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.
22 #include <Main/viewer.hxx>
27 float get__heading() { return fgGetFloat("/orientation/heading-deg") * M_PI / 180.0; }
28 float get__throttleval() { return fgGetFloat("/controls/engines/engine/throttle"); }
29 float get__aoa() { return fgGetFloat("/sim/frame-rate"); } // FIXME
30 float get__Vx() { return fgGetFloat("/velocities/uBody-fps"); }
31 float get__Vy() { return fgGetFloat("/velocities/vBody-fps"); }
32 float get__Vz() { return fgGetFloat("/velocities/wBody-fps"); }
33 float get__Ax() { return fgGetFloat("/acclerations/pilot/x-accel-fps_sec"); }
34 float get__Ay() { return fgGetFloat("/acclerations/pilot/y-accel-fps_sec"); }
35 float get__Az() { return fgGetFloat("/acclerations/pilot/z-accel-fps_sec"); }
39 HUD::Ladder::Ladder(HUD *hud, const SGPropertyNode *n, float x, float y) :
41 _pitch(n->getNode("pitch-input", false)),
42 _roll(n->getNode("roll-input", false)),
43 width_units(int(n->getFloatValue("display-span"))),
44 div_units(int(fabs(n->getFloatValue("divisions")))),
45 minor_div(0 /* hud.cxx: static float minor_division = 0 */),
46 label_pos(n->getIntValue("lbl-pos")),
47 _scr_hole(n->getIntValue("screen-hole")),
48 _compression(n->getFloatValue("compression-factor")),
49 _frl(n->getBoolValue("enable-fuselage-ref-line", false)),
50 _target_spot(n->getBoolValue("enable-target-spot", false)),
51 _velocity_vector(n->getBoolValue("enable-velocity-vector", false)),
52 _drift_marker(n->getBoolValue("enable-drift-marker", false)),
53 _alpha_bracket(n->getBoolValue("enable-alpha-bracket", false)),
54 _energy_marker(n->getBoolValue("enable-energy-marker", false)),
55 _climb_dive_marker(n->getBoolValue("enable-climb-dive-marker", false)), // WTF FIXME
56 _glide_slope_marker(n->getBoolValue("enable-glide-slope-marker",false)),
57 _glide_slope(n->getFloatValue("glide-slope", -4.0)),
58 _energy_worm(n->getBoolValue("enable-energy-marker", false)),
59 _waypoint_marker(n->getBoolValue("enable-waypoint-marker", false)),
60 _zenith(n->getIntValue("zenith")),
61 _nadir(n->getIntValue("nadir")),
62 _hat(n->getIntValue("hat"))
64 const char *t = n->getStringValue("type");
65 _type = strcmp(t, "climb-dive") ? PITCH : CLIMB_DIVE;
70 _vmax = width_units / 2;
75 void HUD::Ladder::draw(void)
77 if (!_pitch.isValid() || !_roll.isValid())
84 float cosine, sine, xvvr, yvvr, Vxx = 0.0, Vyy = 0.0, Vzz = 0.0;
85 float up_vel, ground_vel, actslope = 0.0;
86 float Axx = 0.0, Ayy = 0.0, Azz = 0.0, total_vel = 0.0, pot_slope, t1;
87 float t2 = 0.0, psi = 0.0, alpha, pla;
88 float vel_x = 0.0, vel_y = 0.0, drift;
89 bool pitch_ladder = false;
90 bool climb_dive_ladder = false;
91 bool clip_plane = false;
93 GLdouble eqn_top[4] = {0.0, -1.0, 0.0, 0.0};
94 GLdouble eqn_left[4] = {-1.0, 0.0, 0.0, 100.0};
95 GLdouble eqn_right[4] = {1.0, 0.0, 0.0, 100.0};
97 Point centroid = get_centroid();
98 Rect box = get_location();
100 float half_span = box.right / 2.0;
101 float roll_value = _roll.getFloatValue() * SGD_DEGREES_TO_RADIANS; // FIXME rad/deg conversion
103 pla = get__throttleval();
105 #ifdef ENABLE_SP_FMDS
106 int lgear, wown, wowm, ilcanclaw, ihook;
107 ilcanclaw = get__iaux2();
108 lgear = get__iaux3();
111 ihook = get__iaux6();
113 float pitch_value = _pitch.getFloatValue();
115 if (_type == CLIMB_DIVE) {
116 pitch_ladder = false;
117 climb_dive_ladder = true;
120 } else { // _type == PITCH
122 climb_dive_ladder = false;
126 //**************************************************************
128 // define (0, 0) as center of screen
129 glTranslatef(centroid.x, centroid.y, 0);
131 // OBJECT STATIC RETICLE
132 // TYPE FRL (FUSELAGE REFERENCE LINE)
134 // Draw the FRL spot and line
136 #define FRL_DIAMOND_SIZE 2.0
137 glBegin(GL_LINE_LOOP);
138 glVertex2f(-FRL_DIAMOND_SIZE, 0.0);
139 glVertex2f(0.0, FRL_DIAMOND_SIZE);
140 glVertex2f(FRL_DIAMOND_SIZE, 0.0);
141 glVertex2f(0.0, -FRL_DIAMOND_SIZE);
144 glBegin(GL_LINE_STRIP);
145 glVertex2f(0, FRL_DIAMOND_SIZE);
148 #undef FRL_DIAMOND_SIZE
150 // TYPE WATERLINE_MARK (W shaped _ _ )
153 //****************************************************************
155 // Draw the target spot.
157 #define CENTER_DIAMOND_SIZE 6.0
158 glBegin(GL_LINE_LOOP);
159 glVertex2f(-CENTER_DIAMOND_SIZE, 0.0);
160 glVertex2f(0.0, CENTER_DIAMOND_SIZE);
161 glVertex2f(CENTER_DIAMOND_SIZE, 0.0);
162 glVertex2f(0.0, -CENTER_DIAMOND_SIZE);
164 #undef CENTER_DIAMOND_SIZE
167 //****************************************************************
168 //velocity vector reticle - computations
169 if (_velocity_vector) {
176 psi = get__heading();
181 total_vel = sqrt(Vxx * Vxx + Vyy * Vyy + Vzz * Vzz);
182 ground_vel = sqrt(Vxx * Vxx + Vyy * Vyy);
185 if (ground_vel < 2.0) {
186 if (fabs(up_vel) < 2.0)
189 actslope = (up_vel / fabs(up_vel)) * 90.0;
192 actslope = atan(up_vel / ground_vel) * SGD_RADIANS_TO_DEGREES;
195 xvvr = (((atan2(Vyy, Vxx) * SGD_RADIANS_TO_DEGREES) - psi)
196 * (_compression / globals->get_current_view()->get_aspect_ratio()));
197 drift = ((atan2(Vyy, Vxx) * SGD_RADIANS_TO_DEGREES) - psi);
198 yvvr = ((actslope - pitch_value) * _compression);
199 vel_y = ((actslope - pitch_value) * cos(roll_value) + drift * sin(roll_value)) * _compression;
200 vel_x = (-(actslope - pitch_value) * sin(roll_value) + drift * cos(roll_value))
201 * (_compression / globals->get_current_view()->get_aspect_ratio());
202 // printf("%f %f %f %f\n",vel_x, vel_y, drift, psi);
204 //****************************************************************
205 // OBJECT MOVING RETICLE
206 // TYPE - DRIFT MARKER
210 glBegin(GL_LINE_STRIP);
211 glVertex2f((xvvr * 25 / 120) - 6, -4);
212 glVertex2f(xvvr * 25 / 120, 8);
213 glVertex2f((xvvr * 25 / 120) + 6, -4);
217 //****************************************************************
218 // Clipping coordinates for ladder to be input from xml file
221 glClipPlane(GL_CLIP_PLANE0, eqn_top);
222 glEnable(GL_CLIP_PLANE0);
223 glClipPlane(GL_CLIP_PLANE1, eqn_left);
224 glEnable(GL_CLIP_PLANE1);
225 glClipPlane(GL_CLIP_PLANE2, eqn_right);
226 glEnable(GL_CLIP_PLANE2);
227 // glScissor(-100,-240, 200, 240);
228 // glEnable(GL_SCISSOR_TEST);
231 //****************************************************************
232 // OBJECT MOVING RETICLE
233 // TYPE VELOCITY VECTOR
236 glBegin(GL_LINE_LOOP); // Use polygon to approximate a circle
237 for (count = 0; count < 50; count++) {
238 cosine = 6 * cos(count * SGD_2PI / 50.0);
239 sine = 6 * sin(count * SGD_2PI / 50.0);
240 glVertex2f(cosine + vel_x, sine + vel_y);
244 //velocity vector reticle orientation lines
245 glBegin(GL_LINE_STRIP);
246 glVertex2f(vel_x - 12, vel_y);
247 glVertex2f(vel_x - 6, vel_y);
249 glBegin(GL_LINE_STRIP);
250 glVertex2f(vel_x + 12, vel_y);
251 glVertex2f(vel_x + 6, vel_y);
253 glBegin(GL_LINE_STRIP);
254 glVertex2f(vel_x, vel_y + 12);
255 glVertex2f(vel_x, vel_y + 6);
258 #ifdef ENABLE_SP_FMDS
259 // OBJECT MOVING RETICLE
261 // ATTRIB - ON CONDITION
263 // undercarriage status
264 glBegin(GL_LINE_STRIP);
265 glVertex2f(vel_x + 8, vel_y);
266 glVertex2f(vel_x + 8, vel_y - 4);
269 // OBJECT MOVING RETICLE
271 // ATTRIB - ON CONDITION
272 glBegin(GL_LINE_STRIP);
273 glVertex2f(vel_x - 8, vel_y);
274 glVertex2f(vel_x - 8, vel_y - 4);
277 // OBJECT MOVING RETICLE
279 // ATTRIB - ON CONDITION
280 glBegin(GL_LINE_STRIP);
281 glVertex2f(vel_x, vel_y - 6);
282 glVertex2f(vel_x, vel_y - 10);
286 // OBJECT MOVING RETICLE
288 // ATTRIB - ON CONDITION
290 // arrestor hook status
291 glBegin(GL_LINE_STRIP);
292 glVertex2f(vel_x - 4, vel_y - 8);
293 glVertex2f(vel_x, vel_y - 10);
294 glVertex2f(vel_x + 4, vel_y - 8);
298 } // if _velocity_vector
301 //***************************************************************
302 // OBJECT MOVING RETICLE
303 // TYPE - SQUARE_BRACKET
304 // ATTRIB - ON CONDITION
306 #ifdef ENABLE_SP_FMDS
307 if (_alpha_bracket && ihook == 1) {
308 glBegin(GL_LINE_STRIP);
309 glVertex2f(vel_x - 20 , vel_y - (16 - alpha) * _compression);
310 glVertex2f(vel_x - 17, vel_y - (16 - alpha) * _compression);
311 glVertex2f(vel_x - 17, vel_y - (14 - alpha) * _compression);
312 glVertex2f(vel_x - 20, vel_y - (14 - alpha) * _compression);
315 glBegin(GL_LINE_STRIP);
316 glVertex2f(vel_x + 20 , vel_y - (16 - alpha) * _compression);
317 glVertex2f(vel_x + 17, vel_y - (16 - alpha) * _compression);
318 glVertex2f(vel_x + 17, vel_y - (14 - alpha) * _compression);
319 glVertex2f(vel_x + 20, vel_y - (14 - alpha) * _compression);
323 //printf("xvr=%f, yvr=%f, Vx=%f, Vy=%f, Vz=%f\n",xvvr, yvvr, Vx, Vy, Vz);
324 //printf("Ax=%f, Ay=%f, Az=%f\n",Ax, Ay, Az);
326 //****************************************************************
327 // OBJECT MOVING RETICLE
328 // TYPE ENERGY_MARKERS
330 //energy markers - compute potential slope
331 if (_energy_marker) {
332 if (total_vel < 5.0) {
336 t1 = up_vel / total_vel;
337 t2 = asin((Vxx * Axx + Vyy * Ayy + Vzz * Azz) / (9.81 * total_vel));
339 pot_slope = ((t2 / 3) * SGD_RADIANS_TO_DEGREES) * _compression + vel_y;
340 // if (pot_slope < (vel_y - 45)) pot_slope = vel_y - 45;
341 // if (pot_slope > (vel_y + 45)) pot_slope = vel_y + 45;
344 glBegin(GL_LINE_STRIP);
345 glVertex2f(vel_x - 20, pot_slope - 5);
346 glVertex2f(vel_x - 15, pot_slope);
347 glVertex2f(vel_x - 20, pot_slope + 5);
350 glBegin(GL_LINE_STRIP);
351 glVertex2f(vel_x + 20, pot_slope - 5);
352 glVertex2f(vel_x + 15, pot_slope);
353 glVertex2f(vel_x + 20, pot_slope + 5);
356 if (pla > (105.0 / 131.0)) {
357 glBegin(GL_LINE_STRIP);
358 glVertex2f(vel_x - 24, pot_slope - 5);
359 glVertex2f(vel_x - 19, pot_slope);
360 glVertex2f(vel_x - 24, pot_slope + 5);
363 glBegin(GL_LINE_STRIP);
364 glVertex2f(vel_x + 24, pot_slope - 5);
365 glVertex2f(vel_x + 19, pot_slope);
366 glVertex2f(vel_x + 24, pot_slope + 5);
371 //**********************************************************
373 // OBJECT STATIC RETICLE
375 // ATTRIB - ON CONDITION
376 #ifdef ENABLE_SP_FMDS
377 if (_energy_worm && ilcanclaw == 1) {
378 glBegin(GL_LINE_STRIP);
379 glVertex2f(-15, -134);
380 glVertex2f(15, -134);
383 // OBJECT MOVING RETICLE
385 // ATTRIB - ON CONDITION
386 glBegin(GL_LINE_STRIP);
387 glVertex2f(-6, -134);
388 glVertex2f(-6, t2 * SGD_RADIANS_TO_DEGREES * 4.0 - 134);
389 glVertex2f(+6, t2 * SGD_RADIANS_TO_DEGREES * 4.0 - 134);
393 // OBJECT MOVING RETICLE
395 // ATTRIB - ON CONDITION
396 glBegin(GL_LINE_LOOP);
397 glVertex2f(-6, actslope * 4.0 - 134);
398 glVertex2f(0, actslope * 4.0 -134 + 3);
399 glVertex2f(6, actslope * 4.0 - 134);
400 glVertex2f(0, actslope * 4.0 -134 -3);
405 //*************************************************************
406 // OBJECT MOVING RETICLE
409 // Draw the locked velocity vector.
410 if (_climb_dive_marker) {
411 glBegin(GL_LINE_LOOP);
412 glVertex2f(-3.0, 0.0 + vel_y);
413 glVertex2f(0.0, 6.0 + vel_y);
414 glVertex2f(3.0, 0.0 + vel_y);
415 glVertex2f(0.0, -6.0 + vel_y);
419 //****************************************************************
421 if (climb_dive_ladder) { // CONFORMAL_HUD
422 _vmin = pitch_value - (float)width_units;
423 _vmax = pitch_value + (float)width_units;
424 glTranslatef(vel_x, vel_y, 0);
426 } else { // pitch_ladder - Default Hud
427 _vmin = pitch_value - (float)width_units * 0.5f;
428 _vmax = pitch_value + (float)width_units * 0.5f;
431 glRotatef(roll_value * SGD_RADIANS_TO_DEGREES, 0.0, 0.0, 1.0);
432 // FRL marker not rotated - this line shifted below
435 const int BUFSIZE = 8;
443 float text_offset = 4.0f;
444 float zero_offset = 0.0;
446 if (climb_dive_ladder)
447 zero_offset = 50.0f; // horizon line is wider by this much (hard coded ??)
451 fntFont *font = _hud->_font_renderer->getFont(); // FIXME
452 float pointsize = _hud->_font_renderer->getPointSize();
453 float italic = _hud->_font_renderer->getSlant();
455 _locTextList.setFont(_hud->_font_renderer);
456 _locTextList.erase();
457 _locLineList.erase();
458 _locStippleLineList.erase();
460 int last = int(_vmax) + 1;
466 for (; i<last; i++) {
467 y = (((float)(i - pitch_value) * _compression) + .5f);
469 if (!(i % div_units)) { // At integral multiple of div
470 snprintf(buf, BUFSIZE, "%d", i);
471 font->getBBox(buf, pointsize, italic, &left, &right, &bot, &top);
472 label_length = right - left;
473 label_length += text_offset;
474 label_height = (top - bot) / 2.0f;
479 // Make zero point wider on left
481 x_ini -= zero_offset;
483 // Zero or above draw solid lines
484 draw_line(x_ini, y, x_end, y);
486 if (i == 90 && _zenith == 1)
487 draw_zenith(x_ini, x_end, y);
489 // Below zero draw dashed lines.
490 draw_stipple_line(x_ini, y, x_end, y);
492 if (i == -90 && _nadir ==1)
493 draw_nadir(x_ini, x_end, y);
496 // Calculate the position of the left text and write it.
497 draw_text(x_ini - label_length, y - label_height, buf);
498 draw_text(x_end + text_offset, y - label_height, buf);
502 } else { // if (_scr_hole)
503 // Draw ladder with space in the middle of the lines
504 float hole = (float)((_scr_hole) / 2.0f);
506 x_end = -half_span + hole;
507 x_ini2 = half_span - hole;
509 for (; i < last; i++) {
511 y = (((float)(i - pitch_value) * _compression) + .5);
512 else // _type == CLIMB_DIVE
513 y = (((float)(i - actslope) * _compression) + .5);
515 if (!(i % div_units)) { // At integral multiple of div
516 snprintf(buf, BUFSIZE, "%d", i);
517 font->getBBox(buf, pointsize, italic, &left, &right, &bot, &top);
518 label_length = right - left;
519 label_length += text_offset;
520 label_height = (top - bot) / 2.0f;
521 // printf("l %f r %f b %f t %f\n",left, right, bot, top);
523 // Start by calculating the points and drawing the
529 // Make zero point wider on left
531 x_ini -= zero_offset;
532 x_end2 += zero_offset;
534 //draw climb bar vertical lines
535 if (climb_dive_ladder) {
536 // Zero or above draw solid lines
537 draw_line(x_end, y - 5.0, x_end, y);
538 draw_line(x_ini2, y - 5.0, x_ini2, y);
540 // draw pitch / climb bar
541 draw_line(x_ini, y, x_end, y);
542 draw_line(x_ini2, y, x_end2, y);
544 if (i == 90 && _zenith == 1)
545 draw_zenith(x_ini2, x_end, y);
548 // draw dive bar vertical lines
549 if (climb_dive_ladder) {
550 draw_line(x_end, y + 5.0, x_end, y);
551 draw_line(x_ini2, y + 5.0, x_ini2, y);
554 // draw pitch / dive bars
555 draw_stipple_line(x_ini, y, x_end, y);
556 draw_stipple_line(x_ini2, y, x_end2, y);
558 if (i == -90 && _nadir == 1)
559 draw_nadir(x_ini2, x_end, y);
562 // Now calculate the location of the left side label using
563 draw_text(x_ini - label_length, y - label_height, buf);
564 draw_text(x_end2 + text_offset, y - label_height, buf);
568 // OBJECT LADDER MARK
570 // ATTRIB - ON CONDITION
571 // draw appraoch glide slope marker
572 #ifdef ENABLE_SP_FMDS
573 if (_glide_slope_marker && ihook) {
574 draw_line(-half_span + 15, (_glide_slope - actslope) * _compression,
575 -half_span + hole, (_glide_slope - actslope) * _compression);
576 draw_line(half_span - 15, (_glide_slope - actslope) * _compression,
577 half_span - hole, (_glide_slope - actslope) * _compression);
587 glEnable(GL_LINE_STIPPLE);
588 glLineStipple(1, 0x00FF);
589 _locStippleLineList.draw();
590 glDisable(GL_LINE_STIPPLE);
592 glDisable(GL_CLIP_PLANE0);
593 glDisable(GL_CLIP_PLANE1);
594 glDisable(GL_CLIP_PLANE2);
595 // glDisable(GL_SCISSOR_TEST);
597 //*************************************************************
599 //*************************************************************
600 #ifdef ENABLE_SP_FMDS
601 if (_waypoint_marker) {
602 //waypoint marker computation
603 float fromwp_lat, towp_lat, fromwp_lon, towp_lon, dist, delx, dely, hyp, theta, brg;
605 fromwp_lon = get__longitude() * SGD_DEGREES_TO_RADIANS;
606 fromwp_lat = get__latitude() * SGD_DEGREES_TO_RADIANS;
607 towp_lon = get__aux2() * SGD_DEGREES_TO_RADIANS;
608 towp_lat = get__aux1() * SGD_DEGREES_TO_RADIANS;
610 dist = acos(sin(fromwp_lat) * sin(towp_lat) + cos(fromwp_lat)
611 * cos(towp_lat) * cos(fabs(fromwp_lon - towp_lon)));
612 delx= towp_lat - fromwp_lat;
613 dely = towp_lon - fromwp_lon;
614 hyp = sqrt(pow(delx, 2) + pow(dely, 2));
617 theta = asin(dely / hyp);
621 brg = theta * SGD_RADIANS_TO_DEGREES;
627 // {Brg = asin(cos(towp_lat)*sin(fabs(fromwp_lon-towp_lon))/ sin(dist));
628 // Brg = Brg * SGD_RADIANS_TO_DEGREES; }
630 dist *= SGD_RADIANS_TO_DEGREES * 60.0 * 1852.0; //rad->deg->nm->m
631 // end waypoint marker computation
633 //*********************************************************
634 // OBJECT MOVING RETICLE
637 if (fabs(brg-psi) > 10.0) {
639 glTranslatef(centroid.x, centroid.y, 0);
640 glTranslatef(vel_x, vel_y, 0);
641 glRotatef(brg - psi, 0.0, 0.0, -1.0);
642 glBegin(GL_LINE_LOOP);
643 glVertex2f(-2.5, 20.0);
644 glVertex2f(-2.5, 30.0);
645 glVertex2f(-5.0, 30.0);
646 glVertex2f(0.0, 35.0);
647 glVertex2f(5.0, 30.0);
648 glVertex2f(2.5, 30.0);
649 glVertex2f(2.5, 20.0);
654 // waypoint marker on heading scale
655 if (fabs(brg-psi) < 12.0) {
657 glBegin(GL_LINE_LOOP);
658 glVertex2f(((brg - psi) * 60 / 25) + 320, 240.0);
659 glVertex2f(((brg - psi) * 60 / 25) + 326, 240.0 - 4);
660 glVertex2f(((brg - psi) * 60 / 25) + 323, 240.0 - 4);
661 glVertex2f(((brg - psi) * 60 / 25) + 323, 240.0 - 8);
662 glVertex2f(((brg - psi) * 60 / 25) + 317, 240.0 - 8);
663 glVertex2f(((brg - psi) * 60 / 25) + 317, 240.0 - 4);
664 glVertex2f(((brg - psi) * 60 / 25) + 314, 240.0 - 4);
668 float x = (brg - psi) * 60 / 25 + 320, y = 240.0, r = 5.0;
671 glEnable(GL_POINT_SMOOTH);
674 for (int count = 0; count <= 200; count++) {
675 float temp = count * 3.142 * 3 / (200.0 * 2.0);
676 float temp1 = temp - (45.0 * SGD_DEGREES_TO_RADIANS);
677 x1 = x + r * cos(temp1);
678 y1 = y + r * sin(temp1);
683 glDisable(GL_POINT_SMOOTH);
687 } // if _waypoint_marker
692 /******************************************************************/
693 // draws the zenith symbol for highest possible climb angle (i.e. 90 degree climb angle)
695 void HUD::Ladder::draw_zenith(float xfirst, float xlast, float yvalue)
697 float xcentre = (xfirst + xlast) / 2.0;
698 float ycentre = yvalue;
700 draw_line(xcentre - 9.0, ycentre, xcentre - 3.0, ycentre + 1.3);
701 draw_line(xcentre - 9.0, ycentre, xcentre - 3.0, ycentre - 1.3);
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, ycentre + 9.0, xcentre - 1.3, ycentre + 3.0);
707 draw_line(xcentre, ycentre + 9.0, xcentre + 1.3, ycentre + 3.0);
709 draw_line(xcentre - 3.9, ycentre + 3.9, xcentre - 3.0, ycentre + 1.3);
710 draw_line(xcentre - 3.9, ycentre + 3.9, xcentre - 1.3, ycentre + 3.0);
712 draw_line(xcentre + 3.9, ycentre + 3.9, xcentre + 1.3, ycentre+3.0);
713 draw_line(xcentre + 3.9, ycentre + 3.9, xcentre + 3.0, ycentre+1.3);
715 draw_line(xcentre - 3.9, ycentre - 3.9, xcentre - 3.0, ycentre-1.3);
716 draw_line(xcentre - 3.9, ycentre - 3.9, xcentre - 1.3, ycentre-2.6);
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 - 1.3, ycentre - 2.6, xcentre, ycentre - 27.0);
722 draw_line(xcentre + 1.3, ycentre - 2.6, xcentre, ycentre - 27.0);
726 // draws the nadir symbol for lowest possible dive angle (i.e. 90 degree dive angle)
728 void HUD::Ladder::draw_nadir(float xfirst, float xlast, float yvalue)
730 float xcentre = (xfirst + xlast) / 2.0;
731 float ycentre = yvalue;
734 float x1, y1, x2, y2;
737 float xcent1, xcent2, ycent1, ycent2;
738 xcent1 = xcentre + r;
741 for (int count = 1; count <= 400; count++) {
742 float temp = count * 2 * 3.142 / 400.0;
743 xcent2 = xcentre + r * cos(temp);
744 ycent2 = ycentre + r * sin(temp);
746 draw_line(xcent1, ycent1, xcent2, ycent2);
752 xcent2 = xcentre + r;
755 Item::draw_line(xcent1, ycent1, xcent2, ycent2); //to connect last point to first point
758 //to draw a line above the circle
759 draw_line(xcentre, ycentre + 7.5, xcentre, ycentre + 22.5);
761 //line in the middle of circle
762 draw_line(xcentre - 7.5, ycentre, xcentre + 7.5, ycentre);
764 float theta = asin (2.5 / 7.5);
765 float theta1 = asin(5.0 / 7.5);
767 x1 = xcentre + r * cos(theta);
769 x2 = xcentre + r * cos((180.0 * SGD_DEGREES_TO_RADIANS) - theta);
771 draw_line(x1, y1, x2, y2);
773 x1 = xcentre + r * cos(theta1);
775 x2 = xcentre + r * cos((180.0 * SGD_DEGREES_TO_RADIANS) - theta1);
777 draw_line(x1, y1, x2, y2);
779 x1 = xcentre + r * cos((180.0 * SGD_DEGREES_TO_RADIANS) + theta);
781 x2 = xcentre + r * cos((360.0 * SGD_DEGREES_TO_RADIANS) - theta);
783 draw_line(x1, y1, x2, y2);
785 x1 = xcentre + r * cos((180.0 * SGD_DEGREES_TO_RADIANS) + theta1);
787 x2 = xcentre + r * cos((360.0 * SGD_DEGREES_TO_RADIANS) - theta1);
789 draw_line(x1, y1, x2, y2);