AS3 display object height not reported correctly - actionscript-3

This should be simple. What am I missing?
Create a Sprite (container), put it on the displaylist, add a new Sprite (rect) to container.
Change height of the child (rect).
Height values of both parent (container) and child (rect) are not reported correctly although rendered correctly.
Thanks for your assistance.
var container:Sprite = new Sprite();
addChild(container);
[Embed(source = "../lib/rectangle.swf")] // height is 100
var Rect:Class;
var rect:Sprite = new Rect();
trace(rect.height); // 100 is correct before placement in container
container.addChild(rect);
trace(rect.height); // 100 is correct after placement in container
trace(container.height); // 0 is not correct; should be 100
rect.height = rect.height + 100; // renders correctly at new height
trace(rect.height); // 100 is not correct; should be 200
trace(container.height); // 0 is not correct; should be 200

Apparently your container is not on the stage display list. If a measured DisplayObject is not on the display list (anywhere), its dimensional properties are not properly recalculated, when its own display list is altered. This is apparently to save time for Flash engine to process building of a complex MovieClip frame or any other complex container faster, and recalculation is only done if the container is placed to stage. The resolution is to place the object to be measured to stage (anywhere, anyhow), gather its properties then remove it from stage. An example:
trace(this.stage); // [object Stage] - to make sure we can access stage in here
var sp:Sprite=new Sprite();
var b:Bitmap=new Bitmap(new BitmapData(100,100));
trace(sp.width); // should return 0
trace(sp.height); // 0 also
sp.addChild(b);
trace(sp.height); // 0 again
trace(b.height); // should return 100, as the bitmap data is specified
// as well as in your case, the class's width and height are precalculated
addChild(sp);
trace(sp.height); // returns 100, as expected
removeChild(sp);
trace(sp.height); // 100, stored
sp.removeChild(b);
trace(sp.height); // should also return 100, while there's no content in the sprite
There is also another possibility, width of an object off stage can be in the negative, the solution is again the same - put object on stage, get width, remove object from stage.

Related

actionscript issue adding shape to container

I don't know how to describe this problem but I will try to be clear enought. I am doing an actionscript exercise where I have a DisplayObjetct Container defined as Sprite, and what I want is to add ramdomizely circles with a random radio length between 50 and 100.
The Container called "gameZoneContainer_sp" has been added to the displaylist in the Main class, and everytime the user change the size of the stage the container set its new values of width and height.
Here is the code of what i am saying:
private function refreshScreen(ev:Event= null ):void{
// Remember: we can know stage dimensions accessing to:
// stage.stageWidth
// stage.stageHeight
//CONSTANTS DEFINITION OF MARGIN
const margen:Number=25;
//LOCAL VARIABLES DEFINITION
var cercleWidth:Number, cercleHeight:Number;
var invaderWidth:Number, invaderHeight:Number;
var containerWidth:Number, containerHeight:Number;
var logoWidth:Number, logoHeight:Number;
//STORING DIMENSIONS
cercleWidth=addCercle_bt.width;
cercleHeight=addCercle_bt.height;
invaderWidth=addInvader_bt.width;
invaderHeight=addInvader_bt.height;
containerWidth=gameZoneContainer_sp.width;
containerHeight=gameZoneContainer_sp.height;
logoWidth=logoUOC_sp.width;
logoHeight=logoUOC_sp.height;
//SET HORIZONTAL POSITION OF THE ELEMENTS
addCercle_bt.x=(stage.stageWidth/2)+margen;
addInvader_bt.x=(stage.stageWidth/2)-(invaderWidth+margen);
gameZoneContainer_sp.x=margen;
logoUOC_sp.x=stage.stageWidth-(logoWidth+margen);
//SET VERTICAL POSITION OF THE ELEMENTS
addCercle_bt.y=stage.stageHeight - (cercleHeight+margen);
addInvader_bt.y=stage.stageHeight-(invaderHeight+margen);
gameZoneContainer_sp.y=logoHeight+margen*2;
logoUOC_sp.y=margen;
//SET DIMENSIONS OF CONTAINER gameZoneContainer_sp
gameZoneContainer_sp.width=stage.stageWidth-(margen*2);
gameZoneContainer_sp.height=stage.stageHeight-(margen*4)-invaderHeight-logoHeight;
}
/* THIS METHOD ADD A CIRCLE TO THE CONTAINER gameZoneContainer_sp */
private function addCercle(ev:MouseEvent):void {
// Create new instance of Cercle
// and add it to gameZoneContainer_sp
//CONSTANT DEFINITIONS
const minRadio:Number=50, maxRadio:Number=100;
//LOCAL VARIABLES DEFINITIONS OF RADIO, COLOR AND CIRCLE
//THE RADIO CHOOSE A RANDOM VALUE BETWEEN 50 AND 100
var radio:Number=minRadio+(maxRadio-minRadio)*Math.random();
var color:uint=Math.random() * 0xFFFFFF;
var cercle:Cercle=new Cercle(color,radio);
//
var minPosX:Number=radio;
var maxPosX:Number=gameZoneContainer_sp.width/2;
var minPosY:Number=radio;
var maxPosY:Number=gameZoneContainer_sp.height-(minPosY);
// SET POSITION OF THE CIRCULE INSIDE THE CONTAINER
cercle.x= minPosX + (maxPosX-(2*minPosX))*Math.random();
cercle.y= minPosY + (maxPosY-(2*minPosY))*Math.random();
cercle.drawCercle();
gameZoneContainer_sp.addChild(cercle);
refreshScreen(ev);
//TRACING RESULTS...
trace ("Added cercle!");
trace ("alto del contenedor: "+gameZoneContainer_sp.height);
trace ("Posicion x: "+cercle.x);
trace ("radio: "+radio);
}
//DEFINITION OF THE CIRCLE CLASS
public class Cercle extends Sprite {
private var _color:uint;
private var _radio:Number;
public function Cercle(color:uint,radio:Number){
super();
/* THE CLASS ACCEPT HEX VALUES.*/
_color= color;
_radio=radio;
init();
}
public function init():void{
drawCercle ();
}
//METHOD TO DRAW A CIRCLE
public function drawCercle():void{
var circle:Shape=new Shape();
circle.graphics.beginFill(_color,1);
circle.graphics.drawCircle(0,0,_radio);
addChild(circle);
}
}
Here is my problem:
When I add a circle it seems to be fine until I change the dimensions of the windows (the scene). Everytime I update the dimensions, the event execute the method refreshScreen from the main class which update the dimensions and positions of all elements in scene, but after that if i add a new circle, it change the container, and that is wrong because what I want is to add the circle IN the container.
Hope is not too long. Please any help would be great!
Thank you in advance!!
************ HERE GOES THE SOLUTION ********************
//METHOD TO ADD A CIRCLE TO THE CONTAINER
private function addCercle(ev:MouseEvent):void {
// Create new instance of Cercle
// and add it to gameZoneContainer_sp
const minRadio:Number=50, maxRadio:Number=100;
var radio:Number=minRadio+(maxRadio-minRadio)*Math.random();
var color:uint=Math.random() * 0xFFFFFF;
// CHANGES///////
// gameZoneContainer_sp IS 400X400 ORIGINALLY AND WE WANT TO PUT AN INSTANCE OF CIRCLE OBJETCT
// cercle.x WILL PLACE IN minPosX = radio y maxPosy = 400 - radio
// TAKING INTO ACCOUNT THAT ITS RADIO IS cercle.width/2
// cercle.x WILL PLACE IN minPosX = cercle.width/2 y maxPosy = 400 - cercle.width/2
// (SAME FOR y)
var cercle:Cercle=new Cercle(color,radio);
// Cercle scale correction
//cercle.width= radio/(gameZoneContainer_sp.width/400);
//cercle.height= radio/(gameZoneContainer_sp.height/400);
// Cercle positionning
cercle.x = cercle.width/2 + ((400-cercle.width)*Math.random());
cercle.y = cercle.height/2 + ((400-cercle.height)*Math.random());
// PROPORTION CORRECTIONS
//cercle.width = (2*radio)*gameZoneContainer_sp.width/400;
//I ADD IT TO THE CONTAINER
gameZoneContainer_sp.addChild(cercle);
trace ("Added cercle!");
trace ("alto del contenedor: "+gameZoneContainer_sp.height);
trace ("Posicion x: "+cercle.x);
trace ("radio: "+radio);
}
This is what I think is going on. You basically have 2 problems.
You're adding circles using math meant to adjust for the position of the game window, but you don't need that if you are adding it to the game window container. This is resulting in circles that are being added too far to the right.
Something about your Air setup is making the screen contents scale to show all the contents resulting in everything shrinking. (If we fix the first problem, this one will become inconsequential).
So instead of:
cercle.x = minPosX ...etc
do:
cercle.x = Math.Random()*gameZoneContainer_sp.width;
Do likewise for the y value.
You see, the local origin point of an objects container will be that objects (0,0) point locally. So the top left corner of this game container will be the cercle's (0,0) point and therefore there is no need to adjust it to the right by the amount that you do using minPosX. This is assuming you have not made your game container offset from the default somehow (i.e. When you created the rectangle, you did so using (0,0,width,height) and not something like (xOffset,yOffset,width,height)).

ActionScript 3: How can the re-sizing of the width of a parent object by its child be prevented?

if(_ss.x >= _l.getWidth()){
_ss.x = _l.getWidth();
_vx *= -1;
_ss is the child object of _l.
_l's original width is 1024px.
When ss.x is greater than 1024px the _l's width
is expanded by the same amount of pixels. However, strangely the
Parent, _l, which is essentially a background and container, does not resize visually. The _l.width property, however, increases when its object child _ss, visually a space ship, exceeds the _l.width's original pixel width of 1024.
I want _ss to be prevented from moving beyond its parent's original width of 1024px. I am new to ActionScript. What can be done?
If I understand you, you're noticing that when a child size changes it is reflected by it's parent DisplayObject/width and height properties, but does not visually change the parent. This is expected, a display object's width and height (and getBounds()) reflects the measured size of its contents, and there is no automatic layout of graphics when size changes in this way (such as drawing a background that fills the container bounds).
In other words:
var container:Sprite = new Sprite();
container.graphics.beginFill(0xff0000);
container.graphics.drawRect(0, 0, 100, 100);
trace(container.width, container.height); // 100 100
var child:Shape = new Shape();
child.graphics.beginFill(0x00ff00);
child.graphics.drawRect(0, 0, 500, 500);
trace(child.width, child.height); // 500 500
container.addChild(child);
trace(container.width, container.height); // 500 500
You can't prevent this behavior in a general sense, but you can override it with an extended class. For example:
class UISprite extends Sprite {
private var _width:Number = 0;
override public function set width(value:Number):void {
_width = value;
}
override public function get width():Number {
return _width;
}
}
Now a UISprite instance has a "virtualized" width that doesn't reflect the measured size. You can set it to be anything you like, regardless of the actual size of its contents:
var ui:UISprite = new UISprite();
trace(ui.width); // 0
ui.width = 100;
trace(ui.width); // 100
You can add things to it and it won't effect the width property:
var child:Shape = new Shape();
child.graphics.beginFill(0xff0000);
child.graphics.drawRect(0, 0, 500, 500);
ui.addChild(child);
trace(ui.width); // 100
Flex makes heavy use of this sort of thing to provide layout features.
Hope that helps.

Loop an image in Flash

I want to have a scene where an image which is 5000 pixels high is moving up 5 pixels each frame-refresh. When the image is all up, I'd like to see the top of the image connected to the bottom of the image. This should be done untill the level is 'done'. How can I 'loop' such an Image?
You can create a copy of that image which you keep hidden/above and the trick is to update the position and loop accordingly so when one image goes bellow the screen it goes back on top and repeats.
Here's a basic snippet to illustrate the idea using the DisplayObject class and the scrollRect property:
//ignore this, you have your content already
var dummyContent:BitmapData = new BitmapData(100,100,false);
dummyContent.perlinNoise(10,10,8,12,true,true);
//important stuff starts here
var container:Sprite = addChild(new Sprite()) as Sprite;//make a container
container.scrollRect = new Rectangle(0,0,dummyContent.width,dummyContent.height);//set a scrollRect/'mask'
var part1:DisplayObject = container.addChild(new Bitmap(dummyContent));//add two copies
var part2:DisplayObject = container.addChild(new Bitmap(dummyContent));//of the same content
part2.y -= part2.height;//set the 2nd at the top of the 1st
addEventListener(Event.ENTER_FRAME,update);
function update(e:Event):void{
//move both
part1.y += 5;
part2.y += 5;
//check if any reach the bottom so they can be moved back up
if(part1.y >= part1.height) part1.y = -part1.height;
if(part2.y >= part2.height) part2.y = -part2.height;
//the above can also be nicely placed in a loop if you plan on using more seamless looping clips/images
}
Obviously you will have different content, but the principle is the same.
If you're working with images, you can simply use BitmapData's copyPixels method:
var s:int = 5;//scroll speed
//make some content
var w:int = 100;
var h:int = 100;
var dummyContent:BitmapData = new BitmapData(w,h,false);
dummyContent.perlinNoise(10,10,8,12,true,true);
//prepare for stiching
var renderPos:Point = new Point();//position to render the current image to
var prenderPos:Point = new Point();//position to render the previous image (the 'hidden' copy above)
var render:BitmapData = new BitmapData(w,h,false);//create a bitmap data instance to render updated pixels int
addChild(new Bitmap(render));//and add it to the stage
addEventListener(Event.ENTER_FRAME,update);
function update(e:Event):void{
renderPos.y = (renderPos.y+s)%h;//update the scroll position for the 1st part, % is used to loop back to 0 when the position gets to the content height
prenderPos.y = renderPos.y - h;//update the scroll position for the 2nd part (above)
render.lock();//freeze pixel updates
render.copyPixels(dummyContent,dummyContent.rect,renderPos);//copy pixels from the scroll position to the bottom
render.copyPixels(dummyContent,dummyContent.rect,prenderPos);//copy pixels from the top to the scroll position
render.unlock();//unfreeze/update ALL THE PIXELS
}
You can try to use a Rectangle object which changes height (height-scrollPosition) so you potentially access less pixels each time or you can manually work out single for loops using BitmapData's getVector method, but that's something to look into if performance is actually an issue for such a simple task and it's worth checking what's faster ( copy full bitmap rect vs copy partial bitmap rect vs manually copy values using vector )
Be warned, Flash cannot load an image greater than 16,769,025 pixels (or 4095x4095). The height of 5000 pixels will work as long as the width is not greater than 3353.
That said, I'd loop the image by keeping two copies of the image onstage, move both at the same time with a parent object, and reset to origin once your loop point is met.
Consider the following stage setup:
Stage ¬
0: MainTimeline:MovieClip ¬
0: Container:MovieClip ¬
0: img1:Bitmap
1: img2:Bitmap
Now moving container up, you'd just need to check that the looping second image reaches the origin point of the first image.
function onEnterFrame(e:Event):void {
Container.y = Container.y - 5;
if (Container.y < -5000) {
Container.y = -5;
}
}

make visual clone of displayObject that's nested within other displayObjects, and add the clone to the stage layer in the same location, rotation, etc

I want to be able to grab a copy of a DisplayObject that is nested within other transformed DisplayObjects (rotated, scaled, stretched objects), and be able to stamp it back into the same visual location, but on the stage layer. Essentially, being able to make a clone of a nested DisplayObject, but be able to add the clone to the stage layer, yet have it perfectly align (visually) with the original (same position, scale, rotation)
I have been working with something along the lines of:
// draw the pixels of a displayobject into a new bitmap object
var bitmapData:BitmapData = new BitmapData(nestedSprite.width, nestedSprite.height, true, 0xFFFFFF);
var bitmap:Bitmap = new Bitmap(bitmapData);
bitmapData.draw(nestedSprite);
// put the copy on the top most layer
stage.addChild(bitmap);
// position the copy to perfectly overlay the original, but on the top stage layer
var point:Point = nestedSprite.localToGlobal(new Point(0, 0));
bitmap.x = point.x;
bitmap.y = point.y;
But this only works well for displayObjects whose parents are not transformed; and for displayObjetcs that are perectly at the (0,0) origin. It falls apart for centered aligned objects or scaled parents, etc.
I am aware that I can add a matrix param to the .draw() method, as well as a clipping rectngle, and scale my bitmap afterwards, or setting the transform of one object to another, or use .transform.concatenatedMatrix, or use nestedObject.getBounds(null), or nestedSprite.getBounds(nestedSprite), etc. But I have unfortunately fallen into doing trial and error programming on this one, and with some many variables, this is never a good way to solve a programming problem.
I believe this function should work, the only extra step was offsetting the concatenated matrix so that the target would draw with its top left at (0, 0) on the Bitmap even if its origin was somewhere else. Hopefully the rest is self explanatory, but I can add more comments if anything doesn't make sense.
function createBitmapClone(target:DisplayObject):Bitmap {
var targetTransform:Matrix = target.transform.concatenatedMatrix;
var targetGlobalBounds:Rectangle = target.getBounds(target.stage);
var targetGlobalPos:Point = target.localToGlobal(new Point());
// Calculate difference between target origin and top left.
var targetOriginOffset:Point = new Point(targetGlobalPos.x - targetGlobalBounds.left, targetGlobalPos.y - targetGlobalBounds.top);
// Move transform matrix so that top left of target will be at (0, 0).
targetTransform.tx = targetOriginOffset.x;
targetTransform.ty = targetOriginOffset.y;
var cloneData:BitmapData = new BitmapData(targetGlobalBounds.width, targetGlobalBounds.height, true, 0x00000000);
cloneData.draw(target, targetTransform);
var clone:Bitmap = new Bitmap(cloneData);
// Move clone to target's global position, minus the origin offset.
clone.x = targetGlobalPos.x - targetOriginOffset.x;
clone.y = targetGlobalPos.y - targetOriginOffset.y;
return clone;
}
Unfortunately, pixelBounds seems to return an origin of (0, 0) if there are any filters on the DisplayObjects, which obviously breaks things.
Edit: Replaced target.transform.pixelBounds with target.getBounds(target.stage) as a slight improvement. This keeps the position correct if there are filters, but filters on parent DisplayObjects still won't be included, and filters on the target can overlap the edges of the Bitmap. I'm not sure if there's a simple way to work around that.
Update: Jimmi Heiserman spotted that this function is broken if the swf is scaled. Without stage.scaleMode = StageScaleMode.NO_SCALE; though, the stageWidth and stageHeight parameters seem to stay unchanged, so the only (rather hacky) workaround I've found is to add an "unscaled" test Sprite and use its concatenatedMatrix to adjust the clone's position and scale:
function createScaledBitmapClone(target:DisplayObject):Bitmap {
var targetTransform:Matrix = target.transform.concatenatedMatrix;
var targetGlobalBounds:Rectangle = target.getBounds(target.stage);
var targetGlobalPos:Point = target.localToGlobal(new Point());
// Calculate difference between target origin and top left.
var targetOriginOffset:Point = new Point(targetGlobalPos.x - targetGlobalBounds.left, targetGlobalPos.y - targetGlobalBounds.top);
// Create a test Sprite to check if the stage is scaled.
var testSprite:Sprite = new Sprite();
target.stage.addChild(testSprite);
var testMatrix:Matrix = testSprite.transform.concatenatedMatrix;
target.stage.removeChild(testSprite);
// Move transform matrix so that top left of target will be at (0, 0).
targetTransform.tx = targetOriginOffset.x * testMatrix.a;
targetTransform.ty = targetOriginOffset.y * testMatrix.d;
var cloneData:BitmapData = new BitmapData(targetGlobalBounds.width * testMatrix.a, targetGlobalBounds.height * testMatrix.d, true, 0x00000000);
cloneData.draw(target, targetTransform);
var clone:Bitmap = new Bitmap(cloneData);
// Move clone to target's global position, minus the origin offset, and cancel out stage scaling.
clone.x = targetGlobalPos.x - targetOriginOffset.x;
clone.y = targetGlobalPos.y - targetOriginOffset.y;
clone.scaleX = 1 / testMatrix.a;
clone.scaleY = 1 / testMatrix.d;
return clone;
}
Have you tried passing the parents transform into draw? draw takes a transform matrix as the second param.
If you have a handle on the parent you can use something like this
bitmapData.draw(nestedSprite, parent.transform.matrix);

Why scrollRect only effects in the next frame?

running this code
var sp:Sprite = new Sprite();
sp.graphics.beginFill(0xff);
sp.graphics.drawRect(0,0,400,400);
sp.graphics.endFill();
sp.scrollRect = new Rectangle(0,0,350,350);
addChild(sp);
var count:int = 0;
var f:Function = function(...args):void{
trace(count++,sp.width,sp.height);
if(count>5){
removeEventListener(Event.ENTER_FRAME,f);
}
}
addEventListener(Event.ENTER_FRAME,f);
get
0 400 400
1 350 350
2 350 350
3 350 350
4 350 350
5 350 350
is there anyway i can made the scrollRect work at the first frame?
I just checked, and its probably because of some internal rendering stuff in Flash Player (it actually takes two frames to get the real dimensions, the current one, and the one after). Visually the rectangle doesn't change sizes, so it's only the values of the object's bounds that are updated two frames later (you can easily prove this by setting a very low framerate, like 1 FPS).
One workaround is to force a "hard" rendering pass by drawing the stage to a 1x1 BitmapData... this will effectively update the entire display list, and those values should be correct immediately after the draw() call. So your code would look like this:
var sp:Sprite = new Sprite();
sp.graphics.beginFill(0xff);
sp.graphics.drawRect(0,0,400,400);
sp.graphics.endFill();
sp.scrollRect = new Rectangle(0,0,350,350);
addChild(sp);
var count:int = 0;
function f(event:Event = null):void{
new BitmapData(1,1).draw(stage);
trace(count++,sp.width,sp.height);
if(count>5){
removeEventListener(Event.ENTER_FRAME,f);
}
}
addEventListener(Event.ENTER_FRAME,f);
f();
(Note that I changed the way you declared the function, as this is the preferred way among most (if not all) Flash developers.)
You could do the draw call only once after adding the object to the stage, but I don't know how safe it would be if the object changes.