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
  58 #include "newcloud.hxx"
  59 #include "cloudfield.hxx"
  60 #include "cloud.hxx"
  61
  62 using namespace simgear;
  63 using namespace osg;
  64
  65 #if defined(__MINGW32__)
  66 #define isnan(x) _isnan(x)
  67 #endif
  68
  69 // #if defined (__FreeBSD__)
  70 // #  if __FreeBSD_version < 500000
  71 //      extern "C" {
  72 //        inline int isnan(double r) { return !(r <= 0 || r >= 0); }
  73 //      }
  74 // #  endif
  75 // #endif
  76
  77 static osg::ref_ptr<osg::StateSet> layer_states[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  78 static osg::ref_ptr<osg::StateSet> layer_states2[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  79 static osg::ref_ptr<osg::TextureCubeMap> cubeMap;
  80 static bool state_initialized = false;
  81 static bool bump_mapping = false;
  82
  83 bool SGCloudLayer::enable_bump_mapping = false;
  84
  85 // make an StateSet for a cloud layer given the named texture
  86 static osg::StateSet*
  87 SGMakeState(const SGPath &path, const char* colorTexture,
  88             const char* normalTexture)
  89 {
  90     osg::StateSet *stateSet = new osg::StateSet;
  91
  92     osg::ref_ptr<osgDB::ReaderWriter::Options> options
  93         = makeOptionsFromPath(path);
  94     stateSet->setTextureAttribute(0, SGLoadTexture2D(colorTexture,
  95                                                      options.get()));
  96     stateSet->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
  97     StateAttributeFactory* attribFactory = StateAttributeFactory::instance();
  98     stateSet->setAttributeAndModes(attribFactory->getSmoothShadeModel());
  99     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
 100     stateSet->setAttributeAndModes(attribFactory->getStandardAlphaFunc());
 101     stateSet->setAttributeAndModes(attribFactory->getStandardBlendFunc());
 102
 103 //     osg::Material* material = new osg::Material;
 104 //     material->setColorMode(osg::Material::AMBIENT_AND_DIFFUSE);
 105 //     material->setEmission(osg::Material::FRONT_AND_BACK,
 106 //                           osg::Vec4(0.05, 0.05, 0.05, 0));
 107 //     material->setSpecular(osg::Material::FRONT_AND_BACK,
 108 //                           osg::Vec4(0, 0, 0, 1));
 109 //     stateSet->setAttribute(material);
 110
 111     stateSet->setMode(GL_FOG, osg::StateAttribute::OFF);
 112
 113     // OSGFIXME: invented by me ...
 114 //     stateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
 115 //     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::ON);
 116
 117 //     stateSet->setMode(GL_LIGHT0, osg::StateAttribute::OFF);
 118
 119     // If the normal texture is given prepare a bumpmapping enabled state
 120 //     if (normalTexture) {
 121 //       SGPath normalPath(path);
 122 //       normalPath.append(normalTexture);
 123 //       stateSet->setTextureAttribute(2, SGLoadTexture2D(normalPath));
 124 //       stateSet->setTextureMode(2, GL_TEXTURE_2D, osg::StateAttribute::ON);
 125 //     }
 126
 127     return stateSet;
 128 }
 129
 130 // Constructor
 131 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
 132     cloud_root(new osg::Switch),
 133     layer_root(new osg::Switch),
 134     group_top(new osg::Group),
 135     group_bottom(new osg::Group),
 136     layer_transform(new osg::MatrixTransform),
 137     cloud_alpha(1.0),
 138     texture_path(tex_path),
 139     layer_span(0.0),
 140     layer_asl(0.0),
 141     layer_thickness(0.0),
 142     layer_transition(0.0),
 143     layer_coverage(SG_CLOUD_CLEAR),
 144     scale(4000.0),
 145     speed(0.0),
 146     direction(0.0)
 147 {
 148     // XXX
 149     // Render bottoms before the rest of transparent objects (rendered
 150     // in bin 10), tops after. The negative numbers on the bottoms
 151     // RenderBins and the positive numbers on the tops enforce this
 152     // order.
 153   cloud_root->addChild(layer_root.get(), true);
 154   layer_root->addChild(group_bottom.get());
 155   layer_root->addChild(group_top.get());
 156   osg::StateSet *rootSet = layer_root->getOrCreateStateSet();
 157   rootSet->setRenderBinDetails(CLOUDS_BIN, "DepthSortedBin");
 158   rootSet->setTextureAttribute(0, new osg::TexMat);
 159   rootSet->setMode(GL_CULL_FACE, osg::StateAttribute::ON);
 160   // Combiner for fog color and cloud alpha
 161   osg::TexEnvCombine* combine0 = new osg::TexEnvCombine;
 162   osg::TexEnvCombine* combine1 = new osg::TexEnvCombine;
 163   combine0->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 164   combine0->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 165   combine0->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 166   combine0->setSource1_RGB(osg::TexEnvCombine::TEXTURE0);
 167   combine0->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 168   combine0->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 169   combine0->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 170   combine0->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 171   combine0->setSource1_Alpha(osg::TexEnvCombine::TEXTURE0);
 172   combine0->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 173
 174   combine1->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 175   combine1->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 176   combine1->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 177   combine1->setSource1_RGB(osg::TexEnvCombine::CONSTANT);
 178   combine1->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 179   combine1->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 180   combine1->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 181   combine1->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 182   combine1->setSource1_Alpha(osg::TexEnvCombine::CONSTANT);
 183   combine1->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 184   combine1->setDataVariance(osg::Object::DYNAMIC);
 185   rootSet->setTextureAttributeAndModes(0, combine0);
 186   rootSet->setTextureAttributeAndModes(1, combine1);
 187   rootSet->setTextureMode(1, GL_TEXTURE_2D, osg::StateAttribute::ON);
 188   rootSet->setTextureAttributeAndModes(1, StateAttributeFactory::instance()
 189                                        ->getWhiteTexture(),
 190                                        osg::StateAttribute::ON);
 191   rootSet->setDataVariance(osg::Object::DYNAMIC);
 192
 193   base = osg::Vec2(sg_random(), sg_random());
 194   group_top->addChild(layer_transform.get());
 195   group_bottom->addChild(layer_transform.get());
 196
 197   layer3D = new SGCloudField();
 198   cloud_root->addChild(layer3D->getNode(), false);
 199
 200   rebuild();
 201 }
 202
 203 // Destructor
 204 SGCloudLayer::~SGCloudLayer()
 205 {
 206   delete layer3D;
 207 }
 208
 209 float
 210 SGCloudLayer::getSpan_m () const
 211 {
 212     return layer_span;
 213 }
 214
 215 void
 216 SGCloudLayer::setSpan_m (float span_m)
 217 {
 218     if (span_m != layer_span) {
 219         layer_span = span_m;
 220         rebuild();
 221     }
 222 }
 223
 224 float
 225 SGCloudLayer::getElevation_m () const
 226 {
 227     return layer_asl;
 228 }
 229
 230 void
 231 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 232 {
 233     layer_asl = elevation_m;
 234
 235     if (set_span) {
 236         if (elevation_m > 4000)
 237             setSpan_m(  elevation_m * 10 );
 238         else
 239             setSpan_m( 40000 );
 240     }
 241 }
 242
 243 float
 244 SGCloudLayer::getThickness_m () const
 245 {
 246     return layer_thickness;
 247 }
 248
 249 void
 250 SGCloudLayer::setThickness_m (float thickness_m)
 251 {
 252     layer_thickness = thickness_m;
 253 }
 254
 255 float
 256 SGCloudLayer::getTransition_m () const
 257 {
 258     return layer_transition;
 259 }
 260
 261 void
 262 SGCloudLayer::setTransition_m (float transition_m)
 263 {
 264     layer_transition = transition_m;
 265 }
 266
 267 SGCloudLayer::Coverage
 268 SGCloudLayer::getCoverage () const
 269 {
 270     return layer_coverage;
 271 }
 272
 273 void
 274 SGCloudLayer::setCoverage (Coverage coverage)
 275 {
 276     if (coverage != layer_coverage) {
 277         layer_coverage = coverage;
 278         rebuild();
 279
 280         double coverage_norm = 0.0;
 281         if( coverage ==  SG_CLOUD_FEW)
 282             coverage_norm = 2.0/8.0;    // <1-2
 283         else if( coverage == SG_CLOUD_SCATTERED )
 284             coverage_norm = 4.0/8.0;    // 3-4
 285         else if( coverage == SG_CLOUD_BROKEN )
 286             coverage_norm = 6.0/8.0;    // 5-7
 287         else if( coverage == SG_CLOUD_OVERCAST )
 288             coverage_norm = 8.0/8.0;    // 8
 289
 290         layer3D->setCoverage(coverage_norm);
 291         layer3D->applyCoverage();
 292     }
 293 }
 294
 295 void
 296 SGCloudLayer::setTextureOffset(const osg::Vec2& offset)
 297 {
 298     osg::StateAttribute* attr = layer_root->getStateSet()
 299         ->getTextureAttribute(0, osg::StateAttribute::TEXMAT);
 300     osg::TexMat* texMat = dynamic_cast<osg::TexMat*>(attr);
 301     if (!texMat)
 302         return;
 303     texMat->setMatrix(osg::Matrix::translate(offset[0], offset[1], 0.0));
 304 }
 305
 306 // colors for debugging the cloud layers
 307 #ifdef CLOUD_DEBUG
 308 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 0.0f, 0.0f),
 309                       Vec3(0.0f, 1.0f, 0.0f), Vec3(0.0f, 0.0f, 1.0f)};
 310 #else
 311 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f),
 312                       Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f)};
 313 #endif
 314
 315 // build the cloud object
 316 void
 317 SGCloudLayer::rebuild()
 318 {
 319     // Initialize states and sizes if necessary.
 320     if ( !state_initialized ) {
 321         state_initialized = true;
 322
 323         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 324
 325         osg::Texture::Extensions* extensions;
 326         extensions = osg::Texture::getExtensions(0, true);
 327         // OSGFIXME
 328         bump_mapping = extensions->isMultiTexturingSupported() &&
 329           (2 <= extensions->numTextureUnits()) &&
 330           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_combine") &&
 331           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_dot3");
 332
 333         osg::TextureCubeMap::Extensions* extensions2;
 334         extensions2 = osg::TextureCubeMap::getExtensions(0, true);
 335         bump_mapping = bump_mapping && extensions2->isCubeMapSupported();
 336
 337         // This bump mapping code was inspired by the tutorial available at
 338         // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 339         // and a NVidia white paper
 340         //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 341         // The normal map textures were generated by the normal map Gimp plugin :
 342         //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 343         //
 344         cubeMap = new osg::TextureCubeMap;
 345         cubeMap->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
 346         cubeMap->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
 347         cubeMap->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
 348         cubeMap->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE);
 349         cubeMap->setWrap(osg::Texture::WRAP_R, osg::Texture::CLAMP_TO_EDGE);
 350
 351         const int size = 32;
 352         const float half_size = 16.0f;
 353         const float offset = 0.5f;
 354         osg::Vec3 zero_normal(0.5, 0.5, 0.5);
 355
 356         osg::Image* image = new osg::Image;
 357         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 358         unsigned char *ptr = image->data(0, 0);
 359         for (int j = 0; j < size; j++ ) {
 360           for (int i = 0; i < size; i++ ) {
 361             osg::Vec3 tmp(half_size, -( j + offset - half_size ),
 362                           -( i + offset - half_size ) );
 363             tmp.normalize();
 364             tmp = tmp*0.5 - zero_normal;
 365
 366             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 367             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 368             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 369           }
 370         }
 371         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_X, image);
 372
 373         image = new osg::Image;
 374         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 375         ptr = image->data(0, 0);
 376         for (int j = 0; j < size; j++ ) {
 377           for (int i = 0; i < size; i++ ) {
 378             osg::Vec3 tmp(-half_size, -( j + offset - half_size ),
 379                           ( i + offset - half_size ) );
 380             tmp.normalize();
 381             tmp = tmp*0.5 - zero_normal;
 382
 383             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 384             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 385             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 386           }
 387         }
 388         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_X, image);
 389
 390         image = new osg::Image;
 391         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 392         ptr = image->data(0, 0);
 393         for (int j = 0; j < size; j++ ) {
 394           for (int i = 0; i < size; i++ ) {
 395             osg::Vec3 tmp(( i + offset - half_size ), half_size,
 396                           ( j + offset - half_size ) );
 397             tmp.normalize();
 398             tmp = tmp*0.5 - zero_normal;
 399
 400             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 401             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 402             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 403           }
 404         }
 405         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Y, image);
 406
 407         image = new osg::Image;
 408         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 409         ptr = image->data(0, 0);
 410         for (int j = 0; j < size; j++ ) {
 411           for (int i = 0; i < size; i++ ) {
 412             osg::Vec3 tmp(( i + offset - half_size ), -half_size,
 413                           -( j + offset - half_size ) );
 414             tmp.normalize();
 415             tmp = tmp*0.5 - zero_normal;
 416
 417             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 418             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 419             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 420           }
 421         }
 422         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Y, image);
 423
 424         image = new osg::Image;
 425         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 426         ptr = image->data(0, 0);
 427         for (int j = 0; j < size; j++ ) {
 428           for (int i = 0; i < size; i++ ) {
 429             osg::Vec3 tmp(( i + offset - half_size ),
 430                           -( j + offset - half_size ), half_size );
 431             tmp.normalize();
 432             tmp = tmp*0.5 - zero_normal;
 433
 434             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 435             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 436             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 437           }
 438         }
 439         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Z, image);
 440
 441         image = new osg::Image;
 442         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 443         ptr = image->data(0, 0);
 444         for (int j = 0; j < size; j++ ) {
 445           for (int i = 0; i < size; i++ ) {
 446             osg::Vec3 tmp(-( i + offset - half_size ),
 447                           -( j + offset - half_size ), -half_size );
 448             tmp.normalize();
 449             tmp = tmp*0.5 - zero_normal;
 450             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 451             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 452             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 453           }
 454         }
 455         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Z, image);
 456
 457         osg::StateSet* state;
 458         state = SGMakeState(texture_path, "overcast.png", "overcast_n.png");
 459         layer_states[SG_CLOUD_OVERCAST] = state;
 460         state = SGMakeState(texture_path, "overcast_top.png", "overcast_top_n.png");
 461         layer_states2[SG_CLOUD_OVERCAST] = state;
 462
 463         state = SGMakeState(texture_path, "broken.png", "broken_n.png");
 464         layer_states[SG_CLOUD_BROKEN] = state;
 465         layer_states2[SG_CLOUD_BROKEN] = state;
 466
 467         state = SGMakeState(texture_path, "scattered.png", "scattered_n.png");
 468         layer_states[SG_CLOUD_SCATTERED] = state;
 469         layer_states2[SG_CLOUD_SCATTERED] = state;
 470
 471         state = SGMakeState(texture_path, "few.png", "few_n.png");
 472         layer_states[SG_CLOUD_FEW] = state;
 473         layer_states2[SG_CLOUD_FEW] = state;
 474
 475         state = SGMakeState(texture_path, "cirrus.png", "cirrus_n.png");
 476         layer_states[SG_CLOUD_CIRRUS] = state;
 477         layer_states2[SG_CLOUD_CIRRUS] = state;
 478
 479         layer_states[SG_CLOUD_CLEAR] = 0;
 480         layer_states2[SG_CLOUD_CLEAR] = 0;
 481 #if 1
 482         // experimental optimization that may not make any difference
 483         // at all :/
 484         osg::CopyOp copyOp;
 485         for (int i = 0; i < SG_MAX_CLOUD_COVERAGES; ++i) {
 486             StateAttributeFactory *saf = StateAttributeFactory::instance();
 487             if (layer_states[i].valid()) {
 488                 if (layer_states[i] == layer_states2[i])
 489                     layer_states2[i] = static_cast<osg::StateSet*>(layer_states[i]->clone(copyOp));
 490                 layer_states[i]->setAttribute(saf ->getCullFaceFront());
 491                 layer_states2[i]->setAttribute(saf ->getCullFaceBack());
 492             }
 493         }
 494 #endif
 495     }
 496
 497     scale = 4000.0;
 498
 499     setTextureOffset(base);
 500     // build the cloud layer
 501     const float layer_scale = layer_span / scale;
 502     const float mpi = SG_PI/4;
 503
 504     // caclculate the difference between a flat-earth model and
 505     // a round earth model given the span and altutude ASL of
 506     // the cloud layer. This is the difference in altitude between
 507     // the top of the inverted bowl and the edge of the bowl.
 508     // const float alt_diff = layer_asl * 0.8;
 509     const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 510     const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 511     const float border_to_core = layer_to_core * cos(layer_angle);
 512     const float alt_diff = layer_to_core - border_to_core;
 513
 514     for (int i = 0; i < 4; i++) {
 515       if ( layer[i] != NULL ) {
 516         layer_transform->removeChild(layer[i].get()); // automatic delete
 517       }
 518
 519       vl[i] = new osg::Vec3Array;
 520       cl[i] = new osg::Vec4Array;
 521       tl[i] = new osg::Vec2Array;
 522
 523
 524       osg::Vec3 vertex(layer_span*(i-2)/2, -layer_span,
 525                        alt_diff * (sin(i*mpi) - 2));
 526       osg::Vec2 tc(layer_scale * i/4, 0.0f);
 527       osg::Vec4 color(cloudColors[0], (i == 0) ? 0.0f : 0.15f);
 528
 529       cl[i]->push_back(color);
 530       vl[i]->push_back(vertex);
 531       tl[i]->push_back(tc);
 532
 533       for (int j = 0; j < 4; j++) {
 534         vertex = osg::Vec3(layer_span*(i-1)/2, layer_span*(j-2)/2,
 535                            alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2));
 536         tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale * j/4);
 537         color = osg::Vec4(cloudColors[0],
 538                           ( (j == 0) || (i == 3)) ?
 539                           ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 540
 541         cl[i]->push_back(color);
 542         vl[i]->push_back(vertex);
 543         tl[i]->push_back(tc);
 544
 545         vertex = osg::Vec3(layer_span*(i-2)/2, layer_span*(j-1)/2,
 546                            alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 547         tc = osg::Vec2(layer_scale * i/4, layer_scale * (j+1)/4 );
 548         color = osg::Vec4(cloudColors[0],
 549                           ((j == 3) || (i == 0)) ?
 550                           ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 551         cl[i]->push_back(color);
 552         vl[i]->push_back(vertex);
 553         tl[i]->push_back(tc);
 554       }
 555
 556       vertex = osg::Vec3(layer_span*(i-1)/2, layer_span,
 557                          alt_diff * (sin((i+1)*mpi) - 2));
 558
 559       tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale);
 560
 561       color = osg::Vec4(cloudColors[0], (i == 3) ? 0.0f : 0.15f );
 562
 563       cl[i]->push_back( color );
 564       vl[i]->push_back( vertex );
 565       tl[i]->push_back( tc );
 566
 567       osg::Geometry* geometry = new osg::Geometry;
 568       geometry->setUseDisplayList(false);
 569       geometry->setVertexArray(vl[i].get());
 570       geometry->setNormalBinding(osg::Geometry::BIND_OFF);
 571       geometry->setColorArray(cl[i].get());
 572       geometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
 573       geometry->setTexCoordArray(0, tl[i].get());
 574       geometry->addPrimitiveSet(new osg::DrawArrays(GL_TRIANGLE_STRIP, 0, vl[i]->size()));
 575       layer[i] = new osg::Geode;
 576
 577       std::stringstream sstr;
 578       sstr << "Cloud Layer (" << i << ")";
 579       geometry->setName(sstr.str());
 580       layer[i]->setName(sstr.str());
 581       layer[i]->addDrawable(geometry);
 582       layer_transform->addChild(layer[i].get());
 583     }
 584
 585     //OSGFIXME: true
 586     if ( layer_states[layer_coverage].valid() ) {
 587       osg::CopyOp copyOp;    // shallow copy
 588       // render bin will be set in reposition
 589       osg::StateSet* stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 590       stateSet->setDataVariance(osg::Object::DYNAMIC);
 591       group_top->setStateSet(stateSet);
 592       stateSet = static_cast<osg::StateSet*>(layer_states[layer_coverage]->clone(copyOp));
 593       stateSet->setDataVariance(osg::Object::DYNAMIC);
 594       group_bottom->setStateSet(stateSet);
 595     }
 596 }
 597
 598 // repaint the cloud layer colors
 599 bool SGCloudLayer::repaint( const SGVec3f& fog_color ) {
 600     osg::Vec4f combineColor(toOsg(fog_color), cloud_alpha);
 601     osg::TexEnvCombine* combiner
 602         = dynamic_cast<osg::TexEnvCombine*>(layer_root->getStateSet()
 603                                             ->getTextureAttribute(1, osg::StateAttribute::TEXENV));
 604     combiner->setConstantColor(combineColor);
 605
 606     // Set the fog color for the 3D clouds too.
 607     //cloud3dfog->setColor(combineColor);
 608     return true;
 609 }
 610
 611 // reposition the cloud layer at the specified origin and orientation
 612 // lon specifies a rotation about the Z axis
 613 // lat specifies a rotation about the new Y axis
 614 // spin specifies a rotation about the new Z axis (and orients the
 615 // sunrise/set effects
 616 bool SGCloudLayer::reposition( const SGVec3f& p, const SGVec3f& up, double lon, double lat,
 617                                double alt, double dt )
 618 {
 619     // combine p and asl (meters) to get translation offset
 620     osg::Vec3 asl_offset(toOsg(up));
 621     asl_offset.normalize();
 622     if ( alt <= layer_asl ) {
 623         asl_offset *= layer_asl;
 624     } else {
 625         asl_offset *= layer_asl + layer_thickness;
 626     }
 627
 628     // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 629     //      << "," << asl_offset[2] << endl;
 630     asl_offset += toOsg(p);
 631     // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 632     //      << "," << asl_offset[2] << endl;
 633
 634     osg::Matrix T, LON, LAT;
 635     // Translate to zero elevation
 636     // Point3D zero_elev = current_view.get_cur_zero_elev();
 637     T.makeTranslate( asl_offset );
 638
 639     // printf("  Translated to %.2f %.2f %.2f\n",
 640     //        zero_elev.x, zero_elev.y, zero_elev.z );
 641
 642     // Rotate to proper orientation
 643     // printf("  lon = %.2f  lat = %.2f\n",
 644     //        lon * SGD_RADIANS_TO_DEGREES,
 645     //        lat * SGD_RADIANS_TO_DEGREES);
 646     LON.makeRotate(lon, osg::Vec3(0, 0, 1));
 647
 648     // xglRotatef( 90.0 - f->get_Latitude() * SGD_RADIANS_TO_DEGREES,
 649     //             0.0, 1.0, 0.0 );
 650     LAT.makeRotate(90.0 * SGD_DEGREES_TO_RADIANS - lat, osg::Vec3(0, 1, 0));
 651
 652     layer_transform->setMatrix( LAT*LON*T );
 653
 654     // The layers need to be drawn in order because they are
 655     // translucent, but OSG transparency sorting doesn't work because
 656     // the cloud polys are huge. However, the ordering is simple: the
 657     // bottom polys should be drawn from high altitude to low, and the
 658     // top polygons from low to high. The altitude can be used
 659     // directly to order the polygons!
 660     group_bottom->getStateSet()->setRenderBinDetails(-(int)layer_asl,
 661                                                      "RenderBin");
 662     group_top->getStateSet()->setRenderBinDetails((int)layer_asl,
 663                                                   "RenderBin");
 664     if ( alt <= layer_asl ) {
 665       layer_root->setSingleChildOn(0);
 666     } else if ( alt >= layer_asl + layer_thickness ) {
 667       layer_root->setSingleChildOn(1);
 668     } else {
 669       layer_root->setAllChildrenOff();
 670     }
 671
 672
 673     // now calculate update texture coordinates
 674     SGGeod pos = SGGeod::fromRad(lon, lat);
 675     if ( last_pos == SGGeod() ) {
 676         last_pos = pos;
 677     }
 678
 679     double sp_dist = speed*dt;
 680
 681
 682     if ( lon != last_pos.getLongitudeRad() || lat != last_pos.getLatitudeRad() || sp_dist != 0 ) {
 683         double course = SGGeodesy::courseDeg(last_pos, pos) * SG_DEGREES_TO_RADIANS,
 684             dist = SGGeodesy::distanceM(last_pos, pos);
 685
 686         // if start and dest are too close together,
 687         // calc_gc_course_dist() can return a course of "nan".  If
 688         // this happens, lets just use the last known good course.
 689         // This is a hack, and it would probably be better to make
 690         // calc_gc_course_dist() more robust.
 691         if ( isnan(course) ) {
 692             course = last_course;
 693         } else {
 694             last_course = course;
 695         }
 696
 697         // calculate cloud movement due to external forces
 698         double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 699
 700         if (dist > 0.0) {
 701             ax = cos(course) * dist;
 702             ay = sin(course) * dist;
 703         }
 704
 705         if (sp_dist > 0) {
 706             bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 707             by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 708         }
 709
 710
 711         double xoff = (ax + bx) / (2 * scale);
 712         double yoff = (ay + by) / (2 * scale);
 713
 714 //        const float layer_scale = layer_span / scale;
 715
 716         // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 717         base[0] += xoff;
 718
 719         // the while loops can lead to *long* pauses if base[0] comes
 720         // with a bogus value.
 721         // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 722         // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 723         if ( base[0] > -10.0 && base[0] < 10.0 ) {
 724             base[0] -= (int)base[0];
 725         } else {
 726             SG_LOG(SG_ASTRO, SG_DEBUG,
 727                 "Error: base = " << base[0] << "," << base[1] <<
 728                 " course = " << course << " dist = " << dist );
 729             base[0] = 0.0;
 730         }
 731
 732         base[1] += yoff;
 733         // the while loops can lead to *long* pauses if base[0] comes
 734         // with a bogus value.
 735         // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 736         // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 737         if ( base[1] > -10.0 && base[1] < 10.0 ) {
 738             base[1] -= (int)base[1];
 739         } else {
 740             SG_LOG(SG_ASTRO, SG_DEBUG,
 741                     "Error: base = " << base[0] << "," << base[1] <<
 742                     " course = " << course << " dist = " << dist );
 743             base[1] = 0.0;
 744         }
 745
 746         // cout << "base = " << base[0] << "," << base[1] << endl;
 747
 748         setTextureOffset(base);
 749         last_pos = pos;
 750     }
 751
 752     layer3D->reposition( p, up, lon, lat, dt, layer_asl);
 753     return true;
 754 }
 755
 756 void SGCloudLayer::set_enable3dClouds(bool enable) {
 757
 758     if (layer3D->defined3D && enable) {
 759         cloud_root->setChildValue(layer3D->getNode(), true);
 760         cloud_root->setChildValue(layer_root.get(),   false);
 761     } else {
 762         cloud_root->setChildValue(layer3D->getNode(), false);
 763         cloud_root->setChildValue(layer_root.get(),   true);
 764     }
 765 }