Esempio n. 1
0
void CCMissile::step(float dt) {
    // position of target and aimed
    CCNode* target = getTarget();
    CCPoint t = target->getPosition();
    CCPoint a = m_aimed->getPosition();
    
    // position vector degree
    CCPoint v = ccpSub(a, t);
    float r = ccpToAngle(v);
    float d = -CC_RADIANS_TO_DEGREES(r);
    d -= m_presetDegree;
    
    // save dest degree
    if(m_dstDegree != d) {
        m_dstDegree = d;
    }
    
    // rotate to dst degree gradually
    if(m_dstDegree > target->getRotation()) {
        float cur = MIN(m_dstDegree, target->getRotation() + dt * ANGULAR_VELOCITY);
        target->setRotation(cur);
    } else if(m_dstDegree < target->getRotation()) {
        float cur = MAX(m_dstDegree, target->getRotation() - dt * ANGULAR_VELOCITY);
        target->setRotation(cur);
    }
    
    // move target by velocity
    float move = m_velocity * dt;
    float distance = ccpLength(v);
    if(move >= distance) {
        target->setPosition(a);
    } else {
        t.x += move * cosf(r);
        t.y += move * sinf(r);
        target->setPosition(t);
    }
	
	// is done?
	m_done = getTarget()->getPositionX() == m_aimed->getPositionX() &&
		getTarget()->getPositionY() == m_aimed->getPositionY();
	
	// done callback
	if(m_done && m_doneCallFunc) {
		m_doneCallFunc->execute();
	}
}