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/math/polar3d.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 // make an StateSet for a cloud layer given the named texture
  87 static osg::StateSet*
  88 SGMakeState(const SGPath &path, const char* colorTexture,
  89             const char* normalTexture)
  90 {
  91     osg::StateSet *stateSet = new osg::StateSet;
  92
  93     osg::ref_ptr<osgDB::ReaderWriter::Options> options
  94         = makeOptionsFromPath(path);
  95     stateSet->setTextureAttribute(0, SGLoadTexture2D(colorTexture,
  96                                                      options.get()));
  97     stateSet->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
  98     StateAttributeFactory* attribFactory = StateAttributeFactory::instance();
  99     stateSet->setAttributeAndModes(attribFactory->getSmoothShadeModel());
 100     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
 101     stateSet->setAttributeAndModes(attribFactory->getStandardAlphaFunc());
 102     stateSet->setAttributeAndModes(attribFactory->getStandardBlendFunc());
 103
 104 //     osg::Material* material = new osg::Material;
 105 //     material->setColorMode(osg::Material::AMBIENT_AND_DIFFUSE);
 106 //     material->setEmission(osg::Material::FRONT_AND_BACK,
 107 //                           osg::Vec4(0.05, 0.05, 0.05, 0));
 108 //     material->setSpecular(osg::Material::FRONT_AND_BACK,
 109 //                           osg::Vec4(0, 0, 0, 1));
 110 //     stateSet->setAttribute(material);
 111
 112     stateSet->setMode(GL_FOG, osg::StateAttribute::OFF);
 113
 114     // OSGFIXME: invented by me ...
 115 //     stateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
 116 //     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::ON);
 117
 118 //     stateSet->setMode(GL_LIGHT0, osg::StateAttribute::OFF);
 119
 120     // If the normal texture is given prepare a bumpmapping enabled state
 121 //     if (normalTexture) {
 122 //       SGPath normalPath(path);
 123 //       normalPath.append(normalTexture);
 124 //       stateSet->setTextureAttribute(2, SGLoadTexture2D(normalPath));
 125 //       stateSet->setTextureMode(2, GL_TEXTURE_2D, osg::StateAttribute::ON);
 126 //     }
 127
 128     return stateSet;
 129 }
 130
 131 // Constructor
 132 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
 133     cloud_root(new osg::Switch),
 134     layer_root(new osg::Switch),
 135     group_top(new osg::Group),
 136     group_bottom(new osg::Group),
 137     layer_transform(new osg::MatrixTransform),
 138     cloud_alpha(1.0),
 139     texture_path(tex_path),
 140     layer_span(0.0),
 141     layer_asl(0.0),
 142     layer_thickness(0.0),
 143     layer_transition(0.0),
 144     layer_coverage(SG_CLOUD_CLEAR),
 145     scale(4000.0),
 146     speed(0.0),
 147     direction(0.0),
 148     last_lon(0.0),
 149     last_lat(0.0)
 150 {
 151     // XXX
 152     // Render bottoms before the rest of transparent objects (rendered
 153     // in bin 10), tops after. The negative numbers on the bottoms
 154     // RenderBins and the positive numbers on the tops enforce this
 155     // order.
 156   cloud_root->addChild(layer_root.get(), true);
 157   layer_root->addChild(group_bottom.get());
 158   layer_root->addChild(group_top.get());
 159   osg::StateSet *rootSet = layer_root->getOrCreateStateSet();
 160   rootSet->setRenderBinDetails(CLOUDS_BIN, "DepthSortedBin");
 161   rootSet->setTextureAttribute(0, new osg::TexMat);
 162   rootSet->setMode(GL_CULL_FACE, osg::StateAttribute::ON);
 163   // Combiner for fog color and cloud alpha
 164   osg::TexEnvCombine* combine0 = new osg::TexEnvCombine;
 165   osg::TexEnvCombine* combine1 = new osg::TexEnvCombine;
 166   combine0->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 167   combine0->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 168   combine0->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 169   combine0->setSource1_RGB(osg::TexEnvCombine::TEXTURE0);
 170   combine0->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 171   combine0->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 172   combine0->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 173   combine0->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 174   combine0->setSource1_Alpha(osg::TexEnvCombine::TEXTURE0);
 175   combine0->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 176
 177   combine1->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 178   combine1->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 179   combine1->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 180   combine1->setSource1_RGB(osg::TexEnvCombine::CONSTANT);
 181   combine1->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 182   combine1->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 183   combine1->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 184   combine1->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 185   combine1->setSource1_Alpha(osg::TexEnvCombine::CONSTANT);
 186   combine1->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 187   combine1->setDataVariance(osg::Object::DYNAMIC);
 188   rootSet->setTextureAttributeAndModes(0, combine0);
 189   rootSet->setTextureAttributeAndModes(1, combine1);
 190   rootSet->setTextureMode(1, GL_TEXTURE_2D, osg::StateAttribute::ON);
 191   rootSet->setTextureAttributeAndModes(1, StateAttributeFactory::instance()
 192                                        ->getWhiteTexture(),
 193                                        osg::StateAttribute::ON);
 194   rootSet->setDataVariance(osg::Object::DYNAMIC);
 195
 196   base = osg::Vec2(sg_random(), sg_random());
 197   group_top->addChild(layer_transform.get());
 198   group_bottom->addChild(layer_transform.get());
 199
 200   layer3D = new SGCloudField();
 201   cloud_root->addChild(layer3D->getNode(), false);
 202
 203   rebuild();
 204 }
 205
 206 // Destructor
 207 SGCloudLayer::~SGCloudLayer()
 208 {
 209   delete layer3D;
 210 }
 211
 212 float
 213 SGCloudLayer::getSpan_m () const
 214 {
 215     return layer_span;
 216 }
 217
 218 void
 219 SGCloudLayer::setSpan_m (float span_m)
 220 {
 221     if (span_m != layer_span) {
 222         layer_span = span_m;
 223         rebuild();
 224     }
 225 }
 226
 227 float
 228 SGCloudLayer::getElevation_m () const
 229 {
 230     return layer_asl;
 231 }
 232
 233 void
 234 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 235 {
 236     layer_asl = elevation_m;
 237
 238     if (set_span) {
 239         if (elevation_m > 4000)
 240             setSpan_m(  elevation_m * 10 );
 241         else
 242             setSpan_m( 40000 );
 243     }
 244 }
 245
 246 float
 247 SGCloudLayer::getThickness_m () const
 248 {
 249     return layer_thickness;
 250 }
 251
 252 void
 253 SGCloudLayer::setThickness_m (float thickness_m)
 254 {
 255     layer_thickness = thickness_m;
 256 }
 257
 258 float
 259 SGCloudLayer::getTransition_m () const
 260 {
 261     return layer_transition;
 262 }
 263
 264 void
 265 SGCloudLayer::setTransition_m (float transition_m)
 266 {
 267     layer_transition = transition_m;
 268 }
 269
 270 SGCloudLayer::Coverage
 271 SGCloudLayer::getCoverage () const
 272 {
 273     return layer_coverage;
 274 }
 275
 276 void
 277 SGCloudLayer::setCoverage (Coverage coverage)
 278 {
 279     if (coverage != layer_coverage) {
 280         layer_coverage = coverage;
 281         rebuild();
 282
 283         double coverage_norm = 0.0;
 284         if( coverage ==  SG_CLOUD_FEW)
 285             coverage_norm = 2.0/8.0;    // <1-2
 286         else if( coverage == SG_CLOUD_SCATTERED )
 287             coverage_norm = 4.0/8.0;    // 3-4
 288         else if( coverage == SG_CLOUD_BROKEN )
 289             coverage_norm = 6.0/8.0;    // 5-7
 290         else if( coverage == SG_CLOUD_OVERCAST )
 291             coverage_norm = 8.0/8.0;    // 8
 292
 293         layer3D->setCoverage(coverage_norm);
 294         layer3D->applyCoverage();
 295     }
 296 }
 297
 298 void
 299 SGCloudLayer::setTextureOffset(const osg::Vec2& offset)
 300 {
 301     osg::StateAttribute* attr = layer_root->getStateSet()
 302         ->getTextureAttribute(0, osg::StateAttribute::TEXMAT);
 303     osg::TexMat* texMat = dynamic_cast<osg::TexMat*>(attr);
 304     if (!texMat)
 305         return;
 306     texMat->setMatrix(osg::Matrix::translate(offset[0], offset[1], 0.0));
 307 }
 308
 309 // colors for debugging the cloud layers
 310 #ifdef CLOUD_DEBUG
 311 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 0.0f, 0.0f),
 312                       Vec3(0.0f, 1.0f, 0.0f), Vec3(0.0f, 0.0f, 1.0f)};
 313 #else
 314 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f),
 315                       Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f)};
 316 #endif
 317
 318 // build the cloud object
 319 void
 320 SGCloudLayer::rebuild()
 321 {
 322     // Initialize states and sizes if necessary.
 323     if ( !state_initialized ) {
 324         state_initialized = true;
 325
 326         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 327
 328         osg::Texture::Extensions* extensions;
 329         extensions = osg::Texture::getExtensions(0, true);
 330         // OSGFIXME
 331         bump_mapping = extensions->isMultiTexturingSupported() &&
 332           (2 <= extensions->numTextureUnits()) &&
 333           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_combine") &&
 334           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_dot3");
 335
 336         osg::TextureCubeMap::Extensions* extensions2;
 337         extensions2 = osg::TextureCubeMap::getExtensions(0, true);
 338         bump_mapping = bump_mapping && extensions2->isCubeMapSupported();
 339
 340         // This bump mapping code was inspired by the tutorial available at
 341         // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 342         // and a NVidia white paper
 343         //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 344         // The normal map textures were generated by the normal map Gimp plugin :
 345         //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 346         //
 347         cubeMap = new osg::TextureCubeMap;
 348         cubeMap->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
 349         cubeMap->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
 350         cubeMap->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
 351         cubeMap->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE);
 352         cubeMap->setWrap(osg::Texture::WRAP_R, osg::Texture::CLAMP_TO_EDGE);
 353
 354         const int size = 32;
 355         const float half_size = 16.0f;
 356         const float offset = 0.5f;
 357         osg::Vec3 zero_normal(0.5, 0.5, 0.5);
 358
 359         osg::Image* image = new osg::Image;
 360         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 361         unsigned char *ptr = image->data(0, 0);
 362         for (int j = 0; j < size; j++ ) {
 363           for (int i = 0; i < size; i++ ) {
 364             osg::Vec3 tmp(half_size, -( j + offset - half_size ),
 365                           -( i + offset - half_size ) );
 366             tmp.normalize();
 367             tmp = tmp*0.5 - zero_normal;
 368
 369             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 370             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 371             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 372           }
 373         }
 374         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_X, image);
 375
 376         image = new osg::Image;
 377         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 378         ptr = image->data(0, 0);
 379         for (int j = 0; j < size; j++ ) {
 380           for (int i = 0; i < size; i++ ) {
 381             osg::Vec3 tmp(-half_size, -( j + offset - half_size ),
 382                           ( i + offset - half_size ) );
 383             tmp.normalize();
 384             tmp = tmp*0.5 - zero_normal;
 385
 386             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 387             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 388             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 389           }
 390         }
 391         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_X, image);
 392
 393         image = new osg::Image;
 394         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 395         ptr = image->data(0, 0);
 396         for (int j = 0; j < size; j++ ) {
 397           for (int i = 0; i < size; i++ ) {
 398             osg::Vec3 tmp(( i + offset - half_size ), half_size,
 399                           ( j + offset - half_size ) );
 400             tmp.normalize();
 401             tmp = tmp*0.5 - zero_normal;
 402
 403             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 404             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 405             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 406           }
 407         }
 408         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Y, image);
 409
 410         image = new osg::Image;
 411         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 412         ptr = image->data(0, 0);
 413         for (int j = 0; j < size; j++ ) {
 414           for (int i = 0; i < size; i++ ) {
 415             osg::Vec3 tmp(( i + offset - half_size ), -half_size,
 416                           -( j + offset - half_size ) );
 417             tmp.normalize();
 418             tmp = tmp*0.5 - zero_normal;
 419
 420             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 421             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 422             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 423           }
 424         }
 425         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Y, image);
 426
 427         image = new osg::Image;
 428         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 429         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(( i + offset - half_size ),
 433                           -( j + offset - half_size ), 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_Z, 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(-( i + offset - half_size ),
 450                           -( j + offset - half_size ), -half_size );
 451             tmp.normalize();
 452             tmp = tmp*0.5 - zero_normal;
 453             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 454             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 455             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 456           }
 457         }
 458         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Z, image);
 459
 460         osg::StateSet* state;
 461         state = SGMakeState(texture_path, "overcast.png", "overcast_n.png");
 462         layer_states[SG_CLOUD_OVERCAST] = state;
 463         state = SGMakeState(texture_path, "overcast_top.png", "overcast_top_n.png");
 464         layer_states2[SG_CLOUD_OVERCAST] = state;
 465
 466         state = SGMakeState(texture_path, "broken.png", "broken_n.png");
 467         layer_states[SG_CLOUD_BROKEN] = state;
 468         layer_states2[SG_CLOUD_BROKEN] = state;
 469
 470         state = SGMakeState(texture_path, "scattered.png", "scattered_n.png");
 471         layer_states[SG_CLOUD_SCATTERED] = state;
 472         layer_states2[SG_CLOUD_SCATTERED] = state;
 473
 474         state = SGMakeState(texture_path, "few.png", "few_n.png");
 475         layer_states[SG_CLOUD_FEW] = state;
 476         layer_states2[SG_CLOUD_FEW] = state;
 477
 478         state = SGMakeState(texture_path, "cirrus.png", "cirrus_n.png");
 479         layer_states[SG_CLOUD_CIRRUS] = state;
 480         layer_states2[SG_CLOUD_CIRRUS] = state;
 481
 482         layer_states[SG_CLOUD_CLEAR] = 0;
 483         layer_states2[SG_CLOUD_CLEAR] = 0;
 484 #if 1
 485         // experimental optimization that may not make any difference
 486         // at all :/
 487         osg::CopyOp copyOp;
 488         for (int i = 0; i < SG_MAX_CLOUD_COVERAGES; ++i) {
 489             StateAttributeFactory *saf = StateAttributeFactory::instance();
 490             if (layer_states[i].valid()) {
 491                 if (layer_states[i] == layer_states2[i])
 492                     layer_states2[i] = static_cast<osg::StateSet*>(layer_states[i]->clone(copyOp));
 493                 layer_states[i]->setAttribute(saf ->getCullFaceFront());
 494                 layer_states2[i]->setAttribute(saf ->getCullFaceBack());
 495             }
 496         }
 497 #endif
 498     }
 499
 500     scale = 4000.0;
 501     last_lon = last_lat = -999.0f;
 502
 503     setTextureOffset(base);
 504     // build the cloud layer
 505     const float layer_scale = layer_span / scale;
 506     const float mpi = SG_PI/4;
 507
 508     // caclculate the difference between a flat-earth model and
 509     // a round earth model given the span and altutude ASL of
 510     // the cloud layer. This is the difference in altitude between
 511     // the top of the inverted bowl and the edge of the bowl.
 512     // const float alt_diff = layer_asl * 0.8;
 513     const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 514     const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 515     const float border_to_core = layer_to_core * cos(layer_angle);
 516     const float alt_diff = layer_to_core - border_to_core;
 517
 518     for (int i = 0; i < 4; i++) {
 519       if ( layer[i] != NULL ) {
 520         layer_transform->removeChild(layer[i].get()); // automatic delete
 521       }
 522
 523       vl[i] = new osg::Vec3Array;
 524       cl[i] = new osg::Vec4Array;
 525       tl[i] = new osg::Vec2Array;
 526
 527
 528       osg::Vec3 vertex(layer_span*(i-2)/2, -layer_span,
 529                        alt_diff * (sin(i*mpi) - 2));
 530       osg::Vec2 tc(layer_scale * i/4, 0.0f);
 531       osg::Vec4 color(cloudColors[0], (i == 0) ? 0.0f : 0.15f);
 532
 533       cl[i]->push_back(color);
 534       vl[i]->push_back(vertex);
 535       tl[i]->push_back(tc);
 536
 537       for (int j = 0; j < 4; j++) {
 538         vertex = osg::Vec3(layer_span*(i-1)/2, layer_span*(j-2)/2,
 539                            alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2));
 540         tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale * j/4);
 541         color = osg::Vec4(cloudColors[0],
 542                           ( (j == 0) || (i == 3)) ?
 543                           ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 544
 545         cl[i]->push_back(color);
 546         vl[i]->push_back(vertex);
 547         tl[i]->push_back(tc);
 548
 549         vertex = osg::Vec3(layer_span*(i-2)/2, layer_span*(j-1)/2,
 550                            alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 551         tc = osg::Vec2(layer_scale * i/4, layer_scale * (j+1)/4 );
 552         color = osg::Vec4(cloudColors[0],
 553                           ((j == 3) || (i == 0)) ?
 554                           ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 555         cl[i]->push_back(color);
 556         vl[i]->push_back(vertex);
 557         tl[i]->push_back(tc);
 558       }
 559
 560       vertex = osg::Vec3(layer_span*(i-1)/2, layer_span,
 561                          alt_diff * (sin((i+1)*mpi) - 2));
 562
 563       tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale);
 564
 565       color = osg::Vec4(cloudColors[0], (i == 3) ? 0.0f : 0.15f );
 566
 567       cl[i]->push_back( color );
 568       vl[i]->push_back( vertex );
 569       tl[i]->push_back( tc );
 570
 571       osg::Geometry* geometry = new osg::Geometry;
 572       geometry->setUseDisplayList(false);
 573       geometry->setVertexArray(vl[i].get());
 574       geometry->setNormalBinding(osg::Geometry::BIND_OFF);
 575       geometry->setColorArray(cl[i].get());
 576       geometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
 577       geometry->setTexCoordArray(0, tl[i].get());
 578       geometry->addPrimitiveSet(new osg::DrawArrays(GL_TRIANGLE_STRIP, 0, vl[i]->size()));
 579       layer[i] = new osg::Geode;
 580
 581       std::stringstream sstr;
 582       sstr << "Cloud Layer (" << i << ")";
 583       geometry->setName(sstr.str());
 584       layer[i]->setName(sstr.str());
 585       layer[i]->addDrawable(geometry);
 586       layer_transform->addChild(layer[i].get());
 587     }
 588
 589     //OSGFIXME: true
 590     if ( layer_states[layer_coverage].valid() ) {
 591       osg::CopyOp copyOp;    // shallow copy
 592       // render bin will be set in reposition
 593       osg::StateSet* stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 594       stateSet->setDataVariance(osg::Object::DYNAMIC);
 595       group_top->setStateSet(stateSet);
 596       stateSet = static_cast<osg::StateSet*>(layer_states[layer_coverage]->clone(copyOp));
 597       stateSet->setDataVariance(osg::Object::DYNAMIC);
 598       group_bottom->setStateSet(stateSet);
 599     }
 600 }
 601
 602 // repaint the cloud layer colors
 603 bool SGCloudLayer::repaint( const SGVec3f& fog_color ) {
 604     osg::Vec4f combineColor(toOsg(fog_color), cloud_alpha);
 605     osg::TexEnvCombine* combiner
 606         = dynamic_cast<osg::TexEnvCombine*>(layer_root->getStateSet()
 607                                             ->getTextureAttribute(1, osg::StateAttribute::TEXENV));
 608     combiner->setConstantColor(combineColor);
 609
 610     // Set the fog color for the 3D clouds too.
 611     //cloud3dfog->setColor(combineColor);
 612     return true;
 613 }
 614
 615 // reposition the cloud layer at the specified origin and orientation
 616 // lon specifies a rotation about the Z axis
 617 // lat specifies a rotation about the new Y axis
 618 // spin specifies a rotation about the new Z axis (and orients the
 619 // sunrise/set effects
 620 bool SGCloudLayer::reposition( const SGVec3f& p, const SGVec3f& up, double lon, double lat,
 621                                double alt, double dt )
 622 {
 623     // combine p and asl (meters) to get translation offset
 624     osg::Vec3 asl_offset(toOsg(up));
 625     asl_offset.normalize();
 626     if ( alt <= layer_asl ) {
 627         asl_offset *= layer_asl;
 628     } else {
 629         asl_offset *= layer_asl + layer_thickness;
 630     }
 631
 632     // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 633     //      << "," << asl_offset[2] << endl;
 634     asl_offset += toOsg(p);
 635     // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 636     //      << "," << asl_offset[2] << endl;
 637
 638     osg::Matrix T, LON, LAT;
 639     // Translate to zero elevation
 640     // Point3D zero_elev = current_view.get_cur_zero_elev();
 641     T.makeTranslate( asl_offset );
 642
 643     // printf("  Translated to %.2f %.2f %.2f\n",
 644     //        zero_elev.x, zero_elev.y, zero_elev.z );
 645
 646     // Rotate to proper orientation
 647     // printf("  lon = %.2f  lat = %.2f\n",
 648     //        lon * SGD_RADIANS_TO_DEGREES,
 649     //        lat * SGD_RADIANS_TO_DEGREES);
 650     LON.makeRotate(lon, osg::Vec3(0, 0, 1));
 651
 652     // xglRotatef( 90.0 - f->get_Latitude() * SGD_RADIANS_TO_DEGREES,
 653     //             0.0, 1.0, 0.0 );
 654     LAT.makeRotate(90.0 * SGD_DEGREES_TO_RADIANS - lat, osg::Vec3(0, 1, 0));
 655
 656     layer_transform->setMatrix( LAT*LON*T );
 657
 658     // The layers need to be drawn in order because they are
 659     // translucent, but OSG transparency sorting doesn't work because
 660     // the cloud polys are huge. However, the ordering is simple: the
 661     // bottom polys should be drawn from high altitude to low, and the
 662     // top polygons from low to high. The altitude can be used
 663     // directly to order the polygons!
 664     group_bottom->getStateSet()->setRenderBinDetails(-(int)layer_asl,
 665                                                      "RenderBin");
 666     group_top->getStateSet()->setRenderBinDetails((int)layer_asl,
 667                                                   "RenderBin");
 668     if ( alt <= layer_asl ) {
 669       layer_root->setSingleChildOn(0);
 670     } else if ( alt >= layer_asl + layer_thickness ) {
 671       layer_root->setSingleChildOn(1);
 672     } else {
 673       layer_root->setAllChildrenOff();
 674     }
 675
 676
 677     // now calculate update texture coordinates
 678     if ( last_lon < -900 ) {
 679         last_lon = lon;
 680         last_lat = lat;
 681     }
 682
 683     double sp_dist = speed*dt;
 684
 685     if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
 686         Point3D start( last_lon, last_lat, 0.0 );
 687         Point3D dest( lon, lat, 0.0 );
 688         double course = 0.0, dist = 0.0;
 689
 690         calc_gc_course_dist( dest, start, &course, &dist );
 691         // cout << "course = " << course << ", dist = " << dist << endl;
 692
 693         // if start and dest are too close together,
 694         // calc_gc_course_dist() can return a course of "nan".  If
 695         // this happens, lets just use the last known good course.
 696         // This is a hack, and it would probably be better to make
 697         // calc_gc_course_dist() more robust.
 698         if ( isnan(course) ) {
 699             course = last_course;
 700         } else {
 701             last_course = course;
 702         }
 703
 704         // calculate cloud movement due to external forces
 705         double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 706
 707         if (dist > 0.0) {
 708             ax = cos(course) * dist;
 709             ay = sin(course) * dist;
 710         }
 711
 712         if (sp_dist > 0) {
 713             bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 714             by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 715         }
 716
 717
 718         double xoff = (ax + bx) / (2 * scale);
 719         double yoff = (ay + by) / (2 * scale);
 720
 721 //        const float layer_scale = layer_span / scale;
 722
 723         // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 724         base[0] += xoff;
 725
 726         // the while loops can lead to *long* pauses if base[0] comes
 727         // with a bogus value.
 728         // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 729         // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 730         if ( base[0] > -10.0 && base[0] < 10.0 ) {
 731             base[0] -= (int)base[0];
 732         } else {
 733             SG_LOG(SG_ASTRO, SG_DEBUG,
 734                 "Error: base = " << base[0] << "," << base[1] <<
 735                 " course = " << course << " dist = " << dist );
 736             base[0] = 0.0;
 737         }
 738
 739         base[1] += yoff;
 740         // the while loops can lead to *long* pauses if base[0] comes
 741         // with a bogus value.
 742         // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 743         // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 744         if ( base[1] > -10.0 && base[1] < 10.0 ) {
 745             base[1] -= (int)base[1];
 746         } else {
 747             SG_LOG(SG_ASTRO, SG_DEBUG,
 748                     "Error: base = " << base[0] << "," << base[1] <<
 749                     " course = " << course << " dist = " << dist );
 750             base[1] = 0.0;
 751         }
 752
 753         // cout << "base = " << base[0] << "," << base[1] << endl;
 754
 755         setTextureOffset(base);
 756         last_lon = lon;
 757         last_lat = lat;
 758     }
 759
 760     layer3D->reposition( p, up, lon, lat, dt, layer_asl);
 761     return true;
 762 }
 763
 764 void SGCloudLayer::set_enable3dClouds(bool enable) {
 765
 766     if (layer3D->defined3D && enable) {
 767         cloud_root->setChildValue(layer3D->getNode(), true);
 768         cloud_root->setChildValue(layer_root.get(),   false);
 769     } else {
 770         cloud_root->setChildValue(layer3D->getNode(), false);
 771         cloud_root->setChildValue(layer_root.get(),   true);
 772     }
 773 }