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