1 // cloud.cxx -- model a single cloud layer
3 // Written by Curtis Olson, started June 2000.
5 // Copyright (C) 2000 Curtis L. Olson - curt@flightgear.org
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.
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.
19 #include <simgear/compiler.h>
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>
36 static ssgSimpleState *layer_states[SGCloudLayer::SG_MAX_CLOUD_COVERAGES];
37 static bool state_initialized = false;
41 SGCloudLayer::SGCloudLayer( const string &tex_path ) :
42 layer_root(new ssgRoot),
43 layer_transform(new ssgTransform),
44 texture_path(tex_path),
48 layer_transition(0.0),
49 layer_coverage(SG_CLOUD_CLEAR),
56 cl[0] = cl[1] = cl[2] = cl[3] = NULL;
57 vl[0] = vl[1] = vl[2] = vl[3] = NULL;
58 tl[0] = tl[1] = tl[2] = tl[3] = NULL;
59 layer[0] = layer[1] = layer[2] = layer[3] = NULL;
61 layer_root->addKid(layer_transform);
66 SGCloudLayer::~SGCloudLayer()
68 delete layer_root; // deletes layer_transform and layer as well
72 SGCloudLayer::getSpan_m () const
78 SGCloudLayer::setSpan_m (float span_m)
80 if (span_m != layer_span) {
87 SGCloudLayer::getElevation_m () const
93 SGCloudLayer::setElevation_m (float elevation_m, bool set_span)
95 layer_asl = elevation_m;
98 if (elevation_m > 4000)
99 setSpan_m( elevation_m * 10 );
106 SGCloudLayer::getThickness_m () const
108 return layer_thickness;
112 SGCloudLayer::setThickness_m (float thickness_m)
114 layer_thickness = thickness_m;
118 SGCloudLayer::getTransition_m () const
120 return layer_transition;
124 SGCloudLayer::setTransition_m (float transition_m)
126 layer_transition = transition_m;
129 SGCloudLayer::Coverage
130 SGCloudLayer::getCoverage () const
132 return layer_coverage;
136 SGCloudLayer::setCoverage (Coverage coverage)
138 if (coverage != layer_coverage) {
139 layer_coverage = coverage;
145 // build the cloud object
147 SGCloudLayer::rebuild()
149 // Initialize states and sizes if necessary.
150 if ( !state_initialized ) {
151 state_initialized = true;
153 cout << "initializing cloud layers" << endl;
157 cloud_path.set(texture_path.str());
158 cloud_path.append("overcast.rgb");
159 layer_states[SG_CLOUD_OVERCAST] = sgCloudMakeState(cloud_path.str());
161 cloud_path.set(texture_path.str());
162 cloud_path.append("broken.rgba");
163 layer_states[SG_CLOUD_BROKEN]
164 = sgCloudMakeState(cloud_path.str());
166 cloud_path.set(texture_path.str());
167 cloud_path.append("scattered.rgba");
168 layer_states[SG_CLOUD_SCATTERED]
169 = sgCloudMakeState(cloud_path.str());
171 cloud_path.set(texture_path.str());
172 cloud_path.append("few.rgba");
173 layer_states[SG_CLOUD_FEW]
174 = sgCloudMakeState(cloud_path.str());
176 cloud_path.set(texture_path.str());
177 cloud_path.append("cirrus.rgba");
178 layer_states[SG_CLOUD_CIRRUS]
179 = sgCloudMakeState(cloud_path.str());
181 layer_states[SG_CLOUD_CLEAR] = 0;
185 last_lon = last_lat = -999.0f;
188 sgSetVec2( base, sg_random(), sg_random() );
190 // build the cloud layer
195 const float layer_scale = layer_span / scale;
196 const float mpi = SG_PI/4;
197 const float alt_diff = layer_asl * 0.8;
199 for (int i = 0; i < 4; i++)
201 if ( layer[i] != NULL ) {
202 layer_transform->removeKid(layer[i]); // automatic delete
205 vl[i] = new ssgVertexArray( 10 );
206 cl[i] = new ssgColourArray( 10 );
207 tl[i] = new ssgTexCoordArray( 10 );
210 sgSetVec3( vertex, layer_span*(i-2)/2, -layer_span,
211 alt_diff * (sin(i*mpi) - 2) );
213 sgSetVec2( tc, base[0] + layer_scale * i/4, base[1] );
215 sgSetVec4( color, 1.0f, 1.0f, 1.0f, (i == 0) ? 0.0f : 0.15f );
218 vl[i]->add( vertex );
221 for (int j = 0; j < 4; j++)
223 sgSetVec3( vertex, layer_span*(i-1)/2, layer_span*(j-2)/2,
224 alt_diff * (sin((i+1)*mpi) + sin(j*mpi) - 2) );
226 sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
227 base[1] + layer_scale * j/4 );
229 sgSetVec4( color, 1.0f, 1.0f, 1.0f,
230 ( (j == 0) || (i == 3)) ?
231 ( (j == 0) && (i == 3)) ? 0.0f : 0.15f : 1.0f );
234 vl[i]->add( vertex );
238 sgSetVec3( vertex, layer_span*(i-2)/2, layer_span*(j-1)/2,
239 alt_diff * (sin(i*mpi) + sin((j+1)*mpi) - 2) );
241 sgSetVec2( tc, base[0] + layer_scale * i/4,
242 base[1] + layer_scale * (j+1)/4 );
244 sgSetVec4( color, 1.0f, 1.0f, 1.0f,
245 ((j == 3) || (i == 0)) ?
246 ((j == 3) && (i == 0)) ? 0.0f : 0.15f : 1.0f );
248 vl[i]->add( vertex );
252 sgSetVec3( vertex, layer_span*(i-1)/2, layer_span,
253 alt_diff * (sin((i+1)*mpi) - 2) );
255 sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
256 base[1] + layer_scale );
258 sgSetVec4( color, 1.0f, 1.0f, 1.0f, (i == 3) ? 0.0f : 0.15f );
261 vl[i]->add( vertex );
264 layer[i] = new ssgVtxTable(GL_TRIANGLE_STRIP, vl[i], NULL, tl[i], cl[i]);
265 layer_transform->addKid( layer[i] );
267 if ( layer_states[layer_coverage] != NULL ) {
268 layer[i]->setState( layer_states[layer_coverage] );
272 // force a repaint of the sky colors with arbitrary defaults
278 // repaint the cloud layer colors
279 bool SGCloudLayer::repaint( sgVec3 fog_color ) {
282 for ( int i = 0; i < 4; i++ )
283 for ( int j = 0; j < 10; ++j ) {
284 color = cl[i]->get( j );
285 sgCopyVec3( color, fog_color );
292 // reposition the cloud layer at the specified origin and orientation
293 // lon specifies a rotation about the Z axis
294 // lat specifies a rotation about the new Y axis
295 // spin specifies a rotation about the new Z axis (and orients the
296 // sunrise/set effects
297 bool SGCloudLayer::reposition( sgVec3 p, sgVec3 up, double lon, double lat,
298 double alt, double dt )
303 // combine p and asl (meters) to get translation offset
305 sgCopyVec3( asl_offset, up );
306 sgNormalizeVec3( asl_offset );
307 if ( alt <= layer_asl ) {
308 sgScaleVec3( asl_offset, layer_asl );
310 sgScaleVec3( asl_offset, layer_asl + layer_thickness );
312 // cout << "asl_offset = " << asl_offset[0] << "," << asl_offset[1]
313 // << "," << asl_offset[2] << endl;
314 sgAddVec3( asl_offset, p );
315 // cout << " asl_offset = " << asl_offset[0] << "," << asl_offset[1]
316 // << "," << asl_offset[2] << endl;
318 // Translate to zero elevation
319 // Point3D zero_elev = current_view.get_cur_zero_elev();
320 // xglTranslatef( zero_elev.x(), zero_elev.y(), zero_elev.z() );
321 sgMakeTransMat4( T1, asl_offset );
323 // printf(" Translated to %.2f %.2f %.2f\n",
324 // zero_elev.x, zero_elev.y, zero_elev.z );
326 // Rotate to proper orientation
327 // printf(" lon = %.2f lat = %.2f\n",
328 // lon * SGD_RADIANS_TO_DEGREES,
329 // lat * SGD_RADIANS_TO_DEGREES);
330 // xglRotatef( lon * SGD_RADIANS_TO_DEGREES, 0.0, 0.0, 1.0 );
331 sgSetVec3( axis, 0.0, 0.0, 1.0 );
332 sgMakeRotMat4( LON, lon * SGD_RADIANS_TO_DEGREES, axis );
334 // xglRotatef( 90.0 - f->get_Latitude() * SGD_RADIANS_TO_DEGREES,
336 sgSetVec3( axis, 0.0, 1.0, 0.0 );
337 sgMakeRotMat4( LAT, 90.0 - lat * SGD_RADIANS_TO_DEGREES, axis );
341 sgCopyMat4( TRANSFORM, T1 );
342 sgPreMultMat4( TRANSFORM, LON );
343 sgPreMultMat4( TRANSFORM, LAT );
346 sgSetCoord( &layerpos, TRANSFORM );
348 layer_transform->setTransform( &layerpos );
350 // now calculate update texture coordinates
351 if ( last_lon < -900 ) {
356 double sp_dist = speed*dt;
358 if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
359 Point3D start( last_lon, last_lat, 0.0 );
360 Point3D dest( lon, lat, 0.0 );
361 double course = 0.0, dist = 0.0;
364 calc_gc_course_dist( dest, start, &course, &dist );
366 // cout << "course = " << course << ", dist = " << dist << endl;
369 // calculate cloud movement due to external forces
370 double ax = 0.0, ay = 0.0, bx = 0.0, by = 0.0;
373 ax = cos(course) * dist;
374 ay = sin(course) * dist;
378 bx = cos(-direction * SGD_DEGREES_TO_RADIANS) * sp_dist;
379 by = sin(-direction * SGD_DEGREES_TO_RADIANS) * sp_dist;
383 double xoff = (ax + bx) / (2 * scale);
384 double yoff = (ay + by) / (2 * scale);
386 const float layer_scale = layer_span / scale;
388 // cout << "xoff = " << xoff << ", yoff = " << yoff << endl;
392 base = tl[0]->get( 0 );
395 // the while loops can lead to *long* pauses if base[0] comes
396 // with a bogus value.
397 // while ( base[0] > 1.0 ) { base[0] -= 1.0; }
398 // while ( base[0] < 0.0 ) { base[0] += 1.0; }
399 if ( base[0] > -10.0 && base[0] < 10.0 ) {
400 base[0] -= (int)base[0];
403 SG_LOG(SG_ASTRO, SG_DEBUG,
404 "Error: base = " << base[0] << "," << base[1]);
408 // the while loops can lead to *long* pauses if base[0] comes
409 // with a bogus value.
410 // while ( base[1] > 1.0 ) { base[1] -= 1.0; }
411 // while ( base[1] < 0.0 ) { base[1] += 1.0; }
412 if ( base[1] > -10.0 && base[1] < 10.0 ) {
413 base[1] -= (int)base[1];
416 SG_LOG(SG_ASTRO, SG_ALERT,
417 "Error: base = " << base[0] << "," << base[1]);
420 // cout << "base = " << base[0] << "," << base[1] << endl;
422 for (int i = 0; i < 4; i++)
424 tc = tl[i]->get( 0 );
425 sgSetVec2( tc, base[0] + layer_scale * i/4, base[1] );
427 for (int j = 0; j < 4; j++)
429 tc = tl[i]->get( j*2+1 );
430 sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
431 base[1] + layer_scale * j/4 );
433 tc = tl[i]->get( (j+1)*2 );
434 sgSetVec2( tc, base[0] + layer_scale * i/4,
435 base[1] + layer_scale * (j+1)/4 );
438 tc = tl[i]->get( 9 );
439 sgSetVec2( tc, base[0] + layer_scale * (i+1)/4,
440 base[1] + layer_scale );
451 void SGCloudLayer::draw() {
452 if ( layer_coverage != SG_CLOUD_CLEAR ) {
453 ssgCullAndDraw( layer_root );
458 // make an ssgSimpleState for a cloud layer given the named texture
459 ssgSimpleState *sgCloudMakeState( const string &path ) {
460 ssgSimpleState *state = new ssgSimpleState();
462 cout << " texture = " << path << endl;
464 state->setTexture( (char *)path.c_str() );
465 state->setShadeModel( GL_SMOOTH );
466 state->disable( GL_LIGHTING );
467 state->disable( GL_CULL_FACE );
468 state->enable( GL_TEXTURE_2D );
469 state->enable( GL_COLOR_MATERIAL );
470 state->setColourMaterial( GL_AMBIENT_AND_DIFFUSE );
471 state->setMaterial( GL_EMISSION, 0, 0, 0, 1 );
472 state->setMaterial( GL_AMBIENT, 0.7, 0.7, 0.7, 1.0 );
473 state->setMaterial( GL_DIFFUSE, 0.9, 0.9, 0.9, 1.0 );
474 state->setMaterial( GL_SPECULAR, 1.0, 1.0, 1.0, 5.0 );
475 state->enable( GL_BLEND );
476 state->enable( GL_ALPHA_TEST );
477 state->setAlphaClamp( 0.01 );
479 // ref() the state so it doesn't get deleted if the last layer of
480 // it's type is deleted.