
 310 SGCloudLayer::Coverage
 311 SGCloudLayer::getCoverageType( const std::string & coverage )
 312 {
 313         if( SG_CLOUD_OVERCAST_STRING == coverage ) {
 314                 return SG_CLOUD_OVERCAST;
 315         } else if( SG_CLOUD_BROKEN_STRING == coverage ) {
 316                 return SG_CLOUD_BROKEN;
 317         } else if( SG_CLOUD_SCATTERED_STRING == coverage ) {
 318                 return SG_CLOUD_SCATTERED;
 319         } else if( SG_CLOUD_FEW_STRING == coverage ) {
 320                 return SG_CLOUD_FEW;
 321         } else if( SG_CLOUD_CIRRUS_STRING == coverage ) {
 322                 return SG_CLOUD_CIRRUS;
 323         } else {
 324                 return SG_CLOUD_CLEAR;
 325         }
 326 }
 327
 328 const std::string &
 329 SGCloudLayer::getCoverageString() const
 330 {
 331         return getCoverageString(layer_coverage);
 332 }
 333
 334 void
 335 SGCloudLayer::setCoverageString( const std::string & coverage )
 336 {
 337         setCoverage( getCoverageType(coverage) );
 338 }
 339
 340 void
 341 SGCloudLayer::setTextureOffset(const osg::Vec2& offset)
 342 {
 343     osg::StateAttribute* attr = layer_root->getStateSet()
 344         ->getTextureAttribute(0, osg::StateAttribute::TEXMAT);
 345     osg::TexMat* texMat = dynamic_cast<osg::TexMat*>(attr);
 346     if (!texMat)
 347         return;
 348     texMat->setMatrix(osg::Matrix::translate(offset[0], offset[1], 0.0));
 349 }
 350
 351 // colors for debugging the cloud layers
 352 #ifdef CLOUD_DEBUG
 353 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 0.0f, 0.0f),
 354                       Vec3(0.0f, 1.0f, 0.0f), Vec3(0.0f, 0.0f, 1.0f)};
 355 #else
 356 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f),
 357                       Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f)};
 358 #endif
 359
 360 // build the cloud object
 361 void
 362 SGCloudLayer::rebuild()
 363 {
 364     // Initialize states and sizes if necessary.
 365     if ( !state_initialized ) {
 366         state_initialized = true;
 367
 368         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 369
 370         // This bump mapping code was inspired by the tutorial available at
 371         // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 372         // and a NVidia white paper
 373         //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 374         // The normal map textures were generated by the normal map Gimp plugin :
 375         //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 376         //
 377         cubeMap = new osg::TextureCubeMap;
 378         cubeMap->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
 379         cubeMap->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
 380         cubeMap->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
 381         cubeMap->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE);
 382         cubeMap->setWrap(osg::Texture::WRAP_R, osg::Texture::CLAMP_TO_EDGE);
 383
 384         const int size = 32;
 385         const float half_size = 16.0f;
 386         const float offset = 0.5f;
 387         osg::Vec3 zero_normal(0.5, 0.5, 0.5);
 388
 389         osg::Image* image = new osg::Image;
 390         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 391         unsigned char *ptr = image->data(0, 0);
 392         for (int j = 0; j < size; j++ ) {
 393           for (int i = 0; i < size; i++ ) {
 394             osg::Vec3 tmp(half_size, -( j + offset - half_size ),
 395                           -( i + offset - half_size ) );
 396             tmp.normalize();
 397             tmp = tmp*0.5 - zero_normal;
 398
 399             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 400             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 401             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 402           }
 403         }
 404         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_X, image);
 405
 406         image = new osg::Image;
 407         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 408         ptr = image->data(0, 0);
 409         for (int j = 0; j < size; j++ ) {
 410           for (int i = 0; i < size; i++ ) {
 411             osg::Vec3 tmp(-half_size, -( j + offset - half_size ),
 412                           ( i + offset - half_size ) );
 413             tmp.normalize();
 414             tmp = tmp*0.5 - zero_normal;
 415
 416             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 417             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 418             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 419           }
 420         }
 421         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_X, image);
 422
 423         image = new osg::Image;
 424         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 425         ptr = image->data(0, 0);
 426         for (int j = 0; j < size; j++ ) {
 427           for (int i = 0; i < size; i++ ) {
 428             osg::Vec3 tmp(( i + offset - half_size ), half_size,
 429                           ( j + offset - half_size ) );
 430             tmp.normalize();
 431             tmp = tmp*0.5 - zero_normal;
 432
 433             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 434             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 435             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 436           }
 437         }
 438         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Y, image);
 439
 440         image = new osg::Image;
 441         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 442         ptr = image->data(0, 0);
 443         for (int j = 0; j < size; j++ ) {
 444           for (int i = 0; i < size; i++ ) {
 445             osg::Vec3 tmp(( i + offset - half_size ), -half_size,
 446                           -( j + offset - half_size ) );
 447             tmp.normalize();
 448             tmp = tmp*0.5 - zero_normal;
 449
 450             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 451             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 452             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 453           }
 454         }
 455         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Y, image);
 456
 457         image = new osg::Image;
 458         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 459         ptr = image->data(0, 0);
 460         for (int j = 0; j < size; j++ ) {
 461           for (int i = 0; i < size; i++ ) {
 462             osg::Vec3 tmp(( i + offset - half_size ),
 463                           -( j + offset - half_size ), half_size );
 464             tmp.normalize();
 465             tmp = tmp*0.5 - zero_normal;
 466
 467             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 468             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 469             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 470           }
 471         }
 472         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Z, image);
 473
 474         image = new osg::Image;
 475         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 476         ptr = image->data(0, 0);
 477         for (int j = 0; j < size; j++ ) {
 478           for (int i = 0; i < size; i++ ) {
 479             osg::Vec3 tmp(-( i + offset - half_size ),
 480                           -( j + offset - half_size ), -half_size );
 481             tmp.normalize();
 482             tmp = tmp*0.5 - zero_normal;
 483             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 484             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 485             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 486           }
 487         }
 488         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Z, image);
 489
 490         osg::StateSet* state;
 491         state = SGMakeState(texture_path, "overcast.png", "overcast_n.png");
 492         layer_states[SG_CLOUD_OVERCAST] = state;
 493         state = SGMakeState(texture_path, "overcast_top.png", "overcast_top_n.png");
 494         layer_states2[SG_CLOUD_OVERCAST] = state;
 495
 496         state = SGMakeState(texture_path, "broken.png", "broken_n.png");
 497         layer_states[SG_CLOUD_BROKEN] = state;
 498         layer_states2[SG_CLOUD_BROKEN] = state;
 499
 500         state = SGMakeState(texture_path, "scattered.png", "scattered_n.png");
 501         layer_states[SG_CLOUD_SCATTERED] = state;
 502         layer_states2[SG_CLOUD_SCATTERED] = state;
 503
 504         state = SGMakeState(texture_path, "few.png", "few_n.png");
 505         layer_states[SG_CLOUD_FEW] = state;
 506         layer_states2[SG_CLOUD_FEW] = state;
 507
 508         state = SGMakeState(texture_path, "cirrus.png", "cirrus_n.png");
 509         layer_states[SG_CLOUD_CIRRUS] = state;
 510         layer_states2[SG_CLOUD_CIRRUS] = state;
 511
 512         layer_states[SG_CLOUD_CLEAR] = 0;
 513         layer_states2[SG_CLOUD_CLEAR] = 0;
 514 #if 1
 515         // experimental optimization that may not make any difference
 516         // at all :/
 517         osg::CopyOp copyOp;
 518         for (int i = 0; i < SG_MAX_CLOUD_COVERAGES; ++i) {
 519             StateAttributeFactory *saf = StateAttributeFactory::instance();
 520             if (layer_states[i].valid()) {
 521                 if (layer_states[i] == layer_states2[i])
 522                     layer_states2[i] = static_cast<osg::StateSet*>(layer_states[i]->clone(copyOp));
 523                 layer_states[i]->setAttribute(saf ->getCullFaceFront());
 524                 layer_states2[i]->setAttribute(saf ->getCullFaceBack());
 525             }
 526         }
 527 #endif
 528     }
 529
 530     scale = 4000.0;
 531
 532     setTextureOffset(base);
 533     // build the cloud layer
 534     const float layer_scale = layer_span / scale;
 535     const float mpi = SG_PI/4;
 536
 537     // caclculate the difference between a flat-earth model and
 538     // a round earth model given the span and altutude ASL of
 539     // the cloud layer. This is the difference in altitude between
 540     // the top of the inverted bowl and the edge of the bowl.
 541     // const float alt_diff = layer_asl * 0.8;
 542     const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 543     const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 544     const float border_to_core = layer_to_core * cos(layer_angle);
 545     const float alt_diff = layer_to_core - border_to_core;
 546
 547     for (int i = 0; i < 4; i++) {
 548       if ( layer[i] != NULL ) {
 549         layer_transform->removeChild(layer[i].get()); // automatic delete
 550       }
 551
 552       vl[i] = new osg::Vec3Array;
 553       cl[i] = new osg::Vec4Array;
 554       tl[i] = new osg::Vec2Array;
 555
 556
 557       osg::Vec3 vertex(layer_span*(i-2)/2, -layer_span,
 558                        alt_diff * (sin(i*mpi) - 2));
 559       osg::Vec2 tc(layer_scale * i/4, 0.0f);
 560       osg::Vec4 color(cloudColors[0], (i == 0) ? 0.0f : 0.15f);
 561
 562       cl[i]->push_back(color);
 563       vl[i]->push_back(vertex);
 564       tl[i]->push_back(tc);
 565
 566       for (int j = 0; j < 4; j++) {
 567         vertex = osg::Vec3(layer_span*(i-1)/2, layer_span*(j-2)/2,
 568                            alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2));
 569         tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale * j/4);
 570         color = osg::Vec4(cloudColors[0],
 571                           ( (j == 0) || (i == 3)) ?
 572                           ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 573
 574         cl[i]->push_back(color);
 575         vl[i]->push_back(vertex);
 576         tl[i]->push_back(tc);
 577
 578         vertex = osg::Vec3(layer_span*(i-2)/2, layer_span*(j-1)/2,
 579                            alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 580         tc = osg::Vec2(layer_scale * i/4, layer_scale * (j+1)/4 );
 581         color = osg::Vec4(cloudColors[0],
 582                           ((j == 3) || (i == 0)) ?
 583                           ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 584         cl[i]->push_back(color);
 585         vl[i]->push_back(vertex);
 586         tl[i]->push_back(tc);
 587       }
 588
 589       vertex = osg::Vec3(layer_span*(i-1)/2, layer_span,
 590                          alt_diff * (sin((i+1)*mpi) - 2));
 591
 592       tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale);
 593
 594       color = osg::Vec4(cloudColors[0], (i == 3) ? 0.0f : 0.15f );
 595
 596       cl[i]->push_back( color );
 597       vl[i]->push_back( vertex );
 598       tl[i]->push_back( tc );
 599
 600       osg::Geometry* geometry = new osg::Geometry;
 601       geometry->setUseDisplayList(false);
 602       geometry->setVertexArray(vl[i].get());
 603       geometry->setNormalBinding(osg::Geometry::BIND_OFF);
 604       geometry->setColorArray(cl[i].get(), osg::Array::BIND_PER_VERTEX);
 605       geometry->setTexCoordArray(0, tl[i].get(), osg::Array::BIND_PER_VERTEX);
 606       geometry->addPrimitiveSet(new osg::DrawArrays(GL_TRIANGLE_STRIP, 0, vl[i]->size()));
 607       layer[i] = new osg::Geode;
 608
 609       std::stringstream sstr;
 610       sstr << "Cloud Layer (" << i << ")";
 611       geometry->setName(sstr.str());
 612       layer[i]->setName(sstr.str());
 613       layer[i]->addDrawable(geometry);
 614       layer_transform->addChild(layer[i].get());
 615     }
 616
 617     //OSGFIXME: true
 618     if ( layer_states[layer_coverage].valid() ) {
 619       osg::CopyOp copyOp;    // shallow copy
 620       // render bin will be set in reposition
 621       osg::StateSet* stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 622       stateSet->setDataVariance(osg::Object::DYNAMIC);
 623       group_top->setStateSet(stateSet);
 624       stateSet = static_cast<osg::StateSet*>(layer_states[layer_coverage]->clone(copyOp));
 625       stateSet->setDataVariance(osg::Object::DYNAMIC);
 626       group_bottom->setStateSet(stateSet);
 627     }
 628 }
 629
 630 // repaint the cloud layer colors
 631 bool SGCloudLayer::repaint( const SGVec3f& fog_color ) {
 632     osg::Vec4f combineColor(toOsg(fog_color), cloud_alpha);
 633     osg::TexEnvCombine* combiner
 634         = dynamic_cast<osg::TexEnvCombine*>(layer_root->getStateSet()
 635                                             ->getTextureAttribute(1, osg::StateAttribute::TEXENV));
 636     combiner->setConstantColor(combineColor);
 637
 638     // Set the fog color for the 3D clouds too.
 639     //cloud3dfog->setColor(combineColor);
 640     return true;
 641 }
 642
 643 // reposition the cloud layer at the specified origin and orientation
 644 // lon specifies a rotation about the Z axis
 645 // lat specifies a rotation about the new Y axis
 646 // spin specifies a rotation about the new Z axis (and orients the
 647 // sunrise/set effects
 648 bool SGCloudLayer::reposition( const SGVec3f& p, const SGVec3f& up, double lon, double lat,
 649                                double alt, double dt )
 650 {
 651
 652     if (getCoverage() != SGCloudLayer::SG_CLOUD_CLEAR)
 653     {
 654         // combine p and asl (meters) to get translation offset
 655         osg::Vec3 asl_offset(toOsg(up));
 656         asl_offset.normalize();
 657         if ( alt <= layer_asl ) {
 658             asl_offset *= layer_asl;
 659         } else {
 660             asl_offset *= layer_asl + layer_thickness;
 661         }
 662
 663         // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 664         //      << "," << asl_offset[2] << endl;
 665         asl_offset += toOsg(p);
 666         // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 667         //      << "," << asl_offset[2] << endl;
 668
 669         osg::Matrix T, LON, LAT;
 670         // Translate to zero elevation
 671         // Point3D zero_elev = current_view.get_cur_zero_elev();
 672         T.makeTranslate( asl_offset );
 673
 674         // printf("  Translated to %.2f %.2f %.2f\n",
 675         //        zero_elev.x, zero_elev.y, zero_elev.z );
 676
 677         // Rotate to proper orientation
 678         // printf("  lon = %.2f  lat = %.2f\n",
 679         //        lon * SGD_RADIANS_TO_DEGREES,
 680         //        lat * SGD_RADIANS_TO_DEGREES);
 681         LON.makeRotate(lon, osg::Vec3(0, 0, 1));
 682
 683         // xglRotatef( 90.0 - f->get_Latitude() * SGD_RADIANS_TO_DEGREES,
 684         //             0.0, 1.0, 0.0 );
 685         LAT.makeRotate(90.0 * SGD_DEGREES_TO_RADIANS - lat, osg::Vec3(0, 1, 0));
 686
 687         layer_transform->setMatrix( LAT*LON*T );
 688
 689         // The layers need to be drawn in order because they are
 690         // translucent, but OSG transparency sorting doesn't work because
 691         // the cloud polys are huge. However, the ordering is simple: the
 692         // bottom polys should be drawn from high altitude to low, and the
 693         // top polygons from low to high. The altitude can be used
 694         // directly to order the polygons!
 695         group_bottom->getStateSet()->setRenderBinDetails(-(int)layer_asl,
 696                                                          "RenderBin");
 697         group_top->getStateSet()->setRenderBinDetails((int)layer_asl,
 698                                                       "RenderBin");
 699         if ( alt <= layer_asl ) {
 700           layer_root->setSingleChildOn(0);
 701         } else if ( alt >= layer_asl + layer_thickness ) {
 702           layer_root->setSingleChildOn(1);
 703         } else {
 704           layer_root->setAllChildrenOff();
 705         }
 706
 707
 708         // now calculate update texture coordinates
 709         SGGeod pos = SGGeod::fromRad(lon, lat);
 710         if ( last_pos == SGGeod() ) {
 711             last_pos = pos;
 712         }
 713
 714         double sp_dist = speed*dt;
 715
 716
 717         if ( lon != last_pos.getLongitudeRad() || lat != last_pos.getLatitudeRad() || sp_dist != 0 ) {
 718             double course = SGGeodesy::courseDeg(last_pos, pos) * SG_DEGREES_TO_RADIANS,
 719                 dist = SGGeodesy::distanceM(last_pos, pos);
 720
 721             // if start and dest are too close together,
 722             // calc_gc_course_dist() can return a course of "nan".  If
 723             // this happens, lets just use the last known good course.
 724             // This is a hack, and it would probably be better to make
 725             // calc_gc_course_dist() more robust.
 726             if ( isNaN(course) ) {
 727                 course = last_course;
 728             } else {
 729                 last_course = course;
 730             }
 731
 732             // calculate cloud movement due to external forces
 733             double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 734
 735             if (dist > 0.0) {
 736                 ax = -cos(course) * dist;
 737                 ay = sin(course) * dist;
 738             }
 739
 740             if (sp_dist > 0) {
 741                 bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 742                 by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 743             }
 744
 745
 746             double xoff = (ax + bx) / (2 * scale);
 747             double yoff = (ay + by) / (2 * scale);
 748
 749
 750     //        const float layer_scale = layer_span / scale;
 751
 752             // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 753             base[0] += xoff;
 754
 755             // the while loops can lead to *long* pauses if base[0] comes
 756             // with a bogus value.
 757             // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 758             // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 759             if ( base[0] > -10.0 && base[0] < 10.0 ) {
 760                 base[0] -= (int)base[0];
 761             } else {
 762                 SG_LOG(SG_ASTRO, SG_DEBUG,
 763                     "Error: base = " << base[0] << "," << base[1] <<
 764                     " course = " << course << " dist = " << dist );
 765                 base[0] = 0.0;
 766             }
 767
 768             base[1] += yoff;
 769             // the while loops can lead to *long* pauses if base[0] comes
 770             // with a bogus value.
 771             // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 772             // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 773             if ( base[1] > -10.0 && base[1] < 10.0 ) {
 774                 base[1] -= (int)base[1];
 775             } else {
 776                 SG_LOG(SG_ASTRO, SG_DEBUG,
 777                         "Error: base = " << base[0] << "," << base[1] <<
 778                         " course = " << course << " dist = " << dist );
 779                 base[1] = 0.0;
 780             }
 781
 782             // cout << "base = " << base[0] << "," << base[1] << endl;
 783
 784             setTextureOffset(base);
 785             last_pos = pos;
 786         }
 787     }
 788
 789     layer3D->reposition( p, up, lon, lat, dt, layer_asl, speed, direction);
 790     return true;
 791 }
 792
 793 void SGCloudLayer::set_enable3dClouds(bool enable) {
 794
 795     if (layer3D->isDefined3D() && enable) {
 796         cloud_root->setChildValue(layer3D->getNode(), true);
 797         cloud_root->setChildValue(layer_root.get(),   false);
 798     } else {
 799         cloud_root->setChildValue(layer3D->getNode(), false);
 800         cloud_root->setChildValue(layer_root.get(),   true);
 801     }
 802 }