88 lines
2.5 KiB
JavaScript
88 lines
2.5 KiB
JavaScript
class Physics {
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constructor() {
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this.world = new b2World(new b2Vec2(0, 0));
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this.toRemove = [];
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var b2DebugDraw = Box2D.Dynamics.b2DebugDraw;
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var debugDraw = new b2DebugDraw();
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debugDraw.SetSprite(document.getElementById("starbugs_canvas").getContext("2d"));
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debugDraw.SetDrawScale(SCALE);
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debugDraw.SetFillAlpha(0.3);
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debugDraw.SetLineThickness(1.0);
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debugDraw.SetFlags(b2DebugDraw.e_shapeBit | b2DebugDraw.e_jointBit);
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this.world.SetDebugDraw(debugDraw);
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}
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createBody(body) {
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let s = SCALE;
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let bodyDef = new b2BodyDef();
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bodyDef.userData = body;
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bodyDef.position = new b2Vec2(body.x || 0, body.y || 0);
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bodyDef.fixedRotation = false;
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bodyDef.active = true;
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bodyDef.linearVelocity = new b2Vec2(0, 0);
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bodyDef.angularVelocity = 0;
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bodyDef.linearDamping = body.bodyType == 'ship' ? 0.01 : 0.003;
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bodyDef.angularDamping = body.bodyType == 'ship' ? 0.01 : 0.003;
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bodyDef.type = body.bodyType == 'structure' ?
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b2Body.b2_staticBody : b2Body.b2_dynamicBody;
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bodyDef.allowSleep = false;
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var b2body = this.world.CreateBody(bodyDef);
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var fixtureDef = new b2FixtureDef();
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fixtureDef.density = 10;
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fixtureDef.friction = 1;
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fixtureDef.restitution = 1;
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for (var i in body.frame) {
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var poly = body.frame[i].map(function(vertex) {
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return new b2Vec2(vertex[0] / s, vertex[1] / s);
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});
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fixtureDef.shape = new b2PolygonShape();
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fixtureDef.shape.SetAsArray(poly, poly.length);
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//console.log(fixtureDef);
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b2body.CreateFixture(fixtureDef);
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}
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body.b2body = b2body;
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body.com = b2body.GetLocalCenter();
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if (body.bodyType == 'ship') {
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//console.log(body.getPos());
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//console.log(b2body.GetLocalCenter());
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//console.log(body);
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//console.log(b2body.GetMass());
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//console.log(b2body.GetFixtureList().GetShape());
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}
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}
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removeBody(body) {
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this.toRemove.push(body.b2body);
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}
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step() {
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this.world.Step(1, 5, 1 / 60);
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this.world.ClearForces();
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//this.world.DrawDebugData();
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for (var i in game.world.bodies) {
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var s = SCALE;
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var r = 0.1;
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var body = game.world.bodies[i];
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var pos = body.getPos();
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var x = (body.x * r + pos.x) / (r + 1);
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var y = (body.y * r + pos.y) / (r + 1);
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var r = (body.r * r + pos.r) / (r + 1);
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if (body.updated-- <= 0) continue;
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body.b2body.SetPositionAndAngle(new b2Vec2(x, y), r);
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body.b2body.SetLinearVelocity(new b2Vec2(body.xvel, body.yvel));
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body.b2body.SetAngularVelocity(body.rvel);
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}
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for (var i = 0; i < this.toRemove.length; i++) {
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this.world.DestroyBody(this.toRemove[i]);
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}
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this.toRemove = [];
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}
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}
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