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 program is distributed in the hope that it will be useful, but
   8 // WITHOUT ANY WARRANTY; without even the implied warranty of
   9 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  10 // General Public License for more details.
  11 //
  12 // You should have received a copy of the GNU General Public License
  13 // along with this program; if not, write to the Free Software
  14 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  15 //
  16 // $Id$
  17
  18
  19 #include <simgear/compiler.h>
  20
  21 // #include <stdio.h>
  22 #include <math.h>
  23
  24 #if defined (__APPLE__)
  25 // any C++ header file undefines isinf and isnan
  26 // so this should be included before <iostream>
  27 inline int (isinf)(double r) { return isinf(r); }
  28 inline int (isnan)(double r) { return isnan(r); }
  29 #endif
  30
  31 #include <plib/sg.h>
  32 #include <plib/ssg.h>
  33
  34 #include <simgear/math/point3d.hxx>
  35 #include <simgear/math/polar3d.hxx>
  36 #include <simgear/math/sg_random.h>
  37 #include <simgear/debug/logstream.hxx>
  38 #include <simgear/misc/sg_path.hxx>
  39 #include <simgear/screen/extensions.hxx>
  40 #include <simgear/screen/texture.hxx>
  41
  42 #include "cloud.hxx"
  43
  44 #if defined(__MINGW32__)
  45 #define isnan(x) _isnan(x)
  46 #endif
  47
  48 #if defined (__FreeBSD__)
  49 #  if __FreeBSD_version < 500000
  50      extern "C" {
  51        inline int isnan(double r) { return !(r <= 0 || r >= 0); }
  52      }
  53 #  endif
  54 #endif
  55
  56
  57 static ssgStateSelector *layer_states[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  58 static bool state_initialized = false;
  59 static bool bump_mapping = false;
  60 static int nb_texture_unit = 0;
  61 static ssgTexture *normal_map[SGCloudLayer::SG_MAX_CLOUD_COVERAGES][2] = { 0 };
  62 static ssgTexture *color_map[SGCloudLayer::SG_MAX_CLOUD_COVERAGES][2] = { 0 };
  63 static GLuint normalization_cube_map;
  64
  65 static glActiveTextureProc glActiveTexturePtr = 0;
  66 static glClientActiveTextureProc glClientActiveTexturePtr = 0;
  67 static glBlendColorProc glBlendColorPtr = 0;
  68
  69 bool SGCloudLayer::enable_bump_mapping = false;
  70
  71 static void
  72 generateNormalizationCubeMap()
  73 {
  74     unsigned char data[ 32 * 32 * 3 ];
  75     const int size = 32;
  76     const float half_size = 16.0f,
  77                 offset = 0.5f;
  78     sgVec3 zero_normal;
  79     sgSetVec3( zero_normal, 0.5f, 0.5f, 0.5f );
  80     int i, j;
  81
  82     unsigned char *ptr = data;
  83     for ( j = 0; j < size; j++ ) {
  84         for ( i = 0; i < size; i++ ) {
  85             sgVec3 tmp;
  86             sgSetVec3( tmp, half_size,
  87                             -( j + offset - half_size ),
  88                             -( i + offset - half_size ) );
  89             sgNormalizeVec3( tmp );
  90             sgScaleVec3( tmp, 0.5f );
  91             sgAddVec3( tmp, zero_normal );
  92
  93             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
  94             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
  95             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
  96         }
  97     }
  98     glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB,
  99                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 100
 101     ptr = data;
 102     for ( j = 0; j < size; j++ ) {
 103         for ( i = 0; i < size; i++ ) {
 104             sgVec3 tmp;
 105             sgSetVec3( tmp, -half_size,
 106                             -( j + offset - half_size ),
 107                             ( i + offset - half_size ) );
 108             sgNormalizeVec3( tmp );
 109             sgScaleVec3( tmp, 0.5f );
 110             sgAddVec3( tmp, zero_normal );
 111
 112             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 113             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 114             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 115         }
 116     }
 117     glTexImage2D( GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB,
 118                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 119
 120     ptr = data;
 121     for ( j = 0; j < size; j++ ) {
 122         for ( i = 0; i < size; i++ ) {
 123             sgVec3 tmp;
 124             sgSetVec3( tmp, ( i + offset - half_size ),
 125                             half_size,
 126                             ( j + offset - half_size ) );
 127             sgNormalizeVec3( tmp );
 128             sgScaleVec3( tmp, 0.5f );
 129             sgAddVec3( tmp, zero_normal );
 130
 131             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 132             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 133             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 134         }
 135     }
 136     glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB,
 137                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 138
 139     ptr = data;
 140     for ( j = 0; j < size; j++ ) {
 141         for ( i = 0; i < size; i++ ) {
 142             sgVec3 tmp;
 143             sgSetVec3( tmp, ( i + offset - half_size ),
 144                             -half_size,
 145                             -( j + offset - half_size ) );
 146             sgNormalizeVec3( tmp );
 147             sgScaleVec3( tmp, 0.5f );
 148             sgAddVec3( tmp, zero_normal );
 149
 150             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 151             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 152             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 153         }
 154     }
 155     glTexImage2D( GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB,
 156                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 157
 158     ptr = data;
 159     for ( j = 0; j < size; j++ ) {
 160         for ( i = 0; i < size; i++ ) {
 161             sgVec3 tmp;
 162             sgSetVec3( tmp, ( i + offset - half_size ),
 163                             -( j + offset - half_size ),
 164                             half_size );
 165             sgNormalizeVec3( tmp );
 166             sgScaleVec3( tmp, 0.5f );
 167             sgAddVec3( tmp, zero_normal );
 168
 169             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 170             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 171             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 172         }
 173     }
 174     glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB,
 175                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 176
 177     ptr = data;
 178     for ( j = 0; j < size; j++ ) {
 179         for ( i = 0; i < size; i++ ) {
 180             sgVec3 tmp;
 181             sgSetVec3( tmp, -( i + offset - half_size ),
 182                             -( j + offset - half_size ),
 183                             -half_size );
 184             sgNormalizeVec3( tmp );
 185             sgScaleVec3( tmp, 0.5f );
 186             sgAddVec3( tmp, zero_normal );
 187
 188             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 189             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 190             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 191         }
 192     }
 193     glTexImage2D( GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB,
 194                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 195 }
 196
 197
 198 // Constructor
 199 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
 200     vertices(0),
 201     indices(0),
 202     layer_root(new ssgRoot),
 203     layer_transform(new ssgTransform),
 204     state_sel(0),
 205     cloud_alpha(1.0),
 206     texture_path(tex_path),
 207     layer_span(0.0),
 208     layer_asl(0.0),
 209     layer_thickness(0.0),
 210     layer_transition(0.0),
 211     layer_coverage(SG_CLOUD_CLEAR),
 212     scale(4000.0),
 213     speed(0.0),
 214     direction(0.0),
 215     last_lon(0.0),
 216     last_lat(0.0)
 217 {
 218     cl[0] = cl[1] = cl[2] = cl[3] = NULL;
 219     vl[0] = vl[1] = vl[2] = vl[3] = NULL;
 220     tl[0] = tl[1] = tl[2] = tl[3] = NULL;
 221     layer[0] = layer[1] = layer[2] = layer[3] = NULL;
 222
 223     layer_root->addKid(layer_transform);
 224     rebuild();
 225 }
 226
 227 // Destructor
 228 SGCloudLayer::~SGCloudLayer()
 229 {
 230     delete vertices;
 231     delete indices;
 232     delete layer_root;          // deletes layer_transform and layer as well
 233 }
 234
 235 float
 236 SGCloudLayer::getSpan_m () const
 237 {
 238     return layer_span;
 239 }
 240
 241 void
 242 SGCloudLayer::setSpan_m (float span_m)
 243 {
 244     if (span_m != layer_span) {
 245         layer_span = span_m;
 246         rebuild();
 247     }
 248 }
 249
 250 float
 251 SGCloudLayer::getElevation_m () const
 252 {
 253     return layer_asl;
 254 }
 255
 256 void
 257 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 258 {
 259     layer_asl = elevation_m;
 260
 261     if (set_span) {
 262         if (elevation_m > 4000)
 263             setSpan_m(  elevation_m * 10 );
 264         else
 265             setSpan_m( 40000 );
 266     }
 267 }
 268
 269 float
 270 SGCloudLayer::getThickness_m () const
 271 {
 272     return layer_thickness;
 273 }
 274
 275 void
 276 SGCloudLayer::setThickness_m (float thickness_m)
 277 {
 278     layer_thickness = thickness_m;
 279 }
 280
 281 float
 282 SGCloudLayer::getTransition_m () const
 283 {
 284     return layer_transition;
 285 }
 286
 287 void
 288 SGCloudLayer::setTransition_m (float transition_m)
 289 {
 290     layer_transition = transition_m;
 291 }
 292
 293 SGCloudLayer::Coverage
 294 SGCloudLayer::getCoverage () const
 295 {
 296     return layer_coverage;
 297 }
 298
 299 void
 300 SGCloudLayer::setCoverage (Coverage coverage)
 301 {
 302     if (coverage != layer_coverage) {
 303         layer_coverage = coverage;
 304         rebuild();
 305     }
 306 }
 307
 308
 309 // build the cloud object
 310 void
 311 SGCloudLayer::rebuild()
 312 {
 313     // Initialize states and sizes if necessary.
 314     if ( !state_initialized ) {
 315         state_initialized = true;
 316
 317         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 318
 319         bump_mapping = SGIsOpenGLExtensionSupported("GL_ARB_multitexture") &&
 320                        SGIsOpenGLExtensionSupported("GL_ARB_texture_cube_map") &&
 321                        SGIsOpenGLExtensionSupported("GL_ARB_texture_env_combine") &&
 322                        SGIsOpenGLExtensionSupported("GL_ARB_texture_env_dot3") &&
 323                        SGIsOpenGLExtensionSupported("GL_ARB_imaging");
 324
 325         if ( bump_mapping ) {
 326             glGetIntegerv( GL_MAX_TEXTURE_UNITS_ARB, &nb_texture_unit );
 327             if ( nb_texture_unit < 2 ) {
 328                 bump_mapping = false;
 329             }
 330             //nb_texture_unit = 2; // Force the number of units for now
 331         }
 332
 333         if ( bump_mapping ) {
 334
 335             // This bump mapping code was inspired by the tutorial available at
 336             // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 337             // and a NVidia white paper
 338             //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 339             // The normal map textures were generated by the normal map Gimp plugin :
 340             //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 341             //
 342             SGPath cloud_path;
 343
 344             glActiveTexturePtr = (glActiveTextureProc)SGLookupFunction("glActiveTextureARB");
 345             glClientActiveTexturePtr = (glClientActiveTextureProc)SGLookupFunction("glClientActiveTextureARB");
 346             glBlendColorPtr = (glBlendColorProc)SGLookupFunction("glBlendColor");
 347
 348             cloud_path.set(texture_path.str());
 349             cloud_path.append("overcast.rgb");
 350             color_map[ SG_CLOUD_OVERCAST ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 351             color_map[ SG_CLOUD_OVERCAST ][ 0 ]->ref();
 352             cloud_path.set(texture_path.str());
 353             cloud_path.append("overcast_n.rgb");
 354             normal_map[ SG_CLOUD_OVERCAST ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 355             normal_map[ SG_CLOUD_OVERCAST ][ 0 ]->ref();
 356
 357             cloud_path.set(texture_path.str());
 358             cloud_path.append("overcast_top.rgb");
 359             color_map[ SG_CLOUD_OVERCAST ][ 1 ] = new ssgTexture( cloud_path.str().c_str() );
 360             color_map[ SG_CLOUD_OVERCAST ][ 1 ]->ref();
 361             cloud_path.set(texture_path.str());
 362             cloud_path.append("overcast_top_n.rgb");
 363             normal_map[ SG_CLOUD_OVERCAST ][ 1 ] = new ssgTexture( cloud_path.str().c_str() );
 364             normal_map[ SG_CLOUD_OVERCAST ][ 1 ]->ref();
 365
 366             cloud_path.set(texture_path.str());
 367             cloud_path.append("broken.rgba");
 368             color_map[ SG_CLOUD_BROKEN ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 369             color_map[ SG_CLOUD_BROKEN ][ 0 ]->ref();
 370             cloud_path.set(texture_path.str());
 371             cloud_path.append("broken_n.rgb");
 372             normal_map[ SG_CLOUD_BROKEN ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 373             normal_map[ SG_CLOUD_BROKEN ][ 0 ]->ref();
 374
 375             cloud_path.set(texture_path.str());
 376             cloud_path.append("scattered.rgba");
 377             color_map[ SG_CLOUD_SCATTERED ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 378             color_map[ SG_CLOUD_SCATTERED ][ 0 ]->ref();
 379             cloud_path.set(texture_path.str());
 380             cloud_path.append("scattered_n.rgb");
 381             normal_map[ SG_CLOUD_SCATTERED ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 382             normal_map[ SG_CLOUD_SCATTERED ][ 0 ]->ref();
 383
 384             cloud_path.set(texture_path.str());
 385             cloud_path.append("few.rgba");
 386             color_map[ SG_CLOUD_FEW ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 387             color_map[ SG_CLOUD_FEW ][ 0 ]->ref();
 388             cloud_path.set(texture_path.str());
 389             cloud_path.append("few_n.rgb");
 390             normal_map[ SG_CLOUD_FEW ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 391             normal_map[ SG_CLOUD_FEW ][ 0 ]->ref();
 392
 393             cloud_path.set(texture_path.str());
 394             cloud_path.append("cirrus.rgba");
 395             color_map[ SG_CLOUD_CIRRUS ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 396             color_map[ SG_CLOUD_CIRRUS ][ 0 ]->ref();
 397             cloud_path.set(texture_path.str());
 398             cloud_path.append("cirrus_n.rgb");
 399             normal_map[ SG_CLOUD_CIRRUS ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 400             normal_map[ SG_CLOUD_CIRRUS ][ 0 ]->ref();
 401
 402             glGenTextures( 1, &normalization_cube_map );
 403             glBindTexture( GL_TEXTURE_CUBE_MAP_ARB, normalization_cube_map );
 404             generateNormalizationCubeMap();
 405             glTexParameteri( GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
 406             glTexParameteri( GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
 407             glTexParameteri( GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
 408             glTexParameteri( GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
 409             glTexParameteri( GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE );
 410         } /* else */ {
 411             SGPath cloud_path;
 412             ssgStateSelector *state_sel;
 413             ssgSimpleState *state;
 414
 415             state_sel = new ssgStateSelector( 2 );
 416             state_sel->ref();
 417             cloud_path.set(texture_path.str());
 418             cloud_path.append("overcast.rgb");
 419             state_sel->setStep( 0, sgCloudMakeState(cloud_path.str()) );
 420             cloud_path.set(texture_path.str());
 421             cloud_path.append("overcast_top.rgb");
 422             state_sel->setStep( 1, sgCloudMakeState(cloud_path.str()) );
 423             layer_states[SG_CLOUD_OVERCAST] = state_sel;
 424
 425             state_sel = new ssgStateSelector( 2 );
 426             state_sel->ref();
 427             cloud_path.set(texture_path.str());
 428             cloud_path.append("broken.rgba");
 429             state = sgCloudMakeState(cloud_path.str());
 430             state_sel->setStep( 0, state );
 431             state_sel->setStep( 1, state );
 432             layer_states[SG_CLOUD_BROKEN] = state_sel;
 433
 434             state_sel = new ssgStateSelector( 2 );
 435             state_sel->ref();
 436             cloud_path.set(texture_path.str());
 437             cloud_path.append("scattered.rgba");
 438             state = sgCloudMakeState(cloud_path.str());
 439             state_sel->setStep( 0, state );
 440             state_sel->setStep( 1, state );
 441             layer_states[SG_CLOUD_SCATTERED] = state_sel;
 442
 443             state_sel = new ssgStateSelector( 2 );
 444             state_sel->ref();
 445             cloud_path.set(texture_path.str());
 446             cloud_path.append("few.rgba");
 447             state = sgCloudMakeState(cloud_path.str());
 448             state_sel->setStep( 0, state );
 449             state_sel->setStep( 1, state );
 450             layer_states[SG_CLOUD_FEW] = state_sel;
 451
 452             state_sel = new ssgStateSelector( 2 );
 453             state_sel->ref();
 454             cloud_path.set(texture_path.str());
 455             cloud_path.append("cirrus.rgba");
 456             state = sgCloudMakeState(cloud_path.str());
 457             state_sel->setStep( 0, state );
 458             state_sel->setStep( 1, state );
 459             layer_states[SG_CLOUD_CIRRUS] = state_sel;
 460
 461             layer_states[SG_CLOUD_CLEAR] = 0;
 462         }
 463     }
 464
 465     if ( bump_mapping ) {
 466
 467         if ( !vertices ) {
 468             vertices = new CloudVertex[ 25 ];
 469             indices = new unsigned int[ 40 ];
 470         }
 471
 472         sgVec2 base;
 473         sgSetVec2( base, sg_random(), sg_random() );
 474
 475         const float layer_scale = layer_span / scale;
 476         const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 477         const float half_angle = 0.5 * layer_span / layer_to_core;
 478
 479         int i;
 480         for ( i = -2; i <= 2; i++ ) {
 481             for ( int j = -2; j <= 2; j++ ) {
 482                 CloudVertex &v1 = vertices[ (i+2)*5 + (j+2) ];
 483                 sgSetVec3( v1.position,
 484                            0.5 * i * layer_span,
 485                            0.5 * j * layer_span,
 486                            -layer_to_core * ( 1 - cos( i * half_angle ) * cos( j * half_angle ) ) );
 487                 sgSetVec2( v1.texCoord,
 488                            base[0] + layer_scale * i * 0.25,
 489                            base[1] + layer_scale * j * 0.25 );
 490                 sgSetVec3( v1.sTangent,
 491                            cos( i * half_angle ),
 492                            0.f,
 493                            -sin( i * half_angle ) );
 494                 sgSetVec3( v1.tTangent,
 495                            0.f,
 496                            cos( j * half_angle ),
 497                            -sin( j * half_angle ) );
 498                 sgVectorProductVec3( v1.normal, v1.tTangent, v1.sTangent );
 499                 sgSetVec4( v1.color, 1.0f, 1.0f, 1.0f, (i == 0) ? 0.0f : cloud_alpha * 0.15f );
 500             }
 501         }
 502         /*
 503          * 0 1 5 6 10 11 15 16 20 21
 504          * 1 2 6 7 11 12 16 17 21 22
 505          * 2 3 7 8 12 13 17 18 22 23
 506          * 3 4 8 9 13 14 18 19 23 24
 507          */
 508         for ( i = 0; i < 4; i++ ) {
 509             for ( int j = 0; j < 5; j++ ) {
 510                 indices[ i*10 + (j*2) ]     =     i + 5 * j;
 511                 indices[ i*10 + (j*2) + 1 ] = 1 + i + 5 * j;
 512             }
 513         }
 514
 515     } /* else */ {
 516
 517         scale = 4000.0;
 518         last_lon = last_lat = -999.0f;
 519
 520         sgVec2 base;
 521         sgSetVec2( base, sg_random(), sg_random() );
 522
 523         // build the cloud layer
 524         sgVec4 color;
 525         sgVec3 vertex;
 526         sgVec2 tc;
 527
 528         const float layer_scale = layer_span / scale;
 529         const float mpi = SG_PI/4;
 530
 531         // caclculate the difference between a flat-earth model and
 532         // a round earth model given the span and altutude ASL of
 533         // the cloud layer. This is the difference in altitude between
 534         // the top of the inverted bowl and the edge of the bowl.
 535         // const float alt_diff = layer_asl * 0.8;
 536         const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 537         const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 538         const float border_to_core = layer_to_core * cos(layer_angle);
 539         const float alt_diff = layer_to_core - border_to_core;
 540
 541         for (int i = 0; i < 4; i++)
 542         {
 543             if ( layer[i] != NULL ) {
 544                 layer_transform->removeKid(layer[i]); // automatic delete
 545             }
 546
 547             vl[i] = new ssgVertexArray( 10 );
 548             cl[i] = new ssgColourArray( 10 );
 549             tl[i] = new ssgTexCoordArray( 10 );
 550
 551
 552             sgSetVec3( vertex, layer_span*(i-2)/2, -layer_span,
 553                             alt_diff * (sin(i*mpi) - 2) );
 554
 555             sgSetVec2( tc, base[0] + layer_scale * i/4, base[1] );
 556
 557             sgSetVec4( color, 1.0f, 1.0f, 1.0f, (i == 0) ? 0.0f : 0.15f );
 558
 559             cl[i]->add( color );
 560             vl[i]->add( vertex );
 561             tl[i]->add( tc );
 562
 563             for (int j = 0; j < 4; j++)
 564             {
 565                 sgSetVec3( vertex, layer_span*(i-1)/2, layer_span*(j-2)/2,
 566                                 alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2) );
 567
 568                 sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
 569                             base[1] + layer_scale * j/4 );
 570
 571                 sgSetVec4( color, 1.0f, 1.0f, 1.0f,
 572                                 ( (j == 0) || (i == 3)) ?
 573                                 ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 574
 575                 cl[i]->add( color );
 576                 vl[i]->add( vertex );
 577                 tl[i]->add( tc );
 578
 579
 580                 sgSetVec3( vertex, layer_span*(i-2)/2, layer_span*(j-1)/2,
 581                                 alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 582
 583                 sgSetVec2( tc, base[0] + layer_scale * i/4,
 584                             base[1] + layer_scale * (j+1)/4 );
 585
 586                 sgSetVec4( color, 1.0f, 1.0f, 1.0f,
 587                                 ((j == 3) || (i == 0)) ?
 588                                 ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 589                 cl[i]->add( color );
 590                 vl[i]->add( vertex );
 591                 tl[i]->add( tc );
 592             }
 593
 594             sgSetVec3( vertex, layer_span*(i-1)/2, layer_span,
 595                             alt_diff * (sin((i+1)*mpi) - 2) );
 596
 597             sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
 598                         base[1] + layer_scale );
 599
 600             sgSetVec4( color, 1.0f, 1.0f, 1.0f, (i == 3) ? 0.0f : 0.15f );
 601
 602             cl[i]->add( color );
 603             vl[i]->add( vertex );
 604             tl[i]->add( tc );
 605
 606             layer[i] = new ssgVtxTable(GL_TRIANGLE_STRIP, vl[i], NULL, tl[i], cl[i]);
 607             layer_transform->addKid( layer[i] );
 608
 609             if ( layer_states[layer_coverage] != NULL ) {
 610                 layer[i]->setState( layer_states[layer_coverage] );
 611             }
 612             state_sel = layer_states[layer_coverage];
 613         }
 614
 615         // force a repaint of the sky colors with arbitrary defaults
 616         repaint( color );
 617     }
 618 }
 619
 620
 621 // repaint the cloud layer colors
 622 bool SGCloudLayer::repaint( sgVec3 fog_color ) {
 623
 624     if ( bump_mapping && enable_bump_mapping ) {
 625
 626         for ( int i = 0; i < 25; i++ ) {
 627             sgCopyVec3( vertices[ i ].color, fog_color );
 628         }
 629
 630     } else {
 631         float *color;
 632
 633         for ( int i = 0; i < 4; i++ ) {
 634             color = cl[i]->get( 0 );
 635             sgCopyVec3( color, fog_color );
 636             color[3] = (i == 0) ? 0.0f : cloud_alpha * 0.15f;
 637
 638             for ( int j = 0; j < 4; ++j ) {
 639                 color = cl[i]->get( (2*j) + 1 );
 640                 sgCopyVec3( color, fog_color );
 641                 color[3] =
 642                     ((j == 0) || (i == 3)) ?
 643                     ((j == 0) && (i == 3)) ? 0.0f : cloud_alpha * 0.15f : cloud_alpha;
 644
 645                 color = cl[i]->get( (2*j) + 2 );
 646                 sgCopyVec3( color, fog_color );
 647                 color[3] =
 648                     ((j == 3) || (i == 0)) ?
 649                     ((j == 3) && (i == 0)) ? 0.0f : cloud_alpha * 0.15f : cloud_alpha;
 650             }
 651
 652             color = cl[i]->get( 9 );
 653             sgCopyVec3( color, fog_color );
 654             color[3] = (i == 3) ? 0.0f : cloud_alpha * 0.15f;
 655         }
 656     }
 657
 658     return true;
 659 }
 660
 661 // reposition the cloud layer at the specified origin and orientation
 662 // lon specifies a rotation about the Z axis
 663 // lat specifies a rotation about the new Y axis
 664 // spin specifies a rotation about the new Z axis (and orients the
 665 // sunrise/set effects
 666 bool SGCloudLayer::reposition( sgVec3 p, sgVec3 up, double lon, double lat,
 667                                double alt, double dt )
 668 {
 669     sgMat4 T1, LON, LAT;
 670     sgVec3 axis;
 671
 672     // combine p and asl (meters) to get translation offset
 673     sgVec3 asl_offset;
 674     sgCopyVec3( asl_offset, up );
 675     sgNormalizeVec3( asl_offset );
 676     if ( alt <= layer_asl ) {
 677         sgScaleVec3( asl_offset, layer_asl );
 678     } else {
 679         sgScaleVec3( asl_offset, layer_asl + layer_thickness );
 680     }
 681     // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 682     //      << "," << asl_offset[2] << endl;
 683     sgAddVec3( asl_offset, p );
 684     // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 685     //      << "," << asl_offset[2] << endl;
 686
 687     // Translate to zero elevation
 688     // Point3D zero_elev = current_view.get_cur_zero_elev();
 689     sgMakeTransMat4( T1, asl_offset );
 690
 691     // printf("  Translated to %.2f %.2f %.2f\n",
 692     //        zero_elev.x, zero_elev.y, zero_elev.z );
 693
 694     // Rotate to proper orientation
 695     // printf("  lon = %.2f  lat = %.2f\n",
 696     //        lon * SGD_RADIANS_TO_DEGREES,
 697     //        lat * SGD_RADIANS_TO_DEGREES);
 698     sgSetVec3( axis, 0.0, 0.0, 1.0 );
 699     sgMakeRotMat4( LON, lon * SGD_RADIANS_TO_DEGREES, axis );
 700
 701     sgSetVec3( axis, 0.0, 1.0, 0.0 );
 702     sgMakeRotMat4( LAT, 90.0 - lat * SGD_RADIANS_TO_DEGREES, axis );
 703
 704     sgMat4 TRANSFORM;
 705
 706     sgCopyMat4( TRANSFORM, T1 );
 707     sgPreMultMat4( TRANSFORM, LON );
 708     sgPreMultMat4( TRANSFORM, LAT );
 709
 710     sgCoord layerpos;
 711     sgSetCoord( &layerpos, TRANSFORM );
 712
 713     layer_transform->setTransform( &layerpos );
 714
 715     // now calculate update texture coordinates
 716     if ( last_lon < -900 ) {
 717         last_lon = lon;
 718         last_lat = lat;
 719     }
 720
 721     double sp_dist = speed*dt;
 722
 723     if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
 724         Point3D start( last_lon, last_lat, 0.0 );
 725         Point3D dest( lon, lat, 0.0 );
 726         double course = 0.0, dist = 0.0;
 727
 728         calc_gc_course_dist( dest, start, &course, &dist );
 729         // cout << "course = " << course << ", dist = " << dist << endl;
 730
 731         // if start and dest are too close together,
 732         // calc_gc_course_dist() can return a course of "nan".  If
 733         // this happens, lets just use the last known good course.
 734         // This is a hack, and it would probably be better to make
 735         // calc_gc_course_dist() more robust.
 736         if ( isnan(course) ) {
 737             course = last_course;
 738         } else {
 739             last_course = course;
 740         }
 741
 742         // calculate cloud movement due to external forces
 743         double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 744
 745         if (dist > 0.0) {
 746             ax = cos(course) * dist;
 747             ay = sin(course) * dist;
 748         }
 749
 750         if (sp_dist > 0) {
 751             bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 752             by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 753         }
 754
 755
 756         double xoff = (ax + bx) / (2 * scale);
 757         double yoff = (ay + by) / (2 * scale);
 758
 759         const float layer_scale = layer_span / scale;
 760
 761         // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 762
 763         float *base;
 764         if ( bump_mapping && enable_bump_mapping ) {
 765             base = vertices[12].texCoord;
 766         } else {
 767             base = tl[0]->get( 0 );
 768         }
 769         base[0] += xoff;
 770
 771         // the while loops can lead to *long* pauses if base[0] comes
 772         // with a bogus value.
 773         // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 774         // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 775         if ( base[0] > -10.0 && base[0] < 10.0 ) {
 776             base[0] -= (int)base[0];
 777         } else {
 778             SG_LOG(SG_ASTRO, SG_DEBUG,
 779                 "Error: base = " << base[0] << "," << base[1] <<
 780                 " course = " << course << " dist = " << dist );
 781             base[0] = 0.0;
 782         }
 783
 784         base[1] += yoff;
 785         // the while loops can lead to *long* pauses if base[0] comes
 786         // with a bogus value.
 787         // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 788         // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 789         if ( base[1] > -10.0 && base[1] < 10.0 ) {
 790             base[1] -= (int)base[1];
 791         } else {
 792             SG_LOG(SG_ASTRO, SG_ALERT,
 793                     "Error: base = " << base[0] << "," << base[1] <<
 794                     " course = " << course << " dist = " << dist );
 795             base[1] = 0.0;
 796         }
 797
 798         if ( bump_mapping && enable_bump_mapping ) {
 799
 800             for ( int i = -2; i <= 2; i++ ) {
 801                 for ( int j = -2; j <= 2; j++ ) {
 802                     if ( i == 0 && j == 0 )
 803                         continue; // Already done on base
 804                     CloudVertex &v1 = vertices[ (i+2)*5 + (j+2) ];
 805                     sgSetVec2( v1.texCoord,
 806                             base[0] + layer_scale * i * 0.25,
 807                             base[1] + layer_scale * j * 0.25 );
 808                 }
 809             }
 810
 811         } else {
 812                 // cout << "base = " << base[0] << "," << base[1] << endl;
 813
 814             float *tc;
 815             for (int i = 0; i < 4; i++) {
 816                 tc = tl[i]->get( 0 );
 817                 sgSetVec2( tc, base[0] + layer_scale * i/4, base[1] );
 818
 819                 for (int j = 0; j < 4; j++)
 820                 {
 821                     tc = tl[i]->get( j*2+1 );
 822                     sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
 823                                 base[1] + layer_scale * j/4 );
 824
 825                     tc = tl[i]->get( (j+1)*2 );
 826                     sgSetVec2( tc, base[0] + layer_scale * i/4,
 827                                 base[1] + layer_scale * (j+1)/4 );
 828                 }
 829
 830                 tc = tl[i]->get( 9 );
 831                 sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
 832                             base[1] + layer_scale );
 833             }
 834         }
 835
 836         last_lon = lon;
 837         last_lat = lat;
 838     }
 839
 840     return true;
 841 }
 842
 843
 844 void SGCloudLayer::draw( bool top ) {
 845     if ( layer_coverage != SG_CLOUD_CLEAR ) {
 846
 847         if ( bump_mapping && enable_bump_mapping ) {
 848
 849             sgMat4 modelview,
 850                    tmp,
 851                    transform;
 852             ssgGetModelviewMatrix( modelview );
 853             layer_transform->getTransform( transform );
 854
 855             sgTransposeNegateMat4( tmp, transform );
 856
 857             sgPostMultMat4( transform, modelview );
 858             ssgLoadModelviewMatrix( transform );
 859
 860             sgVec3 lightVec;
 861             ssgGetLight( 0 )->getPosition( lightVec );
 862             sgNegateVec3( lightVec );
 863             sgXformVec3( lightVec, tmp );
 864
 865             for ( int i = 0; i < 25; i++ ) {
 866                 CloudVertex &v = vertices[ i ];
 867                 sgSetVec3( v.tangentSpLight,
 868                            sgScalarProductVec3( v.sTangent, lightVec ),
 869                            sgScalarProductVec3( v.tTangent, lightVec ),
 870                            sgScalarProductVec3( v.normal, lightVec ) );
 871             }
 872
 873             ssgTexture *decal = color_map[ layer_coverage ][ top ? 1 : 0 ];
 874             if ( top && decal == 0 ) {
 875                 decal = color_map[ layer_coverage ][ 0 ];
 876             }
 877             ssgTexture *normal = normal_map[ layer_coverage ][ top ? 1 : 0 ];
 878             if ( top && normal == 0 ) {
 879                 normal = normal_map[ layer_coverage ][ 0 ];
 880             }
 881
 882             glDisable( GL_LIGHTING );
 883             glDisable( GL_CULL_FACE );
 884 //            glDisable( GL_ALPHA_TEST );
 885             if ( layer_coverage == SG_CLOUD_FEW ) {
 886                 glEnable( GL_ALPHA_TEST );
 887                 glAlphaFunc ( GL_GREATER, 0.01 );
 888             }
 889             glEnable( GL_BLEND );
 890             glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 891
 892             glShadeModel( GL_SMOOTH );
 893             glEnable( GL_COLOR_MATERIAL );
 894             sgVec4 color;
 895             float emis = 0.05;
 896             if ( 1 ) {
 897                 ssgGetLight( 0 )->getColour( GL_DIFFUSE, color );
 898                 emis = ( color[0]+color[1]+color[2] ) / 3.0;
 899                 if ( emis < 0.05 )
 900                     emis = 0.05;
 901             }
 902             sgSetVec4( color, emis, emis, emis, 0.0 );
 903             glMaterialfv( GL_FRONT_AND_BACK, GL_EMISSION, color );
 904             sgSetVec4( color, 1.0f, 1.0f, 1.0f, 0.0 );
 905             glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT, color );
 906             sgSetVec4( color, 1.0, 1.0, 1.0, 0.0 );
 907             glMaterialfv( GL_FRONT_AND_BACK, GL_DIFFUSE, color );
 908             sgSetVec4( color, 0.0, 0.0, 0.0, 0.0 );
 909             glMaterialfv( GL_FRONT_AND_BACK, GL_SPECULAR, color );
 910
 911             glColor4f( 1.0f, 1.0f, 1.0f, 1.0f );
 912
 913             glActiveTexturePtr( GL_TEXTURE0_ARB );
 914             glBindTexture( GL_TEXTURE_2D, normal->getHandle() );
 915             glEnable( GL_TEXTURE_2D );
 916
 917             //Bind normalisation cube map to texture unit 1
 918             glActiveTexturePtr( GL_TEXTURE1_ARB );
 919             glBindTexture( GL_TEXTURE_CUBE_MAP_ARB, normalization_cube_map );
 920             glEnable( GL_TEXTURE_CUBE_MAP_ARB );
 921             glActiveTexturePtr( GL_TEXTURE0_ARB );
 922
 923             //Set vertex arrays for cloud
 924             glVertexPointer( 3, GL_FLOAT, sizeof(CloudVertex), &vertices[0].position );
 925             glEnableClientState( GL_VERTEX_ARRAY );
 926 /*
 927             if ( nb_texture_unit >= 3 ) {
 928                 glColorPointer( 4, GL_FLOAT, sizeof(CloudVertex), &vertices[0].color );
 929                 glEnableClientState( GL_COLOR_ARRAY );
 930             }
 931 */
 932             //Send texture coords for normal map to unit 0
 933             glTexCoordPointer( 2, GL_FLOAT, sizeof(CloudVertex), &vertices[0].texCoord );
 934             glEnableClientState( GL_TEXTURE_COORD_ARRAY );
 935
 936             //Send tangent space light vectors for normalisation to unit 1
 937             glClientActiveTexturePtr( GL_TEXTURE1_ARB );
 938             glTexCoordPointer( 3, GL_FLOAT, sizeof(CloudVertex), &vertices[0].tangentSpLight );
 939             glEnableClientState( GL_TEXTURE_COORD_ARRAY );
 940
 941             //Set up texture environment to do (tex0 dot tex1)*color
 942             glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB );
 943             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE );
 944             glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_REPLACE );
 945             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_ALPHA_ARB, GL_TEXTURE );
 946             glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_ALPHA_ARB, GL_REPLACE );
 947
 948             glActiveTexturePtr( GL_TEXTURE1_ARB );
 949
 950             glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB );
 951             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE );
 952             glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_DOT3_RGB_ARB );
 953             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB );
 954             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_ALPHA_ARB, GL_PREVIOUS_ARB );
 955             glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_ALPHA_ARB, GL_REPLACE );
 956
 957             if ( nb_texture_unit >= 3 ) {
 958                 glActiveTexturePtr( GL_TEXTURE2_ARB );
 959                 glBindTexture( GL_TEXTURE_2D, decal->getHandle() );
 960
 961                 glClientActiveTexturePtr( GL_TEXTURE2_ARB );
 962                 glTexCoordPointer( 2, GL_FLOAT, sizeof(CloudVertex), &vertices[0].texCoord );
 963                 glEnableClientState( GL_TEXTURE_COORD_ARRAY );
 964
 965                 glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB );
 966                 glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_ADD );
 967                 glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE );
 968                 glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB );
 969
 970                 glClientActiveTexturePtr( GL_TEXTURE0_ARB );
 971                 glActiveTexturePtr( GL_TEXTURE0_ARB );
 972
 973                 //Draw cloud layer
 974                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[0] );
 975                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[10] );
 976                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[20] );
 977                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[30] );
 978
 979                 glDisable( GL_TEXTURE_2D );
 980                 glActiveTexturePtr( GL_TEXTURE1_ARB );
 981                 glDisable( GL_TEXTURE_CUBE_MAP_ARB );
 982                 glActiveTexturePtr( GL_TEXTURE2_ARB );
 983                 glDisable( GL_TEXTURE_2D );
 984                 glActiveTexturePtr( GL_TEXTURE0_ARB );
 985
 986                 glDisableClientState( GL_TEXTURE_COORD_ARRAY );
 987                 glClientActiveTexturePtr( GL_TEXTURE1_ARB );
 988                 glDisableClientState( GL_TEXTURE_COORD_ARRAY );
 989                 glClientActiveTexturePtr( GL_TEXTURE2_ARB );
 990                 glDisableClientState( GL_TEXTURE_COORD_ARRAY );
 991                 glClientActiveTexturePtr( GL_TEXTURE0_ARB );
 992
 993                 glDisableClientState( GL_COLOR_ARRAY );
 994                 glEnable( GL_LIGHTING );
 995
 996                 glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
 997
 998             } else {
 999                 glClientActiveTexturePtr( GL_TEXTURE0_ARB );
1000                 glActiveTexturePtr( GL_TEXTURE0_ARB );
1001
1002                 //Draw cloud layer
1003                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[0] );
1004                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[10] );
1005                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[20] );
1006                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[30] );
1007
1008                 //Disable textures
1009                 glDisable( GL_TEXTURE_2D );
1010
1011                 glActiveTexturePtr( GL_TEXTURE1_ARB );
1012                 glDisable( GL_TEXTURE_CUBE_MAP_ARB );
1013                 glActiveTexturePtr( GL_TEXTURE0_ARB );
1014
1015                 //disable vertex arrays
1016                 glDisableClientState( GL_VERTEX_ARRAY );
1017
1018                 glDisableClientState( GL_TEXTURE_COORD_ARRAY );
1019                 glClientActiveTexturePtr( GL_TEXTURE1_ARB );
1020                 glDisableClientState( GL_TEXTURE_COORD_ARRAY );
1021                 glClientActiveTexturePtr( GL_TEXTURE0_ARB );
1022
1023                 //Return to standard modulate texenv
1024                 glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
1025
1026                 if ( layer_coverage == SG_CLOUD_OVERCAST ) {
1027                     glDepthFunc(GL_LEQUAL);
1028
1029                     glEnable( GL_LIGHTING );
1030                     sgVec4 color;
1031                     ssgGetLight( 0 )->getColour( GL_DIFFUSE, color );
1032                     float average = ( color[0] + color[1] + color[2] ) / 3.0f;
1033                     average = 0.15 + average/10;
1034                     sgVec4 averageColor;
1035                     sgSetVec4( averageColor, average, average, average, 1.0f );
1036                     ssgGetLight( 0 )->setColour( GL_DIFFUSE, averageColor );
1037
1038                     glBlendColorPtr( average, average, average, 1.0f );
1039                     glBlendFunc( GL_ONE_MINUS_CONSTANT_COLOR, GL_CONSTANT_COLOR );
1040
1041                     //Perform a second pass to color the torus
1042                     //Bind decal texture
1043                     glBindTexture( GL_TEXTURE_2D, decal->getHandle() );
1044                     glEnable(GL_TEXTURE_2D);
1045
1046                     //Set vertex arrays for torus
1047                     glVertexPointer( 3, GL_FLOAT, sizeof(CloudVertex), &vertices[0].position );
1048                     glEnableClientState( GL_VERTEX_ARRAY );
1049
1050                     //glColorPointer( 4, GL_FLOAT, sizeof(CloudVertex), &vertices[0].color );
1051                     //glEnableClientState( GL_COLOR_ARRAY );
1052
1053                     glNormalPointer( GL_FLOAT, sizeof(CloudVertex), &vertices[0].normal );
1054                     glEnableClientState( GL_NORMAL_ARRAY );
1055
1056                     glTexCoordPointer( 2, GL_FLOAT, sizeof(CloudVertex), &vertices[0].texCoord );
1057                     glEnableClientState( GL_TEXTURE_COORD_ARRAY );
1058
1059                     //Draw cloud layer
1060                     glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[0] );
1061                     glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[10] );
1062                     glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[20] );
1063                     glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[30] );
1064
1065                     ssgGetLight( 0 )->setColour( GL_DIFFUSE, color );
1066
1067                     glDisableClientState( GL_TEXTURE_COORD_ARRAY );
1068                 }
1069             }
1070             //Disable texture
1071             glDisable( GL_TEXTURE_2D );
1072
1073             glDisableClientState( GL_VERTEX_ARRAY );
1074             glDisableClientState( GL_NORMAL_ARRAY );
1075
1076             glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
1077             glEnable( GL_CULL_FACE );
1078             glDepthFunc(GL_LESS);
1079
1080             ssgLoadModelviewMatrix( modelview );
1081
1082         } else {
1083             state_sel->selectStep( top ? 1 : 0 );
1084             ssgCullAndDraw( layer_root );
1085         }
1086     }
1087 }
1088
1089
1090 // make an ssgSimpleState for a cloud layer given the named texture
1091 ssgSimpleState *sgCloudMakeState( const string &path ) {
1092     ssgSimpleState *state = new ssgSimpleState();
1093
1094     SG_LOG(SG_ASTRO, SG_INFO, " texture = ");
1095
1096     state->setTexture( (char *)path.c_str() );
1097     state->setShadeModel( GL_SMOOTH );
1098     state->disable( GL_LIGHTING );
1099     state->disable( GL_CULL_FACE );
1100     state->enable( GL_TEXTURE_2D );
1101     state->enable( GL_COLOR_MATERIAL );
1102     state->setColourMaterial( GL_AMBIENT_AND_DIFFUSE );
1103     state->setMaterial( GL_EMISSION, 0.05, 0.05, 0.05, 0.0 );
1104     state->setMaterial( GL_AMBIENT, 0.2, 0.2, 0.2, 0.0 );
1105     state->setMaterial( GL_DIFFUSE, 0.5, 0.5, 0.5, 0.0 );
1106     state->setMaterial( GL_SPECULAR, 0.0, 0.0, 0.0, 0.0 );
1107     state->enable( GL_BLEND );
1108     state->enable( GL_ALPHA_TEST );
1109     state->setAlphaClamp( 0.01 );
1110
1111     return state;
1112 }