-
Notifications
You must be signed in to change notification settings - Fork 0
/
matter.js
10336 lines (8735 loc) · 336 KB
/
matter.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/**
* matter-js 0.14.1 by @liabru 2018-01-10
* http://brm.io/matter-js/
* License MIT
*/
/**
* The MIT License (MIT)
*
* Copyright (c) Liam Brummitt and contributors.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.Matter = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(_dereq_,module,exports){
/**
* The `Matter.Body` module contains methods for creating and manipulating body models.
* A `Matter.Body` is a rigid body that can be simulated by a `Matter.Engine`.
* Factories for commonly used body configurations (such as rectangles, circles and other polygons) can be found in the module `Matter.Bodies`.
*
* See the included usage [examples](https://github.com/liabru/matter-js/tree/master/examples).
* @class Body
*/
var Body = {};
module.exports = Body;
var Vertices = _dereq_('../geometry/Vertices');
var Vector = _dereq_('../geometry/Vector');
var Sleeping = _dereq_('../core/Sleeping');
var Render = _dereq_('../render/Render');
var Common = _dereq_('../core/Common');
var Bounds = _dereq_('../geometry/Bounds');
var Axes = _dereq_('../geometry/Axes');
(function() {
Body._inertiaScale = 4;
Body._nextCollidingGroupId = 1;
Body._nextNonCollidingGroupId = -1;
Body._nextCategory = 0x0001;
/**
* Creates a new rigid body model. The options parameter is an object that specifies any properties you wish to override the defaults.
* All properties have default values, and many are pre-calculated automatically based on other properties.
* Vertices must be specified in clockwise order.
* See the properties section below for detailed information on what you can pass via the `options` object.
* @method create
* @param {} options
* @return {body} body
*/
Body.create = function(options) {
var defaults = {
id: Common.nextId(),
type: 'body',
label: 'Body',
parts: [],
plugin: {},
angle: 0,
vertices: Vertices.fromPath('L 0 0 L 40 0 L 40 40 L 0 40'),
position: { x: 0, y: 0 },
force: { x: 0, y: 0 },
torque: 0,
positionImpulse: { x: 0, y: 0 },
constraintImpulse: { x: 0, y: 0, angle: 0 },
totalContacts: 0,
speed: 0,
angularSpeed: 0,
velocity: { x: 0, y: 0 },
angularVelocity: 0,
isSensor: false,
isStatic: false,
isSleeping: false,
motion: 0,
sleepThreshold: 60,
density: 0.001,
restitution: 0,
friction: 0.1,
frictionStatic: 0.5,
frictionAir: 0.01,
collisionFilter: {
category: 0x0001,
mask: 0xFFFFFFFF,
group: 0
},
slop: 0.05,
timeScale: 1,
render: {
visible: true,
opacity: 1,
sprite: {
xScale: 1,
yScale: 1,
xOffset: 0,
yOffset: 0
},
lineWidth: 0
}
};
var body = Common.extend(defaults, options);
_initProperties(body, options);
return body;
};
/**
* Returns the next unique group index for which bodies will collide.
* If `isNonColliding` is `true`, returns the next unique group index for which bodies will _not_ collide.
* See `body.collisionFilter` for more information.
* @method nextGroup
* @param {bool} [isNonColliding=false]
* @return {Number} Unique group index
*/
Body.nextGroup = function(isNonColliding) {
if (isNonColliding)
return Body._nextNonCollidingGroupId--;
return Body._nextCollidingGroupId++;
};
/**
* Returns the next unique category bitfield (starting after the initial default category `0x0001`).
* There are 32 available. See `body.collisionFilter` for more information.
* @method nextCategory
* @return {Number} Unique category bitfield
*/
Body.nextCategory = function() {
Body._nextCategory = Body._nextCategory << 1;
return Body._nextCategory;
};
/**
* Initialises body properties.
* @method _initProperties
* @private
* @param {body} body
* @param {} [options]
*/
var _initProperties = function(body, options) {
options = options || {};
// init required properties (order is important)
Body.set(body, {
bounds: body.bounds || Bounds.create(body.vertices),
positionPrev: body.positionPrev || Vector.clone(body.position),
anglePrev: body.anglePrev || body.angle,
vertices: body.vertices,
parts: body.parts || [body],
isStatic: body.isStatic,
isSleeping: body.isSleeping,
parent: body.parent || body
});
Vertices.rotate(body.vertices, body.angle, body.position);
Axes.rotate(body.axes, body.angle);
Bounds.update(body.bounds, body.vertices, body.velocity);
// allow options to override the automatically calculated properties
Body.set(body, {
axes: options.axes || body.axes,
area: options.area || body.area,
mass: options.mass || body.mass,
inertia: options.inertia || body.inertia
});
// render properties
var defaultFillStyle = (body.isStatic ? '#2e2b44' : Common.choose(['#006BA6', '#0496FF', '#FFBC42', '#D81159', '#8F2D56'])),
defaultStrokeStyle = '#000';
body.render.fillStyle = body.render.fillStyle || defaultFillStyle;
body.render.strokeStyle = body.render.strokeStyle || defaultStrokeStyle;
body.render.sprite.xOffset += -(body.bounds.min.x - body.position.x) / (body.bounds.max.x - body.bounds.min.x);
body.render.sprite.yOffset += -(body.bounds.min.y - body.position.y) / (body.bounds.max.y - body.bounds.min.y);
};
/**
* Given a property and a value (or map of), sets the property(s) on the body, using the appropriate setter functions if they exist.
* Prefer to use the actual setter functions in performance critical situations.
* @method set
* @param {body} body
* @param {} settings A property name (or map of properties and values) to set on the body.
* @param {} value The value to set if `settings` is a single property name.
*/
Body.set = function(body, settings, value) {
var property;
if (typeof settings === 'string') {
property = settings;
settings = {};
settings[property] = value;
}
for (property in settings) {
value = settings[property];
if (!settings.hasOwnProperty(property))
continue;
switch (property) {
case 'isStatic':
Body.setStatic(body, value);
break;
case 'isSleeping':
Sleeping.set(body, value);
break;
case 'mass':
Body.setMass(body, value);
break;
case 'density':
Body.setDensity(body, value);
break;
case 'inertia':
Body.setInertia(body, value);
break;
case 'vertices':
Body.setVertices(body, value);
break;
case 'position':
Body.setPosition(body, value);
break;
case 'angle':
Body.setAngle(body, value);
break;
case 'velocity':
Body.setVelocity(body, value);
break;
case 'angularVelocity':
Body.setAngularVelocity(body, value);
break;
case 'parts':
Body.setParts(body, value);
break;
default:
body[property] = value;
}
}
};
/**
* Sets the body as static, including isStatic flag and setting mass and inertia to Infinity.
* @method setStatic
* @param {body} body
* @param {bool} isStatic
*/
Body.setStatic = function(body, isStatic) {
for (var i = 0; i < body.parts.length; i++) {
var part = body.parts[i];
part.isStatic = isStatic;
if (isStatic) {
part._original = {
restitution: part.restitution,
friction: part.friction,
mass: part.mass,
inertia: part.inertia,
density: part.density,
inverseMass: part.inverseMass,
inverseInertia: part.inverseInertia
};
part.restitution = 0;
part.friction = 1;
part.mass = part.inertia = part.density = Infinity;
part.inverseMass = part.inverseInertia = 0;
part.positionPrev.x = part.position.x;
part.positionPrev.y = part.position.y;
part.anglePrev = part.angle;
part.angularVelocity = 0;
part.speed = 0;
part.angularSpeed = 0;
part.motion = 0;
} else if (part._original) {
part.restitution = part._original.restitution;
part.friction = part._original.friction;
part.mass = part._original.mass;
part.inertia = part._original.inertia;
part.density = part._original.density;
part.inverseMass = part._original.inverseMass;
part.inverseInertia = part._original.inverseInertia;
delete part._original;
}
}
};
/**
* Sets the mass of the body. Inverse mass, density and inertia are automatically updated to reflect the change.
* @method setMass
* @param {body} body
* @param {number} mass
*/
Body.setMass = function(body, mass) {
var moment = body.inertia / (body.mass / 6);
body.inertia = moment * (mass / 6);
body.inverseInertia = 1 / body.inertia;
body.mass = mass;
body.inverseMass = 1 / body.mass;
body.density = body.mass / body.area;
};
/**
* Sets the density of the body. Mass and inertia are automatically updated to reflect the change.
* @method setDensity
* @param {body} body
* @param {number} density
*/
Body.setDensity = function(body, density) {
Body.setMass(body, density * body.area);
body.density = density;
};
/**
* Sets the moment of inertia (i.e. second moment of area) of the body of the body.
* Inverse inertia is automatically updated to reflect the change. Mass is not changed.
* @method setInertia
* @param {body} body
* @param {number} inertia
*/
Body.setInertia = function(body, inertia) {
body.inertia = inertia;
body.inverseInertia = 1 / body.inertia;
};
/**
* Sets the body's vertices and updates body properties accordingly, including inertia, area and mass (with respect to `body.density`).
* Vertices will be automatically transformed to be orientated around their centre of mass as the origin.
* They are then automatically translated to world space based on `body.position`.
*
* The `vertices` argument should be passed as an array of `Matter.Vector` points (or a `Matter.Vertices` array).
* Vertices must form a convex hull, concave hulls are not supported.
*
* @method setVertices
* @param {body} body
* @param {vector[]} vertices
*/
Body.setVertices = function(body, vertices) {
// change vertices
if (vertices[0].body === body) {
body.vertices = vertices;
} else {
body.vertices = Vertices.create(vertices, body);
}
// update properties
body.axes = Axes.fromVertices(body.vertices);
body.area = Vertices.area(body.vertices);
Body.setMass(body, body.density * body.area);
// orient vertices around the centre of mass at origin (0, 0)
var centre = Vertices.centre(body.vertices);
Vertices.translate(body.vertices, centre, -1);
// update inertia while vertices are at origin (0, 0)
Body.setInertia(body, Body._inertiaScale * Vertices.inertia(body.vertices, body.mass));
// update geometry
Vertices.translate(body.vertices, body.position);
Bounds.update(body.bounds, body.vertices, body.velocity);
};
/**
* Sets the parts of the `body` and updates mass, inertia and centroid.
* Each part will have its parent set to `body`.
* By default the convex hull will be automatically computed and set on `body`, unless `autoHull` is set to `false.`
* Note that this method will ensure that the first part in `body.parts` will always be the `body`.
* @method setParts
* @param {body} body
* @param [body] parts
* @param {bool} [autoHull=true]
*/
Body.setParts = function(body, parts, autoHull) {
var i;
// add all the parts, ensuring that the first part is always the parent body
parts = parts.slice(0);
body.parts.length = 0;
body.parts.push(body);
body.parent = body;
for (i = 0; i < parts.length; i++) {
var part = parts[i];
if (part !== body) {
part.parent = body;
body.parts.push(part);
}
}
if (body.parts.length === 1)
return;
autoHull = typeof autoHull !== 'undefined' ? autoHull : true;
// find the convex hull of all parts to set on the parent body
if (autoHull) {
var vertices = [];
for (i = 0; i < parts.length; i++) {
vertices = vertices.concat(parts[i].vertices);
}
Vertices.clockwiseSort(vertices);
var hull = Vertices.hull(vertices),
hullCentre = Vertices.centre(hull);
Body.setVertices(body, hull);
Vertices.translate(body.vertices, hullCentre);
}
// sum the properties of all compound parts of the parent body
var total = Body._totalProperties(body);
body.area = total.area;
body.parent = body;
body.position.x = total.centre.x;
body.position.y = total.centre.y;
body.positionPrev.x = total.centre.x;
body.positionPrev.y = total.centre.y;
Body.setMass(body, total.mass);
Body.setInertia(body, total.inertia);
Body.setPosition(body, total.centre);
};
/**
* Sets the position of the body instantly. Velocity, angle, force etc. are unchanged.
* @method setPosition
* @param {body} body
* @param {vector} position
*/
Body.setPosition = function(body, position) {
var delta = Vector.sub(position, body.position);
body.positionPrev.x += delta.x;
body.positionPrev.y += delta.y;
for (var i = 0; i < body.parts.length; i++) {
var part = body.parts[i];
part.position.x += delta.x;
part.position.y += delta.y;
Vertices.translate(part.vertices, delta);
Bounds.update(part.bounds, part.vertices, body.velocity);
}
};
/**
* Sets the angle of the body instantly. Angular velocity, position, force etc. are unchanged.
* @method setAngle
* @param {body} body
* @param {number} angle
*/
Body.setAngle = function(body, angle) {
var delta = angle - body.angle;
body.anglePrev += delta;
for (var i = 0; i < body.parts.length; i++) {
var part = body.parts[i];
part.angle += delta;
Vertices.rotate(part.vertices, delta, body.position);
Axes.rotate(part.axes, delta);
Bounds.update(part.bounds, part.vertices, body.velocity);
if (i > 0) {
Vector.rotateAbout(part.position, delta, body.position, part.position);
}
}
};
/**
* Sets the linear velocity of the body instantly. Position, angle, force etc. are unchanged. See also `Body.applyForce`.
* @method setVelocity
* @param {body} body
* @param {vector} velocity
*/
Body.setVelocity = function(body, velocity) {
body.positionPrev.x = body.position.x - velocity.x;
body.positionPrev.y = body.position.y - velocity.y;
body.velocity.x = velocity.x;
body.velocity.y = velocity.y;
body.speed = Vector.magnitude(body.velocity);
};
/**
* Sets the angular velocity of the body instantly. Position, angle, force etc. are unchanged. See also `Body.applyForce`.
* @method setAngularVelocity
* @param {body} body
* @param {number} velocity
*/
Body.setAngularVelocity = function(body, velocity) {
body.anglePrev = body.angle - velocity;
body.angularVelocity = velocity;
body.angularSpeed = Math.abs(body.angularVelocity);
};
/**
* Moves a body by a given vector relative to its current position, without imparting any velocity.
* @method translate
* @param {body} body
* @param {vector} translation
*/
Body.translate = function(body, translation) {
Body.setPosition(body, Vector.add(body.position, translation));
};
/**
* Rotates a body by a given angle relative to its current angle, without imparting any angular velocity.
* @method rotate
* @param {body} body
* @param {number} rotation
* @param {vector} [point]
*/
Body.rotate = function(body, rotation, point) {
if (!point) {
Body.setAngle(body, body.angle + rotation);
} else {
var cos = Math.cos(rotation),
sin = Math.sin(rotation),
dx = body.position.x - point.x,
dy = body.position.y - point.y;
Body.setPosition(body, {
x: point.x + (dx * cos - dy * sin),
y: point.y + (dx * sin + dy * cos)
});
Body.setAngle(body, body.angle + rotation);
}
};
/**
* Scales the body, including updating physical properties (mass, area, axes, inertia), from a world-space point (default is body centre).
* @method scale
* @param {body} body
* @param {number} scaleX
* @param {number} scaleY
* @param {vector} [point]
*/
Body.scale = function(body, scaleX, scaleY, point) {
var totalArea = 0,
totalInertia = 0;
point = point || body.position;
for (var i = 0; i < body.parts.length; i++) {
var part = body.parts[i];
// scale vertices
Vertices.scale(part.vertices, scaleX, scaleY, point);
// update properties
part.axes = Axes.fromVertices(part.vertices);
part.area = Vertices.area(part.vertices);
Body.setMass(part, body.density * part.area);
// update inertia (requires vertices to be at origin)
Vertices.translate(part.vertices, { x: -part.position.x, y: -part.position.y });
Body.setInertia(part, Body._inertiaScale * Vertices.inertia(part.vertices, part.mass));
Vertices.translate(part.vertices, { x: part.position.x, y: part.position.y });
if (i > 0) {
totalArea += part.area;
totalInertia += part.inertia;
}
// scale position
part.position.x = point.x + (part.position.x - point.x) * scaleX;
part.position.y = point.y + (part.position.y - point.y) * scaleY;
// update bounds
Bounds.update(part.bounds, part.vertices, body.velocity);
}
// handle parent body
if (body.parts.length > 1) {
body.area = totalArea;
if (!body.isStatic) {
Body.setMass(body, body.density * totalArea);
Body.setInertia(body, totalInertia);
}
}
// handle circles
if (body.circleRadius) {
if (scaleX === scaleY) {
body.circleRadius *= scaleX;
} else {
// body is no longer a circle
body.circleRadius = null;
}
}
};
/**
* Performs a simulation step for the given `body`, including updating position and angle using Verlet integration.
* @method update
* @param {body} body
* @param {number} deltaTime
* @param {number} timeScale
* @param {number} correction
*/
Body.update = function(body, deltaTime, timeScale, correction) {
var deltaTimeSquared = Math.pow(deltaTime * timeScale * body.timeScale, 2);
// from the previous step
var frictionAir = 1 - body.frictionAir * timeScale * body.timeScale,
velocityPrevX = body.position.x - body.positionPrev.x,
velocityPrevY = body.position.y - body.positionPrev.y;
// update velocity with Verlet integration
body.velocity.x = (velocityPrevX * frictionAir * correction) + (body.force.x / body.mass) * deltaTimeSquared;
body.velocity.y = (velocityPrevY * frictionAir * correction) + (body.force.y / body.mass) * deltaTimeSquared;
body.positionPrev.x = body.position.x;
body.positionPrev.y = body.position.y;
body.position.x += body.velocity.x;
body.position.y += body.velocity.y;
// update angular velocity with Verlet integration
body.angularVelocity = ((body.angle - body.anglePrev) * frictionAir * correction) + (body.torque / body.inertia) * deltaTimeSquared;
body.anglePrev = body.angle;
body.angle += body.angularVelocity;
// track speed and acceleration
body.speed = Vector.magnitude(body.velocity);
body.angularSpeed = Math.abs(body.angularVelocity);
// transform the body geometry
for (var i = 0; i < body.parts.length; i++) {
var part = body.parts[i];
Vertices.translate(part.vertices, body.velocity);
if (i > 0) {
part.position.x += body.velocity.x;
part.position.y += body.velocity.y;
}
if (body.angularVelocity !== 0) {
Vertices.rotate(part.vertices, body.angularVelocity, body.position);
Axes.rotate(part.axes, body.angularVelocity);
if (i > 0) {
Vector.rotateAbout(part.position, body.angularVelocity, body.position, part.position);
}
}
Bounds.update(part.bounds, part.vertices, body.velocity);
}
};
/**
* Applies a force to a body from a given world-space position, including resulting torque.
* @method applyForce
* @param {body} body
* @param {vector} position
* @param {vector} force
*/
Body.applyForce = function(body, position, force) {
body.force.x += force.x;
body.force.y += force.y;
var offset = { x: position.x - body.position.x, y: position.y - body.position.y };
body.torque += offset.x * force.y - offset.y * force.x;
};
/**
* Returns the sums of the properties of all compound parts of the parent body.
* @method _totalProperties
* @private
* @param {body} body
* @return {}
*/
Body._totalProperties = function(body) {
// from equations at:
// https://ecourses.ou.edu/cgi-bin/ebook.cgi?doc=&topic=st&chap_sec=07.2&page=theory
// http://output.to/sideway/default.asp?qno=121100087
var properties = {
mass: 0,
area: 0,
inertia: 0,
centre: { x: 0, y: 0 }
};
// sum the properties of all compound parts of the parent body
for (var i = body.parts.length === 1 ? 0 : 1; i < body.parts.length; i++) {
var part = body.parts[i],
mass = part.mass !== Infinity ? part.mass : 1;
properties.mass += mass;
properties.area += part.area;
properties.inertia += part.inertia;
properties.centre = Vector.add(properties.centre, Vector.mult(part.position, mass));
}
properties.centre = Vector.div(properties.centre, properties.mass);
return properties;
};
/*
*
* Events Documentation
*
*/
/**
* Fired when a body starts sleeping (where `this` is the body).
*
* @event sleepStart
* @this {body} The body that has started sleeping
* @param {} event An event object
* @param {} event.source The source object of the event
* @param {} event.name The name of the event
*/
/**
* Fired when a body ends sleeping (where `this` is the body).
*
* @event sleepEnd
* @this {body} The body that has ended sleeping
* @param {} event An event object
* @param {} event.source The source object of the event
* @param {} event.name The name of the event
*/
/*
*
* Properties Documentation
*
*/
/**
* An integer `Number` uniquely identifying number generated in `Body.create` by `Common.nextId`.
*
* @property id
* @type number
*/
/**
* A `String` denoting the type of object.
*
* @property type
* @type string
* @default "body"
* @readOnly
*/
/**
* An arbitrary `String` name to help the user identify and manage bodies.
*
* @property label
* @type string
* @default "Body"
*/
/**
* An array of bodies that make up this body.
* The first body in the array must always be a self reference to the current body instance.
* All bodies in the `parts` array together form a single rigid compound body.
* Parts are allowed to overlap, have gaps or holes or even form concave bodies.
* Parts themselves should never be added to a `World`, only the parent body should be.
* Use `Body.setParts` when setting parts to ensure correct updates of all properties.
*
* @property parts
* @type body[]
*/
/**
* An object reserved for storing plugin-specific properties.
*
* @property plugin
* @type {}
*/
/**
* A self reference if the body is _not_ a part of another body.
* Otherwise this is a reference to the body that this is a part of.
* See `body.parts`.
*
* @property parent
* @type body
*/
/**
* A `Number` specifying the angle of the body, in radians.
*
* @property angle
* @type number
* @default 0
*/
/**
* An array of `Vector` objects that specify the convex hull of the rigid body.
* These should be provided about the origin `(0, 0)`. E.g.
*
* [{ x: 0, y: 0 }, { x: 25, y: 50 }, { x: 50, y: 0 }]
*
* When passed via `Body.create`, the vertices are translated relative to `body.position` (i.e. world-space, and constantly updated by `Body.update` during simulation).
* The `Vector` objects are also augmented with additional properties required for efficient collision detection.
*
* Other properties such as `inertia` and `bounds` are automatically calculated from the passed vertices (unless provided via `options`).
* Concave hulls are not currently supported. The module `Matter.Vertices` contains useful methods for working with vertices.
*
* @property vertices
* @type vector[]
*/
/**
* A `Vector` that specifies the current world-space position of the body.
*
* @property position
* @type vector
* @default { x: 0, y: 0 }
*/
/**
* A `Vector` that specifies the force to apply in the current step. It is zeroed after every `Body.update`. See also `Body.applyForce`.
*
* @property force
* @type vector
* @default { x: 0, y: 0 }
*/
/**
* A `Number` that specifies the torque (turning force) to apply in the current step. It is zeroed after every `Body.update`.
*
* @property torque
* @type number
* @default 0
*/
/**
* A `Number` that _measures_ the current speed of the body after the last `Body.update`. It is read-only and always positive (it's the magnitude of `body.velocity`).
*
* @readOnly
* @property speed
* @type number
* @default 0
*/
/**
* A `Number` that _measures_ the current angular speed of the body after the last `Body.update`. It is read-only and always positive (it's the magnitude of `body.angularVelocity`).
*
* @readOnly
* @property angularSpeed
* @type number
* @default 0
*/
/**
* A `Vector` that _measures_ the current velocity of the body after the last `Body.update`. It is read-only.
* If you need to modify a body's velocity directly, you should either apply a force or simply change the body's `position` (as the engine uses position-Verlet integration).
*
* @readOnly
* @property velocity
* @type vector
* @default { x: 0, y: 0 }
*/
/**
* A `Number` that _measures_ the current angular velocity of the body after the last `Body.update`. It is read-only.
* If you need to modify a body's angular velocity directly, you should apply a torque or simply change the body's `angle` (as the engine uses position-Verlet integration).
*
* @readOnly
* @property angularVelocity
* @type number
* @default 0
*/
/**
* A flag that indicates whether a body is considered static. A static body can never change position or angle and is completely fixed.
* If you need to set a body as static after its creation, you should use `Body.setStatic` as this requires more than just setting this flag.
*
* @property isStatic
* @type boolean
* @default false
*/
/**
* A flag that indicates whether a body is a sensor. Sensor triggers collision events, but doesn't react with colliding body physically.
*
* @property isSensor
* @type boolean
* @default false
*/
/**
* A flag that indicates whether the body is considered sleeping. A sleeping body acts similar to a static body, except it is only temporary and can be awoken.
* If you need to set a body as sleeping, you should use `Sleeping.set` as this requires more than just setting this flag.
*
* @property isSleeping
* @type boolean
* @default false
*/
/**
* A `Number` that _measures_ the amount of movement a body currently has (a combination of `speed` and `angularSpeed`). It is read-only and always positive.
* It is used and updated by the `Matter.Sleeping` module during simulation to decide if a body has come to rest.
*
* @readOnly
* @property motion
* @type number
* @default 0
*/
/**
* A `Number` that defines the number of updates in which this body must have near-zero velocity before it is set as sleeping by the `Matter.Sleeping` module (if sleeping is enabled by the engine).
*
* @property sleepThreshold
* @type number
* @default 60
*/
/**
* A `Number` that defines the density of the body, that is its mass per unit area.
* If you pass the density via `Body.create` the `mass` property is automatically calculated for you based on the size (area) of the object.
* This is generally preferable to simply setting mass and allows for more intuitive definition of materials (e.g. rock has a higher density than wood).
*
* @property density
* @type number
* @default 0.001
*/
/**
* A `Number` that defines the mass of the body, although it may be more appropriate to specify the `density` property instead.
* If you modify this value, you must also modify the `body.inverseMass` property (`1 / mass`).
*
* @property mass
* @type number
*/
/**
* A `Number` that defines the inverse mass of the body (`1 / mass`).
* If you modify this value, you must also modify the `body.mass` property.
*
* @property inverseMass
* @type number
*/
/**
* A `Number` that defines the moment of inertia (i.e. second moment of area) of the body.
* It is automatically calculated from the given convex hull (`vertices` array) and density in `Body.create`.
* If you modify this value, you must also modify the `body.inverseInertia` property (`1 / inertia`).
*
* @property inertia
* @type number
*/
/**
* A `Number` that defines the inverse moment of inertia of the body (`1 / inertia`).
* If you modify this value, you must also modify the `body.inertia` property.
*
* @property inverseInertia
* @type number
*/
/**
* A `Number` that defines the restitution (elasticity) of the body. The value is always positive and is in the range `(0, 1)`.
* A value of `0` means collisions may be perfectly inelastic and no bouncing may occur.
* A value of `0.8` means the body may bounce back with approximately 80% of its kinetic energy.
* Note that collision response is based on _pairs_ of bodies, and that `restitution` values are _combined_ with the following formula:
*
* Math.max(bodyA.restitution, bodyB.restitution)
*
* @property restitution
* @type number
* @default 0
*/
/**
* A `Number` that defines the friction of the body. The value is always positive and is in the range `(0, 1)`.
* A value of `0` means that the body may slide indefinitely.
* A value of `1` means the body may come to a stop almost instantly after a force is applied.
*
* The effects of the value may be non-linear.
* High values may be unstable depending on the body.
* The engine uses a Coulomb friction model including static and kinetic friction.
* Note that collision response is based on _pairs_ of bodies, and that `friction` values are _combined_ with the following formula:
*
* Math.min(bodyA.friction, bodyB.friction)