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_visibility(25.0),
 152     layer_coverage(SG_CLOUD_CLEAR),
 153     scale(4000.0),
 154     speed(0.0),
 155     direction(0.0)
 156 {
 157     // XXX
 158     // Render bottoms before the rest of transparent objects (rendered
 159     // in bin 10), tops after. The negative numbers on the bottoms
 160     // RenderBins and the positive numbers on the tops enforce this
 161     // order.
 162   cloud_root->addChild(layer_root.get(), true);
 163   layer_root->addChild(group_bottom.get());
 164   layer_root->addChild(group_top.get());
 165   osg::StateSet *rootSet = layer_root->getOrCreateStateSet();
 166   rootSet->setRenderBinDetails(CLOUDS_BIN, "DepthSortedBin");
 167   rootSet->setTextureAttribute(0, new osg::TexMat);
 168   rootSet->setMode(GL_CULL_FACE, osg::StateAttribute::ON);
 169   // Combiner for fog color and cloud alpha
 170   osg::TexEnvCombine* combine0 = new osg::TexEnvCombine;
 171   osg::TexEnvCombine* combine1 = new osg::TexEnvCombine;
 172   combine0->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 173   combine0->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 174   combine0->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 175   combine0->setSource1_RGB(osg::TexEnvCombine::TEXTURE0);
 176   combine0->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 177   combine0->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 178   combine0->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 179   combine0->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 180   combine0->setSource1_Alpha(osg::TexEnvCombine::TEXTURE0);
 181   combine0->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 182
 183   combine1->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 184   combine1->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 185   combine1->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 186   combine1->setSource1_RGB(osg::TexEnvCombine::CONSTANT);
 187   combine1->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 188   combine1->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 189   combine1->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 190   combine1->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 191   combine1->setSource1_Alpha(osg::TexEnvCombine::CONSTANT);
 192   combine1->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 193   combine1->setDataVariance(osg::Object::DYNAMIC);
 194   rootSet->setTextureAttributeAndModes(0, combine0);
 195   rootSet->setTextureAttributeAndModes(1, combine1);
 196   rootSet->setTextureMode(1, GL_TEXTURE_2D, osg::StateAttribute::ON);
 197   rootSet->setTextureAttributeAndModes(1, StateAttributeFactory::instance()
 198                                        ->getWhiteTexture(),
 199                                        osg::StateAttribute::ON);
 200   rootSet->setDataVariance(osg::Object::DYNAMIC);
 201
 202   base = osg::Vec2(sg_random(), sg_random());
 203   group_top->addChild(layer_transform.get());
 204   group_bottom->addChild(layer_transform.get());
 205
 206   layer3D = new SGCloudField();
 207   cloud_root->addChild(layer3D->getNode(), false);
 208
 209   rebuild();
 210 }
 211
 212 // Destructor
 213 SGCloudLayer::~SGCloudLayer()
 214 {
 215   delete layer3D;
 216 }
 217
 218 float
 219 SGCloudLayer::getSpan_m () const
 220 {
 221     return layer_span;
 222 }
 223
 224 void
 225 SGCloudLayer::setSpan_m (float span_m)
 226 {
 227     if (span_m != layer_span) {
 228         layer_span = span_m;
 229         rebuild();
 230     }
 231 }
 232
 233 float
 234 SGCloudLayer::getElevation_m () const
 235 {
 236     return layer_asl;
 237 }
 238
 239 void
 240 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 241 {
 242     layer_asl = elevation_m;
 243
 244     if (set_span) {
 245         if (elevation_m > 4000)
 246             setSpan_m(  elevation_m * 10 );
 247         else
 248             setSpan_m( 40000 );
 249     }
 250 }
 251
 252 float
 253 SGCloudLayer::getThickness_m () const
 254 {
 255     return layer_thickness;
 256 }
 257
 258 void
 259 SGCloudLayer::setThickness_m (float thickness_m)
 260 {
 261     layer_thickness = thickness_m;
 262 }
 263
 264 float
 265 SGCloudLayer::getVisibility_m() const
 266 {
 267     return layer_visibility;
 268 }
 269
 270 void
 271 SGCloudLayer::setVisibility_m (float visibility_m)
 272 {
 273     layer_visibility = visibility_m;
 274 }
 275
 276 float
 277 SGCloudLayer::getTransition_m () const
 278 {
 279     return layer_transition;
 280 }
 281
 282 void
 283 SGCloudLayer::setTransition_m (float transition_m)
 284 {
 285     layer_transition = transition_m;
 286 }
 287
 288 SGCloudLayer::Coverage
 289 SGCloudLayer::getCoverage () const
 290 {
 291     return layer_coverage;
 292 }
 293
 294 void
 295 SGCloudLayer::setCoverage (Coverage coverage)
 296 {
 297     if (coverage != layer_coverage) {
 298         layer_coverage = coverage;
 299         rebuild();
 300
 301         double coverage_norm = 0.0;
 302         if( coverage ==  SG_CLOUD_FEW)
 303             coverage_norm = 2.0/8.0;    // <1-2
 304         else if( coverage == SG_CLOUD_SCATTERED )
 305             coverage_norm = 4.0/8.0;    // 3-4
 306         else if( coverage == SG_CLOUD_BROKEN )
 307             coverage_norm = 6.0/8.0;    // 5-7
 308         else if( coverage == SG_CLOUD_OVERCAST )
 309             coverage_norm = 8.0/8.0;    // 8
 310
 311         layer3D->setCoverage(coverage_norm);
 312         layer3D->applyCoverage();
 313     }
 314 }
 315
 316 const std::string &
 317 SGCloudLayer::getCoverageString( Coverage coverage )
 318 {
 319         switch( coverage ) {
 320                 case SG_CLOUD_OVERCAST:
 321                         return SG_CLOUD_OVERCAST_STRING;
 322                 case SG_CLOUD_BROKEN:
 323                         return SG_CLOUD_BROKEN_STRING;
 324                 case SG_CLOUD_SCATTERED:
 325                         return SG_CLOUD_SCATTERED_STRING;
 326                 case SG_CLOUD_FEW:
 327                         return SG_CLOUD_FEW_STRING;
 328                 case SG_CLOUD_CIRRUS:
 329                         return SG_CLOUD_CIRRUS_STRING;
 330                 case SG_CLOUD_CLEAR:
 331                 default:
 332                         return SG_CLOUD_CLEAR_STRING;
 333         }
 334 }
 335
 336 SGCloudLayer::Coverage
 337 SGCloudLayer::getCoverageType( const std::string & coverage )
 338 {
 339         if( SG_CLOUD_OVERCAST_STRING == coverage ) {
 340                 return SG_CLOUD_OVERCAST;
 341         } else if( SG_CLOUD_BROKEN_STRING == coverage ) {
 342                 return SG_CLOUD_BROKEN;
 343         } else if( SG_CLOUD_SCATTERED_STRING == coverage ) {
 344                 return SG_CLOUD_SCATTERED;
 345         } else if( SG_CLOUD_FEW_STRING == coverage ) {
 346                 return SG_CLOUD_FEW;
 347         } else if( SG_CLOUD_CIRRUS_STRING == coverage ) {
 348                 return SG_CLOUD_CIRRUS;
 349         } else {
 350                 return SG_CLOUD_CLEAR;
 351         }
 352 }
 353
 354 const std::string &
 355 SGCloudLayer::getCoverageString() const
 356 {
 357         return getCoverageString(layer_coverage);
 358 }
 359
 360 void
 361 SGCloudLayer::setCoverageString( const std::string & coverage )
 362 {
 363         setCoverage( getCoverageType(coverage) );
 364 }
 365
 366 void
 367 SGCloudLayer::setTextureOffset(const osg::Vec2& offset)
 368 {
 369     osg::StateAttribute* attr = layer_root->getStateSet()
 370         ->getTextureAttribute(0, osg::StateAttribute::TEXMAT);
 371     osg::TexMat* texMat = dynamic_cast<osg::TexMat*>(attr);
 372     if (!texMat)
 373         return;
 374     texMat->setMatrix(osg::Matrix::translate(offset[0], offset[1], 0.0));
 375 }
 376
 377 // colors for debugging the cloud layers
 378 #ifdef CLOUD_DEBUG
 379 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 0.0f, 0.0f),
 380                       Vec3(0.0f, 1.0f, 0.0f), Vec3(0.0f, 0.0f, 1.0f)};
 381 #else
 382 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f),
 383                       Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f)};
 384 #endif
 385
 386 // build the cloud object
 387 void
 388 SGCloudLayer::rebuild()
 389 {
 390     // Initialize states and sizes if necessary.
 391     if ( !state_initialized ) {
 392         state_initialized = true;
 393
 394         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 395
 396         osg::Texture::Extensions* extensions;
 397         extensions = osg::Texture::getExtensions(0, true);
 398         // OSGFIXME
 399         bump_mapping = extensions->isMultiTexturingSupported() &&
 400           (2 <= extensions->numTextureUnits()) &&
 401           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_combine") &&
 402           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_dot3");
 403
 404         osg::TextureCubeMap::Extensions* extensions2;
 405         extensions2 = osg::TextureCubeMap::getExtensions(0, true);
 406         bump_mapping = bump_mapping && extensions2->isCubeMapSupported();
 407
 408         // This bump mapping code was inspired by the tutorial available at
 409         // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 410         // and a NVidia white paper
 411         //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 412         // The normal map textures were generated by the normal map Gimp plugin :
 413         //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 414         //
 415         cubeMap = new osg::TextureCubeMap;
 416         cubeMap->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
 417         cubeMap->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
 418         cubeMap->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
 419         cubeMap->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE);
 420         cubeMap->setWrap(osg::Texture::WRAP_R, osg::Texture::CLAMP_TO_EDGE);
 421
 422         const int size = 32;
 423         const float half_size = 16.0f;
 424         const float offset = 0.5f;
 425         osg::Vec3 zero_normal(0.5, 0.5, 0.5);
 426
 427         osg::Image* image = new osg::Image;
 428         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 429         unsigned char *ptr = image->data(0, 0);
 430         for (int j = 0; j < size; j++ ) {
 431           for (int i = 0; i < size; i++ ) {
 432             osg::Vec3 tmp(half_size, -( j + offset - half_size ),
 433                           -( i + offset - half_size ) );
 434             tmp.normalize();
 435             tmp = tmp*0.5 - zero_normal;
 436
 437             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 438             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 439             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 440           }
 441         }
 442         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_X, image);
 443
 444         image = new osg::Image;
 445         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 446         ptr = image->data(0, 0);
 447         for (int j = 0; j < size; j++ ) {
 448           for (int i = 0; i < size; i++ ) {
 449             osg::Vec3 tmp(-half_size, -( j + offset - half_size ),
 450                           ( i + offset - half_size ) );
 451             tmp.normalize();
 452             tmp = tmp*0.5 - zero_normal;
 453
 454             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 455             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 456             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 457           }
 458         }
 459         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_X, image);
 460
 461         image = new osg::Image;
 462         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 463         ptr = image->data(0, 0);
 464         for (int j = 0; j < size; j++ ) {
 465           for (int i = 0; i < size; i++ ) {
 466             osg::Vec3 tmp(( i + offset - half_size ), half_size,
 467                           ( j + offset - half_size ) );
 468             tmp.normalize();
 469             tmp = tmp*0.5 - zero_normal;
 470
 471             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 472             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 473             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 474           }
 475         }
 476         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Y, image);
 477
 478         image = new osg::Image;
 479         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 480         ptr = image->data(0, 0);
 481         for (int j = 0; j < size; j++ ) {
 482           for (int i = 0; i < size; i++ ) {
 483             osg::Vec3 tmp(( i + offset - half_size ), -half_size,
 484                           -( j + offset - half_size ) );
 485             tmp.normalize();
 486             tmp = tmp*0.5 - zero_normal;
 487
 488             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 489             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 490             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 491           }
 492         }
 493         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Y, image);
 494
 495         image = new osg::Image;
 496         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 497         ptr = image->data(0, 0);
 498         for (int j = 0; j < size; j++ ) {
 499           for (int i = 0; i < size; i++ ) {
 500             osg::Vec3 tmp(( i + offset - half_size ),
 501                           -( j + offset - half_size ), half_size );
 502             tmp.normalize();
 503             tmp = tmp*0.5 - zero_normal;
 504
 505             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 506             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 507             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 508           }
 509         }
 510         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Z, image);
 511
 512         image = new osg::Image;
 513         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 514         ptr = image->data(0, 0);
 515         for (int j = 0; j < size; j++ ) {
 516           for (int i = 0; i < size; i++ ) {
 517             osg::Vec3 tmp(-( i + offset - half_size ),
 518                           -( j + offset - half_size ), -half_size );
 519             tmp.normalize();
 520             tmp = tmp*0.5 - zero_normal;
 521             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 522             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 523             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 524           }
 525         }
 526         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Z, image);
 527
 528         osg::StateSet* state;
 529         state = SGMakeState(texture_path, "overcast.png", "overcast_n.png");
 530         layer_states[SG_CLOUD_OVERCAST] = state;
 531         state = SGMakeState(texture_path, "overcast_top.png", "overcast_top_n.png");
 532         layer_states2[SG_CLOUD_OVERCAST] = state;
 533
 534         state = SGMakeState(texture_path, "broken.png", "broken_n.png");
 535         layer_states[SG_CLOUD_BROKEN] = state;
 536         layer_states2[SG_CLOUD_BROKEN] = state;
 537
 538         state = SGMakeState(texture_path, "scattered.png", "scattered_n.png");
 539         layer_states[SG_CLOUD_SCATTERED] = state;
 540         layer_states2[SG_CLOUD_SCATTERED] = state;
 541
 542         state = SGMakeState(texture_path, "few.png", "few_n.png");
 543         layer_states[SG_CLOUD_FEW] = state;
 544         layer_states2[SG_CLOUD_FEW] = state;
 545
 546         state = SGMakeState(texture_path, "cirrus.png", "cirrus_n.png");
 547         layer_states[SG_CLOUD_CIRRUS] = state;
 548         layer_states2[SG_CLOUD_CIRRUS] = state;
 549
 550         layer_states[SG_CLOUD_CLEAR] = 0;
 551         layer_states2[SG_CLOUD_CLEAR] = 0;
 552 #if 1
 553         // experimental optimization that may not make any difference
 554         // at all :/
 555         osg::CopyOp copyOp;
 556         for (int i = 0; i < SG_MAX_CLOUD_COVERAGES; ++i) {
 557             StateAttributeFactory *saf = StateAttributeFactory::instance();
 558             if (layer_states[i].valid()) {
 559                 if (layer_states[i] == layer_states2[i])
 560                     layer_states2[i] = static_cast<osg::StateSet*>(layer_states[i]->clone(copyOp));
 561                 layer_states[i]->setAttribute(saf ->getCullFaceFront());
 562                 layer_states2[i]->setAttribute(saf ->getCullFaceBack());
 563             }
 564         }
 565 #endif
 566     }
 567
 568     scale = 4000.0;
 569
 570     setTextureOffset(base);
 571     // build the cloud layer
 572     const float layer_scale = layer_span / scale;
 573     const float mpi = SG_PI/4;
 574
 575     // caclculate the difference between a flat-earth model and
 576     // a round earth model given the span and altutude ASL of
 577     // the cloud layer. This is the difference in altitude between
 578     // the top of the inverted bowl and the edge of the bowl.
 579     // const float alt_diff = layer_asl * 0.8;
 580     const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 581     const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 582     const float border_to_core = layer_to_core * cos(layer_angle);
 583     const float alt_diff = layer_to_core - border_to_core;
 584
 585     for (int i = 0; i < 4; i++) {
 586       if ( layer[i] != NULL ) {
 587         layer_transform->removeChild(layer[i].get()); // automatic delete
 588       }
 589
 590       vl[i] = new osg::Vec3Array;
 591       cl[i] = new osg::Vec4Array;
 592       tl[i] = new osg::Vec2Array;
 593
 594
 595       osg::Vec3 vertex(layer_span*(i-2)/2, -layer_span,
 596                        alt_diff * (sin(i*mpi) - 2));
 597       osg::Vec2 tc(layer_scale * i/4, 0.0f);
 598       osg::Vec4 color(cloudColors[0], (i == 0) ? 0.0f : 0.15f);
 599
 600       cl[i]->push_back(color);
 601       vl[i]->push_back(vertex);
 602       tl[i]->push_back(tc);
 603
 604       for (int j = 0; j < 4; j++) {
 605         vertex = osg::Vec3(layer_span*(i-1)/2, layer_span*(j-2)/2,
 606                            alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2));
 607         tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale * j/4);
 608         color = osg::Vec4(cloudColors[0],
 609                           ( (j == 0) || (i == 3)) ?
 610                           ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 611
 612         cl[i]->push_back(color);
 613         vl[i]->push_back(vertex);
 614         tl[i]->push_back(tc);
 615
 616         vertex = osg::Vec3(layer_span*(i-2)/2, layer_span*(j-1)/2,
 617                            alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 618         tc = osg::Vec2(layer_scale * i/4, layer_scale * (j+1)/4 );
 619         color = osg::Vec4(cloudColors[0],
 620                           ((j == 3) || (i == 0)) ?
 621                           ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 622         cl[i]->push_back(color);
 623         vl[i]->push_back(vertex);
 624         tl[i]->push_back(tc);
 625       }
 626
 627       vertex = osg::Vec3(layer_span*(i-1)/2, layer_span,
 628                          alt_diff * (sin((i+1)*mpi) - 2));
 629
 630       tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale);
 631
 632       color = osg::Vec4(cloudColors[0], (i == 3) ? 0.0f : 0.15f );
 633
 634       cl[i]->push_back( color );
 635       vl[i]->push_back( vertex );
 636       tl[i]->push_back( tc );
 637
 638       osg::Geometry* geometry = new osg::Geometry;
 639       geometry->setUseDisplayList(false);
 640       geometry->setVertexArray(vl[i].get());
 641       geometry->setNormalBinding(osg::Geometry::BIND_OFF);
 642       geometry->setColorArray(cl[i].get());
 643       geometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
 644       geometry->setTexCoordArray(0, tl[i].get());
 645       geometry->addPrimitiveSet(new osg::DrawArrays(GL_TRIANGLE_STRIP, 0, vl[i]->size()));
 646       layer[i] = new osg::Geode;
 647
 648       std::stringstream sstr;
 649       sstr << "Cloud Layer (" << i << ")";
 650       geometry->setName(sstr.str());
 651       layer[i]->setName(sstr.str());
 652       layer[i]->addDrawable(geometry);
 653       layer_transform->addChild(layer[i].get());
 654     }
 655
 656     //OSGFIXME: true
 657     if ( layer_states[layer_coverage].valid() ) {
 658       osg::CopyOp copyOp;    // shallow copy
 659       // render bin will be set in reposition
 660       osg::StateSet* stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 661       stateSet->setDataVariance(osg::Object::DYNAMIC);
 662       group_top->setStateSet(stateSet);
 663       stateSet = static_cast<osg::StateSet*>(layer_states[layer_coverage]->clone(copyOp));
 664       stateSet->setDataVariance(osg::Object::DYNAMIC);
 665       group_bottom->setStateSet(stateSet);
 666     }
 667 }
 668
 669 // repaint the cloud layer colors
 670 bool SGCloudLayer::repaint( const SGVec3f& fog_color ) {
 671     osg::Vec4f combineColor(toOsg(fog_color), cloud_alpha);
 672     osg::TexEnvCombine* combiner
 673         = dynamic_cast<osg::TexEnvCombine*>(layer_root->getStateSet()
 674                                             ->getTextureAttribute(1, osg::StateAttribute::TEXENV));
 675     combiner->setConstantColor(combineColor);
 676
 677     // Set the fog color for the 3D clouds too.
 678     //cloud3dfog->setColor(combineColor);
 679     return true;
 680 }
 681
 682 // reposition the cloud layer at the specified origin and orientation
 683 // lon specifies a rotation about the Z axis
 684 // lat specifies a rotation about the new Y axis
 685 // spin specifies a rotation about the new Z axis (and orients the
 686 // sunrise/set effects
 687 bool SGCloudLayer::reposition( const SGVec3f& p, const SGVec3f& up, double lon, double lat,
 688                                double alt, double dt )
 689 {
 690     // combine p and asl (meters) to get translation offset
 691     osg::Vec3 asl_offset(toOsg(up));
 692     asl_offset.normalize();
 693     if ( alt <= layer_asl ) {
 694         asl_offset *= layer_asl;
 695     } else {
 696         asl_offset *= layer_asl + layer_thickness;
 697     }
 698
 699     // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 700     //      << "," << asl_offset[2] << endl;
 701     asl_offset += toOsg(p);
 702     // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 703     //      << "," << asl_offset[2] << endl;
 704
 705     osg::Matrix T, LON, LAT;
 706     // Translate to zero elevation
 707     // Point3D zero_elev = current_view.get_cur_zero_elev();
 708     T.makeTranslate( asl_offset );
 709
 710     // printf("  Translated to %.2f %.2f %.2f\n",
 711     //        zero_elev.x, zero_elev.y, zero_elev.z );
 712
 713     // Rotate to proper orientation
 714     // printf("  lon = %.2f  lat = %.2f\n",
 715     //        lon * SGD_RADIANS_TO_DEGREES,
 716     //        lat * SGD_RADIANS_TO_DEGREES);
 717     LON.makeRotate(lon, osg::Vec3(0, 0, 1));
 718
 719     // xglRotatef( 90.0 - f->get_Latitude() * SGD_RADIANS_TO_DEGREES,
 720     //             0.0, 1.0, 0.0 );
 721     LAT.makeRotate(90.0 * SGD_DEGREES_TO_RADIANS - lat, osg::Vec3(0, 1, 0));
 722
 723     layer_transform->setMatrix( LAT*LON*T );
 724
 725     // The layers need to be drawn in order because they are
 726     // translucent, but OSG transparency sorting doesn't work because
 727     // the cloud polys are huge. However, the ordering is simple: the
 728     // bottom polys should be drawn from high altitude to low, and the
 729     // top polygons from low to high. The altitude can be used
 730     // directly to order the polygons!
 731     group_bottom->getStateSet()->setRenderBinDetails(-(int)layer_asl,
 732                                                      "RenderBin");
 733     group_top->getStateSet()->setRenderBinDetails((int)layer_asl,
 734                                                   "RenderBin");
 735     if ( alt <= layer_asl ) {
 736       layer_root->setSingleChildOn(0);
 737     } else if ( alt >= layer_asl + layer_thickness ) {
 738       layer_root->setSingleChildOn(1);
 739     } else {
 740       layer_root->setAllChildrenOff();
 741     }
 742
 743
 744     // now calculate update texture coordinates
 745     SGGeod pos = SGGeod::fromRad(lon, lat);
 746     if ( last_pos == SGGeod() ) {
 747         last_pos = pos;
 748     }
 749
 750     double sp_dist = speed*dt;
 751
 752
 753     if ( lon != last_pos.getLongitudeRad() || lat != last_pos.getLatitudeRad() || sp_dist != 0 ) {
 754         double course = SGGeodesy::courseDeg(last_pos, pos) * SG_DEGREES_TO_RADIANS,
 755             dist = SGGeodesy::distanceM(last_pos, pos);
 756
 757         // if start and dest are too close together,
 758         // calc_gc_course_dist() can return a course of "nan".  If
 759         // this happens, lets just use the last known good course.
 760         // This is a hack, and it would probably be better to make
 761         // calc_gc_course_dist() more robust.
 762         if ( isnan(course) ) {
 763             course = last_course;
 764         } else {
 765             last_course = course;
 766         }
 767
 768         // calculate cloud movement due to external forces
 769         double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 770
 771         if (dist > 0.0) {
 772             ax = -cos(course) * dist;
 773             ay = sin(course) * dist;
 774         }
 775
 776         if (sp_dist > 0) {
 777             bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 778             by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 779         }
 780
 781
 782         double xoff = (ax + bx) / (2 * scale);
 783         double yoff = (ay + by) / (2 * scale);
 784
 785
 786 //        const float layer_scale = layer_span / scale;
 787
 788         // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 789         base[0] += xoff;
 790
 791         // the while loops can lead to *long* pauses if base[0] comes
 792         // with a bogus value.
 793         // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 794         // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 795         if ( base[0] > -10.0 && base[0] < 10.0 ) {
 796             base[0] -= (int)base[0];
 797         } else {
 798             SG_LOG(SG_ASTRO, SG_DEBUG,
 799                 "Error: base = " << base[0] << "," << base[1] <<
 800                 " course = " << course << " dist = " << dist );
 801             base[0] = 0.0;
 802         }
 803
 804         base[1] += yoff;
 805         // the while loops can lead to *long* pauses if base[0] comes
 806         // with a bogus value.
 807         // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 808         // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 809         if ( base[1] > -10.0 && base[1] < 10.0 ) {
 810             base[1] -= (int)base[1];
 811         } else {
 812             SG_LOG(SG_ASTRO, SG_DEBUG,
 813                     "Error: base = " << base[0] << "," << base[1] <<
 814                     " course = " << course << " dist = " << dist );
 815             base[1] = 0.0;
 816         }
 817
 818         // cout << "base = " << base[0] << "," << base[1] << endl;
 819
 820         setTextureOffset(base);
 821         last_pos = pos;
 822     }
 823
 824     layer3D->reposition( p, up, lon, lat, dt, layer_asl);
 825     return true;
 826 }
 827
 828 void SGCloudLayer::set_enable3dClouds(bool enable) {
 829
 830     if (layer3D->defined3D && enable) {
 831         cloud_root->setChildValue(layer3D->getNode(), true);
 832         cloud_root->setChildValue(layer_root.get(),   false);
 833     } else {
 834         cloud_root->setChildValue(layer3D->getNode(), false);
 835         cloud_root->setChildValue(layer_root.get(),   true);
 836     }
 837 }