1 // HUD_ladder.cxx -- HUD Ladder Instrument
3 // Written by Michele America, started September 1997.
5 // Copyright (C) 1997 Michele F. America [micheleamerica#geocities:com]
6 // Copyright (C) 2006 Melchior FRANZ [mfranz#aon:at]
8 // This program is free software; you can redistribute it and/or
9 // modify it under the terms of the GNU General Public License as
10 // published by the Free Software Foundation; either version 2 of the
11 // License, or (at your option) any later version.
13 // This program is distributed in the hope that it will be useful, but
14 // WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 // General Public License for more details.
18 // You should have received a copy of the GNU General Public License
19 // along with this program; if not, write to the Free Software
20 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
26 #include <Main/viewer.hxx>
31 float get__heading() { return fgGetFloat("/orientation/heading-deg") * M_PI / 180.0; }
32 float get__throttleval() { return fgGetFloat("/controls/engines/engine/throttle"); }
33 float get__aoa() { return fgGetFloat("/sim/frame-rate"); } // FIXME
34 float get__Vx() { return fgGetFloat("/velocities/uBody-fps"); }
35 float get__Vy() { return fgGetFloat("/velocities/vBody-fps"); }
36 float get__Vz() { return fgGetFloat("/velocities/wBody-fps"); }
37 float get__Ax() { return fgGetFloat("/acclerations/pilot/x-accel-fps_sec"); }
38 float get__Ay() { return fgGetFloat("/acclerations/pilot/y-accel-fps_sec"); }
39 float get__Az() { return fgGetFloat("/acclerations/pilot/z-accel-fps_sec"); }
43 HUD::Ladder::Ladder(HUD *hud, const SGPropertyNode *n, float x, float y) :
45 _pitch(n->getNode("pitch-input", false)),
46 _roll(n->getNode("roll-input", false)),
47 _width_units(int(n->getFloatValue("display-span"))),
48 div_units(int(fabs(n->getFloatValue("divisions")))),
49 label_pos(n->getIntValue("lbl-pos")),
50 _scr_hole(n->getIntValue("screen-hole")),
51 _compression(n->getFloatValue("compression-factor")),
52 _frl(n->getBoolValue("enable-fuselage-ref-line", false)),
53 _target_spot(n->getBoolValue("enable-target-spot", false)),
54 _velocity_vector(n->getBoolValue("enable-velocity-vector", false)),
55 _drift_marker(n->getBoolValue("enable-drift-marker", false)),
56 _alpha_bracket(n->getBoolValue("enable-alpha-bracket", false)),
57 _energy_marker(n->getBoolValue("enable-energy-marker", false)),
58 _climb_dive_marker(n->getBoolValue("enable-climb-dive-marker", false)),
59 _glide_slope_marker(n->getBoolValue("enable-glide-slope-marker",false)),
60 _glide_slope(n->getFloatValue("glide-slope", -4.0)),
61 _energy_worm(n->getBoolValue("enable-energy-marker", false)),
62 _waypoint_marker(n->getBoolValue("enable-waypoint-marker", false)),
63 _zenith(n->getIntValue("zenith")),
64 _nadir(n->getIntValue("nadir")),
65 _hat(n->getIntValue("hat"))
67 const char *t = n->getStringValue("type");
68 _type = strcmp(t, "climb-dive") ? PITCH : CLIMB_DIVE;
73 _vmax = _width_units / 2;
78 void HUD::Ladder::draw(void)
80 if (!_pitch.isValid() || !_roll.isValid())
87 float cosine, sine, xvvr, yvvr, Vxx = 0.0, Vyy = 0.0, Vzz = 0.0;
88 float up_vel, ground_vel, actslope = 0.0;
89 float Axx = 0.0, Ayy = 0.0, Azz = 0.0, total_vel = 0.0, pot_slope, t1;
90 float t2 = 0.0, psi = 0.0, alpha, pla;
91 float vel_x = 0.0, vel_y = 0.0, drift;
92 bool pitch_ladder = false;
93 bool climb_dive_ladder = false;
94 bool clip_plane = false;
96 GLdouble eqn_top[4] = {0.0, -1.0, 0.0, 0.0};
97 GLdouble eqn_left[4] = {-1.0, 0.0, 0.0, 100.0};
98 GLdouble eqn_right[4] = {1.0, 0.0, 0.0, 100.0};
100 Point centroid = get_centroid();
101 Rect box = get_location();
103 float half_span = box.right / 2.0;
104 float roll_value = _roll.getFloatValue() * SGD_DEGREES_TO_RADIANS; // FIXME rad/deg conversion
106 pla = get__throttleval();
108 #ifdef ENABLE_SP_FMDS
109 int lgear, wown, wowm, ilcanclaw, ihook;
110 ilcanclaw = get__iaux2();
111 lgear = get__iaux3();
114 ihook = get__iaux6();
116 float pitch_value = _pitch.getFloatValue();
118 if (_type == CLIMB_DIVE) {
119 pitch_ladder = false;
120 climb_dive_ladder = true;
123 } else { // _type == PITCH
125 climb_dive_ladder = false;
129 //**************************************************************
131 // define (0, 0) as center of screen
132 glTranslatef(centroid.x, centroid.y, 0);
134 // OBJECT STATIC RETICLE
135 // TYPE FRL (FUSELAGE REFERENCE LINE)
137 // Draw the FRL spot and line
139 #define FRL_DIAMOND_SIZE 2.0
140 glBegin(GL_LINE_LOOP);
141 glVertex2f(-FRL_DIAMOND_SIZE, 0.0);
142 glVertex2f(0.0, FRL_DIAMOND_SIZE);
143 glVertex2f(FRL_DIAMOND_SIZE, 0.0);
144 glVertex2f(0.0, -FRL_DIAMOND_SIZE);
147 glBegin(GL_LINE_STRIP);
148 glVertex2f(0, FRL_DIAMOND_SIZE);
151 #undef FRL_DIAMOND_SIZE
153 // TYPE WATERLINE_MARK (W shaped _ _ )
156 //****************************************************************
158 // Draw the target spot.
160 #define CENTER_DIAMOND_SIZE 6.0
161 glBegin(GL_LINE_LOOP);
162 glVertex2f(-CENTER_DIAMOND_SIZE, 0.0);
163 glVertex2f(0.0, CENTER_DIAMOND_SIZE);
164 glVertex2f(CENTER_DIAMOND_SIZE, 0.0);
165 glVertex2f(0.0, -CENTER_DIAMOND_SIZE);
167 #undef CENTER_DIAMOND_SIZE
170 //****************************************************************
171 //velocity vector reticle - computations
172 if (_velocity_vector) {
179 psi = get__heading();
184 total_vel = sqrt(Vxx * Vxx + Vyy * Vyy + Vzz * Vzz);
185 ground_vel = sqrt(Vxx * Vxx + Vyy * Vyy);
188 if (ground_vel < 2.0) {
189 if (fabs(up_vel) < 2.0)
192 actslope = (up_vel / fabs(up_vel)) * 90.0;
195 actslope = atan(up_vel / ground_vel) * SGD_RADIANS_TO_DEGREES;
198 xvvr = (((atan2(Vyy, Vxx) * SGD_RADIANS_TO_DEGREES) - psi)
199 * (_compression / globals->get_current_view()->get_aspect_ratio()));
200 drift = ((atan2(Vyy, Vxx) * SGD_RADIANS_TO_DEGREES) - psi);
201 yvvr = ((actslope - pitch_value) * _compression);
202 vel_y = ((actslope - pitch_value) * cos(roll_value) + drift * sin(roll_value)) * _compression;
203 vel_x = (-(actslope - pitch_value) * sin(roll_value) + drift * cos(roll_value))
204 * (_compression / globals->get_current_view()->get_aspect_ratio());
205 // printf("%f %f %f %f\n",vel_x, vel_y, drift, psi);
207 //****************************************************************
208 // OBJECT MOVING RETICLE
209 // TYPE - DRIFT MARKER
213 glBegin(GL_LINE_STRIP);
214 glVertex2f((xvvr * 25 / 120) - 6, -4);
215 glVertex2f(xvvr * 25 / 120, 8);
216 glVertex2f((xvvr * 25 / 120) + 6, -4);
220 //****************************************************************
221 // Clipping coordinates for ladder to be input from xml file
224 glClipPlane(GL_CLIP_PLANE0, eqn_top);
225 glEnable(GL_CLIP_PLANE0);
226 glClipPlane(GL_CLIP_PLANE1, eqn_left);
227 glEnable(GL_CLIP_PLANE1);
228 glClipPlane(GL_CLIP_PLANE2, eqn_right);
229 glEnable(GL_CLIP_PLANE2);
230 // glScissor(-100,-240, 200, 240);
231 // glEnable(GL_SCISSOR_TEST);
234 //****************************************************************
235 // OBJECT MOVING RETICLE
236 // TYPE VELOCITY VECTOR
239 glBegin(GL_LINE_LOOP); // Use polygon to approximate a circle
240 for (count = 0; count < 50; count++) {
241 cosine = 6 * cos(count * SGD_2PI / 50.0);
242 sine = 6 * sin(count * SGD_2PI / 50.0);
243 glVertex2f(cosine + vel_x, sine + vel_y);
247 //velocity vector reticle orientation lines
248 glBegin(GL_LINE_STRIP);
249 glVertex2f(vel_x - 12, vel_y);
250 glVertex2f(vel_x - 6, vel_y);
252 glBegin(GL_LINE_STRIP);
253 glVertex2f(vel_x + 12, vel_y);
254 glVertex2f(vel_x + 6, vel_y);
256 glBegin(GL_LINE_STRIP);
257 glVertex2f(vel_x, vel_y + 12);
258 glVertex2f(vel_x, vel_y + 6);
261 #ifdef ENABLE_SP_FMDS
262 // OBJECT MOVING RETICLE
264 // ATTRIB - ON CONDITION
266 // undercarriage status
267 glBegin(GL_LINE_STRIP);
268 glVertex2f(vel_x + 8, vel_y);
269 glVertex2f(vel_x + 8, vel_y - 4);
272 // OBJECT MOVING RETICLE
274 // ATTRIB - ON CONDITION
275 glBegin(GL_LINE_STRIP);
276 glVertex2f(vel_x - 8, vel_y);
277 glVertex2f(vel_x - 8, vel_y - 4);
280 // OBJECT MOVING RETICLE
282 // ATTRIB - ON CONDITION
283 glBegin(GL_LINE_STRIP);
284 glVertex2f(vel_x, vel_y - 6);
285 glVertex2f(vel_x, vel_y - 10);
289 // OBJECT MOVING RETICLE
291 // ATTRIB - ON CONDITION
293 // arrestor hook status
294 glBegin(GL_LINE_STRIP);
295 glVertex2f(vel_x - 4, vel_y - 8);
296 glVertex2f(vel_x, vel_y - 10);
297 glVertex2f(vel_x + 4, vel_y - 8);
301 } // if _velocity_vector
304 //***************************************************************
305 // OBJECT MOVING RETICLE
306 // TYPE - SQUARE_BRACKET
307 // ATTRIB - ON CONDITION
309 #ifdef ENABLE_SP_FMDS
310 if (_alpha_bracket && ihook == 1) {
311 glBegin(GL_LINE_STRIP);
312 glVertex2f(vel_x - 20 , vel_y - (16 - alpha) * _compression);
313 glVertex2f(vel_x - 17, vel_y - (16 - alpha) * _compression);
314 glVertex2f(vel_x - 17, vel_y - (14 - alpha) * _compression);
315 glVertex2f(vel_x - 20, vel_y - (14 - alpha) * _compression);
318 glBegin(GL_LINE_STRIP);
319 glVertex2f(vel_x + 20 , vel_y - (16 - alpha) * _compression);
320 glVertex2f(vel_x + 17, vel_y - (16 - alpha) * _compression);
321 glVertex2f(vel_x + 17, vel_y - (14 - alpha) * _compression);
322 glVertex2f(vel_x + 20, vel_y - (14 - alpha) * _compression);
326 //printf("xvr=%f, yvr=%f, Vx=%f, Vy=%f, Vz=%f\n",xvvr, yvvr, Vx, Vy, Vz);
327 //printf("Ax=%f, Ay=%f, Az=%f\n",Ax, Ay, Az);
329 //****************************************************************
330 // OBJECT MOVING RETICLE
331 // TYPE ENERGY_MARKERS
333 //energy markers - compute potential slope
334 if (_energy_marker) {
335 if (total_vel < 5.0) {
339 t1 = up_vel / total_vel;
340 t2 = asin((Vxx * Axx + Vyy * Ayy + Vzz * Azz) / (9.81 * total_vel));
342 pot_slope = ((t2 / 3) * SGD_RADIANS_TO_DEGREES) * _compression + vel_y;
343 // if (pot_slope < (vel_y - 45)) pot_slope = vel_y - 45;
344 // if (pot_slope > (vel_y + 45)) pot_slope = vel_y + 45;
347 glBegin(GL_LINE_STRIP);
348 glVertex2f(vel_x - 20, pot_slope - 5);
349 glVertex2f(vel_x - 15, pot_slope);
350 glVertex2f(vel_x - 20, pot_slope + 5);
353 glBegin(GL_LINE_STRIP);
354 glVertex2f(vel_x + 20, pot_slope - 5);
355 glVertex2f(vel_x + 15, pot_slope);
356 glVertex2f(vel_x + 20, pot_slope + 5);
359 if (pla > (105.0 / 131.0)) {
360 glBegin(GL_LINE_STRIP);
361 glVertex2f(vel_x - 24, pot_slope - 5);
362 glVertex2f(vel_x - 19, pot_slope);
363 glVertex2f(vel_x - 24, pot_slope + 5);
366 glBegin(GL_LINE_STRIP);
367 glVertex2f(vel_x + 24, pot_slope - 5);
368 glVertex2f(vel_x + 19, pot_slope);
369 glVertex2f(vel_x + 24, pot_slope + 5);
374 //**********************************************************
376 // OBJECT STATIC RETICLE
378 // ATTRIB - ON CONDITION
379 #ifdef ENABLE_SP_FMDS
380 if (_energy_worm && ilcanclaw == 1) {
381 glBegin(GL_LINE_STRIP);
382 glVertex2f(-15, -134);
383 glVertex2f(15, -134);
386 // OBJECT MOVING RETICLE
388 // ATTRIB - ON CONDITION
389 glBegin(GL_LINE_STRIP);
390 glVertex2f(-6, -134);
391 glVertex2f(-6, t2 * SGD_RADIANS_TO_DEGREES * 4.0 - 134);
392 glVertex2f(+6, t2 * SGD_RADIANS_TO_DEGREES * 4.0 - 134);
396 // OBJECT MOVING RETICLE
398 // ATTRIB - ON CONDITION
399 glBegin(GL_LINE_LOOP);
400 glVertex2f(-6, actslope * 4.0 - 134);
401 glVertex2f(0, actslope * 4.0 -134 + 3);
402 glVertex2f(6, actslope * 4.0 - 134);
403 glVertex2f(0, actslope * 4.0 -134 -3);
408 //*************************************************************
409 // OBJECT MOVING RETICLE
412 // Draw the locked velocity vector.
413 if (_climb_dive_marker) {
414 glBegin(GL_LINE_LOOP);
415 glVertex2f(-3.0, 0.0 + vel_y);
416 glVertex2f(0.0, 6.0 + vel_y);
417 glVertex2f(3.0, 0.0 + vel_y);
418 glVertex2f(0.0, -6.0 + vel_y);
422 //****************************************************************
424 if (climb_dive_ladder) { // CONFORMAL_HUD
425 _vmin = pitch_value - _width_units;
426 _vmax = pitch_value + _width_units;
427 glTranslatef(vel_x, vel_y, 0);
429 } else { // pitch_ladder - Default Hud
430 _vmin = pitch_value - _width_units * 0.5f;
431 _vmax = pitch_value + _width_units * 0.5f;
434 glRotatef(roll_value * SGD_RADIANS_TO_DEGREES, 0.0, 0.0, 1.0);
435 // FRL marker not rotated - this line shifted below
438 const int BUFSIZE = 8;
446 float text_offset = 4.0f;
447 float zero_offset = 0.0;
449 if (climb_dive_ladder)
450 zero_offset = 50.0f; // horizon line is wider by this much (hard coded ??)
454 fntFont *font = _hud->_font_renderer->getFont(); // FIXME
455 float pointsize = _hud->_font_renderer->getPointSize();
456 float italic = _hud->_font_renderer->getSlant();
458 _locTextList.setFont(_hud->_font_renderer);
459 _locTextList.erase();
460 _locLineList.erase();
461 _locStippleLineList.erase();
463 int last = int(_vmax) + 1;
469 for (; i < last; i++) {
470 y = (i - pitch_value) * _compression + .5f;
472 if (!(i % div_units)) { // At integral multiple of div
473 snprintf(buf, BUFSIZE, "%d", i);
474 font->getBBox(buf, pointsize, italic, &left, &right, &bot, &top);
475 label_length = right - left;
476 label_length += text_offset;
477 label_height = (top - bot) / 2.0f;
482 // Make zero point wider on left
484 x_ini -= zero_offset;
486 // Zero or above draw solid lines
487 draw_line(x_ini, y, x_end, y);
489 if (i == 90 && _zenith == 1)
490 draw_zenith(x_ini, x_end, y);
492 // Below zero draw dashed lines.
493 draw_stipple_line(x_ini, y, x_end, y);
495 if (i == -90 && _nadir ==1)
496 draw_nadir(x_ini, x_end, y);
499 // Calculate the position of the left text and write it.
500 draw_text(x_ini - label_length, y - label_height, buf);
501 draw_text(x_end + text_offset, y - label_height, buf);
505 } else { // if (_scr_hole)
506 // Draw ladder with space in the middle of the lines
507 float hole = _scr_hole / 2.0f;
509 x_end = -half_span + hole;
510 x_ini2 = half_span - hole;
512 for (; i < last; i++) {
514 y = float(i - pitch_value) * _compression + .5;
515 else // _type == CLIMB_DIVE
516 y = float(i - actslope) * _compression + .5;
518 if (!(i % div_units)) { // At integral multiple of div
519 snprintf(buf, BUFSIZE, "%d", i);
520 font->getBBox(buf, pointsize, italic, &left, &right, &bot, &top);
521 label_length = right - left;
522 label_length += text_offset;
523 label_height = (top - bot) / 2.0f;
524 // printf("l %f r %f b %f t %f\n",left, right, bot, top);
526 // Start by calculating the points and drawing the
532 // Make zero point wider on left
534 x_ini -= zero_offset;
535 x_end2 += zero_offset;
537 //draw climb bar vertical lines
538 if (climb_dive_ladder) {
539 // Zero or above draw solid lines
540 draw_line(x_end, y - 5.0, x_end, y);
541 draw_line(x_ini2, y - 5.0, x_ini2, y);
543 // draw pitch / climb bar
544 draw_line(x_ini, y, x_end, y);
545 draw_line(x_ini2, y, x_end2, y);
547 if (i == 90 && _zenith == 1)
548 draw_zenith(x_ini2, x_end, y);
551 // draw dive bar vertical lines
552 if (climb_dive_ladder) {
553 draw_line(x_end, y + 5.0, x_end, y);
554 draw_line(x_ini2, y + 5.0, x_ini2, y);
557 // draw pitch / dive bars
558 draw_stipple_line(x_ini, y, x_end, y);
559 draw_stipple_line(x_ini2, y, x_end2, y);
561 if (i == -90 && _nadir == 1)
562 draw_nadir(x_ini2, x_end, y);
565 // Now calculate the location of the left side label using
566 draw_text(x_ini - label_length, y - label_height, buf);
567 draw_text(x_end2 + text_offset, y - label_height, buf);
571 // OBJECT LADDER MARK
573 // ATTRIB - ON CONDITION
574 // draw appraoch glide slope marker
575 #ifdef ENABLE_SP_FMDS
576 if (_glide_slope_marker && ihook) {
577 draw_line(-half_span + 15, (_glide_slope - actslope) * _compression,
578 -half_span + hole, (_glide_slope - actslope) * _compression);
579 draw_line(half_span - 15, (_glide_slope - actslope) * _compression,
580 half_span - hole, (_glide_slope - actslope) * _compression);
590 glEnable(GL_LINE_STIPPLE);
591 glLineStipple(1, 0x00FF);
592 _locStippleLineList.draw();
593 glDisable(GL_LINE_STIPPLE);
595 glDisable(GL_CLIP_PLANE0);
596 glDisable(GL_CLIP_PLANE1);
597 glDisable(GL_CLIP_PLANE2);
598 // glDisable(GL_SCISSOR_TEST);
600 //*************************************************************
602 //*************************************************************
603 #ifdef ENABLE_SP_FMDS
604 if (_waypoint_marker) {
605 //waypoint marker computation
606 float fromwp_lat, towp_lat, fromwp_lon, towp_lon, dist, delx, dely, hyp, theta, brg;
608 fromwp_lon = get__longitude() * SGD_DEGREES_TO_RADIANS;
609 fromwp_lat = get__latitude() * SGD_DEGREES_TO_RADIANS;
610 towp_lon = get__aux2() * SGD_DEGREES_TO_RADIANS;
611 towp_lat = get__aux1() * SGD_DEGREES_TO_RADIANS;
613 dist = acos(sin(fromwp_lat) * sin(towp_lat) + cos(fromwp_lat)
614 * cos(towp_lat) * cos(fabs(fromwp_lon - towp_lon)));
615 delx= towp_lat - fromwp_lat;
616 dely = towp_lon - fromwp_lon;
617 hyp = sqrt(pow(delx, 2) + pow(dely, 2));
620 theta = asin(dely / hyp);
624 brg = theta * SGD_RADIANS_TO_DEGREES;
630 // {Brg = asin(cos(towp_lat)*sin(fabs(fromwp_lon-towp_lon))/ sin(dist));
631 // Brg = Brg * SGD_RADIANS_TO_DEGREES; }
633 dist *= SGD_RADIANS_TO_DEGREES * 60.0 * 1852.0; //rad->deg->nm->m
634 // end waypoint marker computation
636 //*********************************************************
637 // OBJECT MOVING RETICLE
640 if (fabs(brg-psi) > 10.0) {
642 glTranslatef(centroid.x, centroid.y, 0);
643 glTranslatef(vel_x, vel_y, 0);
644 glRotatef(brg - psi, 0.0, 0.0, -1.0);
645 glBegin(GL_LINE_LOOP);
646 glVertex2f(-2.5, 20.0);
647 glVertex2f(-2.5, 30.0);
648 glVertex2f(-5.0, 30.0);
649 glVertex2f(0.0, 35.0);
650 glVertex2f(5.0, 30.0);
651 glVertex2f(2.5, 30.0);
652 glVertex2f(2.5, 20.0);
657 // waypoint marker on heading scale
658 if (fabs(brg-psi) < 12.0) {
660 glBegin(GL_LINE_LOOP);
661 glVertex2f(((brg - psi) * 60 / 25) + 320, 240.0);
662 glVertex2f(((brg - psi) * 60 / 25) + 326, 240.0 - 4);
663 glVertex2f(((brg - psi) * 60 / 25) + 323, 240.0 - 4);
664 glVertex2f(((brg - psi) * 60 / 25) + 323, 240.0 - 8);
665 glVertex2f(((brg - psi) * 60 / 25) + 317, 240.0 - 8);
666 glVertex2f(((brg - psi) * 60 / 25) + 317, 240.0 - 4);
667 glVertex2f(((brg - psi) * 60 / 25) + 314, 240.0 - 4);
671 float x = (brg - psi) * 60 / 25 + 320, y = 240.0, r = 5.0;
674 glEnable(GL_POINT_SMOOTH);
677 for (int count = 0; count <= 200; count++) {
678 float temp = count * SG_PI * 3 / (200.0 * 2.0);
679 float temp1 = temp - (45.0 * SGD_DEGREES_TO_RADIANS);
680 x1 = x + r * cos(temp1);
681 y1 = y + r * sin(temp1);
686 glDisable(GL_POINT_SMOOTH);
690 } // if _waypoint_marker
695 /******************************************************************/
696 // draws the zenith symbol for highest possible climb angle (i.e. 90 degree climb angle)
698 void HUD::Ladder::draw_zenith(float xfirst, float xlast, float yvalue)
700 float xcentre = (xfirst + xlast) / 2.0;
701 float ycentre = yvalue;
703 draw_line(xcentre - 9.0, ycentre, xcentre - 3.0, ycentre + 1.3);
704 draw_line(xcentre - 9.0, ycentre, xcentre - 3.0, ycentre - 1.3);
706 draw_line(xcentre + 9.0, ycentre, xcentre + 3.0, ycentre + 1.3);
707 draw_line(xcentre + 9.0, ycentre, xcentre + 3.0, ycentre - 1.3);
709 draw_line(xcentre, ycentre + 9.0, xcentre - 1.3, ycentre + 3.0);
710 draw_line(xcentre, ycentre + 9.0, xcentre + 1.3, ycentre + 3.0);
712 draw_line(xcentre - 3.9, ycentre + 3.9, xcentre - 3.0, ycentre + 1.3);
713 draw_line(xcentre - 3.9, ycentre + 3.9, xcentre - 1.3, ycentre + 3.0);
715 draw_line(xcentre + 3.9, ycentre + 3.9, xcentre + 1.3, ycentre+3.0);
716 draw_line(xcentre + 3.9, ycentre + 3.9, xcentre + 3.0, ycentre+1.3);
718 draw_line(xcentre - 3.9, ycentre - 3.9, xcentre - 3.0, ycentre-1.3);
719 draw_line(xcentre - 3.9, ycentre - 3.9, xcentre - 1.3, ycentre-2.6);
721 draw_line(xcentre + 3.9, ycentre - 3.9, xcentre + 3.0, ycentre-1.3);
722 draw_line(xcentre + 3.9, ycentre - 3.9, xcentre + 1.3, ycentre-2.6);
724 draw_line(xcentre - 1.3, ycentre - 2.6, xcentre, ycentre - 27.0);
725 draw_line(xcentre + 1.3, ycentre - 2.6, xcentre, ycentre - 27.0);
729 // draws the nadir symbol for lowest possible dive angle (i.e. 90 degree dive angle)
731 void HUD::Ladder::draw_nadir(float xfirst, float xlast, float yvalue)
733 float xcentre = (xfirst + xlast) / 2.0;
734 float ycentre = yvalue;
737 float x1, y1, x2, y2;
740 float xcent1, xcent2, ycent1, ycent2;
741 xcent1 = xcentre + r;
744 for (int count = 1; count <= 400; count++) {
745 float temp = count * 2 * SG_PI / 400.0;
746 xcent2 = xcentre + r * cos(temp);
747 ycent2 = ycentre + r * sin(temp);
749 draw_line(xcent1, ycent1, xcent2, ycent2);
755 xcent2 = xcentre + r;
758 Item::draw_line(xcent1, ycent1, xcent2, ycent2); //to connect last point to first point
761 //to draw a line above the circle
762 draw_line(xcentre, ycentre + 7.5, xcentre, ycentre + 22.5);
764 //line in the middle of circle
765 draw_line(xcentre - 7.5, ycentre, xcentre + 7.5, ycentre);
767 float theta = asin(2.5 / 7.5);
768 float theta1 = asin(5.0 / 7.5);
770 x1 = xcentre + r * cos(theta);
772 x2 = xcentre + r * cos((180.0 * SGD_DEGREES_TO_RADIANS) - theta);
774 draw_line(x1, y1, x2, y2);
776 x1 = xcentre + r * cos(theta1);
778 x2 = xcentre + r * cos((180.0 * SGD_DEGREES_TO_RADIANS) - theta1);
780 draw_line(x1, y1, x2, y2);
782 x1 = xcentre + r * cos((180.0 * SGD_DEGREES_TO_RADIANS) + theta);
784 x2 = xcentre + r * cos((360.0 * SGD_DEGREES_TO_RADIANS) - theta);
786 draw_line(x1, y1, x2, y2);
788 x1 = xcentre + r * cos((180.0 * SGD_DEGREES_TO_RADIANS) + theta1);
790 x2 = xcentre + r * cos((360.0 * SGD_DEGREES_TO_RADIANS) - theta1);
792 draw_line(x1, y1, x2, y2);