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 <simgear/structure/OSGVersion.hxx>
  34 #include <osg/AlphaFunc>
  35 #include <osg/BlendFunc>
  36 #include <osg/CullFace>
  37 #include <osg/Geode>
  38 #include <osg/Geometry>
  39 #include <osg/Material>
  40 #include <osg/ShadeModel>
  41 #include <osg/TexEnv>
  42 #include <osg/TexEnvCombine>
  43 #include <osg/Texture2D>
  44 #include <osg/TextureCubeMap>
  45 #include <osg/TexMat>
  46 #include <osg/Fog>
  47 #if SG_OSG_MIN_VERSION_REQUIRED(2,9,5)
  48 #include <osgDB/Options>
  49 #endif
  50
  51 #include <simgear/math/sg_random.h>
  52 #include <simgear/misc/PathOptions.hxx>
  53 #include <simgear/debug/logstream.hxx>
  54 #include <simgear/scene/model/model.hxx>
  55 #include <simgear/scene/util/RenderConstants.hxx>
  56 #include <simgear/scene/util/StateAttributeFactory.hxx>
  57 #include <simgear/screen/extensions.hxx>
  58
  59 #include "newcloud.hxx"
  60 #include "cloudfield.hxx"
  61 #include "cloud.hxx"
  62
  63 using namespace simgear;
  64 using namespace osg;
  65
  66 #if defined(__MINGW32__)
  67 #define isnan(x) _isnan(x)
  68 #endif
  69
  70 // #if defined (__FreeBSD__)
  71 // #  if __FreeBSD_version < 500000
  72 //      extern "C" {
  73 //        inline int isnan(double r) { return !(r <= 0 || r >= 0); }
  74 //      }
  75 // #  endif
  76 // #endif
  77
  78 static osg::ref_ptr<osg::StateSet> layer_states[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  79 static osg::ref_ptr<osg::StateSet> layer_states2[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  80 static osg::ref_ptr<osg::TextureCubeMap> cubeMap;
  81 static bool state_initialized = false;
  82 static bool bump_mapping = false;
  83
  84 bool SGCloudLayer::enable_bump_mapping = false;
  85
  86 const std::string SGCloudLayer::SG_CLOUD_OVERCAST_STRING = "overcast";
  87 const std::string SGCloudLayer::SG_CLOUD_BROKEN_STRING = "broken";
  88 const std::string SGCloudLayer::SG_CLOUD_SCATTERED_STRING = "scattered";
  89 const std::string SGCloudLayer::SG_CLOUD_FEW_STRING = "few";
  90 const std::string SGCloudLayer::SG_CLOUD_CIRRUS_STRING = "cirrus";
  91 const std::string SGCloudLayer::SG_CLOUD_CLEAR_STRING = "clear";
  92
  93 // make an StateSet for a cloud layer given the named texture
  94 static osg::StateSet*
  95 SGMakeState(const SGPath &path, const char* colorTexture,
  96             const char* normalTexture)
  97 {
  98     osg::StateSet *stateSet = new osg::StateSet;
  99
 100     osg::ref_ptr<osgDB::ReaderWriter::Options> options
 101         = makeOptionsFromPath(path);
 102     stateSet->setTextureAttribute(0, SGLoadTexture2D(colorTexture,
 103                                                      options.get()));
 104     stateSet->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
 105     StateAttributeFactory* attribFactory = StateAttributeFactory::instance();
 106     stateSet->setAttributeAndModes(attribFactory->getSmoothShadeModel());
 107     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
 108     stateSet->setAttributeAndModes(attribFactory->getStandardAlphaFunc());
 109     stateSet->setAttributeAndModes(attribFactory->getStandardBlendFunc());
 110
 111 //     osg::Material* material = new osg::Material;
 112 //     material->setColorMode(osg::Material::AMBIENT_AND_DIFFUSE);
 113 //     material->setEmission(osg::Material::FRONT_AND_BACK,
 114 //                           osg::Vec4(0.05, 0.05, 0.05, 0));
 115 //     material->setSpecular(osg::Material::FRONT_AND_BACK,
 116 //                           osg::Vec4(0, 0, 0, 1));
 117 //     stateSet->setAttribute(material);
 118
 119     stateSet->setMode(GL_FOG, osg::StateAttribute::OFF);
 120
 121     // OSGFIXME: invented by me ...
 122 //     stateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
 123 //     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::ON);
 124
 125 //     stateSet->setMode(GL_LIGHT0, osg::StateAttribute::OFF);
 126
 127     // If the normal texture is given prepare a bumpmapping enabled state
 128 //     if (normalTexture) {
 129 //       SGPath normalPath(path);
 130 //       normalPath.append(normalTexture);
 131 //       stateSet->setTextureAttribute(2, SGLoadTexture2D(normalPath));
 132 //       stateSet->setTextureMode(2, GL_TEXTURE_2D, osg::StateAttribute::ON);
 133 //     }
 134
 135     return stateSet;
 136 }
 137
 138 // Constructor
 139 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
 140     cloud_root(new osg::Switch),
 141     layer_root(new osg::Switch),
 142     group_top(new osg::Group),
 143     group_bottom(new osg::Group),
 144     layer_transform(new osg::MatrixTransform),
 145     cloud_alpha(1.0),
 146     texture_path(tex_path),
 147     layer_span(0.0),
 148     layer_asl(0.0),
 149     layer_thickness(0.0),
 150     layer_transition(0.0),
 151     layer_coverage(SG_CLOUD_CLEAR),
 152     scale(4000.0),
 153     speed(0.0),
 154     direction(0.0)
 155 {
 156     // XXX
 157     // Render bottoms before the rest of transparent objects (rendered
 158     // in bin 10), tops after. The negative numbers on the bottoms
 159     // RenderBins and the positive numbers on the tops enforce this
 160     // order.
 161   cloud_root->addChild(layer_root.get(), true);
 162   layer_root->addChild(group_bottom.get());
 163   layer_root->addChild(group_top.get());
 164   osg::StateSet *rootSet = layer_root->getOrCreateStateSet();
 165   rootSet->setRenderBinDetails(CLOUDS_BIN, "DepthSortedBin");
 166   rootSet->setTextureAttribute(0, new osg::TexMat);
 167   rootSet->setMode(GL_CULL_FACE, osg::StateAttribute::ON);
 168   // Combiner for fog color and cloud alpha
 169   osg::TexEnvCombine* combine0 = new osg::TexEnvCombine;
 170   osg::TexEnvCombine* combine1 = new osg::TexEnvCombine;
 171   combine0->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 172   combine0->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 173   combine0->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 174   combine0->setSource1_RGB(osg::TexEnvCombine::TEXTURE0);
 175   combine0->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 176   combine0->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 177   combine0->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 178   combine0->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 179   combine0->setSource1_Alpha(osg::TexEnvCombine::TEXTURE0);
 180   combine0->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 181
 182   combine1->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 183   combine1->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 184   combine1->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 185   combine1->setSource1_RGB(osg::TexEnvCombine::CONSTANT);
 186   combine1->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 187   combine1->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 188   combine1->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 189   combine1->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 190   combine1->setSource1_Alpha(osg::TexEnvCombine::CONSTANT);
 191   combine1->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 192   combine1->setDataVariance(osg::Object::DYNAMIC);
 193   rootSet->setTextureAttributeAndModes(0, combine0);
 194   rootSet->setTextureAttributeAndModes(1, combine1);
 195   rootSet->setTextureMode(1, GL_TEXTURE_2D, osg::StateAttribute::ON);
 196   rootSet->setTextureAttributeAndModes(1, StateAttributeFactory::instance()
 197                                        ->getWhiteTexture(),
 198                                        osg::StateAttribute::ON);
 199   rootSet->setDataVariance(osg::Object::DYNAMIC);
 200
 201   base = osg::Vec2(sg_random(), sg_random());
 202   group_top->addChild(layer_transform.get());
 203   group_bottom->addChild(layer_transform.get());
 204
 205   layer3D = new SGCloudField();
 206   cloud_root->addChild(layer3D->getNode(), false);
 207
 208   rebuild();
 209 }
 210
 211 // Destructor
 212 SGCloudLayer::~SGCloudLayer()
 213 {
 214   delete layer3D;
 215 }
 216
 217 float
 218 SGCloudLayer::getSpan_m () const
 219 {
 220     return layer_span;
 221 }
 222
 223 void
 224 SGCloudLayer::setSpan_m (float span_m)
 225 {
 226     if (span_m != layer_span) {
 227         layer_span = span_m;
 228         rebuild();
 229     }
 230 }
 231
 232 float
 233 SGCloudLayer::getElevation_m () const
 234 {
 235     return layer_asl;
 236 }
 237
 238 void
 239 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 240 {
 241     layer_asl = elevation_m;
 242
 243     if (set_span) {
 244         if (elevation_m > 4000)
 245             setSpan_m(  elevation_m * 10 );
 246         else
 247             setSpan_m( 40000 );
 248     }
 249 }
 250
 251 float
 252 SGCloudLayer::getThickness_m () const
 253 {
 254     return layer_thickness;
 255 }
 256
 257 void
 258 SGCloudLayer::setThickness_m (float thickness_m)
 259 {
 260     layer_thickness = thickness_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         double coverage_norm = 0.0;
 289         if( coverage ==  SG_CLOUD_FEW)
 290             coverage_norm = 2.0/8.0;    // <1-2
 291         else if( coverage == SG_CLOUD_SCATTERED )
 292             coverage_norm = 4.0/8.0;    // 3-4
 293         else if( coverage == SG_CLOUD_BROKEN )
 294             coverage_norm = 6.0/8.0;    // 5-7
 295         else if( coverage == SG_CLOUD_OVERCAST )
 296             coverage_norm = 8.0/8.0;    // 8
 297
 298         layer3D->setCoverage(coverage_norm);
 299         layer3D->applyCoverage();
 300     }
 301 }
 302
 303 const std::string &
 304 SGCloudLayer::getCoverageString( Coverage coverage )
 305 {
 306         switch( coverage ) {
 307                 case SG_CLOUD_OVERCAST:
 308                         return SG_CLOUD_OVERCAST_STRING;
 309                 case SG_CLOUD_BROKEN:
 310                         return SG_CLOUD_BROKEN_STRING;
 311                 case SG_CLOUD_SCATTERED:
 312                         return SG_CLOUD_SCATTERED_STRING;
 313                 case SG_CLOUD_FEW:
 314                         return SG_CLOUD_FEW_STRING;
 315                 case SG_CLOUD_CIRRUS:
 316                         return SG_CLOUD_CIRRUS_STRING;
 317                 case SG_CLOUD_CLEAR:
 318                 default:
 319                         return SG_CLOUD_CLEAR_STRING;
 320         }
 321 }
 322
 323 SGCloudLayer::Coverage
 324 SGCloudLayer::getCoverageType( const std::string & coverage )
 325 {
 326         if( SG_CLOUD_OVERCAST_STRING == coverage ) {
 327                 return SG_CLOUD_OVERCAST;
 328         } else if( SG_CLOUD_BROKEN_STRING == coverage ) {
 329                 return SG_CLOUD_BROKEN;
 330         } else if( SG_CLOUD_SCATTERED_STRING == coverage ) {
 331                 return SG_CLOUD_SCATTERED;
 332         } else if( SG_CLOUD_FEW_STRING == coverage ) {
 333                 return SG_CLOUD_FEW;
 334         } else if( SG_CLOUD_CIRRUS_STRING == coverage ) {
 335                 return SG_CLOUD_CIRRUS;
 336         } else {
 337                 return SG_CLOUD_CLEAR;
 338         }
 339 }
 340
 341 const std::string &
 342 SGCloudLayer::getCoverageString() const
 343 {
 344         return getCoverageString(layer_coverage);
 345 }
 346
 347 void
 348 SGCloudLayer::setCoverageString( const std::string & coverage )
 349 {
 350         setCoverage( getCoverageType(coverage) );
 351 }
 352
 353 void
 354 SGCloudLayer::setTextureOffset(const osg::Vec2& offset)
 355 {
 356     osg::StateAttribute* attr = layer_root->getStateSet()
 357         ->getTextureAttribute(0, osg::StateAttribute::TEXMAT);
 358     osg::TexMat* texMat = dynamic_cast<osg::TexMat*>(attr);
 359     if (!texMat)
 360         return;
 361     texMat->setMatrix(osg::Matrix::translate(offset[0], offset[1], 0.0));
 362 }
 363
 364 // colors for debugging the cloud layers
 365 #ifdef CLOUD_DEBUG
 366 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 0.0f, 0.0f),
 367                       Vec3(0.0f, 1.0f, 0.0f), Vec3(0.0f, 0.0f, 1.0f)};
 368 #else
 369 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f),
 370                       Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f)};
 371 #endif
 372
 373 // build the cloud object
 374 void
 375 SGCloudLayer::rebuild()
 376 {
 377     // Initialize states and sizes if necessary.
 378     if ( !state_initialized ) {
 379         state_initialized = true;
 380
 381         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 382
 383         osg::Texture::Extensions* extensions;
 384         extensions = osg::Texture::getExtensions(0, true);
 385         // OSGFIXME
 386         bump_mapping = extensions->isMultiTexturingSupported() &&
 387           (2 <= extensions->numTextureUnits()) &&
 388           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_combine") &&
 389           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_dot3");
 390
 391         osg::TextureCubeMap::Extensions* extensions2;
 392         extensions2 = osg::TextureCubeMap::getExtensions(0, true);
 393         bump_mapping = bump_mapping && extensions2->isCubeMapSupported();
 394
 395         // This bump mapping code was inspired by the tutorial available at
 396         // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 397         // and a NVidia white paper
 398         //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 399         // The normal map textures were generated by the normal map Gimp plugin :
 400         //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 401         //
 402         cubeMap = new osg::TextureCubeMap;
 403         cubeMap->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
 404         cubeMap->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
 405         cubeMap->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
 406         cubeMap->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE);
 407         cubeMap->setWrap(osg::Texture::WRAP_R, osg::Texture::CLAMP_TO_EDGE);
 408
 409         const int size = 32;
 410         const float half_size = 16.0f;
 411         const float offset = 0.5f;
 412         osg::Vec3 zero_normal(0.5, 0.5, 0.5);
 413
 414         osg::Image* image = new osg::Image;
 415         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 416         unsigned char *ptr = image->data(0, 0);
 417         for (int j = 0; j < size; j++ ) {
 418           for (int i = 0; i < size; i++ ) {
 419             osg::Vec3 tmp(half_size, -( j + offset - half_size ),
 420                           -( i + offset - half_size ) );
 421             tmp.normalize();
 422             tmp = tmp*0.5 - zero_normal;
 423
 424             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 425             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 426             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 427           }
 428         }
 429         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_X, image);
 430
 431         image = new osg::Image;
 432         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 433         ptr = image->data(0, 0);
 434         for (int j = 0; j < size; j++ ) {
 435           for (int i = 0; i < size; i++ ) {
 436             osg::Vec3 tmp(-half_size, -( j + offset - half_size ),
 437                           ( i + offset - half_size ) );
 438             tmp.normalize();
 439             tmp = tmp*0.5 - zero_normal;
 440
 441             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 442             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 443             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 444           }
 445         }
 446         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_X, image);
 447
 448         image = new osg::Image;
 449         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 450         ptr = image->data(0, 0);
 451         for (int j = 0; j < size; j++ ) {
 452           for (int i = 0; i < size; i++ ) {
 453             osg::Vec3 tmp(( i + offset - half_size ), half_size,
 454                           ( j + offset - half_size ) );
 455             tmp.normalize();
 456             tmp = tmp*0.5 - zero_normal;
 457
 458             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 459             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 460             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 461           }
 462         }
 463         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Y, image);
 464
 465         image = new osg::Image;
 466         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 467         ptr = image->data(0, 0);
 468         for (int j = 0; j < size; j++ ) {
 469           for (int i = 0; i < size; i++ ) {
 470             osg::Vec3 tmp(( i + offset - half_size ), -half_size,
 471                           -( j + offset - half_size ) );
 472             tmp.normalize();
 473             tmp = tmp*0.5 - zero_normal;
 474
 475             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 476             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 477             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 478           }
 479         }
 480         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Y, image);
 481
 482         image = new osg::Image;
 483         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 484         ptr = image->data(0, 0);
 485         for (int j = 0; j < size; j++ ) {
 486           for (int i = 0; i < size; i++ ) {
 487             osg::Vec3 tmp(( i + offset - half_size ),
 488                           -( j + offset - half_size ), half_size );
 489             tmp.normalize();
 490             tmp = tmp*0.5 - zero_normal;
 491
 492             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 493             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 494             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 495           }
 496         }
 497         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Z, image);
 498
 499         image = new osg::Image;
 500         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 501         ptr = image->data(0, 0);
 502         for (int j = 0; j < size; j++ ) {
 503           for (int i = 0; i < size; i++ ) {
 504             osg::Vec3 tmp(-( i + offset - half_size ),
 505                           -( j + offset - half_size ), -half_size );
 506             tmp.normalize();
 507             tmp = tmp*0.5 - zero_normal;
 508             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 509             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 510             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 511           }
 512         }
 513         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Z, image);
 514
 515         osg::StateSet* state;
 516         state = SGMakeState(texture_path, "overcast.png", "overcast_n.png");
 517         layer_states[SG_CLOUD_OVERCAST] = state;
 518         state = SGMakeState(texture_path, "overcast_top.png", "overcast_top_n.png");
 519         layer_states2[SG_CLOUD_OVERCAST] = state;
 520
 521         state = SGMakeState(texture_path, "broken.png", "broken_n.png");
 522         layer_states[SG_CLOUD_BROKEN] = state;
 523         layer_states2[SG_CLOUD_BROKEN] = state;
 524
 525         state = SGMakeState(texture_path, "scattered.png", "scattered_n.png");
 526         layer_states[SG_CLOUD_SCATTERED] = state;
 527         layer_states2[SG_CLOUD_SCATTERED] = state;
 528
 529         state = SGMakeState(texture_path, "few.png", "few_n.png");
 530         layer_states[SG_CLOUD_FEW] = state;
 531         layer_states2[SG_CLOUD_FEW] = state;
 532
 533         state = SGMakeState(texture_path, "cirrus.png", "cirrus_n.png");
 534         layer_states[SG_CLOUD_CIRRUS] = state;
 535         layer_states2[SG_CLOUD_CIRRUS] = state;
 536
 537         layer_states[SG_CLOUD_CLEAR] = 0;
 538         layer_states2[SG_CLOUD_CLEAR] = 0;
 539 #if 1
 540         // experimental optimization that may not make any difference
 541         // at all :/
 542         osg::CopyOp copyOp;
 543         for (int i = 0; i < SG_MAX_CLOUD_COVERAGES; ++i) {
 544             StateAttributeFactory *saf = StateAttributeFactory::instance();
 545             if (layer_states[i].valid()) {
 546                 if (layer_states[i] == layer_states2[i])
 547                     layer_states2[i] = static_cast<osg::StateSet*>(layer_states[i]->clone(copyOp));
 548                 layer_states[i]->setAttribute(saf ->getCullFaceFront());
 549                 layer_states2[i]->setAttribute(saf ->getCullFaceBack());
 550             }
 551         }
 552 #endif
 553     }
 554
 555     scale = 4000.0;
 556
 557     setTextureOffset(base);
 558     // build the cloud layer
 559     const float layer_scale = layer_span / scale;
 560     const float mpi = SG_PI/4;
 561
 562     // caclculate the difference between a flat-earth model and
 563     // a round earth model given the span and altutude ASL of
 564     // the cloud layer. This is the difference in altitude between
 565     // the top of the inverted bowl and the edge of the bowl.
 566     // const float alt_diff = layer_asl * 0.8;
 567     const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 568     const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 569     const float border_to_core = layer_to_core * cos(layer_angle);
 570     const float alt_diff = layer_to_core - border_to_core;
 571
 572     for (int i = 0; i < 4; i++) {
 573       if ( layer[i] != NULL ) {
 574         layer_transform->removeChild(layer[i].get()); // automatic delete
 575       }
 576
 577       vl[i] = new osg::Vec3Array;
 578       cl[i] = new osg::Vec4Array;
 579       tl[i] = new osg::Vec2Array;
 580
 581
 582       osg::Vec3 vertex(layer_span*(i-2)/2, -layer_span,
 583                        alt_diff * (sin(i*mpi) - 2));
 584       osg::Vec2 tc(layer_scale * i/4, 0.0f);
 585       osg::Vec4 color(cloudColors[0], (i == 0) ? 0.0f : 0.15f);
 586
 587       cl[i]->push_back(color);
 588       vl[i]->push_back(vertex);
 589       tl[i]->push_back(tc);
 590
 591       for (int j = 0; j < 4; j++) {
 592         vertex = osg::Vec3(layer_span*(i-1)/2, layer_span*(j-2)/2,
 593                            alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2));
 594         tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale * j/4);
 595         color = osg::Vec4(cloudColors[0],
 596                           ( (j == 0) || (i == 3)) ?
 597                           ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 598
 599         cl[i]->push_back(color);
 600         vl[i]->push_back(vertex);
 601         tl[i]->push_back(tc);
 602
 603         vertex = osg::Vec3(layer_span*(i-2)/2, layer_span*(j-1)/2,
 604                            alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 605         tc = osg::Vec2(layer_scale * i/4, layer_scale * (j+1)/4 );
 606         color = osg::Vec4(cloudColors[0],
 607                           ((j == 3) || (i == 0)) ?
 608                           ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 609         cl[i]->push_back(color);
 610         vl[i]->push_back(vertex);
 611         tl[i]->push_back(tc);
 612       }
 613
 614       vertex = osg::Vec3(layer_span*(i-1)/2, layer_span,
 615                          alt_diff * (sin((i+1)*mpi) - 2));
 616
 617       tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale);
 618
 619       color = osg::Vec4(cloudColors[0], (i == 3) ? 0.0f : 0.15f );
 620
 621       cl[i]->push_back( color );
 622       vl[i]->push_back( vertex );
 623       tl[i]->push_back( tc );
 624
 625       osg::Geometry* geometry = new osg::Geometry;
 626       geometry->setUseDisplayList(false);
 627       geometry->setVertexArray(vl[i].get());
 628       geometry->setNormalBinding(osg::Geometry::BIND_OFF);
 629       geometry->setColorArray(cl[i].get());
 630       geometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
 631       geometry->setTexCoordArray(0, tl[i].get());
 632       geometry->addPrimitiveSet(new osg::DrawArrays(GL_TRIANGLE_STRIP, 0, vl[i]->size()));
 633       layer[i] = new osg::Geode;
 634
 635       std::stringstream sstr;
 636       sstr << "Cloud Layer (" << i << ")";
 637       geometry->setName(sstr.str());
 638       layer[i]->setName(sstr.str());
 639       layer[i]->addDrawable(geometry);
 640       layer_transform->addChild(layer[i].get());
 641     }
 642
 643     //OSGFIXME: true
 644     if ( layer_states[layer_coverage].valid() ) {
 645       osg::CopyOp copyOp;    // shallow copy
 646       // render bin will be set in reposition
 647       osg::StateSet* stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 648       stateSet->setDataVariance(osg::Object::DYNAMIC);
 649       group_top->setStateSet(stateSet);
 650       stateSet = static_cast<osg::StateSet*>(layer_states[layer_coverage]->clone(copyOp));
 651       stateSet->setDataVariance(osg::Object::DYNAMIC);
 652       group_bottom->setStateSet(stateSet);
 653     }
 654 }
 655
 656 // repaint the cloud layer colors
 657 bool SGCloudLayer::repaint( const SGVec3f& fog_color ) {
 658     osg::Vec4f combineColor(toOsg(fog_color), cloud_alpha);
 659     osg::TexEnvCombine* combiner
 660         = dynamic_cast<osg::TexEnvCombine*>(layer_root->getStateSet()
 661                                             ->getTextureAttribute(1, osg::StateAttribute::TEXENV));
 662     combiner->setConstantColor(combineColor);
 663
 664     // Set the fog color for the 3D clouds too.
 665     //cloud3dfog->setColor(combineColor);
 666     return true;
 667 }
 668
 669 // reposition the cloud layer at the specified origin and orientation
 670 // lon specifies a rotation about the Z axis
 671 // lat specifies a rotation about the new Y axis
 672 // spin specifies a rotation about the new Z axis (and orients the
 673 // sunrise/set effects
 674 bool SGCloudLayer::reposition( const SGVec3f& p, const SGVec3f& up, double lon, double lat,
 675                                double alt, double dt )
 676 {
 677     // combine p and asl (meters) to get translation offset
 678     osg::Vec3 asl_offset(toOsg(up));
 679     asl_offset.normalize();
 680     if ( alt <= layer_asl ) {
 681         asl_offset *= layer_asl;
 682     } else {
 683         asl_offset *= layer_asl + layer_thickness;
 684     }
 685
 686     // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 687     //      << "," << asl_offset[2] << endl;
 688     asl_offset += toOsg(p);
 689     // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 690     //      << "," << asl_offset[2] << endl;
 691
 692     osg::Matrix T, LON, LAT;
 693     // Translate to zero elevation
 694     // Point3D zero_elev = current_view.get_cur_zero_elev();
 695     T.makeTranslate( asl_offset );
 696
 697     // printf("  Translated to %.2f %.2f %.2f\n",
 698     //        zero_elev.x, zero_elev.y, zero_elev.z );
 699
 700     // Rotate to proper orientation
 701     // printf("  lon = %.2f  lat = %.2f\n",
 702     //        lon * SGD_RADIANS_TO_DEGREES,
 703     //        lat * SGD_RADIANS_TO_DEGREES);
 704     LON.makeRotate(lon, osg::Vec3(0, 0, 1));
 705
 706     // xglRotatef( 90.0 - f->get_Latitude() * SGD_RADIANS_TO_DEGREES,
 707     //             0.0, 1.0, 0.0 );
 708     LAT.makeRotate(90.0 * SGD_DEGREES_TO_RADIANS - lat, osg::Vec3(0, 1, 0));
 709
 710     layer_transform->setMatrix( LAT*LON*T );
 711
 712     // The layers need to be drawn in order because they are
 713     // translucent, but OSG transparency sorting doesn't work because
 714     // the cloud polys are huge. However, the ordering is simple: the
 715     // bottom polys should be drawn from high altitude to low, and the
 716     // top polygons from low to high. The altitude can be used
 717     // directly to order the polygons!
 718     group_bottom->getStateSet()->setRenderBinDetails(-(int)layer_asl,
 719                                                      "RenderBin");
 720     group_top->getStateSet()->setRenderBinDetails((int)layer_asl,
 721                                                   "RenderBin");
 722     if ( alt <= layer_asl ) {
 723       layer_root->setSingleChildOn(0);
 724     } else if ( alt >= layer_asl + layer_thickness ) {
 725       layer_root->setSingleChildOn(1);
 726     } else {
 727       layer_root->setAllChildrenOff();
 728     }
 729
 730
 731     // now calculate update texture coordinates
 732     SGGeod pos = SGGeod::fromRad(lon, lat);
 733     if ( last_pos == SGGeod() ) {
 734         last_pos = pos;
 735     }
 736
 737     double sp_dist = speed*dt;
 738
 739
 740     if ( lon != last_pos.getLongitudeRad() || lat != last_pos.getLatitudeRad() || sp_dist != 0 ) {
 741         double course = SGGeodesy::courseDeg(last_pos, pos) * SG_DEGREES_TO_RADIANS,
 742             dist = SGGeodesy::distanceM(last_pos, pos);
 743
 744         // if start and dest are too close together,
 745         // calc_gc_course_dist() can return a course of "nan".  If
 746         // this happens, lets just use the last known good course.
 747         // This is a hack, and it would probably be better to make
 748         // calc_gc_course_dist() more robust.
 749         if ( isnan(course) ) {
 750             course = last_course;
 751         } else {
 752             last_course = course;
 753         }
 754
 755         // calculate cloud movement due to external forces
 756         double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 757
 758         if (dist > 0.0) {
 759             ax = -cos(course) * dist;
 760             ay = sin(course) * dist;
 761         }
 762
 763         if (sp_dist > 0) {
 764             bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 765             by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 766         }
 767
 768
 769         double xoff = (ax + bx) / (2 * scale);
 770         double yoff = (ay + by) / (2 * scale);
 771
 772
 773 //        const float layer_scale = layer_span / scale;
 774
 775         // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 776         base[0] += xoff;
 777
 778         // the while loops can lead to *long* pauses if base[0] comes
 779         // with a bogus value.
 780         // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 781         // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 782         if ( base[0] > -10.0 && base[0] < 10.0 ) {
 783             base[0] -= (int)base[0];
 784         } else {
 785             SG_LOG(SG_ASTRO, SG_DEBUG,
 786                 "Error: base = " << base[0] << "," << base[1] <<
 787                 " course = " << course << " dist = " << dist );
 788             base[0] = 0.0;
 789         }
 790
 791         base[1] += yoff;
 792         // the while loops can lead to *long* pauses if base[0] comes
 793         // with a bogus value.
 794         // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 795         // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 796         if ( base[1] > -10.0 && base[1] < 10.0 ) {
 797             base[1] -= (int)base[1];
 798         } else {
 799             SG_LOG(SG_ASTRO, SG_DEBUG,
 800                     "Error: base = " << base[0] << "," << base[1] <<
 801                     " course = " << course << " dist = " << dist );
 802             base[1] = 0.0;
 803         }
 804
 805         // cout << "base = " << base[0] << "," << base[1] << endl;
 806
 807         setTextureOffset(base);
 808         last_pos = pos;
 809     }
 810
 811     layer3D->reposition( p, up, lon, lat, dt, layer_asl);
 812     return true;
 813 }
 814
 815 void SGCloudLayer::set_enable3dClouds(bool enable) {
 816
 817     if (layer3D->defined3D && enable) {
 818         cloud_root->setChildValue(layer3D->getNode(), true);
 819         cloud_root->setChildValue(layer_root.get(),   false);
 820     } else {
 821         cloud_root->setChildValue(layer3D->getNode(), false);
 822         cloud_root->setChildValue(layer_root.get(),   true);
 823     }
 824 }