/** * What happens with the widget when another widget touches it. * * @param other_body The body that touched it. * @param f The x,y coordinate that is the contact point. */ public void reactToTouchingBody(CollisionEvent e) { float speed = MOVEMENT_SPEED + (MOVEMENT_SPEED * bounces * 0.05f); if (currentDirection == Direction.WEST) { currentDirection = direction.EAST; body.setForce(2 * speed, 0); } else if (currentDirection == Direction.EAST) { currentDirection = Direction.WEST; body.setForce(-2 * speed, 0); } else if (currentDirection == Direction.NORTH) { currentDirection = Direction.SOUTH; body.setForce(0, 2 * speed); } else if (currentDirection == Direction.SOUTH) { currentDirection = direction.NORTH; body.setForce(0, -2 * speed); } bounces++; }
/** Resets the widget to start state. */ public void resetWidget() { // Reset has been made, so we CAN activate this later. reset = true; // Make inactive active = false; // Not collided. collided = false; bounces = 0; currentDirection = direction; image = frames.get(0); body.setEnabled(false); // Move to initial position. body.set(shape, MASS); body.setPosition(position.x + WIDTH / 2, position.y + HEIGHT / 2); // Make sure the gameplay didn't mess with any initial properties. body.setCanRest(true); body.setDamping(0.0f); body.setFriction(0.01f); body.setGravityEffected(false); body.setIsResting(true); body.setMoveable(true); body.setRestitution(1.5f); body.setRotatable(true); body.setRotation(0.0f); body.setRotDamping(0.0f); body.setMaxVelocity(50f, 50f); body.setForce(-body.getForce().getX(), -body.getForce().getY()); if (currentDirection == Direction.WEST) { body.setForce(-MOVEMENT_SPEED, 0); } else if (currentDirection == Direction.EAST) { body.setForce(MOVEMENT_SPEED, 0); } if (currentDirection == Direction.NORTH) { body.setForce(0, -MOVEMENT_SPEED); } else if (currentDirection == Direction.SOUTH) { body.setForce(0, MOVEMENT_SPEED); } body.adjustVelocity(new Vector2f(-body.getVelocity().getX(), -body.getVelocity().getY())); body.adjustAngularVelocity(-body.getAngularVelocity()); }
/** * Step the simulation. Currently anything other than 1/60f as a step leads to unpredictable * results - hence the default step fixes us to this step * * @param dt The amount of time to step */ public void step(float dt) { for (int i = 0; i < bodies.size(); ++i) { for (int j = 0; j < sources.size(); j++) { ((ForceSource) sources.get(j)).apply(bodies.get(i), dt); } } BodyList bodies = getActiveBodies(); JointList joints = getActiveJoints(); float invDT = dt > 0.0f ? 1.0f / dt : 0.0f; if (restingBodyDetection) { for (int i = 0; i < bodies.size(); ++i) { Body b = bodies.get(i); b.startFrame(); } for (int i = 0; i < joints.size(); ++i) { Joint j = joints.get(i); j.getBody1().setIsResting(false); j.getBody2().setIsResting(false); } } broadPhase(dt); for (int i = 0; i < bodies.size(); ++i) { Body b = bodies.get(i); if (b.getInvMass() == 0.0f) { continue; } if (b.isResting() && restingBodyDetection) { continue; } Vector2f temp = new Vector2f(b.getForce()); temp.scale(b.getInvMass()); if (b.getGravityEffected()) { temp.add(gravity); } temp.scale(dt); b.adjustVelocity(temp); Vector2f damping = new Vector2f(b.getVelocity()); damping.scale(-b.getDamping() * b.getInvMass()); b.adjustVelocity(damping); b.adjustAngularVelocity(dt * b.getInvI() * b.getTorque()); b.adjustAngularVelocity(-b.getAngularVelocity() * b.getInvI() * b.getRotDamping()); } for (int i = 0; i < arbiters.size(); i++) { Arbiter arb = arbiters.get(i); if (!restingBodyDetection || !arb.hasRestingPair()) { arb.preStep(invDT, dt, damping); } } for (int i = 0; i < joints.size(); ++i) { Joint j = joints.get(i); j.preStep(invDT); } for (int i = 0; i < iterations; ++i) { for (int k = 0; k < arbiters.size(); k++) { Arbiter arb = arbiters.get(k); if (!restingBodyDetection || !arb.hasRestingPair()) { arb.applyImpulse(); } else { arb.getBody1().collided(arb.getBody2()); arb.getBody2().collided(arb.getBody1()); } } for (int k = 0; k < joints.size(); ++k) { Joint j = joints.get(k); j.applyImpulse(); } } for (int i = 0; i < bodies.size(); ++i) { Body b = bodies.get(i); if (b.getInvMass() == 0.0f) { continue; } if (restingBodyDetection) { if (b.isResting()) { continue; } } b.adjustPosition(b.getVelocity(), dt); b.adjustPosition(b.getBiasedVelocity(), dt); b.adjustRotation(dt * b.getAngularVelocity()); b.adjustRotation(dt * b.getBiasedAngularVelocity()); b.resetBias(); b.setForce(0, 0); b.setTorque(0); } if (restingBodyDetection) { for (int i = 0; i < bodies.size(); ++i) { Body b = bodies.get(i); b.endFrame(); } } cleanUpArbiters(); }