Passing Objects from Script to C++ ?

#1 What is the actual value of argv[2]? The uncommented version is guaranteed not to work, but the second one should work fine if argv[2] is a simObjectID that was created with a new (QuamBlock2D), and the QuamBlock2D does the proper DECLARE_XXX_OBJECT macro in it's implementation.

#2 This is how the Object is created (in script) that is passed in argv[2]

$player = new QuamBlock2D() { scenegraph = t2dSceneGraph; } ;

And I believe this is what you are talking about for the marco... this comes from QuamBlock2D.h

class QuamBlock2D : public fxSceneObject2D
{
	typedef fxSceneObject2D			Parent;
	QuamBlockDatablock2D*		mConfigDataBlock;
	         ...
public:
	QuamBlock2D();
	virtual ~QuamBlock2D();
        ....
       
       DECLARE_CONOBJECT(QuamBlock2D);

I thought that a CONOBJECT was visible to both areas of the engine, but I'm really not that clear on the whole thing.

#3 Also, I don't know if this matters or not but this is how I am calling the function from script...

function fxSceneObject2D::onCollision( %srcObj, %dstObj, %srcRef, %dstRef, %time, %normal, %contactCount, %contacts )
{	
	if (%srcObj == $player)
	{
				
		//set the Block in the data structure
		%position = %srcObj.getPosition();
		%posX = getWord(%position, 0);
		%posY = getWord(%position, 1);
		t2dSceneGraph.setBlock(%srcObj, %posX, %posY);
        }
...
}

#4 Brandon,

The answer here really depends on where the crash is happening. From what I can see, it may be in the mysterious "setBlock" C++ call. Assuming that the "QuamBlock2D" is valid, you need to make a few changes to your method. The first is that you're casting a string argument directly into an integer which is a bad idea as you'll get crazy coords from this conversion. You can use "dAtoi(argv[3])" for this to do the conversion from "ascii to integer" which is a T2D version of the standard "atoi()" call.

Also, as Stephen mentioned, your casting of the arg directly to a class pointer is wrong whereas the comment-out version is correct although I'd always recommend checking the resultant value before using it, maybe using a "dynamic_cast<>()" as in this example from T2D...

//-----------------------------------------------------------------------------
// Add to Scene.
//-----------------------------------------------------------------------------
ConsoleMethod(t2dSceneObject, addToScene, void, 3, 3, "(t2dSceneGraph) - Add to SceneGraph.")
{
	// Find t2dSceneGraph Object.
	t2dSceneGraph* pT2DSceneGraph = dynamic_cast<t2dSceneGraph*>(Sim::findObject(argv[2]));

	// Validate Object.
	if ( !pT2DSceneGraph )
	{
		Con::warnf("t2dSceneObject::addToScene() - Couldn't find/Invalid object '%s'.", argv[2]);
		return;
	}

	// Add to Scene.
	pT2DSceneGraph->addToScene( object );
}

Here's a version that should work, assuming the problem isn't in the "setBlock" C++ function call...

ConsoleMethod(fxSceneGraph2D, setBlock, bool, 5, 5, "Set the block)
{
    QuamBlock2D* nBlock = dynamic_cast<QuamBlock2D*>(Sim::findObject(argv[2]));
    if ( !nBlock  )
    {
	Con::warnf("fxSceneGraph2D::setBlock() - Couldn't find/Invalid object '%s'.", argv[2]);
	return;
    }

    U32 xCoord = dAtoi(argv[3]);
    U32 yCoord = dAtoi(argv[4]);
   
    xCoord = xCoord % 5;
    yCoord = yCoord % 5;
    yCoord = object->mSizeOfBoardX * yCoord - 1;
    U32 elem = yCoord + xCoord;  
   
    return object->setBlock(nBlock, elem);
}

If this crashes then I'd check your code in the "setBlock()" call or look at the stack-trace.

Hope this helps,

- Melv.

#5 Thanks for the info Melv, I have a Java background so I'm still picking up all the C++ syntax.

Also, you were right about this being a problem with the setBlock function. Apparently I am having trouble with an iterator.

Here is the code....

bool fxSceneGraph2D::setBlock(QuamBlock2D* newBlock, U32 dsElement)
{
	//Given the object newBlock and the Element loaction
	//Get an Iterator for the Vector
	Vector<QuamBlock2D*>::iterator p = FQGameBoard.begin();		
	//insert puts the object right before the iterator
	for(int x = 0; x< dsElement+1; x++)
	{
		p++;
	}
	//insert this object into the Vector FQGameBoard
	FQGameBoard.insert(p, newBlock);
	
	return true;
}

I'm sure this probably isn't the best way to insert something into a Vector but it was all I could figure out. Am I creating the iterator correctly? I am using the extended Vector class that is included in the engine, is there another way to insert an object into a Vector given an element location?

Thanks for your help guys I really appreaciate you both answering my questions.