1 /* 2 * Copyright (c) 2007-2013 Scott Lembcke and Howling Moon Software 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a copy 5 * of this software and associated documentation files (the "Software"), to deal 6 * in the Software without restriction, including without limitation the rights 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 8 * copies of the Software, and to permit persons to whom the Software is 9 * furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice shall be included in 12 * all copies or substantial portions of the Software. 13 * 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 20 * SOFTWARE. 21 */ 22 module dchip.cpShape; 23 24 import std..string; 25 26 import dchip.cpBB; 27 import dchip.cpBody; 28 import dchip.chipmunk; 29 import dchip.chipmunk_private; 30 import dchip.chipmunk_types; 31 import dchip.cpSpace; 32 import dchip.util; 33 import dchip.cpVect; 34 35 /// The cpShape struct defines the shape of a rigid body_. 36 37 /// Nearest point query info struct. 38 struct cpNearestPointQueryInfo 39 { 40 /// The nearest shape, null if no shape was within range. 41 cpShape* shape; 42 43 /// The closest point on the shape's surface. (in world space coordinates) 44 cpVect p; 45 46 /// The distance to the point. The distance is negative if the point is inside the shape. 47 cpFloat d = 0; 48 49 /// The gradient of the signed distance function. 50 /// The same as info.p/info.d, but accurate even for very small values of info.d. 51 cpVect g; 52 } 53 54 /// Segment query info struct. 55 struct cpSegmentQueryInfo 56 { 57 /// The shape that was hit, null if no collision occured. 58 cpShape* shape; 59 60 /// The normalized distance along the query segment in the range [0, 1]. 61 cpFloat t = 0; 62 63 /// The normal of the surface hit. 64 cpVect n; 65 } 66 67 /// @private 68 enum cpShapeType 69 { 70 CP_CIRCLE_SHAPE, 71 CP_SEGMENT_SHAPE, 72 CP_POLY_SHAPE, 73 CP_NUM_SHAPES 74 } 75 76 /// 77 mixin _ExportEnumMembers!cpShapeType; 78 79 alias cpShapeCacheDataImpl = cpBB function(cpShape* shape, cpVect p, cpVect rot); 80 alias cpShapeDestroyImpl = void function(cpShape* shape); 81 alias cpShapeNearestPointQueryImpl = void function(cpShape* shape, cpVect p, cpNearestPointQueryInfo* info); 82 alias cpShapeSegmentQueryImpl = void function(cpShape* shape, cpVect a, cpVect b, cpSegmentQueryInfo* info); 83 84 /// @private 85 struct cpShapeClass 86 { 87 cpShapeType type; 88 89 cpShapeCacheDataImpl cacheData; 90 cpShapeDestroyImpl destroy; 91 cpShapeNearestPointQueryImpl nearestPointQuery; 92 cpShapeSegmentQueryImpl segmentQuery; 93 } 94 95 /// Opaque collision shape struct. 96 struct cpShape 97 { 98 version (CHIP_ALLOW_PRIVATE_ACCESS) 99 /* const */ cpShapeClass * klass; 100 else 101 package /* const */ cpShapeClass * klass; 102 103 /// The rigid body_ this collision shape is attached to. 104 cpBody* body_; 105 106 /// The current bounding box of the shape. 107 cpBB bb; 108 109 /// Sensor flag. 110 /// Sensor shapes call collision callbacks but don't produce collisions. 111 cpBool sensor; 112 113 /// Coefficient of restitution. (elasticity) 114 cpFloat e = 0; 115 116 /// Coefficient of friction. 117 cpFloat u = 0; 118 119 /// Surface velocity used when solving for friction. 120 cpVect surface_v; 121 122 /// User definable data pointer. 123 /// Generally this points to your the game object class so you can access it 124 /// when given a cpShape reference in a callback. 125 cpDataPointer data; 126 127 /// Collision type of this shape used when picking collision handlers. 128 cpCollisionType collision_type; 129 130 /// Group of this shape. Shapes in the same group don't collide. 131 cpGroup group; 132 133 // Layer bitmask for this shape. Shapes only collide if the bitwise and of their layers is non-zero. 134 cpLayers layers; 135 136 version (CHIP_ALLOW_PRIVATE_ACCESS) 137 cpSpace * space; 138 else 139 package cpSpace * space; 140 141 version (CHIP_ALLOW_PRIVATE_ACCESS) 142 cpShape * next; 143 else 144 package cpShape * next; 145 146 version (CHIP_ALLOW_PRIVATE_ACCESS) 147 cpShape * prev; 148 else 149 package cpShape * prev; 150 151 version (CHIP_ALLOW_PRIVATE_ACCESS) 152 cpHashValue hashid; 153 else 154 package cpHashValue hashid; 155 } 156 157 /// Get the hit point for a segment query. 158 cpVect cpSegmentQueryHitPoint(const cpVect start, const cpVect end, const cpSegmentQueryInfo info) 159 { 160 return cpvlerp(start, end, info.t); 161 } 162 163 /// Get the hit distance for a segment query. 164 cpFloat cpSegmentQueryHitDist(const cpVect start, const cpVect end, const cpSegmentQueryInfo info) 165 { 166 return cpvdist(start, end) * info.t; 167 } 168 169 mixin template CP_DefineShapeStructGetter(type, string member, string name) 170 { 171 mixin(q{ 172 type cpShapeGet%s(const cpShape * shape) { return cast(typeof(return))shape.%s; } 173 }.format(name, member)); 174 } 175 176 mixin template CP_DefineShapeStructSetter(type, string member, string name, bool activates) 177 { 178 mixin(q{ 179 void cpShapeSet%s(cpShape * shape, type value) 180 { 181 %s 182 183 shape.%s = value; 184 } 185 }.format(name, activates ? "if (shape.body_) cpBodyActivate(shape.body_);" : "", member)); 186 } 187 188 mixin template CP_DefineShapeStructProperty(type, string member, string name, bool activates) 189 { 190 mixin CP_DefineShapeStructGetter!(type, member, name); 191 mixin CP_DefineShapeStructSetter!(type, member, name, activates); 192 } 193 194 mixin CP_DefineShapeStructGetter!(cpSpace*, "space", "Space"); 195 196 mixin CP_DefineShapeStructGetter!(cpBody*, "body_", "Body"); 197 198 mixin CP_DefineShapeStructGetter!(cpBB, "bb", "BB"); 199 mixin CP_DefineShapeStructProperty!(cpBool, "sensor", "Sensor", cpTrue); 200 mixin CP_DefineShapeStructProperty!(cpFloat, "e", "Elasticity", cpFalse); 201 mixin CP_DefineShapeStructProperty!(cpFloat, "u", "Friction", cpTrue); 202 mixin CP_DefineShapeStructProperty!(cpVect, "surface_v", "SurfaceVelocity", cpTrue); 203 mixin CP_DefineShapeStructProperty!(cpDataPointer, "data", "UserData", cpFalse); 204 mixin CP_DefineShapeStructProperty!(cpCollisionType, "collision_type", "CollisionType", cpTrue); 205 mixin CP_DefineShapeStructProperty!(cpGroup, "group", "Group", cpTrue); 206 mixin CP_DefineShapeStructProperty!(cpLayers, "layers", "Layers", cpTrue); 207 208 mixin template CP_DeclareShapeGetter(type, string struct_, string member, string name) 209 { 210 mixin(q{ 211 type %sGet%s(const cpShape * shape) 212 }.format(struct_, name, member)); 213 } 214 215 /// @private 216 struct cpCircleShape 217 { 218 cpShape shape; 219 220 cpVect c, tc; 221 cpFloat r = 0; 222 } 223 224 /// @private 225 struct cpSegmentShape 226 { 227 cpShape shape; 228 229 cpVect a, b, n; 230 cpVect ta, tb, tn; 231 cpFloat r = 0; 232 233 cpVect a_tangent, b_tangent; 234 } 235 236 __gshared cpHashValue cpShapeIDCounter = 0; 237 238 void cpResetShapeIdCounter() 239 { 240 cpShapeIDCounter = 0; 241 } 242 243 cpShape* cpShapeInit(cpShape* shape, const cpShapeClass* klass, cpBody* body_) 244 { 245 shape.klass = cast(typeof(shape.klass))klass; 246 247 shape.hashid = cpShapeIDCounter; 248 cpShapeIDCounter++; 249 250 shape.body_ = body_; 251 shape.sensor = 0; 252 253 shape.e = 0.0f; 254 shape.u = 0.0f; 255 shape.surface_v = cpvzero; 256 257 shape.collision_type = 0; 258 shape.group = CP_NO_GROUP; 259 shape.layers = CP_ALL_LAYERS; 260 261 shape.data = null; 262 263 shape.space = null; 264 265 shape.next = null; 266 shape.prev = null; 267 268 return shape; 269 } 270 271 void cpShapeDestroy(cpShape* shape) 272 { 273 if (shape.klass && shape.klass.destroy) 274 shape.klass.destroy(shape); 275 } 276 277 void cpShapeFree(cpShape* shape) 278 { 279 if (shape) 280 { 281 cpShapeDestroy(shape); 282 cpfree(shape); 283 } 284 } 285 286 void cpShapeSetBody(cpShape* shape, cpBody* body_) 287 { 288 cpAssertHard(!cpShapeActive(shape), "You cannot change the body_ on an active shape. You must remove the shape from the space before changing the body_."); 289 shape.body_ = body_; 290 } 291 292 cpBB cpShapeCacheBB(cpShape* shape) 293 { 294 cpBody* body_ = shape.body_; 295 return cpShapeUpdate(shape, body_.p, body_.rot); 296 } 297 298 cpBB cpShapeUpdate(cpShape* shape, cpVect pos, cpVect rot) 299 { 300 return (shape.bb = shape.klass.cacheData(shape, pos, rot)); 301 } 302 303 cpBool cpShapePointQuery(cpShape* shape, cpVect p) 304 { 305 cpNearestPointQueryInfo info = { null, cpvzero, INFINITY, cpvzero }; 306 cpShapeNearestPointQuery(shape, p, &info); 307 308 return (info.d < 0.0f); 309 } 310 311 cpFloat cpShapeNearestPointQuery(cpShape* shape, cpVect p, cpNearestPointQueryInfo* info) 312 { 313 cpNearestPointQueryInfo blank = { null, cpvzero, INFINITY, cpvzero }; 314 315 if (info) 316 { 317 (*info) = blank; 318 } 319 else 320 { 321 info = ␣ 322 } 323 324 shape.klass.nearestPointQuery(shape, p, info); 325 return info.d; 326 } 327 328 cpBool cpShapeSegmentQuery(cpShape* shape, cpVect a, cpVect b, cpSegmentQueryInfo* info) 329 { 330 cpSegmentQueryInfo blank = { null, 1.0f, cpvzero }; 331 332 if (info) 333 { 334 (*info) = blank; 335 } 336 else 337 { 338 info = ␣ 339 } 340 341 cpNearestPointQueryInfo nearest; 342 shape.klass.nearestPointQuery(shape, a, &nearest); 343 344 if (nearest.d <= 0.0) 345 { 346 info.shape = shape; 347 info.t = 0.0; 348 info.n = cpvnormalize(cpvsub(a, nearest.p)); 349 } 350 else 351 { 352 shape.klass.segmentQuery(shape, a, b, info); 353 } 354 355 return (info.shape != null); 356 } 357 358 cpCircleShape* cpCircleShapeAlloc() 359 { 360 return cast(cpCircleShape*)cpcalloc(1, cpCircleShape.sizeof); 361 } 362 363 cpBB cpCircleShapeCacheData(cpCircleShape* circle, cpVect p, cpVect rot) 364 { 365 cpVect c = circle.tc = cpvadd(p, cpvrotate(circle.c, rot)); 366 return cpBBNewForCircle(c, circle.r); 367 } 368 369 void cpCicleShapeNearestPointQuery(cpCircleShape* circle, cpVect p, cpNearestPointQueryInfo* info) 370 { 371 cpVect delta = cpvsub(p, circle.tc); 372 cpFloat d = cpvlength(delta); 373 cpFloat r = circle.r; 374 375 info.shape = cast(cpShape*)circle; 376 info.p = cpvadd(circle.tc, cpvmult(delta, r / d)); // TODO div/0 377 info.d = d - r; 378 379 // Use up for the gradient if the distance is very small. 380 info.g = (d > MAGIC_EPSILON ? cpvmult(delta, 1.0f / d) : cpv(0.0f, 1.0f)); 381 } 382 383 void cpCircleShapeSegmentQuery(cpCircleShape* circle, cpVect a, cpVect b, cpSegmentQueryInfo* info) 384 { 385 CircleSegmentQuery(cast(cpShape*)circle, circle.tc, circle.r, a, b, info); 386 } 387 388 cpCircleShape* cpCircleShapeInit(cpCircleShape* circle, cpBody* body_, cpFloat radius, cpVect offset) 389 { 390 circle.c = offset; 391 circle.r = radius; 392 393 cpShapeInit(cast(cpShape*)circle, &cpCircleShapeClass, body_); 394 395 return circle; 396 } 397 398 cpShape* cpCircleShapeNew(cpBody* body_, cpFloat radius, cpVect offset) 399 { 400 return cast(cpShape*)cpCircleShapeInit(cpCircleShapeAlloc(), body_, radius, offset); 401 } 402 403 cpSegmentShape * 404 cpSegmentShapeAlloc() 405 { 406 return cast(cpSegmentShape*)cpcalloc(1, cpSegmentShape.sizeof); 407 } 408 409 cpBB cpSegmentShapeCacheData(cpSegmentShape* seg, cpVect p, cpVect rot) 410 { 411 seg.ta = cpvadd(p, cpvrotate(seg.a, rot)); 412 seg.tb = cpvadd(p, cpvrotate(seg.b, rot)); 413 seg.tn = cpvrotate(seg.n, rot); 414 415 cpFloat l = 0, r = 0, b = 0, t = 0; 416 417 if (seg.ta.x < seg.tb.x) 418 { 419 l = seg.ta.x; 420 r = seg.tb.x; 421 } 422 else 423 { 424 l = seg.tb.x; 425 r = seg.ta.x; 426 } 427 428 if (seg.ta.y < seg.tb.y) 429 { 430 b = seg.ta.y; 431 t = seg.tb.y; 432 } 433 else 434 { 435 b = seg.tb.y; 436 t = seg.ta.y; 437 } 438 439 cpFloat rad = seg.r; 440 return cpBBNew(l - rad, b - rad, r + rad, t + rad); 441 } 442 443 void cpSegmentShapeNearestPointQuery(cpSegmentShape* seg, cpVect p, cpNearestPointQueryInfo* info) 444 { 445 cpVect closest = cpClosetPointOnSegment(p, seg.ta, seg.tb); 446 447 cpVect delta = cpvsub(p, closest); 448 cpFloat d = cpvlength(delta); 449 cpFloat r = seg.r; 450 cpVect g = cpvmult(delta, 1.0f / d); 451 452 info.shape = cast(cpShape*)seg; 453 info.p = (d ? cpvadd(closest, cpvmult(g, r)) : closest); 454 info.d = d - r; 455 456 // Use the segment's normal if the distance is very small. 457 info.g = (d > MAGIC_EPSILON ? g : seg.n); 458 } 459 460 void cpSegmentShapeSegmentQuery(cpSegmentShape* seg, cpVect a, cpVect b, cpSegmentQueryInfo* info) 461 { 462 cpVect n = seg.tn; 463 cpFloat d = cpvdot(cpvsub(seg.ta, a), n); 464 cpFloat r = seg.r; 465 466 cpVect flipped_n = (d > 0.0f ? cpvneg(n) : n); 467 cpVect seg_offset = cpvsub(cpvmult(flipped_n, r), a); 468 469 // Make the endpoints relative to 'a' and move them by the thickness of the segment. 470 cpVect seg_a = cpvadd(seg.ta, seg_offset); 471 cpVect seg_b = cpvadd(seg.tb, seg_offset); 472 cpVect delta = cpvsub(b, a); 473 474 if (cpvcross(delta, seg_a) * cpvcross(delta, seg_b) <= 0.0f) 475 { 476 cpFloat d_offset = d + (d > 0.0f ? -r : r); 477 cpFloat ad = -d_offset; 478 cpFloat bd = cpvdot(delta, n) - d_offset; 479 480 if (ad * bd < 0.0f) 481 { 482 info.shape = cast(cpShape*)seg; 483 info.t = ad / (ad - bd); 484 info.n = flipped_n; 485 } 486 } 487 else if (r != 0.0f) 488 { 489 cpSegmentQueryInfo info1 = { null, 1.0f, cpvzero }; 490 cpSegmentQueryInfo info2 = { null, 1.0f, cpvzero }; 491 CircleSegmentQuery(cast(cpShape*)seg, seg.ta, seg.r, a, b, &info1); 492 CircleSegmentQuery(cast(cpShape*)seg, seg.tb, seg.r, a, b, &info2); 493 494 if (info1.t < info2.t) 495 { 496 (*info) = info1; 497 } 498 else 499 { 500 (*info) = info2; 501 } 502 } 503 } 504 505 __gshared cpShapeClass cpSegmentShapeClass; 506 __gshared cpShapeClass cpCircleShapeClass; 507 508 void _initModuleCtor_cpShape() 509 { 510 cpSegmentShapeClass = cpShapeClass( 511 CP_SEGMENT_SHAPE, 512 cast(cpShapeCacheDataImpl)&cpSegmentShapeCacheData, 513 null, 514 cast(cpShapeNearestPointQueryImpl)&cpSegmentShapeNearestPointQuery, 515 cast(cpShapeSegmentQueryImpl)&cpSegmentShapeSegmentQuery, 516 ); 517 518 cpCircleShapeClass = cpShapeClass( 519 CP_CIRCLE_SHAPE, 520 cast(cpShapeCacheDataImpl)&cpCircleShapeCacheData, 521 null, 522 cast(cpShapeNearestPointQueryImpl)&cpCicleShapeNearestPointQuery, 523 cast(cpShapeSegmentQueryImpl)&cpCircleShapeSegmentQuery, 524 ); 525 } 526 527 cpSegmentShape* cpSegmentShapeInit(cpSegmentShape* seg, cpBody* body_, cpVect a, cpVect b, cpFloat r) 528 { 529 seg.a = a; 530 seg.b = b; 531 seg.n = cpvperp(cpvnormalize(cpvsub(b, a))); 532 533 seg.r = r; 534 535 seg.a_tangent = cpvzero; 536 seg.b_tangent = cpvzero; 537 538 cpShapeInit(cast(cpShape*)seg, &cpSegmentShapeClass, body_); 539 540 return seg; 541 } 542 543 cpShape* cpSegmentShapeNew(cpBody* body_, cpVect a, cpVect b, cpFloat r) 544 { 545 return cast(cpShape*)cpSegmentShapeInit(cpSegmentShapeAlloc(), body_, a, b, r); 546 } 547 548 void cpSegmentShapeSetNeighbors(cpShape* shape, cpVect prev, cpVect next) 549 { 550 cpAssertHard(shape.klass == &cpSegmentShapeClass, "Shape is not a segment shape."); 551 cpSegmentShape* seg = cast(cpSegmentShape*)shape; 552 553 seg.a_tangent = cpvsub(prev, seg.a); 554 seg.b_tangent = cpvsub(next, seg.b); 555 } 556 557 // Unsafe API (chipmunk_unsafe.h) 558 559 void cpCircleShapeSetRadius(cpShape* shape, cpFloat radius) 560 { 561 cpAssertHard(shape.klass == &cpCircleShapeClass, "Shape is not a circle shape."); 562 cpCircleShape* circle = cast(cpCircleShape*)shape; 563 564 circle.r = radius; 565 } 566 567 void cpCircleShapeSetOffset(cpShape* shape, cpVect offset) 568 { 569 cpAssertHard(shape.klass == &cpCircleShapeClass, "Shape is not a circle shape."); 570 cpCircleShape* circle = cast(cpCircleShape*)shape; 571 572 circle.c = offset; 573 } 574 575 void cpSegmentShapeSetEndpoints(cpShape* shape, cpVect a, cpVect b) 576 { 577 cpAssertHard(shape.klass == &cpSegmentShapeClass, "Shape is not a segment shape."); 578 cpSegmentShape* seg = cast(cpSegmentShape*)shape; 579 580 seg.a = a; 581 seg.b = b; 582 seg.n = cpvperp(cpvnormalize(cpvsub(b, a))); 583 } 584 585 void cpSegmentShapeSetRadius(cpShape* shape, cpFloat radius) 586 { 587 cpAssertHard(shape.klass == &cpSegmentShapeClass, "Shape is not a segment shape."); 588 cpSegmentShape* seg = cast(cpSegmentShape*)shape; 589 590 seg.r = radius; 591 }