9 _base[0] = _base[1] = _base[2] = 0;
42 for(int i=0; i<_surfs.size(); i++) {
43 SurfRec* s = (SurfRec*)_surfs.get(i);
49 int Wing::numSurfaces()
54 Surface* Wing::getSurface(int n)
56 return ((SurfRec*)_surfs.get(n))->surface;
59 float Wing::getSurfaceWeight(int n)
61 return ((SurfRec*)_surfs.get(n))->weight;
64 void Wing::setMirror(bool mirror)
69 void Wing::setBase(float* base)
71 for(int i=0; i<3; i++) _base[i] = base[i];
74 void Wing::setLength(float length)
79 void Wing::setChord(float chord)
84 void Wing::setTaper(float taper)
89 void Wing::setSweep(float sweep)
94 void Wing::setDihedral(float dihedral)
99 void Wing::setStall(float aoa)
104 void Wing::setStallWidth(float angle)
109 void Wing::setStallPeak(float fraction)
111 _stallPeak = fraction;
114 void Wing::setCamber(float camber)
119 void Wing::setIncidence(float incidence)
121 _incidence = incidence;
122 for(int i=0; i<_surfs.size(); i++)
123 ((SurfRec*)_surfs.get(i))->surface->setIncidence(incidence);
126 void Wing::setFlap0(float start, float end, float lift, float drag)
134 void Wing::setFlap1(float start, float end, float lift, float drag)
142 void Wing::setSlat(float start, float end, float aoa, float drag)
150 void Wing::setSpoiler(float start, float end, float lift, float drag)
152 _spoilerStart = start;
158 void Wing::setFlap0(float lval, float rval)
160 lval = Math::clamp(lval, -1, 1);
161 rval = Math::clamp(rval, -1, 1);
162 for(int i=0; i<_flap0Surfs.size(); i++) {
163 ((Surface*)_flap0Surfs.get(i))->setFlap(lval);
164 if(_mirror) ((Surface*)_flap0Surfs.get(++i))->setFlap(rval);
168 void Wing::setFlap1(float lval, float rval)
170 lval = Math::clamp(lval, -1, 1);
171 rval = Math::clamp(rval, -1, 1);
172 for(int i=0; i<_flap1Surfs.size(); i++) {
173 ((Surface*)_flap1Surfs.get(i))->setFlap(lval);
174 if(_mirror) ((Surface*)_flap1Surfs.get(++i))->setFlap(rval);
178 void Wing::setSpoiler(float lval, float rval)
180 lval = Math::clamp(lval, 0, 1);
181 rval = Math::clamp(rval, 0, 1);
182 for(int i=0; i<_spoilerSurfs.size(); i++) {
183 ((Surface*)_spoilerSurfs.get(i))->setSpoiler(lval);
184 if(_mirror) ((Surface*)_spoilerSurfs.get(++i))->setSpoiler(rval);
188 void Wing::setSlat(float val)
190 val = Math::clamp(val, 0, 1);
191 for(int i=0; i<_slatSurfs.size(); i++)
192 ((Surface*)_slatSurfs.get(i))->setSlat(val);
195 float Wing::getGroundEffect(float* posOut)
197 for(int i=0; i<3; i++) posOut[i] = _base[i];
198 float span = _length * Math::cos(_sweep) * Math::cos(_dihedral);
199 span = 2*(span + Math::abs(_base[2]));
205 // Have we already been compiled?
206 if(_surfs.size() != 0) return;
208 // Assemble the start/end coordinates into an array, sort them,
209 // and remove duplicates. This gives us the boundaries of our
212 bounds[0] = _flap0Start; bounds[1] = _flap0End;
213 bounds[2] = _flap1Start; bounds[3] = _flap1End;
214 bounds[4] = _spoilerStart; bounds[5] = _spoilerEnd;
215 bounds[6] = _slatStart; bounds[7] = _slatEnd;
217 // Sort in increasing order
218 for(int i=0; i<8; i++) {
220 float minVal = bounds[i];
221 for(int j=i+1; j<8; j++) {
222 if(bounds[j] < minVal) {
227 float tmp = bounds[i];
228 bounds[i] = minVal; bounds[minIdx] = tmp;
232 float last = bounds[0];
234 for(int i=1; i<8; i++) {
235 if(bounds[i] != last)
236 bounds[nbounds++] = bounds[i];
240 // Calculate a "nominal" segment length equal to an average chord,
241 // normalized to lie within 0-1 over the length of the wing.
242 float segLen = _chord * (0.5*(_taper+1)) / _length;
244 // Generating a unit vector pointing out the left wing.
246 left[0] = -Math::tan(_sweep);
247 left[1] = Math::cos(_dihedral);
248 left[2] = Math::sin(_dihedral);
249 Math::unit3(left, left);
251 // Calculate coordinates for the root and tip of the wing
252 float root[3], tip[3];
253 Math::set3(_base, root);
254 Math::set3(left, tip);
255 Math::mul3(_length, tip, tip);
256 Math::add3(root, tip, tip);
258 // The wing's Y axis will be the "left" vector. The Z axis will
259 // be perpendicular to this and the local (!) X axis, because we
260 // want motion along the local X axis to be zero AoA (i.e. in the
261 // wing's XY plane) by definition. Then the local X coordinate is
263 float orient[9], rightOrient[9];
264 float *x = orient, *y = orient+3, *z = orient+6;
265 x[0] = 1; x[1] = 0; x[2] = 0;
267 Math::cross3(x, y, z);
269 Math::cross3(y, z, x);
272 // Derive the right side orientation matrix from this one.
273 for(int i=0; i<9; i++) rightOrient[i] = orient[i];
275 // Negate all Y coordinates, this gets us a valid basis, but
276 // it's left handed! So...
277 for(int i=1; i<9; i+=3) rightOrient[i] = -rightOrient[i];
279 // Change the direction of the Y axis to get back to a
280 // right-handed system.
281 for(int i=3; i<6; i++) rightOrient[i] = -rightOrient[i];
284 // Now go through each boundary and make segments
285 for(int i=0; i<(nbounds-1); i++) {
286 float start = bounds[i];
287 float end = bounds[i+1];
288 float mid = (start+end)/2;
290 bool flap0=0, flap1=0, slat=0, spoiler=0;
291 if(_flap0Start < mid && mid < _flap0End) flap0 = 1;
292 if(_flap1Start < mid && mid < _flap1End) flap1 = 1;
293 if(_slatStart < mid && mid < _slatEnd) slat = 1;
294 if(_spoilerStart < mid && mid < _spoilerEnd) spoiler = 1;
296 // FIXME: Should probably detect an error here if both flap0
297 // and flap1 are set. Right now flap1 overrides.
299 int nSegs = (int)Math::ceil((end-start)/segLen);
300 float segWid = _length * (end - start)/nSegs;
302 for(int j=0; j<nSegs; j++) {
303 float frac = start + (j+0.5) * (end-start)/nSegs;
305 interp(root, tip, frac, pos);
307 float chord = _chord * (1 - (1-_taper)*frac);
309 Surface *s = newSurface(pos, orient, chord,
310 flap0, flap1, slat, spoiler);
312 SurfRec *sr = new SurfRec();
314 sr->weight = chord * segWid;
315 s->setTotalDrag(sr->weight);
320 s = newSurface(pos, rightOrient, chord,
321 flap0, flap1, slat, spoiler);
324 sr->weight = chord * segWid;
325 s->setTotalDrag(sr->weight);
332 float Wing::getDragScale()
337 void Wing::setDragScale(float scale)
340 for(int i=0; i<_surfs.size(); i++) {
341 SurfRec* s = (SurfRec*)_surfs.get(i);
342 s->surface->setTotalDrag(scale * s->weight);
346 void Wing::setLiftRatio(float ratio)
349 for(int i=0; i<_surfs.size(); i++)
350 ((SurfRec*)_surfs.get(i))->surface->setZDrag(ratio);
353 float Wing::getLiftRatio()
358 Surface* Wing::newSurface(float* pos, float* orient, float chord,
359 bool flap0, bool flap1, bool slat, bool spoiler)
361 Surface* s = new Surface();
364 s->setOrientation(orient);
367 // Camber is expressed as a fraction of stall peak, so convert.
368 s->setBaseZDrag(_camber*_stallPeak);
370 // The "main" (i.e. normal) stall angle
371 float stallAoA = _stall - _stallWidth/4;
372 s->setStall(0, stallAoA);
373 s->setStallWidth(0, _stallWidth);
374 s->setStallPeak(0, _stallPeak);
376 // The negative AoA stall is the same if we're using an uncambered
377 // airfoil, otherwise a "little badder".
379 s->setStall(1, stallAoA * 0.8);
380 s->setStallWidth(1, _stallWidth * 0.5);
382 s->setStall(1, stallAoA);
383 s->setStall(1, _stallWidth);
386 // The "reverse" stalls are unmeasurable junk. Just use 13deg and
388 s->setStallPeak(1, 1);
389 for(int i=2; i<4; i++) {
390 s->setStall(i, 0.2267);
391 s->setStallWidth(i, 1);
394 if(flap0) s->setFlapParams(_flap0Lift, _flap0Drag);
395 if(flap1) s->setFlapParams(_flap1Lift, _flap1Drag);
396 if(slat) s->setSlatParams(_slatAoA, _slatDrag);
397 if(spoiler) s->setSpoilerParams(_spoilerLift, _spoilerDrag);
399 if(flap0) _flap0Surfs.add(s);
400 if(flap1) _flap1Surfs.add(s);
401 if(slat) _slatSurfs.add(s);
402 if(spoiler) _spoilerSurfs.add(s);
407 void Wing::interp(float* v1, float* v2, float frac, float* out)
409 out[0] = v1[0] + frac*(v2[0]-v1[0]);
410 out[1] = v1[1] + frac*(v2[1]-v1[1]);
411 out[2] = v1[2] + frac*(v2[2]-v1[2]);
414 }; // namespace yasim