Is reference lost? - actionscript

First a bit of code:
var mc:MovieClip = new MovieClip();
mc.graphics.lineStyle(2, 0x000000);
mc.graphics.beginFill(0xFF00000)
mc.graphics.drawRect(10, 10, 100, 100);
var array:Array = [mc];
this.addChild(array[0]);
mc = new MovieClip();
this.removeChild(array[0]);
this.addChild(array[0]);
I would expect it to update reference held in array and add empty MovieClip to the stage. Is that wrong assumption then?
Thanks

Yes. Changing which movie clip mc refers to does not change which movie clip array[0] refers to. It still refers to the old one. Instead, change the last line to this.addChild(mc); or add another line which says array[0] = mc; between the removeChild and the addChild which follows it.

Related

How to use ApplyForce with box2DWeb

I have a Box2DWeb sketch working ok but I am unable to figure out how to use the ApplyForce method with a body. I have attached the working codepen. On line 85, I have commented out the line that I thought would work but everything disappears when I include it.
If anyone could let me know the correct way to use it, I would be very happy. I have RTFM and seen similar posts on StackO but I still cannot work it out.
http://codepen.io/anon/pen/vOJByN?editors=101
Thanks a lot,
Steven
// single dynamic object----------------------
var fixDef2 = new b2FixtureDef;
fixDef2.density = 1.0
fixDef2.friction = 0.2;
fixDef2.restitution = 0.5;
var bodyDef2 = new b2BodyDef;
bodyDef2.type = b2Body.b2_dynamicBody;
fixDef2.shape = new b2PolygonShape;
fixDef2.shape.SetAsBox((300/SCALE)/2, (60/SCALE) / 2);
bodyDef2.position.x = canvas.width/4/SCALE;
bodyDef2.position.y = canvas.height/2/SCALE;
bodyDef2.angle = 5;
world.CreateBody(bodyDef2).CreateFixture(fixDef2);
// Apply force to object----------------------
/*bodyDef2.ApplyForce(new b2Vec2(500,50) , bodyDef2.GetWorldCenter());
*/
You should call ApplyForce method of b2Body, not of b2BodyDef. You can get b2Body object as result of world.CreateBody(bodyDef2) method.
I've changed your codepen here: http://codepen.io/anon/pen/NqZvqG
Your code:
world.CreateBody(bodyDef2).CreateFixture(fixDef2);
// Apply force to object----------------------
/*bodyDef2.ApplyForce(new b2Vec2(500,50) , bodyDef2.GetWorldCenter());
*/
My code:
var myBody = world.CreateBody(bodyDef2);
var myFixture = mybody.CreateFixture(fixDef2);
// Apply force to object
myBody.ApplyForce(new b2Vec2(500,50), myBody.GetWorldCenter());

How to create a variable number of UIImageViews in swift

My problem is that based on the number of groups a person has I want to dynamically create that many UIImageView and assign them to the view. I know how to create a single UIImageView and put it onto the view but how can I create a variable number of them since creating another with the same name seems to just overwrite the original? I tried sending the UIImageView into an Array but got an optional error.
circleView = UIImageView(frame:CGRectMake(125, y, 75, 75))
y+=150
circleView.image = UIImage(named:"circle.png")
circleView.tag = i
self.view.addSubview(circleView)
circleArray[i] = circleView
The problem is that you keep reusing the same circleView instance. When you add it to the array, you are just adding a reference to it. You then reinitialize it, which wipes it out. I also don't see where you are incrementing i. Try something like this:
var circleArray = Array<UIImageView>()
var y : CGFloat = 0.0
var i = 0
circleArray.append(UIImageView(frame:CGRectMake(125, y, 75, 75)))
var circleView = circleArray[i]
circleView.image = UIImage(named:"circle.png")
circleView.tag = i
self.view.addSubview(circleView)
y+=150
i += 1
You need to use circleArray.append(circleView)

Attempt to index global 'player' (a nil value)

I'm getting a (a nil value) error when i try to do this :
player = display.newSprite( imageSheet, "sequenceDataPlayer"..math.random(1, 7) )
Looking at a test print :
print ("sequenceDataPlayer"..math.random(1, 7) )
It prints the data oky 'sequenceDataPlayer1'
What Im i doing wrong here ?
Your print statement is just printing the string "sequenceDataPlayer" concatenated with a random number between 1 and 7.
It took me a little while to figure out how to use sprites in Corona, but here's how I do it. I'll use Player for the variables since that's what you're using.
First I create an options variable to get the frames from my Player.lua file:
optionsPlayer =
{
frames = require("player").frames,
}
Then I create a variable for the image sheet:
playerSheet = graphics.newImageSheet( "player.png", optionsPlayer )
After that, I create a variable to set up the name, the sequence of frames, the time it takes to play, and set how many times it will loop:
spriteOptionsPlayer = { name="Player", start=1, count=10, time=500, loopCount = 1}
Finally, I create the new sprite:
spriteInstancePlayer = display.newSprite( playerSheet, spriteOptionsPlayer )
Once I've done all this, I usually set up the x and y positions, xScale and yScale, and other properties along with adding it to a display group.
Last of all, then I play the sprite somewhere:
spriteInstancePlayer:play()
From what it looks like, you want to have 7 different sprites to choose from. Personally, I would just create seven different sprites using all of the steps above and then put them in a table.
sprites = { spriteInstancePlayer, spriteInstancePlayer2, spriteInstancePlayer3, etc.. }
Then when I wanted to play them, I would set the position and visibility and just do:
r = math,random(1, 7)
sprites[r].x = x position
sprites[r].y = y position
sprites[r].isVisible = true
sprites[r]:play()
Of course, then I would want to set listeners to either completely remove the sprite or set the visibility to false when it's done playing, there's a collision(you'd have to add a physics body and set that all up), or whatever else might happen...
There are probably simpler ways to do it, but that's what I do.
Hope this helps.

Coins Collections like tiny wings

I am new to box2d. I want to create instance of sprites(Coins like tiny wings) and make it to collide with player.Is there a single sprite body definition is enough or i have to create a sprite body separately for all instance sprite
I need exact collision effect like tiny wings coins collection.Any help plz intimate me.Thanks
If I had to solve that problem I would create a class (for example Coin) then make multiple instances of it and storing them by using an array. Here is the code for creating a new coin and storing it in the array:
//in the constructor function of the playing screen:
coins = new Array();
//the constructor function of the Coin should contain the startX and startY coordinate
var newCoin= new Coin(100, 50);
coins.push( newCoin );
addChild( newCoin );
You can remove an element of an array using either exampleArray.pop ---> this will remove the last element
or exampleArray.splice(x,z) x is the element you remove, z is the number of elements you remove. exampleArray.splice(5,2) will remove 2 elements starting from the 5th. The first element of an array is numbered 0, the second is numbered 1 and so on...
You can check for collisions like this:
for each (var coin in coins)
{
if (coin.hitTestObject(player))
{
//do something
}
}

How to create PieSeries interpolation in flex 4.5 at run time

i make a PieChart at run time, and i want to interpolate data change, but i have some difficult.
The Code is here:
//Pie Chart
pieChart.dataProvider = expenses;
var pieSeries:PieSeries = new PieSeries();
pieSeries.nameField = "position";
pieSeries.field = "value";
pieSeries.explodeRadius = 0.08;
pieChart.series = null;
pieChart.series.push(pieSeries);
I found two method, but i don't know how to use that >.<:
pieSeries.beginInterpolation
pieSeries.interpolate
1) First create a SeriesInterpolate class instance and customize it however you want.
2) You can set the showDataEffect style of your pieSeries object to the interpolate object that you just created.
Whalah.. whenever your data changes the interpolator will get triggered.
See the code snippet below..
I've also created an example application with source enabled.
goto: http://befreestudiosllc.com/demos/flex4/charting/seriesInterpolate/ and right-click to view source.
// Create an interpolator and customize its properties
var interpolateDataIn:SeriesInterpolate = new SeriesInterpolate();
interpolateDataIn.duration = 1000;
var pieSeries:PieSeries = new PieSeries();
pieSeries.setStyle("showDataEffect", interpolateDataIn); // apply interpolators to your series through show/hide dataEffects

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