xmain.d

   1 module xmain is aliced;
   2
   3 import std.math : PI;
   4
   5 import iv.glbinds;
   6 import iv.vmath;
   7 import arsd.color;
   8 import arsd.png;
   9
  10 import b2dlite;
  11
  12
  13 enum GWidth = 800;
  14 enum GHeight = 600;
  15
  16
  17 Body bomb = null;
  18
  19 Float timeStep = FloatNum!(1.0)/FloatNum!(60.0);
  20 int iterations = 10;
  21 vec2 gravity = vec2(FloatNum!(0.0), -FloatNum!(10.0));
  22
  23 int demoIndex = 0;
  24
  25 World world;
  26 static this () { world = new World(gravity, iterations); }
  27
  28
  29 static void LaunchBomb () {
  30   if (bomb is null) {
  31     bomb = new Body();
  32     bomb.set(vec2(FloatNum!(1.0), FloatNum!(1.0)), FloatNum!(50.0));
  33     bomb.friction = FloatNum!(0.2);
  34     world.Add(bomb);
  35   }
  36   bomb.position.set(Random(-FloatNum!(15.0), FloatNum!(15.0)), FloatNum!(15.0));
  37   bomb.rotation = Random(-FloatNum!(1.5), FloatNum!(1.5));
  38   bomb.velocity = bomb.position*(-FloatNum!(1.5));
  39   bomb.angularVelocity = Random(-FloatNum!(20.0), FloatNum!(20.0));
  40 }
  41
  42
  43 static void DrawBody (Body body) {
  44   auto R = Mat22(body.rotation);
  45   vec2 x = body.position;
  46   vec2 h = body.width*FloatNum!(0.5);
  47
  48   vec2 v1 = x+R*vec2(-h.x, -h.y);
  49   vec2 v2 = x+R*vec2( h.x, -h.y);
  50   vec2 v3 = x+R*vec2( h.x,  h.y);
  51   vec2 v4 = x+R*vec2(-h.x,  h.y);
  52
  53   if (body is bomb) {
  54     glColor3f(FloatNum!(0.4), FloatNum!(0.9), FloatNum!(0.4));
  55   } else {
  56     glColor3f(FloatNum!(0.8), FloatNum!(0.8), FloatNum!(0.9));
  57   }
  58
  59   glBegin(GL_LINE_LOOP);
  60   glVertex2f(v1.x, v1.y);
  61   glVertex2f(v2.x, v2.y);
  62   glVertex2f(v3.x, v3.y);
  63   glVertex2f(v4.x, v4.y);
  64   glEnd();
  65 }
  66
  67
  68 static void DrawJoint (Joint joint) {
  69   Body b1 = joint.body1;
  70   Body b2 = joint.body2;
  71
  72   auto R1 = Mat22(b1.rotation);
  73   auto R2 = Mat22(b2.rotation);
  74
  75   vec2 x1 = b1.position;
  76   vec2 p1 = x1+R1*joint.localAnchor1;
  77
  78   vec2 x2 = b2.position;
  79   vec2 p2 = x2+R2*joint.localAnchor2;
  80
  81   glColor3f(FloatNum!(0.5), FloatNum!(0.5), FloatNum!(0.8));
  82   glBegin(GL_LINES);
  83   glVertex2f(x1.x, x1.y);
  84   glVertex2f(p1.x, p1.y);
  85   glVertex2f(x2.x, x2.y);
  86   glVertex2f(p2.x, p2.y);
  87   glEnd();
  88 }
  89
  90
  91 // ////////////////////////////////////////////////////////////////////////// //
  92 // demos
  93 struct DemoInfo { string descr; }
  94 /*
  95   {"A Single Box", Demo1},
  96   {"Simple Pendulum", Demo2},
  97   {"Varying Friction Coefficients", Demo3},
  98   {"Randomized Stacking", Demo4},
  99   {"Pyramid Stacking", Demo5},
 100   {"A Teeter", Demo6},
 101   {"A Suspension Bridge", Demo7},
 102   {"Dominos", Demo8},
 103   {"Multi-pendulum", Demo9},
 104 */
 105
 106 // single box
 107 @DemoInfo("A Single Box") void Demo1 () {
 108   with (auto b = new Body()) {
 109     b.set(vec2(FloatNum!(100.0), FloatNum!(20.0)), Float.max);
 110     b.position.set(FloatNum!(0.0), -FloatNum!(0.5)*b.width.y);
 111     world.Add(b);
 112   }
 113   with (auto b = new Body()) {
 114     b.set(vec2(FloatNum!(1.0), FloatNum!(1.0)), FloatNum!(200.0));
 115     b.position.set(FloatNum!(0.0), FloatNum!(4.0));
 116     world.Add(b);
 117   }
 118 }
 119
 120
 121 // a simple pendulum
 122 @DemoInfo("Simple Pendulum") void Demo2 () {
 123   auto b1 = new Body();
 124   b1.set(vec2(FloatNum!(100.0), FloatNum!(20.0)), Float.max);
 125   b1.friction = FloatNum!(0.2);
 126   b1.position.set(FloatNum!(0.0), -FloatNum!(0.5)*b1.width.y);
 127   b1.rotation = FloatNum!(0.0);
 128   world.Add(b1);
 129
 130   auto b2 = new Body();
 131   b2.set(vec2(FloatNum!(1.0), FloatNum!(1.0)), FloatNum!(100.0));
 132   b2.friction = FloatNum!(0.2);
 133   b2.position.set(FloatNum!(9.0), FloatNum!(11.0));
 134   b2.rotation = FloatNum!(0.0);
 135   world.Add(b2);
 136
 137   with (auto j = new Joint()) {
 138     j.set(b1, b2, vec2(FloatNum!(0.0), FloatNum!(11.0)));
 139     world.Add(j);
 140   }
 141 }
 142
 143
 144 // varying friction coefficients
 145 @DemoInfo("Varying Friction Coefficients") void Demo3 () {
 146   with (auto b = new Body()) {
 147     b.set(vec2(FloatNum!(100.0), FloatNum!(20.0)), Float.max);
 148     b.position.set(FloatNum!(0.0), -FloatNum!(0.5)*b.width.y);
 149     world.Add(b);
 150   }
 151
 152   with (auto b = new Body()) {
 153     b.set(vec2(FloatNum!(13.0), FloatNum!(0.25)), Float.max);
 154     b.position.set(-FloatNum!(2.0), FloatNum!(11.0));
 155     b.rotation = -FloatNum!(0.25);
 156     world.Add(b);
 157   }
 158
 159   with (auto b = new Body()) {
 160     b.set(vec2(FloatNum!(0.25), FloatNum!(1.0)), Float.max);
 161     b.position.set(FloatNum!(5.25), FloatNum!(9.5));
 162     world.Add(b);
 163   }
 164
 165   with (auto b = new Body()) {
 166     b.set(vec2(FloatNum!(13.0), FloatNum!(0.25)), Float.max);
 167     b.position.set(FloatNum!(2.0), FloatNum!(7.0));
 168     b.rotation = FloatNum!(0.25);
 169     world.Add(b);
 170   }
 171
 172   with (auto b = new Body()) {
 173     b.set(vec2(FloatNum!(0.25), FloatNum!(1.0)), Float.max);
 174     b.position.set(-FloatNum!(5.25), FloatNum!(5.5));
 175     world.Add(b);
 176   }
 177
 178   with (auto b = new Body()) {
 179     b.set(vec2(FloatNum!(13.0), FloatNum!(0.25)), Float.max);
 180     b.position.set(-FloatNum!(2.0), FloatNum!(3.0));
 181     b.rotation = -FloatNum!(0.25);
 182     world.Add(b);
 183   }
 184
 185   static immutable Float[5] frictions = [FloatNum!(0.75), FloatNum!(0.5), FloatNum!(0.35), FloatNum!(0.1), FloatNum!(0.0)];
 186   for (int i = 0; i < 5; ++i) {
 187     with (auto b = new Body()) {
 188       b.set(vec2(FloatNum!(0.5), FloatNum!(0.5)), FloatNum!(25.0));
 189       b.friction = frictions[i];
 190       b.position.set(-FloatNum!(7.5)+FloatNum!(2.0)*i, FloatNum!(14.0));
 191       world.Add(b);
 192     }
 193   }
 194 }
 195
 196
 197 // a vertical stack
 198 @DemoInfo("Randomized Stacking") void Demo4 () {
 199   with (auto b = new Body()) {
 200     b.set(vec2(FloatNum!(100.0), FloatNum!(20.0)), Float.max);
 201     b.friction = FloatNum!(0.2);
 202     b.position.set(FloatNum!(0.0), -FloatNum!(0.5)*b.width.y);
 203     b.rotation = FloatNum!(0.0);
 204     world.Add(b);
 205   }
 206
 207   for (int i = 0; i < 10; ++i) {
 208     with (auto b = new Body()) {
 209       b.set(vec2(FloatNum!(1.0), FloatNum!(1.0)), FloatNum!(1.0));
 210       b.friction = FloatNum!(0.2);
 211       Float x = Random(-FloatNum!(0.1), FloatNum!(0.1));
 212       b.position.set(x, FloatNum!(0.51)+FloatNum!(1.05)*i);
 213       world.Add(b);
 214     }
 215   }
 216 }
 217
 218
 219 // a pyramid
 220 @DemoInfo("Pyramid Stacking") void Demo5 () {
 221   with (auto b = new Body()) {
 222     b.set(vec2(FloatNum!(100.0), FloatNum!(20.0)), Float.max);
 223     b.friction = FloatNum!(0.2);
 224     b.position.set(FloatNum!(0.0), -FloatNum!(0.5)*b.width.y);
 225     b.rotation = FloatNum!(0.0);
 226     world.Add(b);
 227   }
 228
 229   vec2 x = vec2(-FloatNum!(6.0), FloatNum!(0.75));
 230   vec2 y;
 231
 232   for (int i = 0; i < 12; ++i) {
 233     y = x;
 234     for (int j = i; j < 12; ++j) {
 235       with (auto b = new Body()) {
 236         b.set(vec2(FloatNum!(1.0), FloatNum!(1.0)), FloatNum!(10.0));
 237         b.friction = FloatNum!(0.2);
 238         b.position = y;
 239         world.Add(b);
 240       }
 241       y += vec2(FloatNum!(1.125), FloatNum!(0.0));
 242     }
 243     //x += vec2(FloatNum!(0.5625), FloatNum!(1.125));
 244     x += vec2(FloatNum!(0.5625), FloatNum!(2.0));
 245   }
 246 }
 247
 248
 249 // a teeter
 250 @DemoInfo("A Teeter") void Demo6 () {
 251   Body b1 = new Body();
 252   b1.set(vec2(FloatNum!(100.0), FloatNum!(20.0)), Float.max);
 253   b1.position.set(FloatNum!(0.0), -FloatNum!(0.5)*b1.width.y);
 254   world.Add(b1);
 255
 256   Body b2 = new Body();
 257   b2.set(vec2(FloatNum!(12.0), FloatNum!(0.25)), FloatNum!(100.0));
 258   b2.position.set(FloatNum!(0.0), FloatNum!(1.0));
 259   world.Add(b2);
 260
 261   Body b3 = new Body();
 262   b3.set(vec2(FloatNum!(0.5), FloatNum!(0.5)), FloatNum!(25.0));
 263   b3.position.set(-FloatNum!(5.0), FloatNum!(2.0));
 264   world.Add(b3);
 265
 266   Body b4 = new Body();
 267   b4.set(vec2(FloatNum!(0.5), FloatNum!(0.5)), FloatNum!(25.0));
 268   b4.position.set(-FloatNum!(5.5), FloatNum!(2.0));
 269   world.Add(b4);
 270
 271   Body b5 = new Body();
 272   b5.set(vec2(FloatNum!(1.0), FloatNum!(1.0)), FloatNum!(100.0));
 273   b5.position.set(FloatNum!(5.5), FloatNum!(15.0));
 274   world.Add(b5);
 275
 276   with (auto j = new Joint()) {
 277     j.set(b1, b2, vec2(FloatNum!(0.0), FloatNum!(1.0)));
 278     world.Add(j);
 279   }
 280 }
 281
 282
 283 // a suspension bridge
 284 @DemoInfo("A Suspension Bridge") void Demo7 () {
 285   with (auto b = new Body()) {
 286     b.set(vec2(FloatNum!(100.0), FloatNum!(20.0)), Float.max);
 287     b.friction = FloatNum!(0.2);
 288     b.position.set(FloatNum!(0.0), -FloatNum!(0.5)*b.width.y);
 289     b.rotation = FloatNum!(0.0);
 290     world.Add(b);
 291   }
 292
 293   enum numPlanks = 15;
 294   Float mass = FloatNum!(50.0);
 295
 296   for (int i = 0; i < numPlanks; ++i) {
 297     auto b = new Body();
 298     b.set(vec2(FloatNum!(1.0), FloatNum!(0.25)), mass);
 299     b.friction = FloatNum!(0.2);
 300     b.position.set(-FloatNum!(8.5)+FloatNum!(1.25)*i, FloatNum!(5.0));
 301     world.Add(b);
 302   }
 303
 304   // tuning
 305   Float frequencyHz = FloatNum!(2.0);
 306   Float dampingRatio = FloatNum!(0.7);
 307
 308   // frequency in radians
 309   Float omega = FloatNum!(2.0)*PI*frequencyHz;
 310
 311   // damping coefficient
 312   Float d = FloatNum!(2.0)*mass*dampingRatio*omega;
 313
 314   // spring stifness
 315   Float k = mass*omega*omega;
 316
 317   // magic formulas
 318   Float softnesss = FloatNum!(1.0)/(d+timeStep*k);
 319   Float biasFactorr = timeStep*k/(d+timeStep*k);
 320
 321   for (int i = 0; i < numPlanks; ++i) {
 322     auto j = new Joint();
 323     j.set(world.bodies[i], world.bodies[i+1], vec2(-FloatNum!(9.125)+FloatNum!(1.25)*i, FloatNum!(5.0)));
 324     j.softness = softnesss;
 325     j.biasFactor = biasFactorr;
 326     world.Add(j);
 327   }
 328
 329   with (auto j = new Joint()) {
 330     j.set(world.bodies[numPlanks], world.bodies[0], vec2(-FloatNum!(9.125)+FloatNum!(1.25)*numPlanks, FloatNum!(5.0)));
 331     j.softness = softnesss;
 332     j.biasFactor = biasFactorr;
 333     world.Add(j);
 334   }
 335 }
 336
 337
 338 // dominos
 339 @DemoInfo("Dominos") void Demo8 () {
 340   Body b1 = new Body();
 341   b1.set(vec2(FloatNum!(100.0), FloatNum!(20.0)), Float.max);
 342   b1.position.set(FloatNum!(0.0), -FloatNum!(0.5)*b1.width.y);
 343   world.Add(b1);
 344
 345   with (auto b = new Body()) {
 346     b.set(vec2(FloatNum!(12.0), FloatNum!(0.5)), Float.max);
 347     b.position.set(-FloatNum!(1.5), FloatNum!(10.0));
 348     world.Add(b);
 349   }
 350
 351   for (int i = 0; i < 10; ++i) {
 352     with (auto b = new Body()) {
 353       b.set(vec2(FloatNum!(0.2), FloatNum!(2.0)), FloatNum!(10.0));
 354       b.position.set(-FloatNum!(6.0)+FloatNum!(1.0)*i, FloatNum!(11.125));
 355       b.friction = FloatNum!(0.1);
 356       world.Add(b);
 357     }
 358   }
 359
 360   with (auto b = new Body()) {
 361     b.set(vec2(FloatNum!(14.0), FloatNum!(0.5)), Float.max);
 362     b.position.set(FloatNum!(1.0), FloatNum!(6.0));
 363     b.rotation = FloatNum!(0.3);
 364     world.Add(b);
 365   }
 366
 367   Body b2 = new Body();
 368   b2.set(vec2(FloatNum!(0.5), FloatNum!(3.0)), Float.max);
 369   b2.position.set(-FloatNum!(7.0), FloatNum!(4.0));
 370   world.Add(b2);
 371
 372   Body b3 = new Body();
 373   b3.set(vec2(FloatNum!(12.0), FloatNum!(0.25)), FloatNum!(20.0));
 374   b3.position.set(-FloatNum!(0.9), FloatNum!(1.0));
 375   world.Add(b3);
 376
 377   with (auto j = new Joint()) {
 378     j.set(b1, b3, vec2(-FloatNum!(2.0), FloatNum!(1.0)));
 379     world.Add(j);
 380   }
 381
 382   Body b4 = new Body();
 383   b4.set(vec2(FloatNum!(0.5), FloatNum!(0.5)), FloatNum!(10.0));
 384   b4.position.set(-FloatNum!(10.0), FloatNum!(15.0));
 385   world.Add(b4);
 386
 387   with (auto j = new Joint()) {
 388     j.set(b2, b4, vec2(-FloatNum!(7.0), FloatNum!(15.0)));
 389     world.Add(j);
 390   }
 391
 392   Body b5 = new Body();
 393   b5.set(vec2(FloatNum!(2.0), FloatNum!(2.0)), FloatNum!(20.0));
 394   b5.position.set(FloatNum!(6.0), FloatNum!(2.5));
 395   b5.friction = FloatNum!(0.1);
 396   world.Add(b5);
 397
 398   with (auto j = new Joint()) {
 399     j.set(b1, b5, vec2(FloatNum!(6.0), FloatNum!(2.6)));
 400     world.Add(j);
 401   }
 402
 403   // box cap
 404   Body b6 = new Body();
 405   b6.set(vec2(FloatNum!(2.0), FloatNum!(0.2)), FloatNum!(10.0));
 406   b6.position.set(FloatNum!(6.0), FloatNum!(3.6));
 407   world.Add(b6);
 408
 409   with (auto j = new Joint()) {
 410     j.set(b5, b6, vec2(FloatNum!(7.0), FloatNum!(3.5)));
 411     world.Add(j);
 412   }
 413 }
 414
 415
 416 // a multi-pendulum
 417 @DemoInfo("Multi-pendulum") void Demo9 () {
 418   Body b1 = new Body();
 419   b1.set(vec2(FloatNum!(100.0), FloatNum!(20.0)), Float.max);
 420   b1.friction = FloatNum!(0.2);
 421   b1.position.set(FloatNum!(0.0), -FloatNum!(0.5)*b1.width.y);
 422   b1.rotation = FloatNum!(0.0);
 423   world.Add(b1);
 424
 425   Float mass = FloatNum!(10.0);
 426
 427   // tuning
 428   Float frequencyHz = FloatNum!(4.0);
 429   Float dampingRatio = FloatNum!(0.7);
 430
 431   // frequency in radians
 432   Float omega = FloatNum!(2.0)*PI*frequencyHz;
 433
 434   // damping coefficient
 435   Float d = FloatNum!(2.0)*mass*dampingRatio*omega;
 436
 437   // spring stiffness
 438   Float k = mass*omega*omega;
 439
 440   // magic formulas
 441   Float softnesss = FloatNum!(1.0)/(d+timeStep*k);
 442   Float biasFactorr = timeStep*k/(d+timeStep*k);
 443
 444   const Float y = FloatNum!(12.0);
 445
 446   for (int i = 0; i < 15; ++i) {
 447     vec2 x = vec2(FloatNum!(0.5)+i, y);
 448     auto b = new Body();
 449     b.set(vec2(FloatNum!(0.75), FloatNum!(0.25)), mass);
 450     b.friction = FloatNum!(0.2);
 451     b.position = x;
 452     b.rotation = FloatNum!(0.0);
 453     world.Add(b);
 454
 455     with (auto j = new Joint()) {
 456       j.set(b1, b, vec2(i, y));
 457       j.softness = softnesss;
 458       j.biasFactor = biasFactorr;
 459       world.Add(j);
 460     }
 461
 462     b1 = b;
 463   }
 464 }
 465
 466
 467 // ////////////////////////////////////////////////////////////////////////// //
 468 __gshared bool paused = false;
 469 __gshared bool slowmo = false;
 470 __gshared int slowmocount = 0;
 471
 472
 473 void InitDemo (int index) {
 474   import std.traits;
 475   alias sms = getSymbolsByUDA!(mixin(__MODULE__), DemoInfo);
 476   foreach (immutable idx, auto memb; sms) {
 477     //pragma(msg, idx, " ", memb);
 478     if (index == idx) {
 479       //mixin(memb~"();");
 480       //{ import std.stdio; writeln(idx); }
 481       world.Clear();
 482       bomb = null;
 483       memb();
 484       demoIndex = index;
 485       return;
 486     }
 487   }
 488   /*
 489   foreach (string memb; __traits(allMembers, mixin(__MODULE__))) {
 490     static if (is(typeof(__traits(getMember, mixin(__MODULE__), memb)))) {
 491       static if (hasUDA!(__traits(getMember, mixin(__MODULE__), memb), DemoInfo)) {
 492         pragma(msg, memb);
 493       }
 494     }
 495   }
 496   */
 497   //demoIndex = -1;
 498 }
 499
 500
 501 void SimulationLoop () {
 502   //static uint64_t t_start = 0;
 503   static double accumulator = 0;
 504   //uint64_t t_cur;
 505   char[128] buf;
 506
 507   glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
 508
 509   /*
 510   snprintf(buf, sizeof(buf), "Demo %d: %s", demoIndex+1, demos[demoIndex].name);
 511   DrawText(5, 15, buf);
 512   DrawText(5, 45, "Keys: 1-9 Demos, Space to Launch the Bomb");
 513
 514   static char buffer[512];
 515   sprintf(buffer, "(A)ccumulation %s", (World::accumulateImpulses ? "ON" : "OFF"));
 516   DrawText(5, 75, buffer);
 517
 518   sprintf(buffer, "(P)osition Correction %s", (World::positionCorrection ? "ON" : "OFF"));
 519   DrawText(5, 105, buffer);
 520
 521   sprintf(buffer, "(W)arm Starting %s", (World::warmStarting ? "ON" : "OFF"));
 522   DrawText(5, 135, buffer);
 523   */
 524
 525   glMatrixMode(GL_MODELVIEW);
 526   glLoadIdentity();
 527   glTranslatef(FloatNum!(0.0), -FloatNum!(7.0), -FloatNum!(25.0));
 528
 529   /*
 530   t_cur = k8clock_msec(NULL);
 531   if (t_start == 0) t_start = t_cur;
 532
 533   //world.Step(timeStep);
 534   accumulator += (t_cur-t_start)/1000.0;
 535   t_start = t_cur;
 536   // clamp
 537   if (accumulator < 0.0) accumulator = 0.0;
 538   else if (accumulator > 0.1) accumulator = 0.1;
 539   // process physics
 540   while (accumulator >= timeStep) {
 541     if (!frameStepping) {
 542       world.Step(timeStep);
 543     } else {
 544       if (canStep) {
 545         world.Step(timeStep);
 546         canStep = false;
 547       }
 548     }
 549     accumulator -= timeStep;
 550   }
 551   */
 552   world.Step(timeStep);
 553 }
 554
 555
 556 void drawWorld () {
 557   glMatrixMode(GL_MODELVIEW);
 558   glLoadIdentity();
 559   glTranslatef(FloatNum!(0.0), -FloatNum!(7.0), -FloatNum!(25.0));
 560
 561   // draw world
 562   foreach (Body b; world.bodies) b.DrawBody();
 563   foreach (Joint j; world.joints) j.DrawJoint();
 564 }
 565
 566
 567 void main () {
 568   //setOpenGLContextVersion(3, 2); // up to GLSL 150
 569   //openGLContextCompatible = false;
 570
 571   auto sdwindow = new SimpleWindow(GWidth, GHeight, "Verlet Physics", OpenGlOptions.yes, Resizablity.fixedSize);
 572   //sdwindow.hideCursor();
 573
 574   //sdwindow.closeQuery = delegate () { concmd("quit"); };
 575
 576   sdwindow.redrawOpenGlScene = delegate () {
 577     glClear(GL_COLOR_BUFFER_BIT);
 578     drawWorld();
 579     /*
 580     world.render();
 581     if (dragVertex !is null) {
 582       glPointSize(FloatNum!(6.0));
 583       glColor3f(FloatNum!(1.0), FloatNum!(1.0), FloatNum!(0.0));
 584       glBegin(GL_POINTS);
 585         glVertex2f(dragVertex.position.x, dragVertex.position.y);
 586       glEnd();
 587     }
 588     */
 589     //glFlush();
 590   };
 591
 592   sdwindow.visibleForTheFirstTime = delegate () {
 593     InitDemo(0);
 594     sdwindow.setAsCurrentOpenGlContext(); // make this window active
 595     glbindLoadFunctions();
 596     // init matrices
 597     /*
 598     glMatrixMode(GL_PROJECTION);
 599     glLoadIdentity();
 600     glOrtho(0, GWidth, GHeight, 0, -1, 1);
 601     glMatrixMode(GL_MODELVIEW);
 602     glLoadIdentity();
 603     */
 604     glViewport(0, 0, GWidth, GHeight);
 605     glMatrixMode(GL_PROJECTION);
 606     glLoadIdentity();
 607     oglPerspective(45.0, cast(Float)GWidth/cast(Float)GHeight, 0.1, 100.0);
 608     sdwindow.redrawOpenGlScene();
 609   };
 610
 611   sdwindow.eventLoop(cast(int)(FloatNum!(1000.0)/FloatNum!(60.0)),
 612     delegate () {
 613       if (sdwindow.closed || world is null) return;
 614       if (!paused) {
 615         if (slowmo) {
 616           if (--slowmocount < 0) {
 617             SimulationLoop();
 618             slowmocount = 10;
 619           }
 620         } else {
 621           SimulationLoop();
 622           slowmocount = 0;
 623         }
 624       }
 625       sdwindow.redrawOpenGlSceneNow();
 626     },
 627     delegate (KeyEvent event) {
 628       if (sdwindow.closed) return;
 629       if (!event.pressed) return;
 630       switch (event.key) {
 631         case Key.Escape: sdwindow.close(); break;
 632         default:
 633       }
 634     },
 635     delegate (MouseEvent event) {
 636       /*
 637       if (event.type == MouseEventType.buttonPressed) {
 638         if (event.button == MouseButton.left) dragVertex = world.FindVertex(event.x, event.y);
 639         if (event.button == MouseButton.right) dragVertex = null;
 640       } else if (event.type == MouseEventType.buttonReleased) {
 641         if (event.button == MouseButton.left) dragVertex = null;
 642       }
 643       if (dragVertex !is null) dragVertex.position = vec2(cast(Float)event.x, cast(Float)event.y); // sets the position of the dragVertex to the mouse position to drag it around
 644       */
 645     },
 646     delegate (dchar ch) {
 647       if (ch == 'q') { sdwindow.close(); return; }
 648       if (ch == 'r') { InitDemo(demoIndex); return; }
 649       if (ch == ' ') { paused = !paused; return; }
 650       if (ch == 's') { slowmo = !slowmo; return; }
 651       if (ch >= '1' && ch <= '9') { InitDemo(ch-'1'); return; }
 652       if (ch == '0') { InitDemo(10); return; }
 653       if (ch == 'a') { World.accumulateImpulses = !World.accumulateImpulses; return; }
 654       if (ch == 'p') { World.positionCorrection = !World.positionCorrection; return; }
 655       if (ch == 'w') { World.warmStarting = !World.warmStarting; return; }
 656       if (ch == '\n' || ch == '\r') { LaunchBomb(); }
 657     },
 658   );
 659 }