3 // Written by Harald JOHNSEN, started April 2005.
5 // Copyright (C) 2005 Harald JOHNSEN - hjohnsen@evc.net
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
24 # include <simgear_config.h>
27 #include <simgear/compiler.h>
31 #include <simgear/math/sg_random.h>
32 #include <simgear/misc/sg_path.hxx>
34 #include STL_ALGORITHM
37 #include "cloudfield.hxx"
38 #include "newcloud.hxx"
44 static ssgTexture *cloudTextures[SGNewCloud::CLTexture_max];
47 bool SGNewCloud::useAnisotropic = true;
48 SGBbCache *SGNewCloud::cldCache = 0;
49 static bool texturesLoaded = false;
50 static float minx, maxx, miny, maxy, minz, maxz;
51 static int cloudIdCounter = 1;
53 float SGNewCloud::nearRadius = 3500.0f;
54 bool SGNewCloud::lowQuality = false;
55 sgVec3 SGNewCloud::sunlight = {0.5f, 0.5f, 0.5f};
56 sgVec3 SGNewCloud::ambLight = {0.5f, 0.5f, 0.5f};
57 sgVec3 SGNewCloud::modelSunDir = {0,1,0};
60 void SGNewCloud::init(void) {
67 familly = CLFamilly_nn;
68 cloudId = ++cloudIdCounter;
69 sgSetVec3(center, 0.0f, 0.0f, 0.0f);
70 sgSetVec3(cloudpos, 0.0f, 0.0f, 0.0f);
73 list_spriteContainer.reserve(8);
74 list_spriteDef.reserve(40);
77 cldCache = new SGBbCache;
83 SGNewCloud::SGNewCloud(CLFamilly_type classification)
86 familly = classification;
89 SGNewCloud::SGNewCloud(string classification)
92 if( classification == "cu" )
93 familly = CLFamilly_cu;
94 else if( classification == "cb" )
95 familly = CLFamilly_cb;
96 else if( classification == "st" )
97 familly = CLFamilly_st;
98 else if( classification == "ns" )
99 familly = CLFamilly_ns;
100 else if( classification == "sc" )
101 familly = CLFamilly_sc;
102 else if( classification == "as" )
103 familly = CLFamilly_as;
104 else if( classification == "ac" )
105 familly = CLFamilly_ac;
106 else if( classification == "ci" )
107 familly = CLFamilly_ci;
108 else if( classification == "cc" )
109 familly = CLFamilly_cc;
110 else if( classification == "cs" )
111 familly = CLFamilly_cs;
114 SGNewCloud::~SGNewCloud() {
115 list_spriteDef.clear();
116 list_spriteContainer.clear();
117 cldCache->free( bbId, cloudId );
121 // load all textures used to draw cloud sprites
122 void SGNewCloud::loadTextures(const string &tex_path) {
125 texturesLoaded = true;
129 cloud_path.set(tex_path);
130 cloud_path.append("cl_cumulus.rgb");
131 cloudTextures[ CLTexture_cumulus ] = new ssgTexture( cloud_path.str().c_str(), false, false, false );
132 cloudTextures[ CLTexture_cumulus ]->ref();
134 cloud_path.set(tex_path);
135 cloud_path.append("cl_stratus.rgb");
136 cloudTextures[ CLTexture_stratus ] = new ssgTexture( cloud_path.str().c_str(), false, false, false );
137 cloudTextures[ CLTexture_stratus ]->ref();
141 void SGNewCloud::startFade(bool direction, float duration, float pauseLength) {
142 if(duration <= 0.0) {
146 this->direction = direction;
148 this->duration = duration;
149 this->pauseLength = pauseLength;
153 void SGNewCloud::setFade(float howMuch) {
161 static inline float rayleighCoeffAngular(float cosAngle) {
162 return 3.0f / 4.0f * (1.0f + cosAngle * cosAngle);
165 // cp is normalized (len==1)
166 static void CartToPolar3d(sgVec3 cp, sgVec3 polar) {
167 polar[0] = atan2(cp[1], cp[0]);
168 polar[1] = SG_PI / 2.0f - atan2(sqrt (cp[0] * cp[0] + cp[1] * cp[1]), cp[2]);
172 static void PolarToCart3d(sgVec3 p, sgVec3 cart) {
173 float tmp = cos(p[1]);
174 cart[0] = cos(p[0]) * tmp;
175 cart[1] = sin(p[0]) * tmp;
180 // compute the light for a cloud sprite corner
181 // from the normal and the sun, scaled by the Rayleigh factor
182 // and finaly added to the ambient light
183 static inline void lightFunction(sgVec3 normal, sgVec4 light, float pf) {
184 float cosAngle = sgScalarProductVec3( normal, SGNewCloud::modelSunDir);
185 float vl = (1.0f - 0.5f + cosAngle * 0.5f) * pf;
186 sgScaleVec3( light, SGNewCloud::sunlight, 0.25f + 0.75f * vl );
187 sgAddVec3( light, SGNewCloud::ambLight );
188 // we need to clamp or else the light will bug when adding transparency
189 if( light[0] > 1.0 ) light[0] = 1.0;
190 if( light[1] > 1.0 ) light[1] = 1.0;
191 if( light[2] > 1.0 ) light[2] = 1.0;
195 // compute the light for a cloud sprite
196 // we use ambient light and orientation versus sun position
197 void SGNewCloud::computeSimpleLight(sgVec3 FakeEyePos) {
198 // constant Rayleigh factor if we are not doing Anisotropic lighting
201 list_of_spriteDef::iterator iSprite;
202 for( iSprite = list_spriteDef.begin() ; iSprite != list_spriteDef.end() ; iSprite++ ) {
203 if( useAnisotropic ) {
205 sgSubVec3(eyeDir, iSprite->pos, FakeEyePos);
206 sgNormaliseVec3(eyeDir);
207 float cosAngle = sgScalarProductVec3(eyeDir, modelSunDir);
208 pf = rayleighCoeffAngular(cosAngle);
210 lightFunction(iSprite->n0, iSprite->l0, pf);
211 lightFunction(iSprite->n1, iSprite->l1, pf);
212 lightFunction(iSprite->n2, iSprite->l2, pf);
213 lightFunction(iSprite->n3, iSprite->l3, pf);
219 // add a new box to the cloud
220 void SGNewCloud::addContainer (float x, float y, float z, float r, CLbox_type type) {
221 spriteContainer cont;
222 sgSetVec3( cont.pos, x, y, z );
224 cont.cont_type = type;
225 sgSetVec3( cont.center, 0.0f, 0.0f, 0.0f);
226 list_spriteContainer.push_back( cont );
227 // don't place cloud below his base
228 if( y - r*0.50 < delta_base )
229 delta_base = y - r*0.50;
232 // add a sprite inside a box
233 void SGNewCloud::addSprite(float x, float y, float z, float r, CLbox_type type, int box) {
234 spriteDef newSpriteDef;
235 int rank = list_spriteDef.size();
236 sgSetVec3( newSpriteDef.pos, x, y - delta_base, z);
237 newSpriteDef.box = box;
238 newSpriteDef.sprite_type = type;
239 newSpriteDef.rank = rank;
241 list_spriteDef.push_back( newSpriteDef );
242 spriteContainer *thisBox = &list_spriteContainer[box];
244 sgSubVec3( deltaPos, newSpriteDef.pos, thisBox->pos );
245 sgAddVec3( thisBox->center, deltaPos );
247 r = r * 0.70f; // 0.5 * 1.xxx
263 // return a random number between -n/2 and n/2
264 static float Rnd(float n) {
265 return n * (-0.5f + sg_random());
268 // generate all sprite with defined boxes
269 void SGNewCloud::genSprites( void ) {
272 minx = miny = minz = 99999.0;
273 maxx = maxy = maxz = -99999.0;
275 N = list_spriteContainer.size();
276 for(int i = 0 ; i < N ; i++ ) {
277 spriteContainer *thisBox = & list_spriteContainer[i];
278 // the type defines how the sprites can be positioned inside the box, their size, etc
279 switch(thisBox->cont_type) {
282 r = thisBox->r + Rnd(0.2f);
283 x = thisBox->pos[SG_X] + Rnd(thisBox->r * 0.75f);
284 y = thisBox->pos[SG_Y] + Rnd(thisBox->r * 0.75f);
285 z = thisBox->pos[SG_Z] + Rnd(thisBox->r * 0.75f);
286 addSprite(x, y, z, r, thisBox->cont_type, i);
291 x = thisBox->pos[SG_X];
292 y = thisBox->pos[SG_Y];
293 z = thisBox->pos[SG_Z];
294 addSprite(x, y, z, r, thisBox->cont_type, i);
297 for( sc = 0 ; sc <= 4 ; sc ++ ) {
298 r = thisBox->r + Rnd(0.2f);
299 x = thisBox->pos[SG_X] + Rnd(thisBox->r * 0.75f);
300 y = thisBox->pos[SG_Y] + Rnd(thisBox->r * 0.5f);
301 z = thisBox->pos[SG_Z] + Rnd(thisBox->r * 0.75f);
302 if ( y < thisBox->pos[SG_Y] - thisBox->r / 10.0f )
303 y = thisBox->pos[SG_Y] - thisBox->r / 10.0f;
304 addSprite(x, y, z, r, thisBox->cont_type, i);
308 for( sc = 0 ; sc <= 4 ; sc ++ ) {
309 r = thisBox->r + Rnd(0.2f);
310 x = thisBox->pos[SG_X] + Rnd(thisBox->r);
311 y = thisBox->pos[SG_Y] + Rnd(thisBox->r);
312 z = thisBox->pos[SG_Z] + Rnd(thisBox->r);
313 addSprite(x, y, z, r, thisBox->cont_type, i);
317 sgScaleVec3(thisBox->center, 1.0f / sc);
320 radius = maxx - minx;
321 if ( (maxy - miny) > radius )
322 radius = (maxy - miny);
323 if ( (maxz - minz) > radius )
324 radius = (maxz - minz);
326 sgSetVec3( center, (maxx + minx) / 2.0f, (maxy + miny) / 2.0f, (maxz + minz) / 2.0f );
328 const float ang = 45.0f * SG_PI / 180.0f;
331 list_of_spriteDef::iterator iSprite;
332 for( iSprite = list_spriteDef.begin() ; iSprite != list_spriteDef.end() ; iSprite++ ) {
334 spriteContainer *thisSpriteContainer = &list_spriteContainer[iSprite->box];
335 if( familly == CLFamilly_sc || familly == CLFamilly_cu || familly == CLFamilly_cb) {
336 sgSubVec3(normal, iSprite->pos, center);
338 sgSubVec3(normal, iSprite->pos, thisSpriteContainer->pos);
339 sgSubVec3(normal, thisSpriteContainer->center);
340 sgSubVec3(normal, cloudpos);
342 if( normal[0] == 0.0f && normal[1] == 0.0f && normal[2] == 0.0f )
343 sgSetVec3( normal, 0.0f, 1.0f, 0.0f );
344 sgNormaliseVec3(normal);
345 // use exotic lightning function, this will give more 'relief' to the clouds
346 // compute a normal for each vextex this will simulate a smooth shading for a round shape
348 // I suspect this code to be bugged...
349 CartToPolar3d(normal, polar);
350 sgCopyVec3(iSprite->normal, normal);
352 // offset the normal vector by some angle for each vertex
353 sgSetVec3(pt, polar[0] - ang, polar[1] - ang, polar[2]);
354 PolarToCart3d(pt, iSprite->n0);
355 sgSetVec3(pt, polar[0] + ang, polar[1] - ang, polar[2]);
356 PolarToCart3d(pt, iSprite->n1);
357 sgSetVec3(pt, polar[0] + ang, polar[1] + ang, polar[2]);
358 PolarToCart3d(pt, iSprite->n2);
359 sgSetVec3(pt, polar[0] - ang, polar[1] + ang, polar[2]);
360 PolarToCart3d(pt, iSprite->n3);
363 // experimental : clouds are dissipating with time
364 if( familly == CLFamilly_cu ) {
365 startFade(true, 300.0f, 30.0f);
366 fadetimer = sg_random() * 300.0f;
371 // definition of a cu cloud, only for testing
372 void SGNewCloud::new_cu(void) {
374 float r = Rnd(1.0) + 0.5;
376 addContainer(0.0f, 0.0f, 0.0f, s, CLbox_cumulus);
377 addContainer(s, 0, 0, s, CLbox_cumulus);
378 addContainer(0, 0, 2 * s, s, CLbox_cumulus);
379 addContainer(s, 0, 2 * s, s, CLbox_cumulus);
381 addContainer(-1.2f * s, 0.2f * s, s, s * 1.4f, CLbox_cumulus);
382 addContainer(0.2f * s, 0.2f * s, s, s * 1.4f, CLbox_cumulus);
383 addContainer(1.6f * s, 0.2f * s, s, s * 1.4f, CLbox_cumulus);
384 } else if ( r < 0.90f ) {
385 addContainer(0, 0, 0, s * 1.2, CLbox_cumulus);
386 addContainer(s, 0, 0, s, CLbox_cumulus);
387 addContainer(0, 0, s, s, CLbox_cumulus);
388 addContainer(s * 1.1, 0, s, s * 1.2, CLbox_cumulus);
390 addContainer(-1.2 * s, 1 + 0.2 * s, s * 0.5, s * 1.4, CLbox_standard);
391 addContainer(0.2 * s, 1 + 0.25 * s, s * 0.5, s * 1.5, CLbox_standard);
392 addContainer(1.6 * s, 1 + 0.2 * s, s * 0.5, s * 1.4, CLbox_standard);
397 addContainer(0, 0, 0, s, CLbox_cumulus);
398 addContainer(0, 0, s, s, CLbox_cumulus);
399 addContainer(s, 0, s, s, CLbox_cumulus);
400 addContainer(s, 0, 0, s, CLbox_cumulus);
402 addContainer(s / 2, s, s / 2, s * 1.5, CLbox_standard);
404 addContainer(0, 2 * s, 0, s, CLbox_standard);
405 addContainer(0, 2 * s, s, s, CLbox_standard);
406 addContainer(s, 2 * s, s, s, CLbox_standard);
407 addContainer(s, 2 * s, 0, s, CLbox_standard);
414 // define the new position of the cloud (inside the cloud field, not on sphere)
415 void SGNewCloud::SetPos(sgVec3 newPos) {
416 int N = list_spriteDef.size();
418 sgSubVec3( deltaPos, newPos, cloudpos );
421 for(int i = 0 ; i < N ; i ++) {
422 sgAddVec3( list_spriteDef[i].pos, deltaPos );
424 sgAddVec3( center, deltaPos );
425 sgSetVec3( cloudpos, newPos[SG_X], newPos[SG_Y], newPos[SG_Z]);
431 void SGNewCloud::drawContainers() {
438 // sort on distance to eye because of transparency
439 void SGNewCloud::sortSprite( sgVec3 eye ) {
440 list_of_spriteDef::iterator iSprite;
442 // compute distance from sprite to eye
443 for( iSprite = list_spriteDef.begin() ; iSprite != list_spriteDef.end() ; iSprite++ ) {
445 sgSubVec3( dist, iSprite->pos, eye );
446 iSprite->dist = -(dist[0]*dist[0] + dist[1]*dist[1] + dist[2]*dist[2]);
448 std::sort( list_spriteDef.begin(), list_spriteDef.end() );
451 // render the cloud on screen or on the RTT texture to build the impostor
452 void SGNewCloud::Render3Dcloud( bool drawBB, sgVec3 FakeEyePos, sgVec3 deltaPos, float dist_center ) {
454 float step = ( list_spriteDef.size() * (direction ? fadetimer : duration-fadetimer)) / duration;
455 int clrank = (int) step;
456 float clfadeinrank = (step - clrank);
459 float CloudVisFade = 1.0 / (0.7f * SGCloudField::get_CloudVis());
460 // blend clouds with sky based on distance to limit the contrast of distant cloud
461 float t = 1.0f - dist_center * CloudVisFade;
465 computeSimpleLight( FakeEyePos );
467 // view point sort, we sort because of transparency
468 sortSprite( FakeEyePos );
470 float dark = (familly == CLFamilly_cb ? 0.9f : 1.0f);
472 GLint previousTexture = -1, thisTexture;
473 list_of_spriteDef::iterator iSprite;
474 for( iSprite = list_spriteDef.begin() ; iSprite != list_spriteDef.end() ; iSprite++ ) {
475 // skip this sprite if faded
476 if(iSprite->rank > clrank)
478 // choose texture to use depending on sprite type
479 switch(iSprite->sprite_type) {
481 thisTexture = CLTexture_stratus;
484 thisTexture = CLTexture_cumulus;
487 // in practice there is no texture switch (atm)
488 if( previousTexture != thisTexture ) {
489 previousTexture = thisTexture;
490 glBindTexture(GL_TEXTURE_2D, cloudTextures[thisTexture]->getHandle());
494 sgSubVec3( translate, iSprite->pos, deltaPos);
497 // flipx and flipy are random texture flip flags, this gives more random clouds
498 float flipx = (float) ( iSprite->rank & 1 );
499 float flipy = (float) ( (iSprite->rank >> 1) & 1 );
500 // cu texture have a flat bottom so we can't do a vertical flip
501 if( iSprite->sprite_type == CLbox_cumulus )
503 // if( iSprite->sprite_type == CLbox_stratus )
505 // adjust colors depending on cloud type
506 // TODO : rewrite that later, still experimental
507 switch(iSprite->sprite_type) {
510 sgScaleVec3(iSprite->l0, 0.8f * dark);
511 sgScaleVec3(iSprite->l1, 0.8f * dark);
512 sgScaleVec3(iSprite->l2, dark);
513 sgScaleVec3(iSprite->l3, dark);
517 if( familly == CLFamilly_st ) {
518 sgScaleVec3(iSprite->l0, 0.8f);
519 sgScaleVec3(iSprite->l1, 0.8f);
520 sgScaleVec3(iSprite->l2, 0.8f);
521 sgScaleVec3(iSprite->l3, 0.8f);
523 sgScaleVec3(iSprite->l0, 0.7f);
524 sgScaleVec3(iSprite->l1, 0.7f);
525 sgScaleVec3(iSprite->l2, 0.7f);
526 sgScaleVec3(iSprite->l3, 0.7f);
530 // darker bottom than top
531 sgScaleVec3(iSprite->l0, 0.8f);
532 sgScaleVec3(iSprite->l1, 0.8f);
535 float r = iSprite->r * 0.5f;
537 sgVec4 l0, l1, l2, l3;
538 sgCopyVec4 ( l0, iSprite->l0 );
539 sgCopyVec4 ( l1, iSprite->l1 );
540 sgCopyVec4 ( l2, iSprite->l2 );
541 sgCopyVec4 ( l3, iSprite->l3 );
543 // now clouds at the far plane are half blended
544 sgScaleVec4( l0, t );
545 sgScaleVec4( l1, t );
546 sgScaleVec4( l2, t );
547 sgScaleVec4( l3, t );
549 if( iSprite->rank == clrank ) {
550 sgScaleVec4( l0, clfadeinrank );
551 sgScaleVec4( l1, clfadeinrank );
552 sgScaleVec4( l2, clfadeinrank );
553 sgScaleVec4( l3, clfadeinrank );
555 // compute the rotations so that the quad is facing the camera
557 sgSetVec3( pos, translate[SG_X], translate[SG_Z], translate[SG_Y] );
558 sgCopyVec3( translate, pos );
559 translate[2] -= FakeEyePos[1];
560 // sgNormaliseVec3( translate );
561 float dist_sprite = sgLengthVec3 ( translate );
562 sgScaleVec3 ( translate, SG_ONE / dist_sprite ) ;
563 sgVec3 x, y, up = {0.0f, 0.0f, 1.0f};
564 if( dist_sprite > 2*r ) {
565 sgVectorProductVec3(x, translate, up);
566 sgVectorProductVec3(y, x, translate);
568 sgCopyVec3( x, SGCloudField::view_X );
569 sgCopyVec3( y, SGCloudField::view_Y );
576 sgSetVec3( left, iSprite->pos[SG_X], iSprite->pos[SG_Z], iSprite->pos[SG_Y]);
578 sgCopyVec3( left, pos );
580 sgAddVec3 (right, left, x);
585 glTexCoord2f(flipx, 1.0f - flipy);
588 glTexCoord2f(1.0f - flipx, 1.0f - flipy);
590 sgScaleVec3( y, 2.0 );
592 sgAddVec3( right, y);
594 glTexCoord2f(1.0f - flipx, flipy);
597 glTexCoord2f(flipx, flipy);
606 // compute rotations so that a quad is facing the camera
607 // TODO:change obsolete code because we dont use glrotate anymore
608 void SGNewCloud::CalcAngles(sgVec3 refpos, sgVec3 FakeEyePos, float *angleY, float *angleX) {
609 sgVec3 upAux, lookAt, objToCamProj, objToCam;
612 sgSetVec3(objToCamProj, -FakeEyePos[SG_X] + refpos[SG_X], -FakeEyePos[SG_Z] + refpos[SG_Z], 0.0f);
613 sgNormaliseVec3(objToCamProj);
615 sgSetVec3(lookAt, 0.0f, 1.0f, 0.0f);
616 sgVectorProductVec3(upAux, lookAt, objToCamProj);
617 angle = sgScalarProductVec3(lookAt, objToCamProj);
618 if( (angle < 0.9999f) && (angle > -0.9999f) ) {
619 angle = acos(angle) * 180.0f / SG_PI;
620 if( upAux[2] < 0.0f )
625 sgSetVec3(objToCam, -FakeEyePos[SG_X] + refpos[SG_X], -FakeEyePos[SG_Z] + refpos[SG_Z], -FakeEyePos[SG_Y] + refpos[SG_Y]);
626 sgNormaliseVec3(objToCam);
628 angle2 = sgScalarProductVec3(objToCamProj, objToCam);
629 if( (angle2 < 0.9999f) && (angle2 > -0.9999f) ) {
630 angle2 = -acos(angle2) * 180.0f / SG_PI;
631 if( objToCam[2] > 0.0f )
642 // draw a cloud but this time we use the impostor texture
643 void SGNewCloud::RenderBB(sgVec3 deltaPos, bool first_time, float dist_center) {
646 sgSubVec3( translate, center, deltaPos);
648 // blend clouds with sky based on distance to limit the contrast of distant cloud
649 float CloudVisFade = (1.0f * SGCloudField::get_CloudVis());
651 float t = 1.0f - (dist_center - 1.0*radius) / CloudVisFade;
658 glColor4f(t, t, t, t);
660 // compute the rotations so that the quad is facing the camera
662 sgSetVec3( pos, translate[SG_X], translate[SG_Z], translate[SG_Y] );
663 sgCopyVec3( translate, pos );
664 pos[2] += deltaPos[1];
666 sgNormaliseVec3( translate );
667 sgVec3 x, y, up = {0.0f, 0.0f, 1.0f};
668 sgVectorProductVec3(x, translate, up);
669 sgVectorProductVec3(y, x, translate);
671 sgCopyVec3( rotX, x );
672 sgCopyVec3( rotY, y );
673 } else if(fabs(sgScalarProductVec3(rotX, x)) < 0.93f || fabs(sgScalarProductVec3(rotY, y)) < 0.93f ) {
674 // ask for a redraw of this impostor if the view angle changed too much
675 sgCopyVec3( rotX, x );
676 sgCopyVec3( rotY, y );
677 cldCache->invalidate(cloudId, bbId);
683 sgCopyVec3( left, pos );
685 sgAddVec3 (right, left, x);
689 glTexCoord2f(0.0f, 0.0f);
691 glTexCoord2f(1.0f, 0.0f);
693 sgScaleVec3( y, 2.0 );
695 sgAddVec3( right, y);
696 glTexCoord2f(1.0f, 1.0f);
698 glTexCoord2f(0.0f, 1.0f);
703 int age = cldCache->queryImpostorAge(bbId);
704 // draw a red border for the newly generated BBs else draw a white border
710 glBindTexture(GL_TEXTURE_2D, 0);
711 glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
718 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
724 // determine if it is a good idea to use an impostor to render the cloud
725 bool SGNewCloud::isBillboardable(float dist) {
727 if( dist <= ( 2.1f * radius ) ) {
731 if( (dist-radius) <= nearRadius ) {
732 // near clouds we don't want to use BB
740 // render the cloud, fakepos is a relative position inside the cloud field
741 void SGNewCloud::Render(sgVec3 FakeEyePos) {
745 sgCopyVec3( deltaPos, FakeEyePos);
747 sgSubVec3( dist, center, FakeEyePos);
748 float dist_center = sgLengthVec3(dist);
751 fadetimer += SGCloudField::timer_dt;
752 if( fadetimer > duration + pauseLength ) {
753 // fade out after fade in, and vice versa
754 direction = ! direction;
759 if( !isBillboardable(dist_center) ) {
760 // not a good candidate for impostors, draw a real cloud
761 Render3Dcloud(false, FakeEyePos, deltaPos, dist_center);
764 bool first_time = false;
765 // lets use our impostor
767 texID = cldCache->QueryTexID(cloudId, bbId);
769 // ok someone took our impostor, so allocate a new one
771 // allocate a new Impostor
772 bbId = cldCache->alloc(cloudId);
773 texID = cldCache->QueryTexID(cloudId, bbId);
777 // no more free texture in the pool
778 Render3Dcloud(false, FakeEyePos, deltaPos, dist_center);
780 float angleX=0.0f, angleY=0.0f;
782 // force a redraw of the impostor if the cloud shape has changed enought
783 float step = ( list_spriteDef.size() * (direction ? fadetimer : duration-fadetimer)) / duration;
784 if( fabs(step - last_step) > 0.5f )
785 cldCache->invalidate(cloudId, bbId);
787 if( ! cldCache->isBbValid( cloudId, bbId, angleY, angleX)) {
788 // we must build or rebuild this billboard
789 // start render to texture
790 cldCache->beginCapture();
791 // set transformation matrices
792 cldCache->setRadius(radius, dist_center);
793 gluLookAt(FakeEyePos[SG_X], FakeEyePos[SG_Z], FakeEyePos[SG_Y], center[SG_X], center[SG_Z], center[SG_Y], 0.0, 0.0, 1.0);
795 Render3Dcloud(true, FakeEyePos, deltaPos, dist_center);
796 // save rotation angles for later use
797 // TODO:this is not ok
798 cldCache->setReference(cloudId, bbId, angleY, angleX);
799 // save the rendered cloud into the cache
800 cldCache->setTextureData( bbId );
801 // finish render to texture and go back into standard context
802 cldCache->endCapture();
804 // draw the newly built BB or an old one
805 glBindTexture(GL_TEXTURE_2D, texID);
806 RenderBB(FakeEyePos, first_time, dist_center);