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 #if SG_OSG_MIN_VERSION_REQUIRED(2,9,5)
  47 #include <osgDB/Options>
  48 #endif
  49
  50 #include <simgear/math/sg_random.h>
  51 #include <simgear/misc/PathOptions.hxx>
  52 #include <simgear/debug/logstream.hxx>
  53 #include <simgear/scene/model/model.hxx>
  54 #include <simgear/scene/util/RenderConstants.hxx>
  55 #include <simgear/scene/util/StateAttributeFactory.hxx>
  56 #include <simgear/screen/extensions.hxx>
  57
  58 #include "newcloud.hxx"
  59 #include "cloudfield.hxx"
  60 #include "cloud.hxx"
  61
  62 using namespace simgear;
  63 using namespace osg;
  64
  65 #if defined(__MINGW32__)
  66 #define isnan(x) _isnan(x)
  67 #endif
  68
  69 // #if defined (__FreeBSD__)
  70 // #  if __FreeBSD_version < 500000
  71 //      extern "C" {
  72 //        inline int isnan(double r) { return !(r <= 0 || r >= 0); }
  73 //      }
  74 // #  endif
  75 // #endif
  76
  77 static osg::ref_ptr<osg::StateSet> layer_states[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  78 static osg::ref_ptr<osg::StateSet> layer_states2[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  79 static osg::ref_ptr<osg::TextureCubeMap> cubeMap;
  80 static bool state_initialized = false;
  81 static bool bump_mapping = false;
  82
  83 bool SGCloudLayer::enable_bump_mapping = false;
  84
  85 const std::string SGCloudLayer::SG_CLOUD_OVERCAST_STRING = "overcast";
  86 const std::string SGCloudLayer::SG_CLOUD_BROKEN_STRING = "broken";
  87 const std::string SGCloudLayer::SG_CLOUD_SCATTERED_STRING = "scattered";
  88 const std::string SGCloudLayer::SG_CLOUD_FEW_STRING = "few";
  89 const std::string SGCloudLayer::SG_CLOUD_CIRRUS_STRING = "cirrus";
  90 const std::string SGCloudLayer::SG_CLOUD_CLEAR_STRING = "clear";
  91
  92 // make an StateSet for a cloud layer given the named texture
  93 static osg::StateSet*
  94 SGMakeState(const SGPath &path, const char* colorTexture,
  95             const char* normalTexture)
  96 {
  97     osg::StateSet *stateSet = new osg::StateSet;
  98
  99     osg::ref_ptr<osgDB::ReaderWriter::Options> options
 100         = makeOptionsFromPath(path);
 101     stateSet->setTextureAttribute(0, SGLoadTexture2D(colorTexture,
 102                                                      options.get()));
 103     stateSet->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
 104     StateAttributeFactory* attribFactory = StateAttributeFactory::instance();
 105     stateSet->setAttributeAndModes(attribFactory->getSmoothShadeModel());
 106     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
 107     stateSet->setAttributeAndModes(attribFactory->getStandardAlphaFunc());
 108     stateSet->setAttributeAndModes(attribFactory->getStandardBlendFunc());
 109
 110 //     osg::Material* material = new osg::Material;
 111 //     material->setColorMode(osg::Material::AMBIENT_AND_DIFFUSE);
 112 //     material->setEmission(osg::Material::FRONT_AND_BACK,
 113 //                           osg::Vec4(0.05, 0.05, 0.05, 0));
 114 //     material->setSpecular(osg::Material::FRONT_AND_BACK,
 115 //                           osg::Vec4(0, 0, 0, 1));
 116 //     stateSet->setAttribute(material);
 117
 118     stateSet->setMode(GL_FOG, osg::StateAttribute::OFF);
 119
 120     // OSGFIXME: invented by me ...
 121 //     stateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
 122 //     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::ON);
 123
 124 //     stateSet->setMode(GL_LIGHT0, osg::StateAttribute::OFF);
 125
 126     // If the normal texture is given prepare a bumpmapping enabled state
 127 //     if (normalTexture) {
 128 //       SGPath normalPath(path);
 129 //       normalPath.append(normalTexture);
 130 //       stateSet->setTextureAttribute(2, SGLoadTexture2D(normalPath));
 131 //       stateSet->setTextureMode(2, GL_TEXTURE_2D, osg::StateAttribute::ON);
 132 //     }
 133
 134     return stateSet;
 135 }
 136
 137 // Constructor
 138 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
 139     cloud_root(new osg::Switch),
 140     layer_root(new osg::Switch),
 141     group_top(new osg::Group),
 142     group_bottom(new osg::Group),
 143     layer_transform(new osg::MatrixTransform),
 144     cloud_alpha(1.0),
 145     texture_path(tex_path),
 146     layer_span(0.0),
 147     layer_asl(0.0),
 148     layer_thickness(0.0),
 149     layer_transition(0.0),
 150     layer_visibility(25.0),
 151     layer_coverage(SG_CLOUD_CLEAR),
 152     scale(4000.0),
 153     speed(0.0),
 154     direction(0.0),
 155     last_course(0.0),
 156     max_alpha(1.0)
 157 {
 158     // XXX
 159     // Render bottoms before the rest of transparent objects (rendered
 160     // in bin 10), tops after. The negative numbers on the bottoms
 161     // RenderBins and the positive numbers on the tops enforce this
 162     // order.
 163   cloud_root->addChild(layer_root.get(), true);
 164   layer_root->addChild(group_bottom.get());
 165   layer_root->addChild(group_top.get());
 166   osg::StateSet *rootSet = layer_root->getOrCreateStateSet();
 167   rootSet->setRenderBinDetails(CLOUDS_BIN, "DepthSortedBin");
 168   rootSet->setTextureAttribute(0, new osg::TexMat);
 169   rootSet->setMode(GL_CULL_FACE, osg::StateAttribute::ON);
 170   // Combiner for fog color and cloud alpha
 171   osg::TexEnvCombine* combine0 = new osg::TexEnvCombine;
 172   osg::TexEnvCombine* combine1 = new osg::TexEnvCombine;
 173   combine0->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 174   combine0->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 175   combine0->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 176   combine0->setSource1_RGB(osg::TexEnvCombine::TEXTURE0);
 177   combine0->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 178   combine0->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 179   combine0->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 180   combine0->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 181   combine0->setSource1_Alpha(osg::TexEnvCombine::TEXTURE0);
 182   combine0->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 183
 184   combine1->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 185   combine1->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 186   combine1->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 187   combine1->setSource1_RGB(osg::TexEnvCombine::CONSTANT);
 188   combine1->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 189   combine1->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 190   combine1->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 191   combine1->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 192   combine1->setSource1_Alpha(osg::TexEnvCombine::CONSTANT);
 193   combine1->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 194   combine1->setDataVariance(osg::Object::DYNAMIC);
 195   rootSet->setTextureAttributeAndModes(0, combine0);
 196   rootSet->setTextureAttributeAndModes(1, combine1);
 197   rootSet->setTextureMode(1, GL_TEXTURE_2D, osg::StateAttribute::ON);
 198   rootSet->setTextureAttributeAndModes(1, StateAttributeFactory::instance()
 199                                        ->getWhiteTexture(),
 200                                        osg::StateAttribute::ON);
 201   rootSet->setDataVariance(osg::Object::DYNAMIC);
 202
 203   base = osg::Vec2(sg_random(), sg_random());
 204   group_top->addChild(layer_transform.get());
 205   group_bottom->addChild(layer_transform.get());
 206
 207   layer3D = new SGCloudField();
 208   cloud_root->addChild(layer3D->getNode(), false);
 209
 210   rebuild();
 211 }
 212
 213 // Destructor
 214 SGCloudLayer::~SGCloudLayer()
 215 {
 216   delete layer3D;
 217 }
 218
 219 float
 220 SGCloudLayer::getSpan_m () const
 221 {
 222     return layer_span;
 223 }
 224
 225 void
 226 SGCloudLayer::setSpan_m (float span_m)
 227 {
 228     if (span_m != layer_span) {
 229         layer_span = span_m;
 230         rebuild();
 231     }
 232 }
 233
 234 float
 235 SGCloudLayer::getElevation_m () const
 236 {
 237     return layer_asl;
 238 }
 239
 240 void
 241 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 242 {
 243     layer_asl = elevation_m;
 244
 245     if (set_span) {
 246         if (elevation_m > 4000)
 247             setSpan_m(  elevation_m * 10 );
 248         else
 249             setSpan_m( 40000 );
 250     }
 251 }
 252
 253 float
 254 SGCloudLayer::getThickness_m () const
 255 {
 256     return layer_thickness;
 257 }
 258
 259 void
 260 SGCloudLayer::setThickness_m (float thickness_m)
 261 {
 262     layer_thickness = thickness_m;
 263 }
 264
 265 float
 266 SGCloudLayer::getVisibility_m() const
 267 {
 268     return layer_visibility;
 269 }
 270
 271 void
 272 SGCloudLayer::setVisibility_m (float visibility_m)
 273 {
 274     layer_visibility = visibility_m;
 275 }
 276
 277 float
 278 SGCloudLayer::getTransition_m () const
 279 {
 280     return layer_transition;
 281 }
 282
 283 void
 284 SGCloudLayer::setTransition_m (float transition_m)
 285 {
 286     layer_transition = transition_m;
 287 }
 288
 289 SGCloudLayer::Coverage
 290 SGCloudLayer::getCoverage () const
 291 {
 292     return layer_coverage;
 293 }
 294
 295 void
 296 SGCloudLayer::setCoverage (Coverage coverage)
 297 {
 298     if (coverage != layer_coverage) {
 299         layer_coverage = coverage;
 300         rebuild();
 301     }
 302 }
 303
 304 const std::string &
 305 SGCloudLayer::getCoverageString( Coverage coverage )
 306 {
 307         switch( coverage ) {
 308                 case SG_CLOUD_OVERCAST:
 309                         return SG_CLOUD_OVERCAST_STRING;
 310                 case SG_CLOUD_BROKEN:
 311                         return SG_CLOUD_BROKEN_STRING;
 312                 case SG_CLOUD_SCATTERED:
 313                         return SG_CLOUD_SCATTERED_STRING;
 314                 case SG_CLOUD_FEW:
 315                         return SG_CLOUD_FEW_STRING;
 316                 case SG_CLOUD_CIRRUS:
 317                         return SG_CLOUD_CIRRUS_STRING;
 318                 case SG_CLOUD_CLEAR:
 319                 default:
 320                         return SG_CLOUD_CLEAR_STRING;
 321         }
 322 }
 323
 324 SGCloudLayer::Coverage
 325 SGCloudLayer::getCoverageType( const std::string & coverage )
 326 {
 327         if( SG_CLOUD_OVERCAST_STRING == coverage ) {
 328                 return SG_CLOUD_OVERCAST;
 329         } else if( SG_CLOUD_BROKEN_STRING == coverage ) {
 330                 return SG_CLOUD_BROKEN;
 331         } else if( SG_CLOUD_SCATTERED_STRING == coverage ) {
 332                 return SG_CLOUD_SCATTERED;
 333         } else if( SG_CLOUD_FEW_STRING == coverage ) {
 334                 return SG_CLOUD_FEW;
 335         } else if( SG_CLOUD_CIRRUS_STRING == coverage ) {
 336                 return SG_CLOUD_CIRRUS;
 337         } else {
 338                 return SG_CLOUD_CLEAR;
 339         }
 340 }
 341
 342 const std::string &
 343 SGCloudLayer::getCoverageString() const
 344 {
 345         return getCoverageString(layer_coverage);
 346 }
 347
 348 void
 349 SGCloudLayer::setCoverageString( const std::string & coverage )
 350 {
 351         setCoverage( getCoverageType(coverage) );
 352 }
 353
 354 void
 355 SGCloudLayer::setTextureOffset(const osg::Vec2& offset)
 356 {
 357     osg::StateAttribute* attr = layer_root->getStateSet()
 358         ->getTextureAttribute(0, osg::StateAttribute::TEXMAT);
 359     osg::TexMat* texMat = dynamic_cast<osg::TexMat*>(attr);
 360     if (!texMat)
 361         return;
 362     texMat->setMatrix(osg::Matrix::translate(offset[0], offset[1], 0.0));
 363 }
 364
 365 // colors for debugging the cloud layers
 366 #ifdef CLOUD_DEBUG
 367 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 0.0f, 0.0f),
 368                       Vec3(0.0f, 1.0f, 0.0f), Vec3(0.0f, 0.0f, 1.0f)};
 369 #else
 370 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f),
 371                       Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f)};
 372 #endif
 373
 374 // build the cloud object
 375 void
 376 SGCloudLayer::rebuild()
 377 {
 378     // Initialize states and sizes if necessary.
 379     if ( !state_initialized ) {
 380         state_initialized = true;
 381
 382         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 383
 384         osg::Texture::Extensions* extensions;
 385         extensions = osg::Texture::getExtensions(0, true);
 386         // OSGFIXME
 387         bump_mapping = extensions->isMultiTexturingSupported() &&
 388           (2 <= extensions->numTextureUnits()) &&
 389           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_combine") &&
 390           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_dot3");
 391
 392         osg::TextureCubeMap::Extensions* extensions2;
 393         extensions2 = osg::TextureCubeMap::getExtensions(0, true);
 394         bump_mapping = bump_mapping && extensions2->isCubeMapSupported();
 395
 396         // This bump mapping code was inspired by the tutorial available at
 397         // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 398         // and a NVidia white paper
 399         //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 400         // The normal map textures were generated by the normal map Gimp plugin :
 401         //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 402         //
 403         cubeMap = new osg::TextureCubeMap;
 404         cubeMap->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
 405         cubeMap->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
 406         cubeMap->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
 407         cubeMap->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE);
 408         cubeMap->setWrap(osg::Texture::WRAP_R, osg::Texture::CLAMP_TO_EDGE);
 409
 410         const int size = 32;
 411         const float half_size = 16.0f;
 412         const float offset = 0.5f;
 413         osg::Vec3 zero_normal(0.5, 0.5, 0.5);
 414
 415         osg::Image* image = new osg::Image;
 416         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 417         unsigned char *ptr = image->data(0, 0);
 418         for (int j = 0; j < size; j++ ) {
 419           for (int i = 0; i < size; i++ ) {
 420             osg::Vec3 tmp(half_size, -( j + offset - half_size ),
 421                           -( i + offset - half_size ) );
 422             tmp.normalize();
 423             tmp = tmp*0.5 - zero_normal;
 424
 425             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 426             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 427             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 428           }
 429         }
 430         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_X, image);
 431
 432         image = new osg::Image;
 433         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 434         ptr = image->data(0, 0);
 435         for (int j = 0; j < size; j++ ) {
 436           for (int i = 0; i < size; i++ ) {
 437             osg::Vec3 tmp(-half_size, -( j + offset - half_size ),
 438                           ( i + offset - half_size ) );
 439             tmp.normalize();
 440             tmp = tmp*0.5 - zero_normal;
 441
 442             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 443             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 444             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 445           }
 446         }
 447         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_X, image);
 448
 449         image = new osg::Image;
 450         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 451         ptr = image->data(0, 0);
 452         for (int j = 0; j < size; j++ ) {
 453           for (int i = 0; i < size; i++ ) {
 454             osg::Vec3 tmp(( i + offset - half_size ), half_size,
 455                           ( j + offset - half_size ) );
 456             tmp.normalize();
 457             tmp = tmp*0.5 - zero_normal;
 458
 459             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 460             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 461             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 462           }
 463         }
 464         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Y, image);
 465
 466         image = new osg::Image;
 467         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 468         ptr = image->data(0, 0);
 469         for (int j = 0; j < size; j++ ) {
 470           for (int i = 0; i < size; i++ ) {
 471             osg::Vec3 tmp(( i + offset - half_size ), -half_size,
 472                           -( j + offset - half_size ) );
 473             tmp.normalize();
 474             tmp = tmp*0.5 - zero_normal;
 475
 476             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 477             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 478             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 479           }
 480         }
 481         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Y, image);
 482
 483         image = new osg::Image;
 484         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 485         ptr = image->data(0, 0);
 486         for (int j = 0; j < size; j++ ) {
 487           for (int i = 0; i < size; i++ ) {
 488             osg::Vec3 tmp(( i + offset - half_size ),
 489                           -( j + offset - half_size ), half_size );
 490             tmp.normalize();
 491             tmp = tmp*0.5 - zero_normal;
 492
 493             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 494             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 495             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 496           }
 497         }
 498         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Z, image);
 499
 500         image = new osg::Image;
 501         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 502         ptr = image->data(0, 0);
 503         for (int j = 0; j < size; j++ ) {
 504           for (int i = 0; i < size; i++ ) {
 505             osg::Vec3 tmp(-( i + offset - half_size ),
 506                           -( j + offset - half_size ), -half_size );
 507             tmp.normalize();
 508             tmp = tmp*0.5 - zero_normal;
 509             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 510             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 511             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 512           }
 513         }
 514         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Z, image);
 515
 516         osg::StateSet* state;
 517         state = SGMakeState(texture_path, "overcast.png", "overcast_n.png");
 518         layer_states[SG_CLOUD_OVERCAST] = state;
 519         state = SGMakeState(texture_path, "overcast_top.png", "overcast_top_n.png");
 520         layer_states2[SG_CLOUD_OVERCAST] = state;
 521
 522         state = SGMakeState(texture_path, "broken.png", "broken_n.png");
 523         layer_states[SG_CLOUD_BROKEN] = state;
 524         layer_states2[SG_CLOUD_BROKEN] = state;
 525
 526         state = SGMakeState(texture_path, "scattered.png", "scattered_n.png");
 527         layer_states[SG_CLOUD_SCATTERED] = state;
 528         layer_states2[SG_CLOUD_SCATTERED] = state;
 529
 530         state = SGMakeState(texture_path, "few.png", "few_n.png");
 531         layer_states[SG_CLOUD_FEW] = state;
 532         layer_states2[SG_CLOUD_FEW] = state;
 533
 534         state = SGMakeState(texture_path, "cirrus.png", "cirrus_n.png");
 535         layer_states[SG_CLOUD_CIRRUS] = state;
 536         layer_states2[SG_CLOUD_CIRRUS] = state;
 537
 538         layer_states[SG_CLOUD_CLEAR] = 0;
 539         layer_states2[SG_CLOUD_CLEAR] = 0;
 540 #if 1
 541         // experimental optimization that may not make any difference
 542         // at all :/
 543         osg::CopyOp copyOp;
 544         for (int i = 0; i < SG_MAX_CLOUD_COVERAGES; ++i) {
 545             StateAttributeFactory *saf = StateAttributeFactory::instance();
 546             if (layer_states[i].valid()) {
 547                 if (layer_states[i] == layer_states2[i])
 548                     layer_states2[i] = static_cast<osg::StateSet*>(layer_states[i]->clone(copyOp));
 549                 layer_states[i]->setAttribute(saf ->getCullFaceFront());
 550                 layer_states2[i]->setAttribute(saf ->getCullFaceBack());
 551             }
 552         }
 553 #endif
 554     }
 555
 556     scale = 4000.0;
 557
 558     setTextureOffset(base);
 559     // build the cloud layer
 560     const float layer_scale = layer_span / scale;
 561     const float mpi = SG_PI/4;
 562
 563     // caclculate the difference between a flat-earth model and
 564     // a round earth model given the span and altutude ASL of
 565     // the cloud layer. This is the difference in altitude between
 566     // the top of the inverted bowl and the edge of the bowl.
 567     // const float alt_diff = layer_asl * 0.8;
 568     const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 569     const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 570     const float border_to_core = layer_to_core * cos(layer_angle);
 571     const float alt_diff = layer_to_core - border_to_core;
 572
 573     for (int i = 0; i < 4; i++) {
 574       if ( layer[i] != NULL ) {
 575         layer_transform->removeChild(layer[i].get()); // automatic delete
 576       }
 577
 578       vl[i] = new osg::Vec3Array;
 579       cl[i] = new osg::Vec4Array;
 580       tl[i] = new osg::Vec2Array;
 581
 582
 583       osg::Vec3 vertex(layer_span*(i-2)/2, -layer_span,
 584                        alt_diff * (sin(i*mpi) - 2));
 585       osg::Vec2 tc(layer_scale * i/4, 0.0f);
 586       osg::Vec4 color(cloudColors[0], (i == 0) ? 0.0f : 0.15f);
 587
 588       cl[i]->push_back(color);
 589       vl[i]->push_back(vertex);
 590       tl[i]->push_back(tc);
 591
 592       for (int j = 0; j < 4; j++) {
 593         vertex = osg::Vec3(layer_span*(i-1)/2, layer_span*(j-2)/2,
 594                            alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2));
 595         tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale * j/4);
 596         color = osg::Vec4(cloudColors[0],
 597                           ( (j == 0) || (i == 3)) ?
 598                           ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 599
 600         cl[i]->push_back(color);
 601         vl[i]->push_back(vertex);
 602         tl[i]->push_back(tc);
 603
 604         vertex = osg::Vec3(layer_span*(i-2)/2, layer_span*(j-1)/2,
 605                            alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 606         tc = osg::Vec2(layer_scale * i/4, layer_scale * (j+1)/4 );
 607         color = osg::Vec4(cloudColors[0],
 608                           ((j == 3) || (i == 0)) ?
 609                           ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 610         cl[i]->push_back(color);
 611         vl[i]->push_back(vertex);
 612         tl[i]->push_back(tc);
 613       }
 614
 615       vertex = osg::Vec3(layer_span*(i-1)/2, layer_span,
 616                          alt_diff * (sin((i+1)*mpi) - 2));
 617
 618       tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale);
 619
 620       color = osg::Vec4(cloudColors[0], (i == 3) ? 0.0f : 0.15f );
 621
 622       cl[i]->push_back( color );
 623       vl[i]->push_back( vertex );
 624       tl[i]->push_back( tc );
 625
 626       osg::Geometry* geometry = new osg::Geometry;
 627       geometry->setUseDisplayList(false);
 628       geometry->setVertexArray(vl[i].get());
 629       geometry->setNormalBinding(osg::Geometry::BIND_OFF);
 630       geometry->setColorArray(cl[i].get());
 631       geometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
 632       geometry->setTexCoordArray(0, tl[i].get());
 633       geometry->addPrimitiveSet(new osg::DrawArrays(GL_TRIANGLE_STRIP, 0, vl[i]->size()));
 634       layer[i] = new osg::Geode;
 635
 636       std::stringstream sstr;
 637       sstr << "Cloud Layer (" << i << ")";
 638       geometry->setName(sstr.str());
 639       layer[i]->setName(sstr.str());
 640       layer[i]->addDrawable(geometry);
 641       layer_transform->addChild(layer[i].get());
 642     }
 643
 644     //OSGFIXME: true
 645     if ( layer_states[layer_coverage].valid() ) {
 646       osg::CopyOp copyOp;    // shallow copy
 647       // render bin will be set in reposition
 648       osg::StateSet* stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 649       stateSet->setDataVariance(osg::Object::DYNAMIC);
 650       group_top->setStateSet(stateSet);
 651       stateSet = static_cast<osg::StateSet*>(layer_states[layer_coverage]->clone(copyOp));
 652       stateSet->setDataVariance(osg::Object::DYNAMIC);
 653       group_bottom->setStateSet(stateSet);
 654     }
 655 }
 656
 657 // repaint the cloud layer colors
 658 bool SGCloudLayer::repaint( const SGVec3f& fog_color ) {
 659     osg::Vec4f combineColor(toOsg(fog_color), cloud_alpha);
 660     osg::TexEnvCombine* combiner
 661         = dynamic_cast<osg::TexEnvCombine*>(layer_root->getStateSet()
 662                                             ->getTextureAttribute(1, osg::StateAttribute::TEXENV));
 663     combiner->setConstantColor(combineColor);
 664
 665     // Set the fog color for the 3D clouds too.
 666     //cloud3dfog->setColor(combineColor);
 667     return true;
 668 }
 669
 670 // reposition the cloud layer at the specified origin and orientation
 671 // lon specifies a rotation about the Z axis
 672 // lat specifies a rotation about the new Y axis
 673 // spin specifies a rotation about the new Z axis (and orients the
 674 // sunrise/set effects
 675 bool SGCloudLayer::reposition( const SGVec3f& p, const SGVec3f& up, double lon, double lat,
 676                                double alt, double dt )
 677 {
 678     // combine p and asl (meters) to get translation offset
 679     osg::Vec3 asl_offset(toOsg(up));
 680     asl_offset.normalize();
 681     if ( alt <= layer_asl ) {
 682         asl_offset *= layer_asl;
 683     } else {
 684         asl_offset *= layer_asl + layer_thickness;
 685     }
 686
 687     // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 688     //      << "," << asl_offset[2] << endl;
 689     asl_offset += toOsg(p);
 690     // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 691     //      << "," << asl_offset[2] << endl;
 692
 693     osg::Matrix T, LON, LAT;
 694     // Translate to zero elevation
 695     // Point3D zero_elev = current_view.get_cur_zero_elev();
 696     T.makeTranslate( asl_offset );
 697
 698     // printf("  Translated to %.2f %.2f %.2f\n",
 699     //        zero_elev.x, zero_elev.y, zero_elev.z );
 700
 701     // Rotate to proper orientation
 702     // printf("  lon = %.2f  lat = %.2f\n",
 703     //        lon * SGD_RADIANS_TO_DEGREES,
 704     //        lat * SGD_RADIANS_TO_DEGREES);
 705     LON.makeRotate(lon, osg::Vec3(0, 0, 1));
 706
 707     // xglRotatef( 90.0 - f->get_Latitude() * SGD_RADIANS_TO_DEGREES,
 708     //             0.0, 1.0, 0.0 );
 709     LAT.makeRotate(90.0 * SGD_DEGREES_TO_RADIANS - lat, osg::Vec3(0, 1, 0));
 710
 711     layer_transform->setMatrix( LAT*LON*T );
 712
 713     // The layers need to be drawn in order because they are
 714     // translucent, but OSG transparency sorting doesn't work because
 715     // the cloud polys are huge. However, the ordering is simple: the
 716     // bottom polys should be drawn from high altitude to low, and the
 717     // top polygons from low to high. The altitude can be used
 718     // directly to order the polygons!
 719     group_bottom->getStateSet()->setRenderBinDetails(-(int)layer_asl,
 720                                                      "RenderBin");
 721     group_top->getStateSet()->setRenderBinDetails((int)layer_asl,
 722                                                   "RenderBin");
 723     if ( alt <= layer_asl ) {
 724       layer_root->setSingleChildOn(0);
 725     } else if ( alt >= layer_asl + layer_thickness ) {
 726       layer_root->setSingleChildOn(1);
 727     } else {
 728       layer_root->setAllChildrenOff();
 729     }
 730
 731
 732     // now calculate update texture coordinates
 733     SGGeod pos = SGGeod::fromRad(lon, lat);
 734     if ( last_pos == SGGeod() ) {
 735         last_pos = pos;
 736     }
 737
 738     double sp_dist = speed*dt;
 739
 740
 741     if ( lon != last_pos.getLongitudeRad() || lat != last_pos.getLatitudeRad() || sp_dist != 0 ) {
 742         double course = SGGeodesy::courseDeg(last_pos, pos) * SG_DEGREES_TO_RADIANS,
 743             dist = SGGeodesy::distanceM(last_pos, pos);
 744
 745         // if start and dest are too close together,
 746         // calc_gc_course_dist() can return a course of "nan".  If
 747         // this happens, lets just use the last known good course.
 748         // This is a hack, and it would probably be better to make
 749         // calc_gc_course_dist() more robust.
 750         if ( isnan(course) ) {
 751             course = last_course;
 752         } else {
 753             last_course = course;
 754         }
 755
 756         // calculate cloud movement due to external forces
 757         double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 758
 759         if (dist > 0.0) {
 760             ax = -cos(course) * dist;
 761             ay = sin(course) * dist;
 762         }
 763
 764         if (sp_dist > 0) {
 765             bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 766             by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 767         }
 768
 769
 770         double xoff = (ax + bx) / (2 * scale);
 771         double yoff = (ay + by) / (2 * scale);
 772
 773
 774 //        const float layer_scale = layer_span / scale;
 775
 776         // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 777         base[0] += xoff;
 778
 779         // the while loops can lead to *long* pauses if base[0] comes
 780         // with a bogus value.
 781         // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 782         // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 783         if ( base[0] > -10.0 && base[0] < 10.0 ) {
 784             base[0] -= (int)base[0];
 785         } else {
 786             SG_LOG(SG_ASTRO, SG_DEBUG,
 787                 "Error: base = " << base[0] << "," << base[1] <<
 788                 " course = " << course << " dist = " << dist );
 789             base[0] = 0.0;
 790         }
 791
 792         base[1] += yoff;
 793         // the while loops can lead to *long* pauses if base[0] comes
 794         // with a bogus value.
 795         // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 796         // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 797         if ( base[1] > -10.0 && base[1] < 10.0 ) {
 798             base[1] -= (int)base[1];
 799         } else {
 800             SG_LOG(SG_ASTRO, SG_DEBUG,
 801                     "Error: base = " << base[0] << "," << base[1] <<
 802                     " course = " << course << " dist = " << dist );
 803             base[1] = 0.0;
 804         }
 805
 806         // cout << "base = " << base[0] << "," << base[1] << endl;
 807
 808         setTextureOffset(base);
 809         last_pos = pos;
 810     }
 811
 812     layer3D->reposition( p, up, lon, lat, dt, layer_asl, speed, direction);
 813     return true;
 814 }
 815
 816 void SGCloudLayer::set_enable3dClouds(bool enable) {
 817
 818     if (layer3D->isDefined3D() && enable) {
 819         cloud_root->setChildValue(layer3D->getNode(), true);
 820         cloud_root->setChildValue(layer_root.get(),   false);
 821     } else {
 822         cloud_root->setChildValue(layer3D->getNode(), false);
 823         cloud_root->setChildValue(layer_root.get(),   true);
 824     }
 825 }