CODEWITHSUNDEEP
objective-ciosmathcocos2d-iphonebox2d
glenstorey
glenstorey

Reputation: 5154

How can I make an impulse so that point b moves away from point a in box2d/ cocos2diphone

I'm applying an impulse on a box2d object with something like this:

b2Vec2 impulse = b2Vec2(4.0f, 15.0f);
body->ApplyLinearImpulse(impulse, body->GetWorldCenter());

I know this is probably high school math, and I promise I have made efforts to discover this for myself; please forgive my ignorance.

If I have objects a, b and c - and object a is at the midpoint of b and c, how can I create a Box2D impulse so that objects b and c move away from a at velocity v?

scientific diagram drawn with great skill and focused intent

Upvotes: 5

Views: 301

Answers (1)

jrtc27
jrtc27

Reputation: 8536

Try using this:

b2Vec2 impulseB = bodyB->GetPosition() - bodyA->GetPosition();
impulseB /= impulseB.Length();
impulseB *= predefinedScaleValue; // predefinedScaleValue is your velocity
b2Vec2 impulseC = -impulseB;
bodyB->ApplyLinearImpulse(impulseB, bodyB->GetWorldCenter());
bodyC->ApplyLinearImpulse(impulseC, bodyC->GetWorldCenter());

I hope it's clear what's going on here. If not, just ask :)

Upvotes: 3

Related Questions