Java Code Examples for com.badlogic.gdx.physics.box2d.ContactImpulse#getNormalImpulses()

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Example 1
Source File: CarImpactManager.java    From uracer-kotd with Apache License 2.0 4 votes vote down vote up 
private void ifCarThenCollide (Contact contact, Fixture f, Fixture other, ContactImpulse impulse) {
	Body body = f.getBody();
	Object userData = f.getUserData();
	if ((body != null) && (userData == CarType.PlayerCar || userData == CarType.ReplayCar)) {
		Car car = (Car)body.getUserData();
		float[] impulses = impulse.getNormalImpulses();
		tmpVec2.set(impulses[0], impulses[1]);

		// dbg
		Fixture fcar = null;
		if (contact.getFixtureA().getUserData() == CarType.PlayerCar) {
			fcar = contact.getFixtureA();
		} else if (contact.getFixtureB().getUserData() == CarType.PlayerCar) {
			fcar = contact.getFixtureB();
		}

		// assumes perfect side collision
		float front_ratio = 0.5f;

		// compute median front/rear ratio for collision points
		if (fcar != null) {
			front_ratio = 0;
			float ml = car.getCarModel().length;
			float half_ml = ml * 0.5f;
			Vector2[] pts = contact.getWorldManifold().getPoints();

			int num_points = contact.getWorldManifold().getNumberOfContactPoints();
			for (int i = 0; i < num_points; i++) {
				Vector2 lp = fcar.getBody().getLocalPoint(pts[i]);

				// examine front/rear ratio
				float r = MathUtils.clamp(lp.y + half_ml, 0, ml);
				r /= ml;
				front_ratio += r;
			}

			front_ratio /= (float)num_points;
			// Gdx.app.log("Cntct", "" + front_ratio);
		}
		// dbg

		car.onCollide(other, tmpVec2, front_ratio);
	}
}