AS3 shuffling movieclips - actionscript-3

Question

I've added the basic targets and applying drag and drop for my puzzle pieces, now Im having trouble making the shuffling aspect. As in, after the player completes or opens up the fla, each time will start the puzzle pieces in random places of the stage. I understand using arrays for shuffling somehow but Im not sure exactly how to achieve this. I've stored the instance of my 19 puzzle pieces inside the array but now I have no idea what to do with this array. Other tutorials were abit out of my league and leaves my head scratching.
Just started doing coding for flash professional so yeah, any help with the shuffling movie clips ie the puzzles pieces would be greatly appreciated.
Heres's my code, Im not posting the whole thing since from P1 to P19 is basically copy pasting:
import flash.events.Event;
stage.addEventListener(Event.ENTER_FRAME, EntFrame)
function EntFrame(e: Event) : void
{
P1.addEventListener(MouseEvent.MOUSE_DOWN, fl_ClickToDrag);
function fl_ClickToDrag(event:MouseEvent):void
{
P1.startDrag();
}
stage.addEventListener(MouseEvent.MOUSE_UP, fl_ReleaseToDrop);
function fl_ReleaseToDrop(event:MouseEvent):void
{
P1.stopDrag();
}
if (T1.hitTestObject(P1.Tar1))
{
P1.x = 313.15;
P1.y = 242.75;
}
P19.addEventListener(MouseEvent.MOUSE_DOWN, fl_ClickToDrag_19);
function fl_ClickToDrag_19(event:MouseEvent):void
{
P19.startDrag();
}
stage.addEventListener(MouseEvent.MOUSE_UP, fl_ReleaseToDrop_19);
function fl_ReleaseToDrop_19(event:MouseEvent):void
{
P19.stopDrag();
}
if (T19.hitTestObject(P19.Tar19))
{
P19.x = 624.35;
P19.y = 455.60;
}
}

Answer 1

Here is what I hope is more holistic answer.
First, ditch those inline functions. Right now you make an ENTER_FRAME listener and inside that function you have inline function defined. This means every frame tick (which is tied to your frame rate, not the main timeline), those functions are going to get created again, and since you are adding them as handlers for listeners, they will stay in memory forever.
Here is a way you code this, showing ways to reduce redundancy and get rid of those memory leaks. This assumes the following:
You have 19 objects on the stage called T1 - T19, that represent the possible locations the pieces can go.
You have 19 pieces on the stage called P1 - P19, that, and the numbers correlate to the T locations as per the correct location of the piece.
//let's create a function to randomize the piece location
function seedPieces() {
//create an array consisting of the integers 1 - 19
var unusedSpaces:Vector.<int> = new Vector.<int>;
var i:int;
for (i = 1; i <= 19; i++) {
//populate that array
unusedSpaces.push(i);
}
var curLocation:DisplayObject; //helper var for the loop below
var curPiece:Sprite; //helper var for the loop below
//loop 19 times (from 1 - 19) - one iteration for each piece
for (i = 1; i <= 19; i++) {
curPiece = this["P" + i] as Sprite; //you can get the piece this way, or use an array if you've made one, like `pieces[i];`
trace(curPiece.name);
//splice removes and returns the item at the specified index (in this case a random number between 0 and arrays length less 1) - the second parameter is amount of items to remove (just 1 for this case)
curLocation = this["T" + unusedSpaces.splice(int(Math.random() * unusedSpaces.length), 1)] as DisplayObject;
trace(" ",curLocation.name);
//move the piece to the random location:
curPiece.x = curLocation.x;
curPiece.y = curLocation.y;
}
}
//NOW, as an aside, you should use a loop to add all your listeners for the sake of sanity - if you have them in an array, loop through that, or use the sloppy way like this:
for (var i:int = 1; i <= 19; i++) {
Sprite(this["P" + i]).addEventListener(MouseEvent.MOUSE_DOWN, fl_ClickToDrag);
}
//create a var to hold any piece that is currently being dragged, so you know which piece to stop drag on later
var currentDraggingItem:Sprite;
seedPieces();
function fl_ClickToDrag(event:MouseEvent):void
{
//assign this clicked item to the currentDraggingItem var
currentDraggingItem = event.currentTarget as Sprite;
//bring this one to the front
currentDraggingItem.parent.addChild(currentDraggingItem);
//you can use this one click handler for all pieces
//the piece that was actually clicked, is referenced by event.currentTarget
currentDraggingItem.startDrag();
//add the mouse up listener now that the mouse is currently DOWN
stage.addEventListener(MouseEvent.MOUSE_UP, fl_ReleaseToDrop);
//listen every frame while dragging
stage.addEventListener(Event.ENTER_FRAME, EntFrame);
}
function fl_ReleaseToDrop(event:MouseEvent):void
{
//if currentDraggingItem has a value, stop drag it
if (currentDraggingItem) {
currentDraggingItem.stopDrag();
//send to the back
currentDraggingItem.parent.addChildAt(currentDraggingItem,0);
}
//remove the mouse up and enter frame listener now that the mouse is UP
stage.removeEventListener(MouseEvent.MOUSE_UP, fl_ReleaseToDrop);
stage.removeEventListener(Event.ENTER_FRAME, EntFrame);
if(checkComplete()){
//game over, do something
}
}
function EntFrame(e: Event) : void
{
//this will snap the peice to the correct spot when the mouse is touching the correct spot
if(currentDraggingItem){
if (this[currentDraggingItem.name.replace("P","T")].hitTestPoint(mouseX,mouseY))
{
currentDraggingItem.x = this[currentDraggingItem.name.replace("P","T")].x;
currentDraggingItem.y = this[currentDraggingItem.name.replace("P","T")].y;
}
}
}
function checkComplete():Boolean {
//use a loop to go through all your pieces and check if they are in the right spot. Again, you could have them in an array, or do it the lazy way
for (var i:int = 1; i <= 19; i++) {
if (!this["T"+i].hitTestObject(this["P"+i]))
{
return false;
}
}
return true;
}

Answer 2

Well, in general you can shuffle with the following code:
var shuffledVector:Vector.<someClass> = new Vector.<someClass>;
while (originalVector.length > 0) {
shuffledVector.push(originalVector.splice(Math.random() * originalVector.length, 1)[0]);
}
Longer, explained version:
var shuffledVector:Vector.<someClass> = new Vector.<someClass>; //We will store our shuffled vector in here
var randomIndex:int; //Random index from the originalVector
var resultVector:Vector.<someClass>; //result from the originalVector.splice(...) function
var randomElement:someClass; //Random element from the originalVector
while (originalVector.length > 0) { //We will reduce the size of the originalVector until the originalVector is empty.
randomIndex = Math.random() * originalVector.length; //Calculate a random index within the range of the originalVector from 0 to originalVector.lenght-1 (note that the range decreases by one on every loop)
randomVector = originalVector.splice(randomIndex, 1); //Use splice to remove one element at the randomly choosen index, we will receive a vector with the removed element...
randomElement = randomVector[0]; //...so we need to access the element
shuffledVector.push(randomElement); //Add the randomly choosen element to our shuffled vector
}
I've written the code for a vector as i suggest to use a vector instead of an array, but the principle behind it is the same for an array.
In your case the originalVector is a vector filled with your P1-P19 Movieclips and someClass would be MovieClip. The originalVector is empty at the end and could be replaced with the shuffled one and of course it would make a lot more sense if you put the code in a seperate function like this:
function Shuffle(originalVector:Vector.<someClass>) : void {
var shuffledVector:Vector.<someClass> = new Vector.<someClass>;
while (originalVector.length > 0) {
shuffledVector.push(originalVector.splice(Math.random() * originalVector.length, 1)[0]);
}
originalVector = shuffledVector;
}
Offtopic, but important for further coding: Someone else already mentioned, that it is not good to add EventListeners on every frame, because it is absolutely unnecessary. You only need to add the Listeners once. Your code is very repetitive, you should use a function which accepts a MovieClip, x and y then call that function 19 times.
e.g.:
function setUpMovieClip(MC:MovieClip, x:int, y:int) : {
MC.addEventListener(MouseEvent.MOUSE_DOWN, clickToDrag);
//more code...
}
within the clickToDrag function you can access the MovieClip which was clicked via the event.target property:
function clickToDrag(e:MouseEvent) : {
e.target.startDrag();
//more code...
}
I hope you get the idea.