src/Instrumentation/HUD/HUD_ladder.cxx

   1 // HUD_ladder.cxx -- HUD Ladder Instrument
   2 //
   3 // Written by Michele America, started September 1997.
   4 //
   5 // Copyright (C) 1997  Michele F. America  [micheleamerica#geocities:com]
   6 // Copyright (C) 2006  Melchior FRANZ  [mfranz#aon:at]
   7 //
   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.
  12 //
  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.
  17 //
  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.
  21
  22 #ifdef HAVE_CONFIG_H
  23 #  include <config.h>
  24 #endif
  25
  26 #include <simgear/math/vector.hxx>
  27 #include <Main/viewer.hxx>
  28 #include "HUD.hxx"
  29
  30
  31 // FIXME
  32 float get__heading() { return fgGetFloat("/orientation/heading-deg") * M_PI / 180.0; }
  33 float get__throttleval() { return fgGetFloat("/controls/engines/engine/throttle"); }
  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"); }
  40 float get__alpha() { return fgGetFloat("/orientation/alpha-deg"); }
  41 float get__beta() { return fgGetFloat("/orientation/side-slip-deg"); }
  42 #undef ENABLE_SP_FDM
  43
  44
  45 HUD::Ladder::Ladder(HUD *hud, const SGPropertyNode *n, float x, float y) :
  46     Item(hud, n, x, y),
  47     _pitch(n->getNode("pitch-input", false)),
  48     _roll(n->getNode("roll-input", false)),
  49     _width_units(int(n->getFloatValue("display-span"))),
  50     _div_units(int(fabs(n->getFloatValue("divisions")))),
  51     _scr_hole(n->getIntValue("screen-hole")),
  52     _compression(n->getFloatValue("compression-factor")),
  53     _dynamic_origin(n->getBoolValue("enable-dynamic-origin")),
  54     _frl(n->getBoolValue("enable-fuselage-ref-line")),
  55     _target_spot(n->getBoolValue("enable-target-spot")),
  56     _target_markers(n->getBoolValue("enable-target-markers")),
  57     _velocity_vector(n->getBoolValue("enable-velocity-vector")),
  58     _drift_marker(n->getBoolValue("enable-drift-marker")),
  59     _alpha_bracket(n->getBoolValue("enable-alpha-bracket")),
  60     _energy_marker(n->getBoolValue("enable-energy-marker")),
  61     _climb_dive_marker(n->getBoolValue("enable-climb-dive-marker")),
  62     _glide_slope_marker(n->getBoolValue("enable-glide-slope-marker")),
  63     _glide_slope(n->getFloatValue("glide-slope", -4.0)),
  64     _energy_worm(n->getBoolValue("enable-energy-marker")),
  65     _waypoint_marker(n->getBoolValue("enable-waypoint-marker")),
  66     _zenith(n->getBoolValue("enable-zenith")),
  67     _nadir(n->getBoolValue("enable-nadir")),
  68     _hat(n->getBoolValue("enable-hat"))
  69 {
  70     const char *t = n->getStringValue("type");
  71     _type = strcmp(t, "climb-dive") ? PITCH : CLIMB_DIVE;
  72
  73     if (!_width_units)
  74         _width_units = 45;
  75
  76     _vmax = _width_units / 2;
  77     _vmin = -_vmax;
  78 }
  79
  80
  81 void HUD::Ladder::draw(void)
  82 {
  83     if (!_pitch.isValid() || !_roll.isValid())
  84         return;
  85
  86     float roll_value = _roll.getFloatValue() * SGD_DEGREES_TO_RADIANS;
  87     float pitch_value = _pitch.getFloatValue();
  88     float alpha;
  89
  90     bool pitch_ladder;
  91     bool clip_plane;
  92
  93     if (_type == CLIMB_DIVE) {
  94         pitch_ladder = false;
  95         clip_plane = true;
  96
  97     } else { // _type == PITCH
  98         pitch_ladder = true;
  99         clip_plane = false;
 100     }
 101
 102     //**************************************************************
 103     glPushMatrix();
 104     glTranslatef(_center_x, _center_y, 0);
 105
 106     // OBJECT STATIC RETICLE
 107     // TYPE FRL (FUSELAGE REFERENCE LINE)
 108     // ATTRIB - ALWAYS
 109     // Draw the FRL spot and line
 110     if (_frl) {
 111 #define FRL_DIAMOND_SIZE 2.0
 112         glBegin(GL_LINE_LOOP);
 113         glVertex2f(-FRL_DIAMOND_SIZE, 0.0);
 114         glVertex2f(0.0, FRL_DIAMOND_SIZE);
 115         glVertex2f(FRL_DIAMOND_SIZE, 0.0);
 116         glVertex2f(0.0, -FRL_DIAMOND_SIZE);
 117         glEnd();
 118
 119         glBegin(GL_LINE_STRIP);
 120         glVertex2f(0, FRL_DIAMOND_SIZE);
 121         glVertex2f(0, 8.0);
 122         glEnd();
 123 #undef FRL_DIAMOND_SIZE
 124     }
 125     // TYPE WATERLINE_MARK (W shaped _    _ )           // TODO (-> HUD_misc.cxx)
 126     //                                \/\/
 127
 128     //****************************************************************
 129     // TYPE TARGET_SPOT
 130     // Draw the target spot.
 131     if (_target_spot) {
 132 #define CENTER_DIAMOND_SIZE 6.0
 133         glBegin(GL_LINE_LOOP);
 134         glVertex2f(-CENTER_DIAMOND_SIZE, 0.0);
 135         glVertex2f(0.0, CENTER_DIAMOND_SIZE);
 136         glVertex2f(CENTER_DIAMOND_SIZE, 0.0);
 137         glVertex2f(0.0, -CENTER_DIAMOND_SIZE);
 138         glEnd();
 139 #undef CENTER_DIAMOND_SIZE
 140     }
 141
 142     //****************************************************************
 143     //velocity vector reticle - computations
 144     float xvvr, /* yvvr, */ Vxx = 0.0, Vyy = 0.0, Vzz = 0.0;
 145     float Axx = 0.0, Ayy = 0.0, Azz = 0.0, total_vel = 0.0, pot_slope, t1;
 146     float up_vel, ground_vel, actslope = 0.0, psi = 0.0;
 147     float vel_x = 0.0, vel_y = 0.0, drift;
 148
 149     if (_velocity_vector) {
 150         drift = get__beta();
 151         alpha = get__alpha();
 152
 153         Vxx = get__Vx();
 154         Vyy = get__Vy();
 155         Vzz = get__Vz();
 156         Axx = get__Ax();
 157         Ayy = get__Ay();
 158         Azz = get__Az();
 159         psi = get__heading();
 160
 161         if (psi > 180.0)
 162             psi = psi - 360;
 163
 164         total_vel = sqrt(Vxx * Vxx + Vyy * Vyy + Vzz * Vzz);
 165         ground_vel = sqrt(Vxx * Vxx + Vyy * Vyy);
 166         up_vel = Vzz;
 167
 168         if (ground_vel < 2.0) {
 169             if (fabs(up_vel) < 2.0)
 170                 actslope = 0.0;
 171             else
 172                 actslope = (up_vel / fabs(up_vel)) * 90.0;
 173
 174         } else {
 175             actslope = atan(up_vel / ground_vel) * SGD_RADIANS_TO_DEGREES;
 176         }
 177
 178         xvvr = (-drift * (_compression / globals->get_current_view()->get_aspect_ratio()));
 179         // drift = ((atan2(Vyy, Vxx) * SGD_RADIANS_TO_DEGREES) - psi);
 180         // yvvr = (-alpha * _compression);
 181         // vel_y = (-alpha * cos(roll_value) + drift * sin(roll_value)) * _compression;
 182         // vel_x = (alpha * sin(roll_value) + drift * cos(roll_value))
 183         //         * (_compression / globals->get_current_view()->get_aspect_ratio());
 184         vel_y = -alpha * _compression;
 185         vel_x = -drift * (_compression / globals->get_current_view()->get_aspect_ratio());
 186         //  printf("%f %f %f %f\n",vel_x, vel_y, drift, psi);
 187
 188         //****************************************************************
 189         // OBJECT MOVING RETICLE
 190         // TYPE - DRIFT MARKER
 191         // ATTRIB - ALWAYS
 192         // drift marker
 193         if (_drift_marker) {
 194             glBegin(GL_LINE_STRIP);
 195             glVertex2f((xvvr * 25 / 120) - 6, -4);
 196             glVertex2f(xvvr * 25 / 120, 8);
 197             glVertex2f((xvvr * 25 / 120) + 6, -4);
 198             glEnd();
 199         }
 200
 201         //****************************************************************
 202         // Clipping coordinates for ladder to be input from xml file
 203         // Clip hud ladder
 204         if (clip_plane) {
 205             GLdouble eqn_top[4] = {0.0, -1.0, 0.0, 0.0};
 206             GLdouble eqn_left[4] = {-1.0, 0.0, 0.0, 100.0};
 207             GLdouble eqn_right[4] = {1.0, 0.0, 0.0, 100.0};
 208
 209             glClipPlane(GL_CLIP_PLANE0, eqn_top);
 210             glEnable(GL_CLIP_PLANE0);
 211             glClipPlane(GL_CLIP_PLANE1, eqn_left);
 212             glEnable(GL_CLIP_PLANE1);
 213             glClipPlane(GL_CLIP_PLANE2, eqn_right);
 214             glEnable(GL_CLIP_PLANE2);
 215         }
 216
 217         //****************************************************************
 218         // OBJECT MOVING RETICLE
 219         // TYPE VELOCITY VECTOR
 220         // ATTRIB - ALWAYS
 221         // velocity vector
 222         draw_circle(vel_x, vel_y, 6);
 223
 224         //velocity vector reticle orientation lines
 225         glBegin(GL_LINE_STRIP);
 226         glVertex2f(vel_x - 12, vel_y);
 227         glVertex2f(vel_x - 6, vel_y);
 228         glEnd();
 229         glBegin(GL_LINE_STRIP);
 230         glVertex2f(vel_x + 12, vel_y);
 231         glVertex2f(vel_x + 6, vel_y);
 232         glEnd();
 233         glBegin(GL_LINE_STRIP);
 234         glVertex2f(vel_x, vel_y + 12);
 235         glVertex2f(vel_x, vel_y + 6);
 236         glEnd();
 237
 238 #ifdef ENABLE_SP_FDM
 239         int lgear = get__iaux3();
 240         int ihook = get__iaux6();
 241
 242         // OBJECT MOVING RETICLE
 243         // TYPE LINE
 244         // ATTRIB - ON CONDITION
 245         if (lgear == 1) {
 246             // undercarriage status
 247             glBegin(GL_LINE_STRIP);
 248             glVertex2f(vel_x + 8, vel_y);
 249             glVertex2f(vel_x + 8, vel_y - 4);
 250             glEnd();
 251
 252             // OBJECT MOVING RETICLE
 253             // TYPE LINE
 254             // ATTRIB - ON CONDITION
 255             glBegin(GL_LINE_STRIP);
 256             glVertex2f(vel_x - 8, vel_y);
 257             glVertex2f(vel_x - 8, vel_y - 4);
 258             glEnd();
 259
 260             // OBJECT MOVING RETICLE
 261             // TYPE LINE
 262             // ATTRIB - ON CONDITION
 263             glBegin(GL_LINE_STRIP);
 264             glVertex2f(vel_x, vel_y - 6);
 265             glVertex2f(vel_x, vel_y - 10);
 266             glEnd();
 267         }
 268
 269         // OBJECT MOVING RETICLE
 270         // TYPE V
 271         // ATTRIB - ON CONDITION
 272         if (ihook == 1) {
 273             // arrestor hook status
 274             glBegin(GL_LINE_STRIP);
 275             glVertex2f(vel_x - 4, vel_y - 8);
 276             glVertex2f(vel_x, vel_y - 10);
 277             glVertex2f(vel_x + 4, vel_y - 8);
 278             glEnd();
 279         }
 280 #endif
 281     } // if _velocity_vector
 282
 283     // draw hud markers on top of each AI/MP target
 284     if (_target_markers) {
 285         SGPropertyNode *models = globals->get_props()->getNode("/ai/models", true);
 286         for (int i = 0; i < models->nChildren(); i++) {
 287             SGPropertyNode *chld = models->getChild(i);
 288             string name;
 289             name = chld->getName();
 290             if (name == "aircraft" || name == "multiplayer") {
 291                 string callsign = chld->getStringValue("callsign");
 292                 if (callsign != "") {
 293                     float h_deg = chld->getFloatValue("radar/h-offset");
 294                     float v_deg = chld->getFloatValue("radar/v-offset");
 295                     float pos_x = (h_deg * cos(roll_value) -
 296                                    v_deg * sin(roll_value)) * _compression;
 297                     float pos_y = (v_deg * cos(roll_value) +
 298                                    h_deg * sin(roll_value)) * _compression;
 299                     draw_circle(pos_x, pos_y, 8);
 300                 }
 301             }
 302         }
 303     }
 304
 305     //***************************************************************
 306     // OBJECT MOVING RETICLE
 307     // TYPE - SQUARE_BRACKET
 308     // ATTRIB - ON CONDITION
 309     // alpha bracket
 310 #ifdef ENABLE_SP_FDM
 311     alpha = get__alpha();
 312
 313     if (_alpha_bracket && ihook == 1) {
 314         glBegin(GL_LINE_STRIP);
 315         glVertex2f(vel_x - 20, vel_y - (16 - alpha) * _compression);
 316         glVertex2f(vel_x - 17, vel_y - (16 - alpha) * _compression);
 317         glVertex2f(vel_x - 17, vel_y - (14 - alpha) * _compression);
 318         glVertex2f(vel_x - 20, vel_y - (14 - alpha) * _compression);
 319         glEnd();
 320
 321         glBegin(GL_LINE_STRIP);
 322         glVertex2f(vel_x + 20, vel_y - (16 - alpha) * _compression);
 323         glVertex2f(vel_x + 17, vel_y - (16 - alpha) * _compression);
 324         glVertex2f(vel_x + 17, vel_y - (14 - alpha) * _compression);
 325         glVertex2f(vel_x + 20, vel_y - (14 - alpha) * _compression);
 326         glEnd();
 327     }
 328 #endif
 329     //printf("xvr=%f, yvr=%f, Vx=%f, Vy=%f, Vz=%f\n",xvvr, yvvr, Vx, Vy, Vz);
 330     //printf("Ax=%f, Ay=%f, Az=%f\n",Ax, Ay, Az);
 331
 332     //****************************************************************
 333     // OBJECT MOVING RETICLE
 334     // TYPE ENERGY_MARKERS
 335     // ATTRIB - ALWAYS
 336     //energy markers - compute potential slope
 337     float pla = get__throttleval();
 338     float t2 = 0.0;
 339
 340     if (_energy_marker) {
 341         if (total_vel < 5.0) {
 342             t1 = 0;
 343             t2 = 0;
 344         } else {
 345             t1 = up_vel / total_vel;
 346             t2 = asin((Vxx * Axx + Vyy * Ayy + Vzz * Azz) / (9.81 * total_vel));
 347         }
 348         pot_slope = ((t2 / 3) * SGD_RADIANS_TO_DEGREES) * _compression + vel_y;
 349         // if (pot_slope < (vel_y - 45)) pot_slope = vel_y - 45;
 350         // if (pot_slope > (vel_y + 45)) pot_slope = vel_y + 45;
 351
 352         //energy markers
 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);
 357         glEnd();
 358
 359         glBegin(GL_LINE_STRIP);
 360         glVertex2f(vel_x + 20, pot_slope - 5);
 361         glVertex2f(vel_x + 15, pot_slope);
 362         glVertex2f(vel_x + 20, pot_slope + 5);
 363         glEnd();
 364
 365         if (pla > (105.0 / 131.0)) {
 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);
 370             glEnd();
 371
 372             glBegin(GL_LINE_STRIP);
 373             glVertex2f(vel_x + 24, pot_slope - 5);
 374             glVertex2f(vel_x + 19, pot_slope);
 375             glVertex2f(vel_x + 24, pot_slope + 5);
 376             glEnd();
 377         }
 378     }
 379
 380     //**********************************************************
 381     // ramp reticle
 382     // OBJECT STATIC RETICLE
 383     // TYPE LINE
 384     // ATTRIB - ON CONDITION
 385 #ifdef ENABLE_SP_FDM
 386     int ilcanclaw = get__iaux2();
 387
 388     if (_energy_worm && ilcanclaw == 1) {
 389         glBegin(GL_LINE_STRIP);
 390         glVertex2f(-15, -134);
 391         glVertex2f(15, -134);
 392         glEnd();
 393
 394         // OBJECT MOVING RETICLE
 395         // TYPE BOX
 396         // ATTRIB - ON CONDITION
 397         glBegin(GL_LINE_STRIP);
 398         glVertex2f(-6, -134);
 399         glVertex2f(-6, t2 * SGD_RADIANS_TO_DEGREES * 4.0 - 134);
 400         glVertex2f(+6, t2 * SGD_RADIANS_TO_DEGREES * 4.0 - 134);
 401         glVertex2f(6, -134);
 402         glEnd();
 403
 404         // OBJECT MOVING RETICLE
 405         // TYPE DIAMOND
 406         // ATTRIB - ON CONDITION
 407         glBegin(GL_LINE_LOOP);
 408         glVertex2f(-6, actslope * 4.0 - 134);
 409         glVertex2f(0, actslope * 4.0 -134 + 3);
 410         glVertex2f(6, actslope * 4.0 - 134);
 411         glVertex2f(0, actslope * 4.0 -134 -3);
 412         glEnd();
 413     }
 414 #endif
 415
 416     //*************************************************************
 417     // OBJECT MOVING RETICLE
 418     // TYPE DIAMOND
 419     // ATTRIB - ALWAYS
 420     // Draw the locked velocity vector.
 421     if (_climb_dive_marker) {
 422         glBegin(GL_LINE_LOOP);
 423         glVertex2f(-3.0, 0.0 + vel_y);
 424         glVertex2f(0.0, 6.0 + vel_y);
 425         glVertex2f(3.0, 0.0 + vel_y);
 426         glVertex2f(0.0, -6.0 + vel_y);
 427         glEnd();
 428     }
 429
 430     //****************************************************************
 431
 432     if (_dynamic_origin) {
 433         // ladder moves with alpha/beta offset projected onto horizon
 434         // line (so that the horizon line always aligns with the
 435         // actual horizon.
 436         _vmin = pitch_value - _width_units * 0.5f;
 437         _vmax = pitch_value + _width_units * 0.5f;
 438         {
 439             // the hud ladder center point should move relative to alpha/beta
 440             // however the horizon line should always stay on the horizon.  We
 441             // project the alpha/beta offset onto the horizon line to get the
 442             // result we want.
 443             sgdVec3 p1; // result
 444             sgdVec3 p; sgdSetVec3(p, vel_x, vel_y, 0.0);
 445             sgdVec3 p0; sgdSetVec3(p0, 0.0, 0.0, 0.0);
 446             sgdVec3 d; sgdSetVec3(d, cos(roll_value), sin(roll_value), 0.0);
 447             sgdClosestPointToLine( p1, p, p0, d );
 448             glTranslatef(p1[0], p1[1], 0);
 449         }
 450     } else {
 451         // ladder position is fixed relative to the center of the screen.
 452         _vmin = pitch_value - _width_units * 0.5f;
 453         _vmax = pitch_value + _width_units * 0.5f;
 454     }
 455
 456     glRotatef(roll_value * SGD_RADIANS_TO_DEGREES, 0.0, 0.0, 1.0);
 457     // FRL marker not rotated - this line shifted below
 458     float half_span = _w / 2.0;
 459     float y = 0, y_end = 0;
 460     float x_ini, x_ini2;
 461     float x_end, x_end2;
 462
 463     if (_div_units) {
 464         const int BUFSIZE = 8;
 465         char buf[BUFSIZE];
 466         float label_length;
 467         float label_height;
 468         float left;
 469         float right;
 470         float bot;
 471         float top;
 472         float text_offset = 4.0f;
 473         float zero_offset = 0.0;
 474
 475         // horizon line is wider by this much (hard coded ??)
 476         zero_offset = 50.0f;
 477
 478         fntFont *font = _hud->_font_renderer->getFont();   // FIXME
 479         float pointsize = _hud->_font_renderer->getPointSize();
 480         float italic = _hud->_font_renderer->getSlant();
 481
 482         _locTextList.setFont(_hud->_font_renderer);
 483         _locTextList.erase();
 484         _locLineList.erase();
 485         _locStippleLineList.erase();
 486
 487         int last = int(_vmax) + 1;
 488         int i = int(_vmin);
 489
 490         if (!_scr_hole) {
 491             x_end = half_span;
 492
 493             for (; i < last; i++) {
 494                 y = (i - pitch_value) * _compression + .5f;
 495
 496                 if (!(i % _div_units)) {           //  At integral multiple of div
 497                     snprintf(buf, BUFSIZE, "%d", i);
 498                     font->getBBox(buf, pointsize, italic, &left, &right, &bot, &top);
 499                     label_length = right + left;
 500                     label_height = (top + bot) / 2.0f;
 501
 502                     x_ini = -half_span;
 503
 504                     if (i >= 0) {
 505                         // Make zero point wider on left
 506                         if (i == 0)
 507                             x_ini -= zero_offset;
 508
 509                         // Zero or above draw solid lines
 510                         draw_line(x_ini, y, x_end, y);
 511
 512                         if (i == 90 && _zenith)
 513                             draw_zenith(0.0, y);
 514                     } else {
 515                         // Below zero draw dashed lines.
 516                         draw_stipple_line(x_ini, y, x_end, y);
 517
 518                         if (i == -90 && _nadir)
 519                             draw_nadir(0.0, y);
 520                     }
 521
 522                     // Calculate the position of the left text and write it.
 523                     draw_text(x_ini - text_offset - label_length + 2.5/*hack*/, y - label_height, buf);
 524                     draw_text(x_end + text_offset, y - label_height, buf);
 525                 }
 526             }
 527
 528         } else { // if (_scr_hole)
 529             // Draw ladder with space in the middle of the lines
 530             float hole = _scr_hole / 2.0f;
 531
 532             x_end = -half_span + hole;
 533             x_ini2 = half_span - hole;
 534
 535             for (; i < last; i++) {
 536                 if (_type == PITCH) {
 537                     y = float(i - pitch_value) * _compression + .5;
 538                 } else {
 539                     // _type == CLIMB_DIVE
 540                     y = float(i - actslope) * _compression + .5;
 541                 }
 542                 if ( i < 0 )
 543                     y_end = y +
 544                         sin(0.5 * i * SG_DEGREES_TO_RADIANS * 3/*hack*/) *
 545                         _compression;
 546                 else
 547                     y_end = y;
 548
 549                 if (!(i % _div_units)) {  //  At integral multiple of div
 550                     snprintf(buf, BUFSIZE, "%d", i);
 551                     font->getBBox(buf, pointsize, italic, &left, &right, &bot, &top);
 552                     label_length = right + left;
 553                     label_height = (top + bot) / 2.0f;
 554                     //printf("%s -- l %f r %f b %f t %f\n", buf, left, right, bot, top);
 555
 556                     // Start by calculating the points and drawing the
 557                     // left side lines.
 558                     x_ini = -half_span;
 559                     x_end2 = half_span;
 560
 561                     if (i >= 0) {
 562                         // Make zero point wider on left
 563                         if (i == 0) {
 564                             x_ini -= zero_offset;
 565                             x_end2 += zero_offset;
 566                         } else {
 567                             //draw climb bar vertical lines
 568                             draw_line(x_end, y - 5.0, x_end, y);
 569                             draw_line(x_ini2, y - 5.0, x_ini2, y);
 570                         }
 571                         // draw pitch / climb bar
 572                         draw_line(x_ini, y, x_end, y);
 573                         draw_line(x_ini2, y, x_end2, y);
 574
 575                         if (i == 90 && _zenith)
 576                             draw_zenith(0.0, y);
 577
 578                     } else { // i < 0
 579                         // draw dive bar vertical lines
 580                         draw_line(x_end, y + 5.0, x_end, y);
 581                         draw_line(x_ini2, y + 5.0, x_ini2, y);
 582
 583                         // draw pitch / dive bars
 584                         draw_stipple_line(x_ini, y_end, x_end, y);
 585                         draw_stipple_line(x_ini2, y, x_end2, y_end);
 586
 587                         if (i == -90 && _nadir)
 588                             draw_nadir(0.0, y);
 589                     }
 590
 591                     // Now calculate the location of the left side label using
 592                     draw_text(x_ini - text_offset - label_length + 2.5/*hack*/, y_end - label_height, buf);
 593                     draw_text(x_end2 + text_offset, y_end - label_height, buf);
 594                 }
 595             }
 596
 597             // OBJECT LADDER MARK
 598             // TYPE LINE
 599             // ATTRIB - ON CONDITION
 600             // draw appraoch glide slope marker
 601 #ifdef ENABLE_SP_FDM
 602             if (_glide_slope_marker && ihook) {
 603                 draw_line(-half_span + 15, (_glide_slope - actslope) * _compression,
 604                         -half_span + hole, (_glide_slope - actslope) * _compression);
 605                 draw_line(half_span - 15, (_glide_slope - actslope) * _compression,
 606                         half_span - hole, (_glide_slope - actslope) * _compression);
 607             }
 608 #endif
 609         }
 610         _locTextList.draw();
 611
 612         glLineWidth(0.2);
 613
 614         _locLineList.draw();
 615
 616         glEnable(GL_LINE_STIPPLE);
 617         glLineStipple(1, 0x00FF);
 618         _locStippleLineList.draw();
 619         glDisable(GL_LINE_STIPPLE);
 620     }
 621     glDisable(GL_CLIP_PLANE0);
 622     glDisable(GL_CLIP_PLANE1);
 623     glDisable(GL_CLIP_PLANE2);
 624     glPopMatrix();
 625     //*************************************************************
 626
 627     //*************************************************************
 628 #ifdef ENABLE_SP_FDM
 629     if (_waypoint_marker) {
 630         //waypoint marker computation
 631         float fromwp_lat, towp_lat, fromwp_lon, towp_lon, dist, delx, dely, hyp, theta, brg;
 632
 633         fromwp_lon = get__longitude() * SGD_DEGREES_TO_RADIANS;
 634         fromwp_lat = get__latitude() * SGD_DEGREES_TO_RADIANS;
 635         towp_lon = get__aux2() * SGD_DEGREES_TO_RADIANS;
 636         towp_lat = get__aux1() * SGD_DEGREES_TO_RADIANS;
 637
 638         dist = acos(sin(fromwp_lat) * sin(towp_lat) + cos(fromwp_lat)
 639                 * cos(towp_lat) * cos(fabs(fromwp_lon - towp_lon)));
 640         delx= towp_lat - fromwp_lat;
 641         dely = towp_lon - fromwp_lon;
 642         hyp = sqrt(pow(delx, 2) + pow(dely, 2));
 643
 644         if (hyp != 0)
 645             theta = asin(dely / hyp);
 646         else
 647             theta = 0.0;
 648
 649         brg = theta * SGD_RADIANS_TO_DEGREES;
 650         if (brg > 360.0)
 651             brg = 0.0;
 652         if (delx < 0)
 653             brg = 180 - brg;
 654
 655         // {Brg  = asin(cos(towp_lat)*sin(fabs(fromwp_lon-towp_lon))/ sin(dist));
 656         // Brg = Brg * SGD_RADIANS_TO_DEGREES; }
 657
 658         dist *= SGD_RADIANS_TO_DEGREES * 60.0 * 1852.0; //rad->deg->nm->m
 659         // end waypoint marker computation
 660
 661         //*********************************************************
 662         // OBJECT MOVING RETICLE
 663         // TYPE ARROW
 664         // waypoint marker
 665         if (fabs(brg - psi) > 10.0) {
 666             glPushMatrix();
 667             glTranslatef(_center_x, _center_y, 0);
 668             glTranslatef(vel_x, vel_y, 0);
 669             glRotatef(brg - psi, 0.0, 0.0, -1.0);
 670             glBegin(GL_LINE_LOOP);
 671             glVertex2f(-2.5, 20.0);
 672             glVertex2f(-2.5, 30.0);
 673             glVertex2f(-5.0, 30.0);
 674             glVertex2f(0.0, 35.0);
 675             glVertex2f(5.0, 30.0);
 676             glVertex2f(2.5, 30.0);
 677             glVertex2f(2.5, 20.0);
 678             glEnd();
 679             glPopMatrix();
 680         }
 681
 682         // waypoint marker on heading scale
 683         if (fabs(brg - psi) < 12.0) {
 684             if (!_hat) {
 685                 glBegin(GL_LINE_LOOP);
 686                 GLfloat x = (brg - psi) * 60 / 25;
 687                 glVertex2f(x + 320, 240.0);
 688                 glVertex2f(x + 326, 240.0 - 4);
 689                 glVertex2f(x + 323, 240.0 - 4);
 690                 glVertex2f(x + 323, 240.0 - 8);
 691                 glVertex2f(x + 317, 240.0 - 8);
 692                 glVertex2f(x + 317, 240.0 - 4);
 693                 glVertex2f(x + 314, 240.0 - 4);
 694                 glEnd();
 695
 696             } else { // if (_hat)
 697                 float x = (brg - psi) * 60 / 25 + 320, y = 240.0, r = 5.0;
 698                 float x1, y1;
 699
 700                 glEnable(GL_POINT_SMOOTH);
 701                 glBegin(GL_POINTS);
 702
 703                 for (int count = 0; count <= 200; count++) {
 704                     float temp = count * SG_PI * 3 / (200.0 * 2.0);
 705                     float temp1 = temp - (45.0 * SGD_DEGREES_TO_RADIANS);
 706                     x1 = x + r * cos(temp1);
 707                     y1 = y + r * sin(temp1);
 708                     glVertex2f(x1, y1);
 709                 }
 710
 711                 glEnd();
 712                 glDisable(GL_POINT_SMOOTH);
 713             }
 714
 715          } //brg<12
 716      } // if _waypoint_marker
 717 #endif
 718 }//draw
 719
 720
 721 /******************************************************************/
 722 //  draws the zenith symbol (highest possible climb angle i.e. 90 degree climb angle)
 723 //
 724 void HUD::Ladder::draw_zenith(float x, float y)
 725 {
 726     draw_line(x - 9.0, y, x - 3.0, y + 1.3);
 727     draw_line(x - 9.0, y, x - 3.0, y - 1.3);
 728
 729     draw_line(x + 9.0, y, x + 3.0, y + 1.3);
 730     draw_line(x + 9.0, y, x + 3.0, y - 1.3);
 731
 732     draw_line(x, y + 9.0, x - 1.3, y + 3.0);
 733     draw_line(x, y + 9.0, x + 1.3, y + 3.0);
 734
 735     draw_line(x - 3.9, y + 3.9, x - 3.0, y + 1.3);
 736     draw_line(x - 3.9, y + 3.9, x - 1.3, y + 3.0);
 737
 738     draw_line(x + 3.9, y + 3.9, x + 1.3, y + 3.0);
 739     draw_line(x + 3.9, y + 3.9, x + 3.0, y + 1.3);
 740
 741     draw_line(x - 3.9, y - 3.9, x - 3.0, y - 1.3);
 742     draw_line(x - 3.9, y - 3.9, x - 1.3, y - 2.6);
 743
 744     draw_line(x + 3.9, y - 3.9, x + 3.0, y - 1.3);
 745     draw_line(x + 3.9, y - 3.9, x + 1.3, y - 2.6);
 746
 747     draw_line(x - 1.3, y - 2.6, x, y - 27.0);
 748     draw_line(x + 1.3, y - 2.6, x, y - 27.0);
 749 }
 750
 751
 752 //  draws the nadir symbol (lowest possible dive angle i.e. 90 degree dive angle))
 753 //
 754 void HUD::Ladder::draw_nadir(float x, float y)
 755 {
 756     const float R = 7.5;
 757
 758     draw_circle(x, y, R);
 759     draw_line(x, y + R, x, y + 22.5); // line above the circle
 760     draw_line(x - R, y, x + R, y);    // line at middle of circle
 761
 762     float theta = asin(2.5 / R);
 763     float theta1 = asin(5.0 / R);
 764     float x1, y1, x2, y2;
 765
 766     x1 = x + R * cos(theta);
 767     y1 = y + 2.5;
 768     x2 = x + R * cos((180.0 * SGD_DEGREES_TO_RADIANS) - theta);
 769     y2 = y + 2.5;
 770     draw_line(x1, y1, x2, y2);
 771
 772     x1 = x + R * cos(theta1);
 773     y1 = y + 5.0;
 774     x2 = x + R * cos((180.0 * SGD_DEGREES_TO_RADIANS) - theta1);
 775     y2 = y + 5.0;
 776     draw_line(x1, y1, x2, y2);
 777
 778     x1 = x + R * cos((180.0 * SGD_DEGREES_TO_RADIANS) + theta);
 779     y1 = y - 2.5;
 780     x2 = x + R * cos((360.0 * SGD_DEGREES_TO_RADIANS) - theta);
 781     y2 = y - 2.5;
 782     draw_line(x1, y1, x2, y2);
 783
 784     x1 = x + R * cos((180.0 * SGD_DEGREES_TO_RADIANS) + theta1);
 785     y1 = y - 5.0;
 786     x2 = x + R * cos((360.0 * SGD_DEGREES_TO_RADIANS) - theta1);
 787     y2 = y - 5.0;
 788     draw_line(x1, y1, x2, y2);
 789 }
 790
 791