void FloatingSprite::moveStepByStep()
{
if(_FoundPathSteps.empty()){
return;
}
PathStep* step = _FoundPathSteps.at(0);
Point stepPos = _HelloLayer->getPositionForTileCoord(step->getPosition());
MoveTo* moveAction = MoveTo::create(0.3f, stepPos);
CallFunc* moveCallback = CallFunc::create(CC_CALLBACK_0(FloatingSprite::moveStepByStep, this));
_FoundPathSteps.erase(0);
Sequence* moveSeq = Sequence::create(moveAction,moveCallback, NULL);
moveSeq->setTag(TAG_FOR_MOVING);
this->runAction(moveSeq);
if(_FoundPathSteps.empty()){
_HelloLayer->setPlayerPosition(stepPos);
_HelloLayer->setViewPointCenter(stepPos);
}
}
//This is the function for A-star pathfinding and moving
void FloatingSprite::moveTowardTarget(const Point &target)
{
if(!_HelloLayer){
return;
}
//Stop current movint action and start a new pathfinding
this->stopActionByTag(TAG_FOR_MOVING);
Point fromTileCoord = _HelloLayer->getTileCoordForPosition(this->getPosition());
Point toTileCoord = _HelloLayer->getTileCoordForPosition(target);
if(fromTileCoord == toTileCoord){
log("It's already there");
return;
}
if((_HelloLayer->isBlockageTile(toTileCoord)) || !(_HelloLayer->isValidTile(toTileCoord))){
log("Target [%f,%f] is unaccessible",toTileCoord.x, toTileCoord.y);
return;
}
log("From: %f, %f", fromTileCoord.x, fromTileCoord.y);
log("To: %f, %f", toTileCoord.x, toTileCoord.y);
_OpenSteps.clear();
_ClosedSteps.clear();
_FoundPathSteps.clear();
//Add current position(start position)
this->insertInOpenSteps(PathStep::createWithPosition(fromTileCoord));
do{
//1. get the top step in open steps array, push it to close steps array, then check the step
PathStep* currentStep = _OpenSteps.at(0);
_ClosedSteps.pushBack(currentStep);
_OpenSteps.erase(0);
//current step is the target to move, finished
//log("%s",currentStep->getDescription().c_str());
if(currentStep->getPosition() == toTileCoord){
PathStep* tmpStep = currentStep;
log("Path found");
//Got the path, start moving to the target point
buildFoundedPathSteps(tmpStep);
moveStepByStep();
_OpenSteps.clear();
_ClosedSteps.clear();
break;
}
//Check all adjacent tiles, put it into open steps array according to the F score
PointArray* adjSteps = _HelloLayer->accessibleTilesAdjacentToTileCoord(currentStep->getPosition());
for(ssize_t i = 0; i < adjSteps->count(); i++){
PathStep* step = PathStep::createWithPosition(adjSteps->getControlPointAtIndex(i));
//log("%s",step->getDescription().c_str());
if(this->getStepIndex(_ClosedSteps,step) != -1){
//the step is already in the closed steps, ignore
continue;
}
int moveCost = this->calcCostFromStepToAdjacent(currentStep, step);
ssize_t openIndex = this->getStepIndex(_OpenSteps, step);
if(openIndex == -1){
//this step is not in the open steps array, calc scores and put it into the array
step->setParent(currentStep);
step->setGScore(currentStep->getGScore() + moveCost);
step->setHScore(this->calcHScoreFromCoordToCoord(step->getPosition(), toTileCoord));
this->insertInOpenSteps(step);
}else{
step = _OpenSteps.at(openIndex);
//this step is already in the open steps array ,recalc scores and refine the score and parent
if((currentStep->getGScore() + moveCost) < step->getGScore()){
//Fix me: why not set parent?
step->setParent(currentStep);
step->setGScore(currentStep->getGScore() + moveCost);
step->retain();
_OpenSteps.erase(openIndex);
this->insertInOpenSteps(step);
step->release();
}
}
}
}while(_OpenSteps.size() > 0);
if(_FoundPathSteps.empty()){
log("Cannot find a path to the destination");
}
}