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 #if defined (__CYGWIN__)
  79 #include <ieeefp.h>
  80 #endif
  81
  82 static osg::ref_ptr<osg::StateSet> layer_states[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  83 static osg::ref_ptr<osg::StateSet> layer_states2[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  84 static osg::ref_ptr<osg::TextureCubeMap> cubeMap;
  85 static bool state_initialized = false;
  86 static bool bump_mapping = false;
  87
  88 bool SGCloudLayer::enable_bump_mapping = false;
  89
  90 // make an StateSet for a cloud layer given the named texture
  91 static osg::StateSet*
  92 SGMakeState(const SGPath &path, const char* colorTexture,
  93             const char* normalTexture)
  94 {
  95     osg::StateSet *stateSet = new osg::StateSet;
  96
  97     osg::ref_ptr<osgDB::ReaderWriter::Options> options
  98         = makeOptionsFromPath(path);
  99     stateSet->setTextureAttribute(0, SGLoadTexture2D(colorTexture,
 100                                                      options.get()));
 101     stateSet->setTextureMode(0, GL_TEXTURE_2D, osg::StateAttribute::ON);
 102     StateAttributeFactory* attribFactory = StateAttributeFactory::instance();
 103     stateSet->setAttributeAndModes(attribFactory->getSmoothShadeModel());
 104     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
 105     stateSet->setAttributeAndModes(attribFactory->getStandardAlphaFunc());
 106     stateSet->setAttributeAndModes(attribFactory->getStandardBlendFunc());
 107
 108 //     osg::Material* material = new osg::Material;
 109 //     material->setColorMode(osg::Material::AMBIENT_AND_DIFFUSE);
 110 //     material->setEmission(osg::Material::FRONT_AND_BACK,
 111 //                           osg::Vec4(0.05, 0.05, 0.05, 0));
 112 //     material->setSpecular(osg::Material::FRONT_AND_BACK,
 113 //                           osg::Vec4(0, 0, 0, 1));
 114 //     stateSet->setAttribute(material);
 115
 116     stateSet->setMode(GL_FOG, osg::StateAttribute::OFF);
 117
 118     // OSGFIXME: invented by me ...
 119 //     stateSet->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
 120 //     stateSet->setMode(GL_LIGHTING, osg::StateAttribute::ON);
 121
 122 //     stateSet->setMode(GL_LIGHT0, osg::StateAttribute::OFF);
 123
 124     // If the normal texture is given prepare a bumpmapping enabled state
 125 //     if (normalTexture) {
 126 //       SGPath normalPath(path);
 127 //       normalPath.append(normalTexture);
 128 //       stateSet->setTextureAttribute(2, SGLoadTexture2D(normalPath));
 129 //       stateSet->setTextureMode(2, GL_TEXTURE_2D, osg::StateAttribute::ON);
 130 //     }
 131
 132     return stateSet;
 133 }
 134
 135 // Constructor
 136 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
 137     cloud_root(new osg::Switch),
 138     layer_root(new osg::Switch),
 139     group_top(new osg::Group),
 140     group_bottom(new osg::Group),
 141     layer_transform(new osg::MatrixTransform),
 142     cloud_alpha(1.0),
 143     texture_path(tex_path),
 144     layer_span(0.0),
 145     layer_asl(0.0),
 146     layer_thickness(0.0),
 147     layer_transition(0.0),
 148     layer_coverage(SG_CLOUD_CLEAR),
 149     scale(4000.0),
 150     speed(0.0),
 151     direction(0.0),
 152     last_lon(0.0),
 153     last_lat(0.0)
 154 {
 155     // XXX
 156     // Render bottoms before the rest of transparent objects (rendered
 157     // in bin 10), tops after. The negative numbers on the bottoms
 158     // RenderBins and the positive numbers on the tops enforce this
 159     // order.
 160   cloud_root->addChild(layer_root.get(), true);
 161   layer_root->addChild(group_bottom.get());
 162   layer_root->addChild(group_top.get());
 163   osg::StateSet *rootSet = layer_root->getOrCreateStateSet();
 164   rootSet->setRenderBinDetails(CLOUDS_BIN, "DepthSortedBin");
 165   rootSet->setTextureAttribute(0, new osg::TexMat);
 166   rootSet->setMode(GL_CULL_FACE, osg::StateAttribute::ON);
 167   // Combiner for fog color and cloud alpha
 168   osg::TexEnvCombine* combine0 = new osg::TexEnvCombine;
 169   osg::TexEnvCombine* combine1 = new osg::TexEnvCombine;
 170   combine0->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 171   combine0->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 172   combine0->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 173   combine0->setSource1_RGB(osg::TexEnvCombine::TEXTURE0);
 174   combine0->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 175   combine0->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 176   combine0->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 177   combine0->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 178   combine0->setSource1_Alpha(osg::TexEnvCombine::TEXTURE0);
 179   combine0->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 180
 181   combine1->setCombine_RGB(osg::TexEnvCombine::MODULATE);
 182   combine1->setSource0_RGB(osg::TexEnvCombine::PREVIOUS);
 183   combine1->setOperand0_RGB(osg::TexEnvCombine::SRC_COLOR);
 184   combine1->setSource1_RGB(osg::TexEnvCombine::CONSTANT);
 185   combine1->setOperand1_RGB(osg::TexEnvCombine::SRC_COLOR);
 186   combine1->setCombine_Alpha(osg::TexEnvCombine::MODULATE);
 187   combine1->setSource0_Alpha(osg::TexEnvCombine::PREVIOUS);
 188   combine1->setOperand0_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 189   combine1->setSource1_Alpha(osg::TexEnvCombine::CONSTANT);
 190   combine1->setOperand1_Alpha(osg::TexEnvCombine::SRC_ALPHA);
 191   combine1->setDataVariance(osg::Object::DYNAMIC);
 192   rootSet->setTextureAttributeAndModes(0, combine0);
 193   rootSet->setTextureAttributeAndModes(1, combine1);
 194   rootSet->setTextureMode(1, GL_TEXTURE_2D, osg::StateAttribute::ON);
 195   rootSet->setTextureAttributeAndModes(1, StateAttributeFactory::instance()
 196                                        ->getWhiteTexture(),
 197                                        osg::StateAttribute::ON);
 198   rootSet->setDataVariance(osg::Object::DYNAMIC);
 199
 200   base = osg::Vec2(sg_random(), sg_random());
 201   group_top->addChild(layer_transform.get());
 202   group_bottom->addChild(layer_transform.get());
 203
 204   layer3D = new SGCloudField();
 205   cloud_root->addChild(layer3D->getNode(), false);
 206
 207   rebuild();
 208 }
 209
 210 // Destructor
 211 SGCloudLayer::~SGCloudLayer()
 212 {
 213   delete layer3D;
 214 }
 215
 216 float
 217 SGCloudLayer::getSpan_m () const
 218 {
 219     return layer_span;
 220 }
 221
 222 void
 223 SGCloudLayer::setSpan_m (float span_m)
 224 {
 225     if (span_m != layer_span) {
 226         layer_span = span_m;
 227         rebuild();
 228     }
 229 }
 230
 231 float
 232 SGCloudLayer::getElevation_m () const
 233 {
 234     return layer_asl;
 235 }
 236
 237 void
 238 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 239 {
 240     layer_asl = elevation_m;
 241
 242     if (set_span) {
 243         if (elevation_m > 4000)
 244             setSpan_m(  elevation_m * 10 );
 245         else
 246             setSpan_m( 40000 );
 247     }
 248 }
 249
 250 float
 251 SGCloudLayer::getThickness_m () const
 252 {
 253     return layer_thickness;
 254 }
 255
 256 void
 257 SGCloudLayer::setThickness_m (float thickness_m)
 258 {
 259     layer_thickness = thickness_m;
 260 }
 261
 262 float
 263 SGCloudLayer::getTransition_m () const
 264 {
 265     return layer_transition;
 266 }
 267
 268 void
 269 SGCloudLayer::setTransition_m (float transition_m)
 270 {
 271     layer_transition = transition_m;
 272 }
 273
 274 SGCloudLayer::Coverage
 275 SGCloudLayer::getCoverage () const
 276 {
 277     return layer_coverage;
 278 }
 279
 280 void
 281 SGCloudLayer::setCoverage (Coverage coverage)
 282 {
 283     if (coverage != layer_coverage) {
 284         layer_coverage = coverage;
 285         rebuild();
 286
 287         double coverage_norm = 0.0;
 288         if( coverage ==  SG_CLOUD_FEW)
 289             coverage_norm = 2.0/8.0;    // <1-2
 290         else if( coverage == SG_CLOUD_SCATTERED )
 291             coverage_norm = 4.0/8.0;    // 3-4
 292         else if( coverage == SG_CLOUD_BROKEN )
 293             coverage_norm = 6.0/8.0;    // 5-7
 294         else if( coverage == SG_CLOUD_OVERCAST )
 295             coverage_norm = 8.0/8.0;    // 8
 296
 297         layer3D->setCoverage(coverage_norm);
 298         layer3D->applyCoverage();
 299     }
 300 }
 301
 302 void
 303 SGCloudLayer::setTextureOffset(const osg::Vec2& offset)
 304 {
 305     osg::StateAttribute* attr = layer_root->getStateSet()
 306         ->getTextureAttribute(0, osg::StateAttribute::TEXMAT);
 307     osg::TexMat* texMat = dynamic_cast<osg::TexMat*>(attr);
 308     if (!texMat)
 309         return;
 310     texMat->setMatrix(osg::Matrix::translate(offset[0], offset[1], 0.0));
 311 }
 312
 313 // colors for debugging the cloud layers
 314 #ifdef CLOUD_DEBUG
 315 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 0.0f, 0.0f),
 316                       Vec3(0.0f, 1.0f, 0.0f), Vec3(0.0f, 0.0f, 1.0f)};
 317 #else
 318 Vec3 cloudColors[] = {Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f),
 319                       Vec3(1.0f, 1.0f, 1.0f), Vec3(1.0f, 1.0f, 1.0f)};
 320 #endif
 321
 322 // build the cloud object
 323 void
 324 SGCloudLayer::rebuild()
 325 {
 326     // Initialize states and sizes if necessary.
 327     if ( !state_initialized ) {
 328         state_initialized = true;
 329
 330         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 331
 332         osg::Texture::Extensions* extensions;
 333         extensions = osg::Texture::getExtensions(0, true);
 334         // OSGFIXME
 335         bump_mapping = extensions->isMultiTexturingSupported() &&
 336           (2 <= extensions->numTextureUnits()) &&
 337           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_combine") &&
 338           SGIsOpenGLExtensionSupported("GL_ARB_texture_env_dot3");
 339
 340         osg::TextureCubeMap::Extensions* extensions2;
 341         extensions2 = osg::TextureCubeMap::getExtensions(0, true);
 342         bump_mapping = bump_mapping && extensions2->isCubeMapSupported();
 343
 344         // This bump mapping code was inspired by the tutorial available at
 345         // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 346         // and a NVidia white paper
 347         //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 348         // The normal map textures were generated by the normal map Gimp plugin :
 349         //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 350         //
 351         cubeMap = new osg::TextureCubeMap;
 352         cubeMap->setFilter(osg::Texture::MIN_FILTER, osg::Texture::LINEAR);
 353         cubeMap->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
 354         cubeMap->setWrap(osg::Texture::WRAP_S, osg::Texture::CLAMP_TO_EDGE);
 355         cubeMap->setWrap(osg::Texture::WRAP_T, osg::Texture::CLAMP_TO_EDGE);
 356         cubeMap->setWrap(osg::Texture::WRAP_R, osg::Texture::CLAMP_TO_EDGE);
 357
 358         const int size = 32;
 359         const float half_size = 16.0f;
 360         const float offset = 0.5f;
 361         osg::Vec3 zero_normal(0.5, 0.5, 0.5);
 362
 363         osg::Image* image = new osg::Image;
 364         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 365         unsigned char *ptr = image->data(0, 0);
 366         for (int j = 0; j < size; j++ ) {
 367           for (int i = 0; i < size; i++ ) {
 368             osg::Vec3 tmp(half_size, -( j + offset - half_size ),
 369                           -( i + offset - half_size ) );
 370             tmp.normalize();
 371             tmp = tmp*0.5 - zero_normal;
 372
 373             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 374             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 375             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 376           }
 377         }
 378         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_X, image);
 379
 380         image = new osg::Image;
 381         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 382         ptr = image->data(0, 0);
 383         for (int j = 0; j < size; j++ ) {
 384           for (int i = 0; i < size; i++ ) {
 385             osg::Vec3 tmp(-half_size, -( j + offset - half_size ),
 386                           ( i + offset - half_size ) );
 387             tmp.normalize();
 388             tmp = tmp*0.5 - zero_normal;
 389
 390             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 391             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 392             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 393           }
 394         }
 395         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_X, image);
 396
 397         image = new osg::Image;
 398         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 399         ptr = image->data(0, 0);
 400         for (int j = 0; j < size; j++ ) {
 401           for (int i = 0; i < size; i++ ) {
 402             osg::Vec3 tmp(( i + offset - half_size ), half_size,
 403                           ( j + offset - half_size ) );
 404             tmp.normalize();
 405             tmp = tmp*0.5 - zero_normal;
 406
 407             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 408             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 409             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 410           }
 411         }
 412         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Y, image);
 413
 414         image = new osg::Image;
 415         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 416         ptr = image->data(0, 0);
 417         for (int j = 0; j < size; j++ ) {
 418           for (int i = 0; i < size; i++ ) {
 419             osg::Vec3 tmp(( i + offset - half_size ), -half_size,
 420                           -( j + offset - half_size ) );
 421             tmp.normalize();
 422             tmp = tmp*0.5 - zero_normal;
 423
 424             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 425             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 426             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 427           }
 428         }
 429         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Y, image);
 430
 431         image = new osg::Image;
 432         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 433         ptr = image->data(0, 0);
 434         for (int j = 0; j < size; j++ ) {
 435           for (int i = 0; i < size; i++ ) {
 436             osg::Vec3 tmp(( i + offset - half_size ),
 437                           -( j + offset - half_size ), half_size );
 438             tmp.normalize();
 439             tmp = tmp*0.5 - zero_normal;
 440
 441             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 442             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 443             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 444           }
 445         }
 446         cubeMap->setImage(osg::TextureCubeMap::POSITIVE_Z, image);
 447
 448         image = new osg::Image;
 449         image->allocateImage(size, size, 1, GL_RGB, GL_UNSIGNED_BYTE);
 450         ptr = image->data(0, 0);
 451         for (int j = 0; j < size; j++ ) {
 452           for (int i = 0; i < size; i++ ) {
 453             osg::Vec3 tmp(-( i + offset - half_size ),
 454                           -( j + offset - half_size ), -half_size );
 455             tmp.normalize();
 456             tmp = tmp*0.5 - zero_normal;
 457             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 458             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 459             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 460           }
 461         }
 462         cubeMap->setImage(osg::TextureCubeMap::NEGATIVE_Z, image);
 463
 464         osg::StateSet* state;
 465         state = SGMakeState(texture_path, "overcast.png", "overcast_n.png");
 466         layer_states[SG_CLOUD_OVERCAST] = state;
 467         state = SGMakeState(texture_path, "overcast_top.png", "overcast_top_n.png");
 468         layer_states2[SG_CLOUD_OVERCAST] = state;
 469
 470         state = SGMakeState(texture_path, "broken.png", "broken_n.png");
 471         layer_states[SG_CLOUD_BROKEN] = state;
 472         layer_states2[SG_CLOUD_BROKEN] = state;
 473
 474         state = SGMakeState(texture_path, "scattered.png", "scattered_n.png");
 475         layer_states[SG_CLOUD_SCATTERED] = state;
 476         layer_states2[SG_CLOUD_SCATTERED] = state;
 477
 478         state = SGMakeState(texture_path, "few.png", "few_n.png");
 479         layer_states[SG_CLOUD_FEW] = state;
 480         layer_states2[SG_CLOUD_FEW] = state;
 481
 482         state = SGMakeState(texture_path, "cirrus.png", "cirrus_n.png");
 483         layer_states[SG_CLOUD_CIRRUS] = state;
 484         layer_states2[SG_CLOUD_CIRRUS] = state;
 485
 486         layer_states[SG_CLOUD_CLEAR] = 0;
 487         layer_states2[SG_CLOUD_CLEAR] = 0;
 488 #if 1
 489         // experimental optimization that may not make any difference
 490         // at all :/
 491         osg::CopyOp copyOp;
 492         for (int i = 0; i < SG_MAX_CLOUD_COVERAGES; ++i) {
 493             StateAttributeFactory *saf = StateAttributeFactory::instance();
 494             if (layer_states[i].valid()) {
 495                 if (layer_states[i] == layer_states2[i])
 496                     layer_states2[i] = static_cast<osg::StateSet*>(layer_states[i]->clone(copyOp));
 497                 layer_states[i]->setAttribute(saf ->getCullFaceFront());
 498                 layer_states2[i]->setAttribute(saf ->getCullFaceBack());
 499             }
 500         }
 501 #endif
 502     }
 503
 504     scale = 4000.0;
 505     last_lon = last_lat = -999.0f;
 506
 507     setTextureOffset(base);
 508     // build the cloud layer
 509     const float layer_scale = layer_span / scale;
 510     const float mpi = SG_PI/4;
 511
 512     // caclculate the difference between a flat-earth model and
 513     // a round earth model given the span and altutude ASL of
 514     // the cloud layer. This is the difference in altitude between
 515     // the top of the inverted bowl and the edge of the bowl.
 516     // const float alt_diff = layer_asl * 0.8;
 517     const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 518     const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 519     const float border_to_core = layer_to_core * cos(layer_angle);
 520     const float alt_diff = layer_to_core - border_to_core;
 521
 522     for (int i = 0; i < 4; i++) {
 523       if ( layer[i] != NULL ) {
 524         layer_transform->removeChild(layer[i].get()); // automatic delete
 525       }
 526
 527       vl[i] = new osg::Vec3Array;
 528       cl[i] = new osg::Vec4Array;
 529       tl[i] = new osg::Vec2Array;
 530
 531
 532       osg::Vec3 vertex(layer_span*(i-2)/2, -layer_span,
 533                        alt_diff * (sin(i*mpi) - 2));
 534       osg::Vec2 tc(layer_scale * i/4, 0.0f);
 535       osg::Vec4 color(cloudColors[0], (i == 0) ? 0.0f : 0.15f);
 536
 537       cl[i]->push_back(color);
 538       vl[i]->push_back(vertex);
 539       tl[i]->push_back(tc);
 540
 541       for (int j = 0; j < 4; j++) {
 542         vertex = osg::Vec3(layer_span*(i-1)/2, layer_span*(j-2)/2,
 543                            alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2));
 544         tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale * j/4);
 545         color = osg::Vec4(cloudColors[0],
 546                           ( (j == 0) || (i == 3)) ?
 547                           ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 548
 549         cl[i]->push_back(color);
 550         vl[i]->push_back(vertex);
 551         tl[i]->push_back(tc);
 552
 553         vertex = osg::Vec3(layer_span*(i-2)/2, layer_span*(j-1)/2,
 554                            alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 555         tc = osg::Vec2(layer_scale * i/4, layer_scale * (j+1)/4 );
 556         color = osg::Vec4(cloudColors[0],
 557                           ((j == 3) || (i == 0)) ?
 558                           ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 559         cl[i]->push_back(color);
 560         vl[i]->push_back(vertex);
 561         tl[i]->push_back(tc);
 562       }
 563
 564       vertex = osg::Vec3(layer_span*(i-1)/2, layer_span,
 565                          alt_diff * (sin((i+1)*mpi) - 2));
 566
 567       tc = osg::Vec2(layer_scale * (i+1)/4, layer_scale);
 568
 569       color = osg::Vec4(cloudColors[0], (i == 3) ? 0.0f : 0.15f );
 570
 571       cl[i]->push_back( color );
 572       vl[i]->push_back( vertex );
 573       tl[i]->push_back( tc );
 574
 575       osg::Geometry* geometry = new osg::Geometry;
 576       geometry->setUseDisplayList(false);
 577       geometry->setVertexArray(vl[i].get());
 578       geometry->setNormalBinding(osg::Geometry::BIND_OFF);
 579       geometry->setColorArray(cl[i].get());
 580       geometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
 581       geometry->setTexCoordArray(0, tl[i].get());
 582       geometry->addPrimitiveSet(new osg::DrawArrays(GL_TRIANGLE_STRIP, 0, vl[i]->size()));
 583       layer[i] = new osg::Geode;
 584
 585       std::stringstream sstr;
 586       sstr << "Cloud Layer (" << i << ")";
 587       geometry->setName(sstr.str());
 588       layer[i]->setName(sstr.str());
 589       layer[i]->addDrawable(geometry);
 590       layer_transform->addChild(layer[i].get());
 591     }
 592
 593     //OSGFIXME: true
 594     if ( layer_states[layer_coverage].valid() ) {
 595       osg::CopyOp copyOp;    // shallow copy
 596       // render bin will be set in reposition
 597       osg::StateSet* stateSet = static_cast<osg::StateSet*>(layer_states2[layer_coverage]->clone(copyOp));
 598       stateSet->setDataVariance(osg::Object::DYNAMIC);
 599       group_top->setStateSet(stateSet);
 600       stateSet = static_cast<osg::StateSet*>(layer_states[layer_coverage]->clone(copyOp));
 601       stateSet->setDataVariance(osg::Object::DYNAMIC);
 602       group_bottom->setStateSet(stateSet);
 603     }
 604 }
 605
 606 // repaint the cloud layer colors
 607 bool SGCloudLayer::repaint( const SGVec3f& fog_color ) {
 608     osg::Vec4f combineColor(toOsg(fog_color), cloud_alpha);
 609     osg::TexEnvCombine* combiner
 610         = dynamic_cast<osg::TexEnvCombine*>(layer_root->getStateSet()
 611                                             ->getTextureAttribute(1, osg::StateAttribute::TEXENV));
 612     combiner->setConstantColor(combineColor);
 613
 614     // Set the fog color for the 3D clouds too.
 615     //cloud3dfog->setColor(combineColor);
 616     return true;
 617 }
 618
 619 // reposition the cloud layer at the specified origin and orientation
 620 // lon specifies a rotation about the Z axis
 621 // lat specifies a rotation about the new Y axis
 622 // spin specifies a rotation about the new Z axis (and orients the
 623 // sunrise/set effects
 624 bool SGCloudLayer::reposition( const SGVec3f& p, const SGVec3f& up, double lon, double lat,
 625                                double alt, double dt )
 626 {
 627     // combine p and asl (meters) to get translation offset
 628     osg::Vec3 asl_offset(toOsg(up));
 629     asl_offset.normalize();
 630     if ( alt <= layer_asl ) {
 631         asl_offset *= layer_asl;
 632     } else {
 633         asl_offset *= layer_asl + layer_thickness;
 634     }
 635
 636     // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 637     //      << "," << asl_offset[2] << endl;
 638     asl_offset += toOsg(p);
 639     // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 640     //      << "," << asl_offset[2] << endl;
 641
 642     osg::Matrix T, LON, LAT;
 643     // Translate to zero elevation
 644     // Point3D zero_elev = current_view.get_cur_zero_elev();
 645     T.makeTranslate( asl_offset );
 646
 647     // printf("  Translated to %.2f %.2f %.2f\n",
 648     //        zero_elev.x, zero_elev.y, zero_elev.z );
 649
 650     // Rotate to proper orientation
 651     // printf("  lon = %.2f  lat = %.2f\n",
 652     //        lon * SGD_RADIANS_TO_DEGREES,
 653     //        lat * SGD_RADIANS_TO_DEGREES);
 654     LON.makeRotate(lon, osg::Vec3(0, 0, 1));
 655
 656     // xglRotatef( 90.0 - f->get_Latitude() * SGD_RADIANS_TO_DEGREES,
 657     //             0.0, 1.0, 0.0 );
 658     LAT.makeRotate(90.0 * SGD_DEGREES_TO_RADIANS - lat, osg::Vec3(0, 1, 0));
 659
 660     layer_transform->setMatrix( LAT*LON*T );
 661
 662     // The layers need to be drawn in order because they are
 663     // translucent, but OSG transparency sorting doesn't work because
 664     // the cloud polys are huge. However, the ordering is simple: the
 665     // bottom polys should be drawn from high altitude to low, and the
 666     // top polygons from low to high. The altitude can be used
 667     // directly to order the polygons!
 668     group_bottom->getStateSet()->setRenderBinDetails(-(int)layer_asl,
 669                                                      "RenderBin");
 670     group_top->getStateSet()->setRenderBinDetails((int)layer_asl,
 671                                                   "RenderBin");
 672     if ( alt <= layer_asl ) {
 673       layer_root->setSingleChildOn(0);
 674     } else if ( alt >= layer_asl + layer_thickness ) {
 675       layer_root->setSingleChildOn(1);
 676     } else {
 677       layer_root->setAllChildrenOff();
 678     }
 679
 680
 681     // now calculate update texture coordinates
 682     if ( last_lon < -900 ) {
 683         last_lon = lon;
 684         last_lat = lat;
 685     }
 686
 687     double sp_dist = speed*dt;
 688
 689     if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
 690         Point3D start( last_lon, last_lat, 0.0 );
 691         Point3D dest( lon, lat, 0.0 );
 692         double course = 0.0, dist = 0.0;
 693
 694         calc_gc_course_dist( dest, start, &course, &dist );
 695         // cout << "course = " << course << ", dist = " << dist << endl;
 696
 697         // if start and dest are too close together,
 698         // calc_gc_course_dist() can return a course of "nan".  If
 699         // this happens, lets just use the last known good course.
 700         // This is a hack, and it would probably be better to make
 701         // calc_gc_course_dist() more robust.
 702         if ( isnan(course) ) {
 703             course = last_course;
 704         } else {
 705             last_course = course;
 706         }
 707
 708         // calculate cloud movement due to external forces
 709         double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 710
 711         if (dist > 0.0) {
 712             ax = cos(course) * dist;
 713             ay = sin(course) * dist;
 714         }
 715
 716         if (sp_dist > 0) {
 717             bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 718             by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 719         }
 720
 721
 722         double xoff = (ax + bx) / (2 * scale);
 723         double yoff = (ay + by) / (2 * scale);
 724
 725 //        const float layer_scale = layer_span / scale;
 726
 727         // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 728         base[0] += xoff;
 729
 730         // the while loops can lead to *long* pauses if base[0] comes
 731         // with a bogus value.
 732         // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 733         // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 734         if ( base[0] > -10.0 && base[0] < 10.0 ) {
 735             base[0] -= (int)base[0];
 736         } else {
 737             SG_LOG(SG_ASTRO, SG_DEBUG,
 738                 "Error: base = " << base[0] << "," << base[1] <<
 739                 " course = " << course << " dist = " << dist );
 740             base[0] = 0.0;
 741         }
 742
 743         base[1] += yoff;
 744         // the while loops can lead to *long* pauses if base[0] comes
 745         // with a bogus value.
 746         // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 747         // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 748         if ( base[1] > -10.0 && base[1] < 10.0 ) {
 749             base[1] -= (int)base[1];
 750         } else {
 751             SG_LOG(SG_ASTRO, SG_DEBUG,
 752                     "Error: base = " << base[0] << "," << base[1] <<
 753                     " course = " << course << " dist = " << dist );
 754             base[1] = 0.0;
 755         }
 756
 757         // cout << "base = " << base[0] << "," << base[1] << endl;
 758
 759         setTextureOffset(base);
 760         last_lon = lon;
 761         last_lat = lat;
 762     }
 763
 764     layer3D->reposition( p, up, lon, lat, dt, layer_asl);
 765     return true;
 766 }
 767
 768 void SGCloudLayer::set_enable3dClouds(bool enable) {
 769
 770     if (layer3D->defined3D && enable) {
 771         cloud_root->setChildValue(layer3D->getNode(), true);
 772         cloud_root->setChildValue(layer_root.get(),   false);
 773     } else {
 774         cloud_root->setChildValue(layer3D->getNode(), false);
 775         cloud_root->setChildValue(layer_root.get(),   true);
 776     }
 777 }