xmain.d

   1 module xmain is aliced;
   2
   3 import arsd.simpledisplay;
   4 import arsd.color;
   5 import arsd.image;
   6
   7 import iv.glbinds.utils;
   8 import iv.vmath;
   9
  10 import b2dlite;
  11
  12
  13 // ////////////////////////////////////////////////////////////////////////// //
  14 enum GWidth = 800;
  15 enum GHeight = 600;
  16
  17
  18 // ////////////////////////////////////////////////////////////////////////// //
  19 struct ContactXY {
  20   VFloat x, y;
  21 }
  22
  23 __gshared ContactXY[] contacts;
  24
  25
  26 // ////////////////////////////////////////////////////////////////////////// //
  27 // random number in range [-1,1]
  28 public VFloat rnd () {
  29   pragma(inline, true);
  30   import std.random : uniform;
  31   return cast(VFloat)uniform!"[]"(-VFloatNum!(1.0), VFloatNum!(1.0));
  32 }
  33
  34 public VFloat rnd (VFloat lo, VFloat hi) {
  35   pragma(inline, true);
  36   import std.random : uniform;
  37   return cast(VFloat)uniform!"[]"(lo, hi);
  38 }
  39
  40
  41 // ////////////////////////////////////////////////////////////////////////// //
  42 __gshared Body bomb = null;
  43
  44 __gshared VFloat timeStep = VFloatNum!(1.0)/VFloatNum!(60.0);
  45 __gshared int iterations = 10;
  46 __gshared Vec2 gravity = Vec2(VFloatNum!(0.0), -VFloatNum!(10.0));
  47
  48 __gshared int demoIndex = 0;
  49
  50 __gshared World world;
  51 shared static this () { world = new World(gravity, iterations); }
  52
  53
  54 // ////////////////////////////////////////////////////////////////////////// //
  55 void launchBomb () {
  56   if (bomb is null) {
  57     bomb = new Body();
  58     bomb.set(Vec2(VFloatNum!(1.0), VFloatNum!(1.0)), VFloatNum!(50.0));
  59     bomb.friction = VFloatNum!(0.2);
  60     world ~= bomb;
  61   }
  62   bomb.position.set(rnd(-VFloatNum!(15.0), VFloatNum!(15.0)), VFloatNum!(15.0));
  63   bomb.rotation = rnd(-VFloatNum!(1.5), VFloatNum!(1.5));
  64   bomb.velocity = bomb.position*(-VFloatNum!(1.5));
  65   bomb.angularVelocity = rnd(-VFloatNum!(20.0), VFloatNum!(20.0));
  66 }
  67
  68
  69 // ////////////////////////////////////////////////////////////////////////// //
  70 void drawBody (Body body) {
  71   auto R = Mat22(body.rotation);
  72   Vec2 x = body.position;
  73   Vec2 h = body.width*VFloatNum!(0.5);
  74
  75   Vec2 v1 = x+R*Vec2(-h.x, -h.y);
  76   Vec2 v2 = x+R*Vec2( h.x, -h.y);
  77   Vec2 v3 = x+R*Vec2( h.x,  h.y);
  78   Vec2 v4 = x+R*Vec2(-h.x,  h.y);
  79
  80   if (body is bomb) {
  81     glColor3f(VFloatNum!(0.4), VFloatNum!(0.9), VFloatNum!(0.4));
  82   } else {
  83     glColor3f(VFloatNum!(0.8), VFloatNum!(0.8), VFloatNum!(0.9));
  84   }
  85
  86   glBegin(GL_LINE_LOOP);
  87   glVertex2f(v1.x, v1.y);
  88   glVertex2f(v2.x, v2.y);
  89   glVertex2f(v3.x, v3.y);
  90   glVertex2f(v4.x, v4.y);
  91   glEnd();
  92 }
  93
  94
  95 void drawJoint (Joint joint) {
  96   Body b1 = joint.body0;
  97   Body b2 = joint.body1;
  98
  99   auto R1 = Mat22(b1.rotation);
 100   auto R2 = Mat22(b2.rotation);
 101
 102   Vec2 x1 = b1.position;
 103   Vec2 p1 = x1+R1*joint.localAnchor1;
 104
 105   Vec2 x2 = b2.position;
 106   Vec2 p2 = x2+R2*joint.localAnchor2;
 107
 108   glColor3f(VFloatNum!(0.5), VFloatNum!(0.5), VFloatNum!(0.8));
 109   glBegin(GL_LINES);
 110   glVertex2f(x1.x, x1.y);
 111   glVertex2f(p1.x, p1.y);
 112   glVertex2f(x2.x, x2.y);
 113   glVertex2f(p2.x, p2.y);
 114   glEnd();
 115 }
 116
 117
 118 // ////////////////////////////////////////////////////////////////////////// //
 119 // demos
 120 struct DemoInfo { string dsc; }
 121
 122
 123 // single box
 124 @DemoInfo("A Single Box") void demo1 () {
 125   with (auto b = new Body()) {
 126     b.set(Vec2(VFloatNum!(100.0), VFloatNum!(20.0)), VFloat.max);
 127     b.position.set(VFloatNum!(0.0), -VFloatNum!(0.5)*b.width.y);
 128     world ~= b;
 129   }
 130   with (auto b = new Body()) {
 131     b.set(Vec2(VFloatNum!(1.0), VFloatNum!(1.0)), VFloatNum!(200.0));
 132     b.position.set(VFloatNum!(0.0), VFloatNum!(4.0));
 133     world ~= b;
 134   }
 135 }
 136
 137
 138 // a simple pendulum
 139 @DemoInfo("Simple Pendulum") void demo2 () {
 140   auto b1 = new Body();
 141   b1.set(Vec2(VFloatNum!(100.0), VFloatNum!(20.0)), VFloat.max);
 142   b1.friction = VFloatNum!(0.2);
 143   b1.position.set(VFloatNum!(0.0), -VFloatNum!(0.5)*b1.width.y);
 144   b1.rotation = VFloatNum!(0.0);
 145   world ~= b1;
 146
 147   auto b2 = new Body();
 148   b2.set(Vec2(VFloatNum!(1.0), VFloatNum!(1.0)), VFloatNum!(100.0));
 149   b2.friction = VFloatNum!(0.2);
 150   b2.position.set(VFloatNum!(9.0), VFloatNum!(11.0));
 151   b2.rotation = VFloatNum!(0.0);
 152   world ~= b2;
 153
 154   with (auto j = new Joint()) {
 155     j.set(b1, b2, Vec2(VFloatNum!(0.0), VFloatNum!(11.0)));
 156     world ~= j;
 157   }
 158 }
 159
 160
 161 // varying friction coefficients
 162 @DemoInfo("Varying Friction Coefficients") void demo3 () {
 163   with (auto b = new Body()) {
 164     b.set(Vec2(VFloatNum!(100.0), VFloatNum!(20.0)), VFloat.max);
 165     b.position.set(VFloatNum!(0.0), -VFloatNum!(0.5)*b.width.y);
 166     world ~= b;
 167   }
 168
 169   with (auto b = new Body()) {
 170     b.set(Vec2(VFloatNum!(13.0), VFloatNum!(0.25)), VFloat.max);
 171     b.position.set(-VFloatNum!(2.0), VFloatNum!(11.0));
 172     b.rotation = -VFloatNum!(0.25);
 173     world ~= b;
 174   }
 175
 176   with (auto b = new Body()) {
 177     b.set(Vec2(VFloatNum!(0.25), VFloatNum!(1.0)), VFloat.max);
 178     b.position.set(VFloatNum!(5.25), VFloatNum!(9.5));
 179     world ~= b;
 180   }
 181
 182   with (auto b = new Body()) {
 183     b.set(Vec2(VFloatNum!(13.0), VFloatNum!(0.25)), VFloat.max);
 184     b.position.set(VFloatNum!(2.0), VFloatNum!(7.0));
 185     b.rotation = VFloatNum!(0.25);
 186     world ~= b;
 187   }
 188
 189   with (auto b = new Body()) {
 190     b.set(Vec2(VFloatNum!(0.25), VFloatNum!(1.0)), VFloat.max);
 191     b.position.set(-VFloatNum!(5.25), VFloatNum!(5.5));
 192     world ~= b;
 193   }
 194
 195   with (auto b = new Body()) {
 196     b.set(Vec2(VFloatNum!(13.0), VFloatNum!(0.25)), VFloat.max);
 197     b.position.set(-VFloatNum!(2.0), VFloatNum!(3.0));
 198     b.rotation = -VFloatNum!(0.25);
 199     world ~= b;
 200   }
 201
 202   static immutable VFloat[5] frictions = [VFloatNum!(0.75), VFloatNum!(0.5), VFloatNum!(0.35), VFloatNum!(0.1), VFloatNum!(0.0)];
 203   for (int idx = 0; idx < 5; ++idx) {
 204     with (auto b = new Body()) {
 205       b.set(Vec2(VFloatNum!(0.5), VFloatNum!(0.5)), VFloatNum!(25.0));
 206       b.friction = frictions[idx];
 207       b.position.set(-VFloatNum!(7.5)+VFloatNum!(2.0)*idx, VFloatNum!(14.0));
 208       world ~= b;
 209     }
 210   }
 211 }
 212
 213
 214 // a vertical stack
 215 @DemoInfo("Randomized Stacking") void demo4 () {
 216   with (auto b = new Body()) {
 217     b.set(Vec2(VFloatNum!(100.0), VFloatNum!(20.0)), VFloat.max);
 218     b.friction = VFloatNum!(0.2);
 219     b.position.set(VFloatNum!(0.0), -VFloatNum!(0.5)*b.width.y);
 220     b.rotation = VFloatNum!(0.0);
 221     world ~= b;
 222   }
 223
 224   for (int idx = 0; idx < 10; ++idx) {
 225     with (auto b = new Body()) {
 226       b.set(Vec2(VFloatNum!(1.0), VFloatNum!(1.0)), VFloatNum!(1.0));
 227       b.friction = VFloatNum!(0.2);
 228       VFloat x = rnd(-VFloatNum!(0.1), VFloatNum!(0.1));
 229       b.position.set(x, VFloatNum!(0.51)+VFloatNum!(1.05)*idx);
 230       world ~= b;
 231     }
 232   }
 233 }
 234
 235
 236 // a pyramid
 237 @DemoInfo("Pyramid Stacking") void demo5 () {
 238   with (auto b = new Body()) {
 239     b.set(Vec2(VFloatNum!(100.0), VFloatNum!(20.0)), VFloat.max);
 240     b.friction = VFloatNum!(0.2);
 241     b.position.set(VFloatNum!(0.0), -VFloatNum!(0.5)*b.width.y);
 242     b.rotation = VFloatNum!(0.0);
 243     world ~= b;
 244   }
 245
 246   Vec2 x = Vec2(-VFloatNum!(6.0), VFloatNum!(0.75));
 247   Vec2 y;
 248
 249   for (int idx = 0; idx < 12; ++idx) {
 250     y = x;
 251     for (int j = idx; j < 12; ++j) {
 252       with (auto b = new Body()) {
 253         b.set(Vec2(VFloatNum!(1.0), VFloatNum!(1.0)), VFloatNum!(10.0));
 254         b.friction = VFloatNum!(0.2);
 255         b.position = y;
 256         world ~= b;
 257       }
 258       y += Vec2(VFloatNum!(1.125), VFloatNum!(0.0));
 259     }
 260     //x += Vec2(VFloatNum!(0.5625), VFloatNum!(1.125));
 261     x += Vec2(VFloatNum!(0.5625), VFloatNum!(2.0));
 262   }
 263 }
 264
 265
 266 // a teeter
 267 @DemoInfo("A Teeter") void demo6 () {
 268   Body b1 = new Body();
 269   b1.set(Vec2(VFloatNum!(100.0), VFloatNum!(20.0)), VFloat.max);
 270   b1.position.set(VFloatNum!(0.0), -VFloatNum!(0.5)*b1.width.y);
 271   world ~= b1;
 272
 273   Body b2 = new Body();
 274   b2.set(Vec2(VFloatNum!(12.0), VFloatNum!(0.25)), VFloatNum!(100.0));
 275   b2.position.set(VFloatNum!(0.0), VFloatNum!(1.0));
 276   world ~= b2;
 277
 278   Body b3 = new Body();
 279   b3.set(Vec2(VFloatNum!(0.5), VFloatNum!(0.5)), VFloatNum!(25.0));
 280   b3.position.set(-VFloatNum!(5.0), VFloatNum!(2.0));
 281   world ~= b3;
 282
 283   Body b4 = new Body();
 284   b4.set(Vec2(VFloatNum!(0.5), VFloatNum!(0.5)), VFloatNum!(25.0));
 285   b4.position.set(-VFloatNum!(5.5), VFloatNum!(2.0));
 286   world ~= b4;
 287
 288   Body b5 = new Body();
 289   b5.set(Vec2(VFloatNum!(1.0), VFloatNum!(1.0)), VFloatNum!(100.0));
 290   b5.position.set(VFloatNum!(5.5), VFloatNum!(15.0));
 291   world ~= b5;
 292
 293   with (auto j = new Joint()) {
 294     j.set(b1, b2, Vec2(VFloatNum!(0.0), VFloatNum!(1.0)));
 295     world ~= j;
 296   }
 297 }
 298
 299
 300 // a suspension bridge
 301 @DemoInfo("A Suspension Bridge") void demo7 () {
 302   import std.math : PI;
 303
 304   with (auto b = new Body()) {
 305     b.set(Vec2(VFloatNum!(100.0), VFloatNum!(20.0)), VFloat.max);
 306     b.friction = VFloatNum!(0.2);
 307     b.position.set(VFloatNum!(0.0), -VFloatNum!(0.5)*b.width.y);
 308     b.rotation = VFloatNum!(0.0);
 309     world ~= b;
 310   }
 311
 312   enum numPlanks = 15;
 313   VFloat mass = VFloatNum!(50.0);
 314
 315   for (int idx = 0; idx < numPlanks; ++idx) {
 316     auto b = new Body();
 317     b.set(Vec2(VFloatNum!(1.0), VFloatNum!(0.25)), mass);
 318     b.friction = VFloatNum!(0.2);
 319     b.position.set(-VFloatNum!(8.5)+VFloatNum!(1.25)*idx, VFloatNum!(5.0));
 320     world ~= b;
 321   }
 322
 323   // tuning
 324   VFloat frequencyHz = VFloatNum!(2.0);
 325   VFloat dampingRatio = VFloatNum!(0.7);
 326
 327   // frequency in radians
 328   VFloat omega = VFloatNum!(2.0)*PI*frequencyHz;
 329
 330   // damping coefficient
 331   VFloat d = VFloatNum!(2.0)*mass*dampingRatio*omega;
 332
 333   // spring stifness
 334   VFloat k = mass*omega*omega;
 335
 336   // magic formulas
 337   VFloat softnesss = VFloatNum!(1.0)/(d+timeStep*k);
 338   VFloat biasFactorr = timeStep*k/(d+timeStep*k);
 339
 340   for (int idx = 0; idx < numPlanks; ++idx) {
 341     auto j = new Joint();
 342     j.set(world.bodies[idx], world.bodies[idx+1], Vec2(-VFloatNum!(9.125)+VFloatNum!(1.25)*idx, VFloatNum!(5.0)));
 343     j.softness = softnesss;
 344     j.biasFactor = biasFactorr;
 345     world ~= j;
 346   }
 347
 348   with (auto j = new Joint()) {
 349     j.set(world.bodies[numPlanks], world.bodies[0], Vec2(-VFloatNum!(9.125)+VFloatNum!(1.25)*numPlanks, VFloatNum!(5.0)));
 350     j.softness = softnesss;
 351     j.biasFactor = biasFactorr;
 352     world ~= j;
 353   }
 354 }
 355
 356
 357 // dominos
 358 @DemoInfo("Dominos") void demo8 () {
 359   Body b1 = new Body();
 360   b1.set(Vec2(VFloatNum!(100.0), VFloatNum!(20.0)), VFloat.max);
 361   b1.position.set(VFloatNum!(0.0), -VFloatNum!(0.5)*b1.width.y);
 362   world ~= b1;
 363
 364   with (auto b = new Body()) {
 365     b.set(Vec2(VFloatNum!(12.0), VFloatNum!(0.5)), VFloat.max);
 366     b.position.set(-VFloatNum!(1.5), VFloatNum!(10.0));
 367     world ~= b;
 368   }
 369
 370   for (int idx = 0; idx < 10; ++idx) {
 371     with (auto b = new Body()) {
 372       b.set(Vec2(VFloatNum!(0.2), VFloatNum!(2.0)), VFloatNum!(10.0));
 373       b.position.set(-VFloatNum!(6.0)+VFloatNum!(1.0)*idx, VFloatNum!(11.125));
 374       b.friction = VFloatNum!(0.1);
 375       world ~= b;
 376     }
 377   }
 378
 379   with (auto b = new Body()) {
 380     b.set(Vec2(VFloatNum!(14.0), VFloatNum!(0.5)), VFloat.max);
 381     b.position.set(VFloatNum!(1.0), VFloatNum!(6.0));
 382     b.rotation = VFloatNum!(0.3);
 383     world ~= b;
 384   }
 385
 386   Body b2 = new Body();
 387   b2.set(Vec2(VFloatNum!(0.5), VFloatNum!(3.0)), VFloat.max);
 388   b2.position.set(-VFloatNum!(7.0), VFloatNum!(4.0));
 389   world ~= b2;
 390
 391   Body b3 = new Body();
 392   b3.set(Vec2(VFloatNum!(12.0), VFloatNum!(0.25)), VFloatNum!(20.0));
 393   b3.position.set(-VFloatNum!(0.9), VFloatNum!(1.0));
 394   world ~= b3;
 395
 396   with (auto j = new Joint()) {
 397     j.set(b1, b3, Vec2(-VFloatNum!(2.0), VFloatNum!(1.0)));
 398     world ~= j;
 399   }
 400
 401   Body b4 = new Body();
 402   b4.set(Vec2(VFloatNum!(0.5), VFloatNum!(0.5)), VFloatNum!(10.0));
 403   b4.position.set(-VFloatNum!(10.0), VFloatNum!(15.0));
 404   world ~= b4;
 405
 406   with (auto j = new Joint()) {
 407     j.set(b2, b4, Vec2(-VFloatNum!(7.0), VFloatNum!(15.0)));
 408     world ~= j;
 409   }
 410
 411   Body b5 = new Body();
 412   b5.set(Vec2(VFloatNum!(2.0), VFloatNum!(2.0)), VFloatNum!(20.0));
 413   b5.position.set(VFloatNum!(6.0), VFloatNum!(2.5));
 414   b5.friction = VFloatNum!(0.1);
 415   world ~= b5;
 416
 417   with (auto j = new Joint()) {
 418     j.set(b1, b5, Vec2(VFloatNum!(6.0), VFloatNum!(2.6)));
 419     world ~= j;
 420   }
 421
 422   // box cap
 423   Body b6 = new Body();
 424   b6.set(Vec2(VFloatNum!(2.0), VFloatNum!(0.2)), VFloatNum!(10.0));
 425   b6.position.set(VFloatNum!(6.0), VFloatNum!(3.6));
 426   world ~= b6;
 427
 428   with (auto j = new Joint()) {
 429     j.set(b5, b6, Vec2(VFloatNum!(7.0), VFloatNum!(3.5)));
 430     world ~= j;
 431   }
 432 }
 433
 434
 435 // a multi-pendulum
 436 @DemoInfo("Multi-pendulum") void demo9 () {
 437   import std.math : PI;
 438
 439   Body b1 = new Body();
 440   b1.set(Vec2(VFloatNum!(100.0), VFloatNum!(20.0)), VFloat.max);
 441   b1.friction = VFloatNum!(0.2);
 442   b1.position.set(VFloatNum!(0.0), -VFloatNum!(0.5)*b1.width.y);
 443   b1.rotation = VFloatNum!(0.0);
 444   world ~= b1;
 445
 446   VFloat mass = VFloatNum!(10.0);
 447
 448   // tuning
 449   VFloat frequencyHz = VFloatNum!(4.0);
 450   VFloat dampingRatio = VFloatNum!(0.7);
 451
 452   // frequency in radians
 453   VFloat omega = VFloatNum!(2.0)*PI*frequencyHz;
 454
 455   // damping coefficient
 456   VFloat d = VFloatNum!(2.0)*mass*dampingRatio*omega;
 457
 458   // spring stiffness
 459   VFloat k = mass*omega*omega;
 460
 461   // magic formulas
 462   VFloat softnesss = VFloatNum!(1.0)/(d+timeStep*k);
 463   VFloat biasFactorr = timeStep*k/(d+timeStep*k);
 464
 465   const VFloat y = VFloatNum!(12.0);
 466
 467   for (int idx = 0; idx < 15; ++idx) {
 468     Vec2 x = Vec2(VFloatNum!(0.5)+idx, y);
 469     auto b = new Body();
 470     b.set(Vec2(VFloatNum!(0.75), VFloatNum!(0.25)), mass);
 471     b.friction = VFloatNum!(0.2);
 472     b.position = x;
 473     b.rotation = VFloatNum!(0.0);
 474     world ~= b;
 475
 476     with (auto j = new Joint()) {
 477       j.set(b1, b, Vec2(idx, y));
 478       j.softness = softnesss;
 479       j.biasFactor = biasFactorr;
 480       world ~= j;
 481     }
 482
 483     b1 = b;
 484   }
 485 }
 486
 487
 488 // ////////////////////////////////////////////////////////////////////////// //
 489 __gshared bool paused = false;
 490 __gshared bool slowmo = false;
 491 __gshared int slowmocount = 0;
 492
 493
 494 bool setupDemo (int index, SimpleWindow w) {
 495   import std.traits;
 496   alias sms = getSymbolsByUDA!(mixin(__MODULE__), DemoInfo);
 497   foreach (immutable idx, auto memb; sms) {
 498     if (index == idx) {
 499       w.title = getUDAs!(memb, DemoInfo)[0].dsc;
 500       world.clear();
 501       bomb = null;
 502       memb();
 503       demoIndex = index;
 504       return true;
 505     }
 506   }
 507   return false;
 508 }
 509
 510
 511 // ////////////////////////////////////////////////////////////////////////// //
 512 void simulationStep () {
 513   static double accumulator = 0;
 514
 515   glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
 516
 517   /*
 518   char[128] buf;
 519
 520   snprintf(buf, sizeof(buf), "Demo %d: %s", demoIndex+1, demos[demoIndex].name);
 521   DrawText(5, 15, buf);
 522   DrawText(5, 45, "Keys: 1-9 Demos, Space to Launch the Bomb");
 523
 524   static char buffer[512];
 525   sprintf(buffer, "(A)ccumulation %s", (World::accumulateImpulses ? "ON" : "OFF"));
 526   DrawText(5, 75, buffer);
 527
 528   sprintf(buffer, "(P)osition Correction %s", (World::positionCorrection ? "ON" : "OFF"));
 529   DrawText(5, 105, buffer);
 530
 531   sprintf(buffer, "(W)arm Starting %s", (World::warmStarting ? "ON" : "OFF"));
 532   DrawText(5, 135, buffer);
 533   */
 534
 535   glMatrixMode(GL_MODELVIEW);
 536   glLoadIdentity();
 537   glTranslatef(VFloatNum!(0.0), -VFloatNum!(7.0), -VFloatNum!(25.0));
 538
 539   contacts.length = 0;
 540   contacts.assumeSafeAppend;
 541
 542   world.step(timeStep);
 543 }
 544
 545
 546 // ////////////////////////////////////////////////////////////////////////// //
 547 void drawWorld () {
 548   glMatrixMode(GL_MODELVIEW);
 549   glLoadIdentity();
 550   glTranslatef(VFloatNum!(0.0), -VFloatNum!(7.0), -VFloatNum!(25.0));
 551
 552   // draw world
 553   foreach (Body b; world.bodies) b.drawBody();
 554   foreach (Joint j; world.joints) j.drawJoint();
 555
 556   // draw contacts
 557   {
 558     import iv.glbinds;
 559     glPointSize(VFloatNum!(4.0));
 560     glColor3f(VFloatNum!(1.0), VFloatNum!(0.0), VFloatNum!(0.0));
 561     glBegin(GL_POINTS);
 562     foreach (const ref cxy; contacts) glVertex2f(cxy.x, cxy.y);
 563     glEnd();
 564     glPointSize(VFloatNum!(1.0));
 565   }
 566 }
 567
 568
 569 // ////////////////////////////////////////////////////////////////////////// //
 570 void main () {
 571   //setOpenGLContextVersion(3, 2); // up to GLSL 150
 572   //openGLContextCompatible = false;
 573
 574   b2dlDrawContactsCB = delegate (VFloat x, VFloat y) {
 575     contacts ~= ContactXY(x, y);
 576   };
 577
 578   auto sdwindow = new SimpleWindow(GWidth, GHeight, "Box2DLite Physics", OpenGlOptions.yes, Resizablity.fixedSize);
 579   //sdwindow.hideCursor();
 580
 581   //sdwindow.closeQuery = delegate () { concmd("quit"); };
 582
 583   sdwindow.redrawOpenGlScene = delegate () {
 584     glClear(GL_COLOR_BUFFER_BIT);
 585     drawWorld();
 586   };
 587
 588   sdwindow.visibleForTheFirstTime = delegate () {
 589     setupDemo(0, sdwindow);
 590     sdwindow.setAsCurrentOpenGlContext(); // make this window active
 591     // init matrices
 592     /*
 593     glMatrixMode(GL_PROJECTION);
 594     glLoadIdentity();
 595     glOrtho(0, GWidth, GHeight, 0, -1, 1);
 596     glMatrixMode(GL_MODELVIEW);
 597     glLoadIdentity();
 598     */
 599     glViewport(0, 0, GWidth, GHeight);
 600     glMatrixMode(GL_PROJECTION);
 601     glLoadIdentity();
 602     oglPerspective(45.0, cast(VFloat)GWidth/cast(VFloat)GHeight, 0.1, 100.0);
 603     sdwindow.redrawOpenGlScene();
 604   };
 605
 606   sdwindow.eventLoop(1000/60,
 607     delegate () {
 608       if (sdwindow.closed || world is null) return;
 609       if (!paused) {
 610         if (slowmo) {
 611           if (--slowmocount < 0) {
 612             simulationStep();
 613             slowmocount = 10;
 614           }
 615         } else {
 616           simulationStep();
 617           slowmocount = 0;
 618         }
 619       }
 620       sdwindow.redrawOpenGlSceneNow();
 621     },
 622     delegate (KeyEvent event) {
 623       if (sdwindow.closed) return;
 624       if (!event.pressed) return;
 625       switch (event.key) {
 626         case Key.Escape: sdwindow.close(); break;
 627         default:
 628       }
 629     },
 630     delegate (MouseEvent event) {
 631     },
 632     delegate (dchar ch) {
 633       if (ch == 'q') { sdwindow.close(); return; }
 634       if (ch == 'r') { setupDemo(demoIndex, sdwindow); return; }
 635       if (ch == ' ') { paused = !paused; return; }
 636       if (ch == 's') { slowmo = !slowmo; return; }
 637       if (ch >= '1' && ch <= '9') { setupDemo(ch-'1', sdwindow); return; }
 638       if (ch == '0') { setupDemo(10, sdwindow); return; }
 639       if (ch == 'a') { World.accumulateImpulses = !World.accumulateImpulses; return; }
 640       if (ch == 'p') { World.positionCorrection = !World.positionCorrection; return; }
 641       if (ch == 'w') { World.warmStarting = !World.warmStarting; return; }
 642       if (ch == '\n' || ch == '\r') { launchBomb(); return; }
 643       if (ch == '+') { setupDemo(demoIndex+1, sdwindow); return; }
 644       if (ch == '-') { if (demoIndex > 0) setupDemo(demoIndex-1, sdwindow); return; }
 645     },
 646   );
 647 }