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 #include <plib/sg.h>
  25 #include <plib/ssg.h>
  26
  27 #include <simgear/math/point3d.hxx>
  28 #include <simgear/math/polar3d.hxx>
  29 #include <simgear/math/sg_random.h>
  30 #include <simgear/debug/logstream.hxx>
  31 #include <simgear/misc/sg_path.hxx>
  32 #include <simgear/screen/extensions.hxx>
  33 #include <simgear/screen/texture.hxx>
  34
  35 #include "newcloud.hxx"
  36 #include "cloudfield.hxx"
  37 #include "cloud.hxx"
  38
  39 #if defined(__MINGW32__)
  40 #define isnan(x) _isnan(x)
  41 #endif
  42
  43 #if defined (__FreeBSD__)
  44 #  if __FreeBSD_version < 500000
  45      extern "C" {
  46        inline int isnan(double r) { return !(r <= 0 || r >= 0); }
  47      }
  48 #  endif
  49 #endif
  50
  51
  52 static ssgStateSelector *layer_states[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
  53 static bool state_initialized = false;
  54 static bool bump_mapping = false;
  55 static GLint nb_texture_unit = 0;
  56 static ssgTexture *normal_map[SGCloudLayer::SG_MAX_CLOUD_COVERAGES][2] = { 0 };
  57 static ssgTexture *color_map[SGCloudLayer::SG_MAX_CLOUD_COVERAGES][2] = { 0 };
  58 static GLuint normalization_cube_map;
  59
  60 static glActiveTextureProc glActiveTexturePtr = 0;
  61 static glClientActiveTextureProc glClientActiveTexturePtr = 0;
  62 static glBlendColorProc glBlendColorPtr = 0;
  63
  64 bool SGCloudLayer::enable_bump_mapping = false;
  65
  66 static void
  67 generateNormalizationCubeMap()
  68 {
  69     unsigned char data[ 32 * 32 * 3 ];
  70     const int size = 32;
  71     const float half_size = 16.0f,
  72                 offset = 0.5f;
  73     sgVec3 zero_normal;
  74     sgSetVec3( zero_normal, 0.5f, 0.5f, 0.5f );
  75     int i, j;
  76
  77     unsigned char *ptr = data;
  78     for ( j = 0; j < size; j++ ) {
  79         for ( i = 0; i < size; i++ ) {
  80             sgVec3 tmp;
  81             sgSetVec3( tmp, half_size,
  82                             -( j + offset - half_size ),
  83                             -( i + offset - half_size ) );
  84             sgNormalizeVec3( tmp );
  85             sgScaleVec3( tmp, 0.5f );
  86             sgAddVec3( tmp, zero_normal );
  87
  88             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
  89             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
  90             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
  91         }
  92     }
  93     glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB,
  94                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
  95
  96     ptr = data;
  97     for ( j = 0; j < size; j++ ) {
  98         for ( i = 0; i < size; i++ ) {
  99             sgVec3 tmp;
 100             sgSetVec3( tmp, -half_size,
 101                             -( j + offset - half_size ),
 102                             ( i + offset - half_size ) );
 103             sgNormalizeVec3( tmp );
 104             sgScaleVec3( tmp, 0.5f );
 105             sgAddVec3( tmp, zero_normal );
 106
 107             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 108             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 109             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 110         }
 111     }
 112     glTexImage2D( GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB,
 113                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 114
 115     ptr = data;
 116     for ( j = 0; j < size; j++ ) {
 117         for ( i = 0; i < size; i++ ) {
 118             sgVec3 tmp;
 119             sgSetVec3( tmp, ( i + offset - half_size ),
 120                             half_size,
 121                             ( j + offset - half_size ) );
 122             sgNormalizeVec3( tmp );
 123             sgScaleVec3( tmp, 0.5f );
 124             sgAddVec3( tmp, zero_normal );
 125
 126             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 127             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 128             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 129         }
 130     }
 131     glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB,
 132                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 133
 134     ptr = data;
 135     for ( j = 0; j < size; j++ ) {
 136         for ( i = 0; i < size; i++ ) {
 137             sgVec3 tmp;
 138             sgSetVec3( tmp, ( i + offset - half_size ),
 139                             -half_size,
 140                             -( j + offset - half_size ) );
 141             sgNormalizeVec3( tmp );
 142             sgScaleVec3( tmp, 0.5f );
 143             sgAddVec3( tmp, zero_normal );
 144
 145             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 146             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 147             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 148         }
 149     }
 150     glTexImage2D( GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB,
 151                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 152
 153     ptr = data;
 154     for ( j = 0; j < size; j++ ) {
 155         for ( i = 0; i < size; i++ ) {
 156             sgVec3 tmp;
 157             sgSetVec3( tmp, ( i + offset - half_size ),
 158                             -( j + offset - half_size ),
 159                             half_size );
 160             sgNormalizeVec3( tmp );
 161             sgScaleVec3( tmp, 0.5f );
 162             sgAddVec3( tmp, zero_normal );
 163
 164             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 165             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 166             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 167         }
 168     }
 169     glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB,
 170                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 171
 172     ptr = data;
 173     for ( j = 0; j < size; j++ ) {
 174         for ( i = 0; i < size; i++ ) {
 175             sgVec3 tmp;
 176             sgSetVec3( tmp, -( i + offset - half_size ),
 177                             -( j + offset - half_size ),
 178                             -half_size );
 179             sgNormalizeVec3( tmp );
 180             sgScaleVec3( tmp, 0.5f );
 181             sgAddVec3( tmp, zero_normal );
 182
 183             *ptr++ = (unsigned char)( tmp[ 0 ] * 255 );
 184             *ptr++ = (unsigned char)( tmp[ 1 ] * 255 );
 185             *ptr++ = (unsigned char)( tmp[ 2 ] * 255 );
 186         }
 187     }
 188     glTexImage2D( GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB,
 189                   0, GL_RGBA8, 32, 32, 0, GL_RGB, GL_UNSIGNED_BYTE, data );
 190 }
 191
 192
 193 // Constructor
 194 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
 195     vertices(0),
 196     indices(0),
 197     layer_root(new ssgRoot),
 198     layer_transform(new ssgTransform),
 199     state_sel(0),
 200     cloud_alpha(1.0),
 201     texture_path(tex_path),
 202     layer_span(0.0),
 203     layer_asl(0.0),
 204     layer_thickness(0.0),
 205     layer_transition(0.0),
 206     layer_coverage(SG_CLOUD_CLEAR),
 207     scale(4000.0),
 208     speed(0.0),
 209     direction(0.0),
 210     last_lon(0.0),
 211     last_lat(0.0)
 212 {
 213     cl[0] = cl[1] = cl[2] = cl[3] = NULL;
 214     vl[0] = vl[1] = vl[2] = vl[3] = NULL;
 215     tl[0] = tl[1] = tl[2] = tl[3] = NULL;
 216     layer[0] = layer[1] = layer[2] = layer[3] = NULL;
 217
 218     layer_root->addKid(layer_transform);
 219         layer3D = new SGCloudField;
 220     rebuild();
 221 }
 222
 223 // Destructor
 224 SGCloudLayer::~SGCloudLayer()
 225 {
 226         delete layer3D;
 227     delete vertices;
 228     delete indices;
 229     delete layer_root;          // deletes layer_transform and layer as well
 230 }
 231
 232 float
 233 SGCloudLayer::getSpan_m () const
 234 {
 235     return layer_span;
 236 }
 237
 238 void
 239 SGCloudLayer::setSpan_m (float span_m)
 240 {
 241     if (span_m != layer_span) {
 242         layer_span = span_m;
 243         rebuild();
 244     }
 245 }
 246
 247 float
 248 SGCloudLayer::getElevation_m () const
 249 {
 250     return layer_asl;
 251 }
 252
 253 void
 254 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
 255 {
 256     layer_asl = elevation_m;
 257
 258     if (set_span) {
 259         if (elevation_m > 4000)
 260             setSpan_m(  elevation_m * 10 );
 261         else
 262             setSpan_m( 40000 );
 263     }
 264 }
 265
 266 float
 267 SGCloudLayer::getThickness_m () const
 268 {
 269     return layer_thickness;
 270 }
 271
 272 void
 273 SGCloudLayer::setThickness_m (float thickness_m)
 274 {
 275     layer_thickness = thickness_m;
 276 }
 277
 278 float
 279 SGCloudLayer::getTransition_m () const
 280 {
 281     return layer_transition;
 282 }
 283
 284 void
 285 SGCloudLayer::setTransition_m (float transition_m)
 286 {
 287     layer_transition = transition_m;
 288 }
 289
 290 SGCloudLayer::Coverage
 291 SGCloudLayer::getCoverage () const
 292 {
 293     return layer_coverage;
 294 }
 295
 296 void
 297 SGCloudLayer::setCoverage (Coverage coverage)
 298 {
 299     if (coverage != layer_coverage) {
 300         layer_coverage = coverage;
 301         rebuild();
 302     }
 303 }
 304
 305
 306 // build the cloud object
 307 void
 308 SGCloudLayer::rebuild()
 309 {
 310     // Initialize states and sizes if necessary.
 311     if ( !state_initialized ) {
 312         state_initialized = true;
 313
 314         SG_LOG(SG_ASTRO, SG_INFO, "initializing cloud layers");
 315
 316         bump_mapping = SGIsOpenGLExtensionSupported("GL_ARB_multitexture") &&
 317                        SGIsOpenGLExtensionSupported("GL_ARB_texture_cube_map") &&
 318                        SGIsOpenGLExtensionSupported("GL_ARB_texture_env_combine") &&
 319                        SGIsOpenGLExtensionSupported("GL_ARB_texture_env_dot3") &&
 320                        SGIsOpenGLExtensionSupported("GL_ARB_imaging");
 321
 322         if ( bump_mapping ) {
 323             glGetIntegerv( GL_MAX_TEXTURE_UNITS_ARB, &nb_texture_unit );
 324             if ( nb_texture_unit < 2 ) {
 325                 bump_mapping = false;
 326             }
 327             //nb_texture_unit = 2; // Force the number of units for now
 328         }
 329
 330         if ( bump_mapping ) {
 331
 332             // This bump mapping code was inspired by the tutorial available at
 333             // http://www.paulsprojects.net/tutorials/simplebump/simplebump.html
 334             // and a NVidia white paper
 335             //  http://developer.nvidia.com/object/bumpmappingwithregistercombiners.html
 336             // The normal map textures were generated by the normal map Gimp plugin :
 337             //  http://nifelheim.dyndns.org/~cocidius/normalmap/
 338             //
 339             SGPath cloud_path;
 340
 341             glActiveTexturePtr = (glActiveTextureProc)SGLookupFunction("glActiveTextureARB");
 342             glClientActiveTexturePtr = (glClientActiveTextureProc)SGLookupFunction("glClientActiveTextureARB");
 343             glBlendColorPtr = (glBlendColorProc)SGLookupFunction("glBlendColor");
 344
 345             cloud_path.set(texture_path.str());
 346             cloud_path.append("overcast.rgb");
 347             color_map[ SG_CLOUD_OVERCAST ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 348             color_map[ SG_CLOUD_OVERCAST ][ 0 ]->ref();
 349             cloud_path.set(texture_path.str());
 350             cloud_path.append("overcast_n.rgb");
 351             normal_map[ SG_CLOUD_OVERCAST ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 352             normal_map[ SG_CLOUD_OVERCAST ][ 0 ]->ref();
 353
 354             cloud_path.set(texture_path.str());
 355             cloud_path.append("overcast_top.rgb");
 356             color_map[ SG_CLOUD_OVERCAST ][ 1 ] = new ssgTexture( cloud_path.str().c_str() );
 357             color_map[ SG_CLOUD_OVERCAST ][ 1 ]->ref();
 358             cloud_path.set(texture_path.str());
 359             cloud_path.append("overcast_top_n.rgb");
 360             normal_map[ SG_CLOUD_OVERCAST ][ 1 ] = new ssgTexture( cloud_path.str().c_str() );
 361             normal_map[ SG_CLOUD_OVERCAST ][ 1 ]->ref();
 362
 363             cloud_path.set(texture_path.str());
 364             cloud_path.append("broken.rgba");
 365             color_map[ SG_CLOUD_BROKEN ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 366             color_map[ SG_CLOUD_BROKEN ][ 0 ]->ref();
 367             cloud_path.set(texture_path.str());
 368             cloud_path.append("broken_n.rgb");
 369             normal_map[ SG_CLOUD_BROKEN ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 370             normal_map[ SG_CLOUD_BROKEN ][ 0 ]->ref();
 371
 372             cloud_path.set(texture_path.str());
 373             cloud_path.append("scattered.rgba");
 374             color_map[ SG_CLOUD_SCATTERED ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 375             color_map[ SG_CLOUD_SCATTERED ][ 0 ]->ref();
 376             cloud_path.set(texture_path.str());
 377             cloud_path.append("scattered_n.rgb");
 378             normal_map[ SG_CLOUD_SCATTERED ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 379             normal_map[ SG_CLOUD_SCATTERED ][ 0 ]->ref();
 380
 381             cloud_path.set(texture_path.str());
 382             cloud_path.append("few.rgba");
 383             color_map[ SG_CLOUD_FEW ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 384             color_map[ SG_CLOUD_FEW ][ 0 ]->ref();
 385             cloud_path.set(texture_path.str());
 386             cloud_path.append("few_n.rgb");
 387             normal_map[ SG_CLOUD_FEW ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 388             normal_map[ SG_CLOUD_FEW ][ 0 ]->ref();
 389
 390             cloud_path.set(texture_path.str());
 391             cloud_path.append("cirrus.rgba");
 392             color_map[ SG_CLOUD_CIRRUS ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 393             color_map[ SG_CLOUD_CIRRUS ][ 0 ]->ref();
 394             cloud_path.set(texture_path.str());
 395             cloud_path.append("cirrus_n.rgb");
 396             normal_map[ SG_CLOUD_CIRRUS ][ 0 ] = new ssgTexture( cloud_path.str().c_str() );
 397             normal_map[ SG_CLOUD_CIRRUS ][ 0 ]->ref();
 398
 399             glGenTextures( 1, &normalization_cube_map );
 400             glBindTexture( GL_TEXTURE_CUBE_MAP_ARB, normalization_cube_map );
 401             generateNormalizationCubeMap();
 402             glTexParameteri( GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
 403             glTexParameteri( GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, GL_LINEAR );
 404             glTexParameteri( GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE );
 405             glTexParameteri( GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE );
 406             glTexParameteri( GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE );
 407         } /* else */ {
 408             SGPath cloud_path;
 409             ssgStateSelector *state_sel;
 410             ssgSimpleState *state;
 411
 412             state_sel = new ssgStateSelector( 2 );
 413             state_sel->ref();
 414             cloud_path.set(texture_path.str());
 415             cloud_path.append("overcast.rgb");
 416             state_sel->setStep( 0, sgCloudMakeState(cloud_path.str()) );
 417             cloud_path.set(texture_path.str());
 418             cloud_path.append("overcast_top.rgb");
 419             state_sel->setStep( 1, sgCloudMakeState(cloud_path.str()) );
 420             layer_states[SG_CLOUD_OVERCAST] = state_sel;
 421
 422             state_sel = new ssgStateSelector( 2 );
 423             state_sel->ref();
 424             cloud_path.set(texture_path.str());
 425             cloud_path.append("broken.rgba");
 426             state = sgCloudMakeState(cloud_path.str());
 427             state_sel->setStep( 0, state );
 428             state_sel->setStep( 1, state );
 429             layer_states[SG_CLOUD_BROKEN] = state_sel;
 430
 431             state_sel = new ssgStateSelector( 2 );
 432             state_sel->ref();
 433             cloud_path.set(texture_path.str());
 434             cloud_path.append("scattered.rgba");
 435             state = sgCloudMakeState(cloud_path.str());
 436             state_sel->setStep( 0, state );
 437             state_sel->setStep( 1, state );
 438             layer_states[SG_CLOUD_SCATTERED] = state_sel;
 439
 440             state_sel = new ssgStateSelector( 2 );
 441             state_sel->ref();
 442             cloud_path.set(texture_path.str());
 443             cloud_path.append("few.rgba");
 444             state = sgCloudMakeState(cloud_path.str());
 445             state_sel->setStep( 0, state );
 446             state_sel->setStep( 1, state );
 447             layer_states[SG_CLOUD_FEW] = state_sel;
 448
 449             state_sel = new ssgStateSelector( 2 );
 450             state_sel->ref();
 451             cloud_path.set(texture_path.str());
 452             cloud_path.append("cirrus.rgba");
 453             state = sgCloudMakeState(cloud_path.str());
 454             state_sel->setStep( 0, state );
 455             state_sel->setStep( 1, state );
 456             layer_states[SG_CLOUD_CIRRUS] = state_sel;
 457
 458             layer_states[SG_CLOUD_CLEAR] = 0;
 459         }
 460                 SGNewCloud::loadTextures(texture_path.str());
 461                 layer3D->buildTestLayer();
 462     }
 463
 464     if ( bump_mapping ) {
 465
 466         if ( !vertices ) {
 467             vertices = new CloudVertex[ 25 ];
 468             indices = new unsigned int[ 40 ];
 469         }
 470
 471         sgVec2 base;
 472         sgSetVec2( base, sg_random(), sg_random() );
 473
 474         const float layer_scale = layer_span / scale;
 475         const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 476         const float half_angle = 0.5 * layer_span / layer_to_core;
 477
 478         int i;
 479         for ( i = -2; i <= 2; i++ ) {
 480             for ( int j = -2; j <= 2; j++ ) {
 481                 CloudVertex &v1 = vertices[ (i+2)*5 + (j+2) ];
 482                 sgSetVec3( v1.position,
 483                            0.5 * i * layer_span,
 484                            0.5 * j * layer_span,
 485                            -layer_to_core * ( 1 - cos( i * half_angle ) * cos( j * half_angle ) ) );
 486                 sgSetVec2( v1.texCoord,
 487                            base[0] + layer_scale * i * 0.25,
 488                            base[1] + layer_scale * j * 0.25 );
 489                 sgSetVec3( v1.sTangent,
 490                            cos( i * half_angle ),
 491                            0.f,
 492                            -sin( i * half_angle ) );
 493                 sgSetVec3( v1.tTangent,
 494                            0.f,
 495                            cos( j * half_angle ),
 496                            -sin( j * half_angle ) );
 497                 sgVectorProductVec3( v1.normal, v1.tTangent, v1.sTangent );
 498                 sgSetVec4( v1.color, 1.0f, 1.0f, 1.0f, (i == 0) ? 0.0f : cloud_alpha * 0.15f );
 499             }
 500         }
 501         /*
 502          * 0 1 5 6 10 11 15 16 20 21
 503          * 1 2 6 7 11 12 16 17 21 22
 504          * 2 3 7 8 12 13 17 18 22 23
 505          * 3 4 8 9 13 14 18 19 23 24
 506          */
 507         for ( i = 0; i < 4; i++ ) {
 508             for ( int j = 0; j < 5; j++ ) {
 509                 indices[ i*10 + (j*2) ]     =     i + 5 * j;
 510                 indices[ i*10 + (j*2) + 1 ] = 1 + i + 5 * j;
 511             }
 512         }
 513
 514     } /* else */ {
 515
 516         scale = 4000.0;
 517         last_lon = last_lat = -999.0f;
 518
 519         sgVec2 base;
 520         sgSetVec2( base, sg_random(), sg_random() );
 521
 522         // build the cloud layer
 523         sgVec4 color;
 524         sgVec3 vertex;
 525         sgVec2 tc;
 526
 527         const float layer_scale = layer_span / scale;
 528         const float mpi = SG_PI/4;
 529
 530         // caclculate the difference between a flat-earth model and
 531         // a round earth model given the span and altutude ASL of
 532         // the cloud layer. This is the difference in altitude between
 533         // the top of the inverted bowl and the edge of the bowl.
 534         // const float alt_diff = layer_asl * 0.8;
 535         const float layer_to_core = (SG_EARTH_RAD * 1000 + layer_asl);
 536         const float layer_angle = 0.5*layer_span / layer_to_core; // The angle is half the span
 537         const float border_to_core = layer_to_core * cos(layer_angle);
 538         const float alt_diff = layer_to_core - border_to_core;
 539
 540         for (int i = 0; i < 4; i++)
 541         {
 542             if ( layer[i] != NULL ) {
 543                 layer_transform->removeKid(layer[i]); // automatic delete
 544             }
 545
 546             vl[i] = new ssgVertexArray( 10 );
 547             cl[i] = new ssgColourArray( 10 );
 548             tl[i] = new ssgTexCoordArray( 10 );
 549
 550
 551             sgSetVec3( vertex, layer_span*(i-2)/2, -layer_span,
 552                             alt_diff * (sin(i*mpi) - 2) );
 553
 554             sgSetVec2( tc, base[0] + layer_scale * i/4, base[1] );
 555
 556             sgSetVec4( color, 1.0f, 1.0f, 1.0f, (i == 0) ? 0.0f : 0.15f );
 557
 558             cl[i]->add( color );
 559             vl[i]->add( vertex );
 560             tl[i]->add( tc );
 561
 562             for (int j = 0; j < 4; j++)
 563             {
 564                 sgSetVec3( vertex, layer_span*(i-1)/2, layer_span*(j-2)/2,
 565                                 alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2) );
 566
 567                 sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
 568                             base[1] + layer_scale * j/4 );
 569
 570                 sgSetVec4( color, 1.0f, 1.0f, 1.0f,
 571                                 ( (j == 0) || (i == 3)) ?
 572                                 ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
 573
 574                 cl[i]->add( color );
 575                 vl[i]->add( vertex );
 576                 tl[i]->add( tc );
 577
 578
 579                 sgSetVec3( vertex, layer_span*(i-2)/2, layer_span*(j-1)/2,
 580                                 alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
 581
 582                 sgSetVec2( tc, base[0] + layer_scale * i/4,
 583                             base[1] + layer_scale * (j+1)/4 );
 584
 585                 sgSetVec4( color, 1.0f, 1.0f, 1.0f,
 586                                 ((j == 3) || (i == 0)) ?
 587                                 ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
 588                 cl[i]->add( color );
 589                 vl[i]->add( vertex );
 590                 tl[i]->add( tc );
 591             }
 592
 593             sgSetVec3( vertex, layer_span*(i-1)/2, layer_span,
 594                             alt_diff * (sin((i+1)*mpi) - 2) );
 595
 596             sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
 597                         base[1] + layer_scale );
 598
 599             sgSetVec4( color, 1.0f, 1.0f, 1.0f, (i == 3) ? 0.0f : 0.15f );
 600
 601             cl[i]->add( color );
 602             vl[i]->add( vertex );
 603             tl[i]->add( tc );
 604
 605             layer[i] = new ssgVtxTable(GL_TRIANGLE_STRIP, vl[i], NULL, tl[i], cl[i]);
 606             layer_transform->addKid( layer[i] );
 607
 608             if ( layer_states[layer_coverage] != NULL ) {
 609                 layer[i]->setState( layer_states[layer_coverage] );
 610             }
 611             state_sel = layer_states[layer_coverage];
 612         }
 613
 614         // force a repaint of the sky colors with arbitrary defaults
 615         repaint( color );
 616     }
 617 }
 618
 619
 620 // repaint the cloud layer colors
 621 bool SGCloudLayer::repaint( sgVec3 fog_color ) {
 622
 623     if ( bump_mapping && enable_bump_mapping ) {
 624
 625         for ( int i = 0; i < 25; i++ ) {
 626             sgCopyVec3( vertices[ i ].color, fog_color );
 627         }
 628
 629     } else {
 630         float *color;
 631
 632         for ( int i = 0; i < 4; i++ ) {
 633             color = cl[i]->get( 0 );
 634             sgCopyVec3( color, fog_color );
 635             color[3] = (i == 0) ? 0.0f : cloud_alpha * 0.15f;
 636
 637             for ( int j = 0; j < 4; ++j ) {
 638                 color = cl[i]->get( (2*j) + 1 );
 639                 sgCopyVec3( color, fog_color );
 640                 color[3] =
 641                     ((j == 0) || (i == 3)) ?
 642                     ((j == 0) && (i == 3)) ? 0.0f : cloud_alpha * 0.15f : cloud_alpha;
 643
 644                 color = cl[i]->get( (2*j) + 2 );
 645                 sgCopyVec3( color, fog_color );
 646                 color[3] =
 647                     ((j == 3) || (i == 0)) ?
 648                     ((j == 3) && (i == 0)) ? 0.0f : cloud_alpha * 0.15f : cloud_alpha;
 649             }
 650
 651             color = cl[i]->get( 9 );
 652             sgCopyVec3( color, fog_color );
 653             color[3] = (i == 3) ? 0.0f : cloud_alpha * 0.15f;
 654         }
 655     }
 656
 657     return true;
 658 }
 659
 660 // reposition the cloud layer at the specified origin and orientation
 661 // lon specifies a rotation about the Z axis
 662 // lat specifies a rotation about the new Y axis
 663 // spin specifies a rotation about the new Z axis (and orients the
 664 // sunrise/set effects
 665 bool SGCloudLayer::reposition( sgVec3 p, sgVec3 up, double lon, double lat,
 666                                double alt, double dt )
 667 {
 668     sgMat4 T1, LON, LAT;
 669     sgVec3 axis;
 670
 671     // combine p and asl (meters) to get translation offset
 672     sgVec3 asl_offset;
 673     sgCopyVec3( asl_offset, up );
 674     sgNormalizeVec3( asl_offset );
 675     if ( alt <= layer_asl ) {
 676         sgScaleVec3( asl_offset, layer_asl );
 677     } else {
 678         sgScaleVec3( asl_offset, layer_asl + layer_thickness );
 679     }
 680     // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 681     //      << "," << asl_offset[2] << endl;
 682     sgAddVec3( asl_offset, p );
 683     // cout << "  asl_offset = " << asl_offset[0] << "," << asl_offset[1]
 684     //      << "," << asl_offset[2] << endl;
 685
 686     // Translate to zero elevation
 687     // Point3D zero_elev = current_view.get_cur_zero_elev();
 688     sgMakeTransMat4( T1, asl_offset );
 689
 690     // printf("  Translated to %.2f %.2f %.2f\n",
 691     //        zero_elev.x, zero_elev.y, zero_elev.z );
 692
 693     // Rotate to proper orientation
 694     // printf("  lon = %.2f  lat = %.2f\n",
 695     //        lon * SGD_RADIANS_TO_DEGREES,
 696     //        lat * SGD_RADIANS_TO_DEGREES);
 697     sgSetVec3( axis, 0.0, 0.0, 1.0 );
 698     sgMakeRotMat4( LON, lon * SGD_RADIANS_TO_DEGREES, axis );
 699
 700     sgSetVec3( axis, 0.0, 1.0, 0.0 );
 701     sgMakeRotMat4( LAT, 90.0 - lat * SGD_RADIANS_TO_DEGREES, axis );
 702
 703     sgMat4 TRANSFORM;
 704
 705     sgCopyMat4( TRANSFORM, T1 );
 706     sgPreMultMat4( TRANSFORM, LON );
 707     sgPreMultMat4( TRANSFORM, LAT );
 708
 709     sgCoord layerpos;
 710     sgSetCoord( &layerpos, TRANSFORM );
 711
 712     layer_transform->setTransform( &layerpos );
 713
 714     // now calculate update texture coordinates
 715     if ( last_lon < -900 ) {
 716         last_lon = lon;
 717         last_lat = lat;
 718     }
 719
 720     double sp_dist = speed*dt;
 721
 722     if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
 723         Point3D start( last_lon, last_lat, 0.0 );
 724         Point3D dest( lon, lat, 0.0 );
 725         double course = 0.0, dist = 0.0;
 726
 727         calc_gc_course_dist( dest, start, &course, &dist );
 728         // cout << "course = " << course << ", dist = " << dist << endl;
 729
 730         // if start and dest are too close together,
 731         // calc_gc_course_dist() can return a course of "nan".  If
 732         // this happens, lets just use the last known good course.
 733         // This is a hack, and it would probably be better to make
 734         // calc_gc_course_dist() more robust.
 735         if ( isnan(course) ) {
 736             course = last_course;
 737         } else {
 738             last_course = course;
 739         }
 740
 741         // calculate cloud movement due to external forces
 742         double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
 743
 744         if (dist > 0.0) {
 745             ax = cos(course) * dist;
 746             ay = sin(course) * dist;
 747         }
 748
 749         if (sp_dist > 0) {
 750             bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 751             by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
 752         }
 753
 754
 755         double xoff = (ax + bx) / (2 * scale);
 756         double yoff = (ay + by) / (2 * scale);
 757
 758         const float layer_scale = layer_span / scale;
 759
 760         // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
 761
 762         float *base;
 763         if ( bump_mapping && enable_bump_mapping ) {
 764             base = vertices[12].texCoord;
 765         } else {
 766             base = tl[0]->get( 0 );
 767         }
 768         base[0] += xoff;
 769
 770         // the while loops can lead to *long* pauses if base[0] comes
 771         // with a bogus value.
 772         // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
 773         // while ( base[0] < 0.0 ) { base[0] += 1.0; }
 774         if ( base[0] > -10.0 && base[0] < 10.0 ) {
 775             base[0] -= (int)base[0];
 776         } else {
 777             SG_LOG(SG_ASTRO, SG_DEBUG,
 778                 "Error: base = " << base[0] << "," << base[1] <<
 779                 " course = " << course << " dist = " << dist );
 780             base[0] = 0.0;
 781         }
 782
 783         base[1] += yoff;
 784         // the while loops can lead to *long* pauses if base[0] comes
 785         // with a bogus value.
 786         // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
 787         // while ( base[1] < 0.0 ) { base[1] += 1.0; }
 788         if ( base[1] > -10.0 && base[1] < 10.0 ) {
 789             base[1] -= (int)base[1];
 790         } else {
 791             SG_LOG(SG_ASTRO, SG_ALERT,
 792                     "Error: base = " << base[0] << "," << base[1] <<
 793                     " course = " << course << " dist = " << dist );
 794             base[1] = 0.0;
 795         }
 796
 797         if ( bump_mapping && enable_bump_mapping ) {
 798
 799             for ( int i = -2; i <= 2; i++ ) {
 800                 for ( int j = -2; j <= 2; j++ ) {
 801                     if ( i == 0 && j == 0 )
 802                         continue; // Already done on base
 803                     CloudVertex &v1 = vertices[ (i+2)*5 + (j+2) ];
 804                     sgSetVec2( v1.texCoord,
 805                             base[0] + layer_scale * i * 0.25,
 806                             base[1] + layer_scale * j * 0.25 );
 807                 }
 808             }
 809
 810         } else {
 811                 // cout << "base = " << base[0] << "," << base[1] << endl;
 812
 813             float *tc;
 814             for (int i = 0; i < 4; i++) {
 815                 tc = tl[i]->get( 0 );
 816                 sgSetVec2( tc, base[0] + layer_scale * i/4, base[1] );
 817
 818                 for (int j = 0; j < 4; j++)
 819                 {
 820                     tc = tl[i]->get( j*2+1 );
 821                     sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
 822                                 base[1] + layer_scale * j/4 );
 823
 824                     tc = tl[i]->get( (j+1)*2 );
 825                     sgSetVec2( tc, base[0] + layer_scale * i/4,
 826                                 base[1] + layer_scale * (j+1)/4 );
 827                 }
 828
 829                 tc = tl[i]->get( 9 );
 830                 sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
 831                             base[1] + layer_scale );
 832             }
 833         }
 834
 835         last_lon = lon;
 836         last_lat = lat;
 837     }
 838
 839         layer3D->reposition( p, up, lon, lat, alt, dt, direction, speed);
 840     return true;
 841 }
 842
 843
 844 void SGCloudLayer::draw( bool top ) {
 845     if ( layer_coverage != SG_CLOUD_CLEAR ) {
 846
 847                 if ( SGCloudField::enable3D && layer3D->is3D())
 848                         layer3D->Render();
 849                 else
 850         if ( bump_mapping && enable_bump_mapping ) {
 851
 852             sgMat4 modelview,
 853                    tmp,
 854                    transform;
 855             ssgGetModelviewMatrix( modelview );
 856             layer_transform->getTransform( transform );
 857
 858             sgTransposeNegateMat4( tmp, transform );
 859
 860             sgPostMultMat4( transform, modelview );
 861             ssgLoadModelviewMatrix( transform );
 862
 863             sgVec3 lightVec;
 864             ssgGetLight( 0 )->getPosition( lightVec );
 865             sgNegateVec3( lightVec );
 866             sgXformVec3( lightVec, tmp );
 867
 868             for ( int i = 0; i < 25; i++ ) {
 869                 CloudVertex &v = vertices[ i ];
 870                 sgSetVec3( v.tangentSpLight,
 871                            sgScalarProductVec3( v.sTangent, lightVec ),
 872                            sgScalarProductVec3( v.tTangent, lightVec ),
 873                            sgScalarProductVec3( v.normal, lightVec ) );
 874             }
 875
 876             ssgTexture *decal = color_map[ layer_coverage ][ top ? 1 : 0 ];
 877             if ( top && decal == 0 ) {
 878                 decal = color_map[ layer_coverage ][ 0 ];
 879             }
 880             ssgTexture *normal = normal_map[ layer_coverage ][ top ? 1 : 0 ];
 881             if ( top && normal == 0 ) {
 882                 normal = normal_map[ layer_coverage ][ 0 ];
 883             }
 884
 885             glDisable( GL_LIGHTING );
 886             glDisable( GL_CULL_FACE );
 887 //            glDisable( GL_ALPHA_TEST );
 888             if ( layer_coverage == SG_CLOUD_FEW ) {
 889                 glEnable( GL_ALPHA_TEST );
 890                 glAlphaFunc ( GL_GREATER, 0.01 );
 891             }
 892             glEnable( GL_BLEND );
 893             glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
 894
 895             glShadeModel( GL_SMOOTH );
 896             glEnable( GL_COLOR_MATERIAL );
 897             sgVec4 color;
 898             float emis = 0.05;
 899             if ( 1 ) {
 900                 ssgGetLight( 0 )->getColour( GL_DIFFUSE, color );
 901                 emis = ( color[0]+color[1]+color[2] ) / 3.0;
 902                 if ( emis < 0.05 )
 903                     emis = 0.05;
 904             }
 905             sgSetVec4( color, emis, emis, emis, 0.0 );
 906             glMaterialfv( GL_FRONT_AND_BACK, GL_EMISSION, color );
 907             sgSetVec4( color, 1.0f, 1.0f, 1.0f, 0.0 );
 908             glMaterialfv( GL_FRONT_AND_BACK, GL_AMBIENT, color );
 909             sgSetVec4( color, 1.0, 1.0, 1.0, 0.0 );
 910             glMaterialfv( GL_FRONT_AND_BACK, GL_DIFFUSE, color );
 911             sgSetVec4( color, 0.0, 0.0, 0.0, 0.0 );
 912             glMaterialfv( GL_FRONT_AND_BACK, GL_SPECULAR, color );
 913
 914             glColor4f( 1.0f, 1.0f, 1.0f, 1.0f );
 915
 916             glActiveTexturePtr( GL_TEXTURE0_ARB );
 917             glBindTexture( GL_TEXTURE_2D, normal->getHandle() );
 918             glEnable( GL_TEXTURE_2D );
 919
 920             //Bind normalisation cube map to texture unit 1
 921             glActiveTexturePtr( GL_TEXTURE1_ARB );
 922             glBindTexture( GL_TEXTURE_CUBE_MAP_ARB, normalization_cube_map );
 923             glEnable( GL_TEXTURE_CUBE_MAP_ARB );
 924             glActiveTexturePtr( GL_TEXTURE0_ARB );
 925
 926             //Set vertex arrays for cloud
 927             glVertexPointer( 3, GL_FLOAT, sizeof(CloudVertex), &vertices[0].position );
 928             glEnableClientState( GL_VERTEX_ARRAY );
 929 /*
 930             if ( nb_texture_unit >= 3 ) {
 931                 glColorPointer( 4, GL_FLOAT, sizeof(CloudVertex), &vertices[0].color );
 932                 glEnableClientState( GL_COLOR_ARRAY );
 933             }
 934 */
 935             //Send texture coords for normal map to unit 0
 936             glTexCoordPointer( 2, GL_FLOAT, sizeof(CloudVertex), &vertices[0].texCoord );
 937             glEnableClientState( GL_TEXTURE_COORD_ARRAY );
 938
 939             //Send tangent space light vectors for normalisation to unit 1
 940             glClientActiveTexturePtr( GL_TEXTURE1_ARB );
 941             glTexCoordPointer( 3, GL_FLOAT, sizeof(CloudVertex), &vertices[0].tangentSpLight );
 942             glEnableClientState( GL_TEXTURE_COORD_ARRAY );
 943
 944             //Set up texture environment to do (tex0 dot tex1)*color
 945             glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB );
 946             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE );
 947             glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_REPLACE );
 948             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_ALPHA_ARB, GL_TEXTURE );
 949             glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_ALPHA_ARB, GL_REPLACE );
 950
 951             glActiveTexturePtr( GL_TEXTURE1_ARB );
 952
 953             glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB );
 954             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE );
 955             glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_DOT3_RGB_ARB );
 956             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB );
 957             glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_ALPHA_ARB, GL_PREVIOUS_ARB );
 958             glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_ALPHA_ARB, GL_REPLACE );
 959
 960             if ( nb_texture_unit >= 3 ) {
 961                 glActiveTexturePtr( GL_TEXTURE2_ARB );
 962                 glBindTexture( GL_TEXTURE_2D, decal->getHandle() );
 963
 964                 glClientActiveTexturePtr( GL_TEXTURE2_ARB );
 965                 glTexCoordPointer( 2, GL_FLOAT, sizeof(CloudVertex), &vertices[0].texCoord );
 966                 glEnableClientState( GL_TEXTURE_COORD_ARRAY );
 967
 968                 glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE_ARB );
 969                 glTexEnvi( GL_TEXTURE_ENV, GL_COMBINE_RGB_ARB, GL_ADD );
 970                 glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE0_RGB_ARB, GL_TEXTURE );
 971                 glTexEnvi( GL_TEXTURE_ENV, GL_SOURCE1_RGB_ARB, GL_PREVIOUS_ARB );
 972
 973                 glClientActiveTexturePtr( GL_TEXTURE0_ARB );
 974                 glActiveTexturePtr( GL_TEXTURE0_ARB );
 975
 976                 //Draw cloud layer
 977                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[0] );
 978                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[10] );
 979                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[20] );
 980                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[30] );
 981
 982                 glDisable( GL_TEXTURE_2D );
 983                 glActiveTexturePtr( GL_TEXTURE1_ARB );
 984                 glDisable( GL_TEXTURE_CUBE_MAP_ARB );
 985                 glActiveTexturePtr( GL_TEXTURE2_ARB );
 986                 glDisable( GL_TEXTURE_2D );
 987                 glActiveTexturePtr( GL_TEXTURE0_ARB );
 988
 989                 glDisableClientState( GL_TEXTURE_COORD_ARRAY );
 990                 glClientActiveTexturePtr( GL_TEXTURE1_ARB );
 991                 glDisableClientState( GL_TEXTURE_COORD_ARRAY );
 992                 glClientActiveTexturePtr( GL_TEXTURE2_ARB );
 993                 glDisableClientState( GL_TEXTURE_COORD_ARRAY );
 994                 glClientActiveTexturePtr( GL_TEXTURE0_ARB );
 995
 996                 glDisableClientState( GL_COLOR_ARRAY );
 997                 glEnable( GL_LIGHTING );
 998
 999                 glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
1000
1001             } else {
1002                 glClientActiveTexturePtr( GL_TEXTURE0_ARB );
1003                 glActiveTexturePtr( GL_TEXTURE0_ARB );
1004
1005                 //Draw cloud layer
1006                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[0] );
1007                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[10] );
1008                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[20] );
1009                 glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[30] );
1010
1011                 //Disable textures
1012                 glDisable( GL_TEXTURE_2D );
1013
1014                 glActiveTexturePtr( GL_TEXTURE1_ARB );
1015                 glDisable( GL_TEXTURE_CUBE_MAP_ARB );
1016                 glActiveTexturePtr( GL_TEXTURE0_ARB );
1017
1018                 //disable vertex arrays
1019                 glDisableClientState( GL_VERTEX_ARRAY );
1020
1021                 glDisableClientState( GL_TEXTURE_COORD_ARRAY );
1022                 glClientActiveTexturePtr( GL_TEXTURE1_ARB );
1023                 glDisableClientState( GL_TEXTURE_COORD_ARRAY );
1024                 glClientActiveTexturePtr( GL_TEXTURE0_ARB );
1025
1026                 //Return to standard modulate texenv
1027                 glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
1028
1029                 if ( layer_coverage == SG_CLOUD_OVERCAST ) {
1030                     glDepthFunc(GL_LEQUAL);
1031
1032                     glEnable( GL_LIGHTING );
1033                     sgVec4 color;
1034                     ssgGetLight( 0 )->getColour( GL_DIFFUSE, color );
1035                     float average = ( color[0] + color[1] + color[2] ) / 3.0f;
1036                     average = 0.15 + average/10;
1037                     sgVec4 averageColor;
1038                     sgSetVec4( averageColor, average, average, average, 1.0f );
1039                     ssgGetLight( 0 )->setColour( GL_DIFFUSE, averageColor );
1040
1041                     glBlendColorPtr( average, average, average, 1.0f );
1042                     glBlendFunc( GL_ONE_MINUS_CONSTANT_COLOR, GL_CONSTANT_COLOR );
1043
1044                     //Perform a second pass to color the torus
1045                     //Bind decal texture
1046                     glBindTexture( GL_TEXTURE_2D, decal->getHandle() );
1047                     glEnable(GL_TEXTURE_2D);
1048
1049                     //Set vertex arrays for torus
1050                     glVertexPointer( 3, GL_FLOAT, sizeof(CloudVertex), &vertices[0].position );
1051                     glEnableClientState( GL_VERTEX_ARRAY );
1052
1053                     //glColorPointer( 4, GL_FLOAT, sizeof(CloudVertex), &vertices[0].color );
1054                     //glEnableClientState( GL_COLOR_ARRAY );
1055
1056                     glNormalPointer( GL_FLOAT, sizeof(CloudVertex), &vertices[0].normal );
1057                     glEnableClientState( GL_NORMAL_ARRAY );
1058
1059                     glTexCoordPointer( 2, GL_FLOAT, sizeof(CloudVertex), &vertices[0].texCoord );
1060                     glEnableClientState( GL_TEXTURE_COORD_ARRAY );
1061
1062                     //Draw cloud layer
1063                     glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[0] );
1064                     glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[10] );
1065                     glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[20] );
1066                     glDrawElements( GL_TRIANGLE_STRIP, 10, GL_UNSIGNED_INT, &indices[30] );
1067
1068                     ssgGetLight( 0 )->setColour( GL_DIFFUSE, color );
1069
1070                     glDisableClientState( GL_TEXTURE_COORD_ARRAY );
1071                 }
1072             }
1073             //Disable texture
1074             glDisable( GL_TEXTURE_2D );
1075
1076             glDisableClientState( GL_VERTEX_ARRAY );
1077             glDisableClientState( GL_NORMAL_ARRAY );
1078
1079             glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA );
1080             glEnable( GL_CULL_FACE );
1081             glDepthFunc(GL_LESS);
1082
1083             ssgLoadModelviewMatrix( modelview );
1084
1085         } else {
1086             state_sel->selectStep( top ? 1 : 0 );
1087             ssgCullAndDraw( layer_root );
1088         }
1089     }
1090 }
1091
1092
1093 // make an ssgSimpleState for a cloud layer given the named texture
1094 ssgSimpleState *sgCloudMakeState( const string &path ) {
1095     ssgSimpleState *state = new ssgSimpleState();
1096
1097     SG_LOG(SG_ASTRO, SG_INFO, " texture = ");
1098
1099     state->setTexture( (char *)path.c_str() );
1100     state->setShadeModel( GL_SMOOTH );
1101     state->disable( GL_LIGHTING );
1102     state->disable( GL_CULL_FACE );
1103     state->enable( GL_TEXTURE_2D );
1104     state->enable( GL_COLOR_MATERIAL );
1105     state->setColourMaterial( GL_AMBIENT_AND_DIFFUSE );
1106     state->setMaterial( GL_EMISSION, 0.05, 0.05, 0.05, 0.0 );
1107     state->setMaterial( GL_AMBIENT, 0.2, 0.2, 0.2, 0.0 );
1108     state->setMaterial( GL_DIFFUSE, 0.5, 0.5, 0.5, 0.0 );
1109     state->setMaterial( GL_SPECULAR, 0.0, 0.0, 0.0, 0.0 );
1110     state->enable( GL_BLEND );
1111     state->enable( GL_ALPHA_TEST );
1112     state->setAlphaClamp( 0.01 );
1113
1114     return state;
1115 }