I have a strange problem. I have a two sprites that are added to other Sprite and I, with localToGlobal(), get their global x,y coordinates, but when I add another movieclip and try to move them to "global" coordinates on ENTER_FRAME event, they are locked on 0,0 of the stage??
I have traced coords and they are correct but no positioning... Why?
var point:Point = new Point();
addChild(pl_name);
pl_name.addEventListener(Event.ENTER_FRAME, mov);
function mov(e:Event):void
{
for (var i in players)
{
var gglobal:Point = players[i].localToGlobal(point);
pl_name.x = gglobal.x;
pl_name.y = gglobal.y;
trace ("nameX "+pl_name.x+" nameY "+pl_name.y);
}
}
The point you are giving it isnt set to anything before it is used. Try this.
point.x = players[i].x;
point.y = players[i].y;
var gglobal:Point = players[i].localToGlobal(point);
Related
It seems that if a display object has a perspective projection applied to it, calling localToGlobal gives you the wrong coordinates. In the following code, I draw a rectangle, rotate it slightly about its X axis, then draw an oval inside it using coordinates derived from localToGlobal. It works fine, until I try to apply a perspective projection, then the coordinates are all wrong. Anyone know how to get around this problem?
var w:uint = 300, h:uint = 150;
var s:Sprite = new Sprite();
s.graphics.beginFill(0x000000);
s.graphics.drawRect(-w/2,0,w,h);
s.graphics.endFill();
s.x = 275; s.y = 200; s.z = 600;
s.rotationX = -45;
addChild(s);
var point00:Point = new Point(0,0);
var point0h:Point = new Point(0,h);
var midL:Point = new Point(-w/2,h/2);
var midR:Point = new Point(w/2,h/2);
/*var VP:PerspectiveProjection = new PerspectiveProjection();
VP.fieldOfView = 55;
var p:Point = new Point(275,100);
VP.projectionCenter = p;
s.transform.perspectiveProjection = VP;*/
var o:Shape = new Shape();
o.graphics.beginFill(0x00ff00);
o.graphics.drawEllipse(
s.localToGlobal(midL).x,
s.localToGlobal(point00).y,
s.localToGlobal(midR).x - s.localToGlobal(midL).x,
s.localToGlobal(point0h).y - s.localToGlobal(point00).y
);
addChild(o);
It seems that setting perspectiveProjection does not force the player to redraw the object, and localToGlobal depends on redraw for correct results. You can wait 1 tick like you found (setTimeout for 0ms or enterFrame for 1 frame will do it) or you can force the player to redraw using BitmapData/draw():
// ...
s.transform.perspectiveProjection = VP;
new BitmapData(1, 1).draw(s); // forces player to redraw the sprite
var o:Shape = new Shape();
o.graphics.beginFill(0x00ff00);
o.graphics.drawEllipse(
s.localToGlobal(midL).x,
s.localToGlobal(point00).y,
s.localToGlobal(midR).x - s.localToGlobal(midL).x,
s.localToGlobal(point0h).y - s.localToGlobal(point00).y
);
addChild(o);
I found a workaround that isn't terrible. All you have to do is put a slight delay before the localToGlobal calls and then they will return the right coordinates. That also fixes local3DToGlobal.
I'm having trouble with AS3 which I have to use for a little research project of mine.
The AS3 project would create a number of randomly placed squares which all would rotate around its center point.
I managed to figure out how to rotate it internally using this handy walkthrough.
However I am having trouble applying this method to all squares which were created in a for loop with randomly selected stage points. Only the first created will rotate
Here is the code in question:-
for(var i=0; i<10; i++)
{
var square:Shape = new Shape();
this.addChild(square);
var posX = Math.floor(Math.random() * stage.stageWidth) + 50;
var posY = Math.floor(Math.random() * stage.stageHeight) + 50;
square.x=posX;
square.y=posY;
var curSquareAng:Number=0;
var squareRotCenter:Point=new Point(0,0);
drawShapes();
var squareMat:Matrix=square.transform.matrix.clone();
}
this.addEventListener(Event.ENTER_FRAME, onEnter);
function onEnter(e:Event):void {
curSquareAng = (curSquareAng+2)%360;
rotateSquare(curSquareAng);
}
function rotateSquare(deg:Number):void {
var mat:Matrix= squareMat.clone();
MatrixTransformer.rotateAroundInternalPoint(mat,squareRotCenter.x, squareRotCenter.y, deg);
square.transform.matrix = mat;
}
I realize I likely have to create an array for each of the squares initial center points and loop through them. However I am completely lost on how to do so. As you can likely tell I am unfamiliar with AS3 and would much appreciate any help you can give this beginner programmer. :P
You need to create your own class based on a shape, then you stuff it full of properties that represent rotation center point, current angle and whatever else you'd want your squares to contain, then give the class update method which will do what you wrote in onEnter function for itself only. Then you will have easier control over what your squares are able to do. This technique is called "encapsulation".
On a side note, if you're wanting your square to rotate around internal point of (0,0), you can set their rotation property to achieve the desired effect. For other points, the walkthrough or its equivalent should be used.
public class Square extends Shape {
public var rotationCenter:Point=new Point();
private var currentAngle:Number=0;
public var rotationSpeed:Number=2; // degrees per frame
private var baseMatrix:Matrix;
public function Square() {
// draw the shape on "this.graphics"
this.graphics.beginFill(0xffff00,1);
this.graphics.moveTo(-20,-20);
this.graphics.lineTo(20,-20);
this.graphics.lineTo(20,20);
this.graphics.lineTo(20,-20);
this.graphics.lineTo(-20,-20);
this.graphics.endFill();
// if not set in declaration, set internal vars
baseMatrix=this.transform.matrix; // likely identity matrix, but let's initialize anyway
}
public function storeMatrix():void {
// you are positioning a square after you create it, so probably you want its new location to be transformed
// that one's matrix will no longer be an identity, so go capture
baseMatrix=this.transform.matrix;
}
public function update():void {
// should be called once per frame
currentAngle=(currentAngle+rotationSpeed)%360;
var mat:Matrix= baseMatrix.clone();
MatrixTransformer.rotateAroundInternalPoint(mat,rotationCenter.x, rotationCenter.y, currentAngle);
this.transform.matrix = mat;
}
}
Now, you will have to maintain an array of squares to make them rotate separately:
var squares:Array=[];
for (var i:int=0;i<10;i++) {
var square:Square=new Square();
var posX = Math.floor(Math.random() * stage.stageWidth) + 50;
var posY = Math.floor(Math.random() * stage.stageHeight) + 50;
square.x=posX;
square.y=posY;
// after you position, give it a rotation point
square.rotationCenter.x=Math.random()*40-20;
square.rotationCenter.y=Math.random()*40-20; // -20 to 20, should do for this example
// now fix the position so your square will know that it should rotate
// its *current* transform matrix
square.storeMatrix();
// even if it's actually unchanged by changing X or Y
// also, should you desire to scale some square, you should do that prior to calling this
// now add the square to an array
squares.push(square);
}
addEventListener(Event.ENTER_FRAME,onEnter);
function onEnter(e:Event):void {
for (var i:int=0;i<squares.length;i++) squares[i].update();
// simple, isn't it? Each square will know what to do.
}
Nevermind. Thank you Vesper for putting me on the right track I've managed to solve my problem thanks to your input (not necessarily through your way but your input helped me get to the destination per say).
I think I was making it a little too complicated going though the matrix route and instead used a shape array to loop through the squares and add rotation. The solution I came to is a little simple but gets the job done.
public var rotationSpeed:Number=2; // degrees per frame
public var square:Array = new Array( );
public function Square() {
for (var i:int=0;i<10;i++) {
square[i] = new Shape();
var posX = Math.floor(Math.random() * stage.stageWidth) + 50;
var posY = Math.floor(Math.random() * stage.stageHeight) + 50;
square[i].graphics.lineStyle();
var rgb = Math.random() * 0xFFFFFF;
square[i].graphics.beginFill(rgb);
// -50 determines where the spin will center from.
square[i].graphics.drawRect(-50,-50,100,100);
square[i].graphics.endFill();
square[i].x = posX;
square[i].y = posY;
addChild(square[i]);
}
addEventListener(Event.ENTER_FRAME,onEnter);
}
private function onEnter(e:Event):void {
for (var i:int=0; i < square.length; i++) {
getChildAt(i).rotation += rotationSpeed;
}
}
var theTextField:TextField = new TextField();
var theText:TextField = new TextField();
theTextField.type = TextFieldType.INPUT;
theTextField.border = true;
theTextField.x = 50;
theTextField.y = 10;
theTextField.height = 20;
theTextField.multiline = true;
theTextField.wordWrap = true;
theText.border = false;
theText.x = 10;
theText.y = 10;
theText.text = "Angle";
addChild(theText);
addChild(theTextField);
submit.addEventListener(MouseEvent.CLICK, click_handler);
function click_handler(event:MouseEvent):void
{
var txt:String = theTextField.text;
ang = Number(txt);
if (ang<0)
{
angle = - ang;
}
else
{
angle = 360 - ang;
}
var circleSlider:CircleSlider=new CircleSlider(120,angle); //draw Circle According to the angle i think here is problem becoz every time clicked it creates new circle and draw over the old circle.
circleSlider.x = stage.stageWidth / 2;
circleSlider.y = stage.stageHeight / 2;
circleSlider.addEventListener(CircleSliderEvent.CHANGE, circleSliderEventHandler);
addChild(circleSlider);
}
Can someone help me.
var circleSlider:CircleSlider=new CircleSlider(120,angle);//draw Circle According to the angle i think here is problem becoz every time clicked it creates new circle and draw over the old circle.
this code is the problem. CircleSlider is a separate class.I tried like this
circleSlider.CircleSlider(120,angle);
but it gives an error "" Call to a possibly undefined method CircleSlider through a reference with static type CircleSlider.""
when i run the program and input value as 90.
then i enter another value as 180 then it becomes
how can i overcome this error
Every time your click handler is executed you're creating a new instance of your circle class and adding it to the stage without removing the old instance. I think the best way to resolve it would be to move the logic you have in the constructor of your CircleSlider class into a separate public method, say draw and call that in the click handler.
Your code would look something like this:
// Set up the circle once
var circleSlider = new CircleSlider();
circleSlider.x = stage.stageWidth / 2;
circleSlider.y = stage.stageHeight / 2;
circleSlider.addEventListener(CircleSliderEvent.CHANGE, circleSliderEventHandler);
// and add it to the stage once
addChild(circleSlider);
function click_handler(event:MouseEvent):void
{
var txt:String = theTextField.text;
ang = Number(txt);
if (ang<0)
{
angle = - ang;
}
else
{
angle = 360 - ang;
}
// Now simply redraw in the same circle instance
circleSlider.draw(120,angle); //draw Circle According to the angle i think here is problem becoz every time clicked it creates new circle and draw over the old circle.
}
Assuming you're using the drawing API to draw the graphic, you could draw the circle (which seems to be constant) in the constructor (once) and the line illustrating the angle in the draw method (repeatedly). You'll need to clear the old line each time like this:
// Assumes you're drawing in the graphics property of the class
this.graphics.clear();
I am using matrix.rotate method to rotate the rectangle (box in my case).
My rotate event looks like below
public function transformObject(transformEvent:TransformEvent):void{
var numChildrn:int = _markedObjectLayer.numChildren;
var tempMatrix: Matrix = null;
var tempx:Number;
var tempy:Number;
var tempHeight:Number;
var tempWidth:Number;
for(var i:int = 0; i < numChildrn; i++){
var chld:MarkedObject = ObjectLayer.getChildAt(i)
if (chld.selected){
var height:int = (BoxObject) chld.height;
var width:int = (BoxObject) chld.width;
tempMatrix = chld.transform.matrix;
tempHeight=height;
tempWidth=width;
tempMatrix = MatrixTransformer.transform(tempMatrix,transformEvent.angle);
tempMatrix.tx=tempx;
tempMatrix.ty=tempy
chld.transform.matrix = tempMatrix;
}
}
invalidateDisplayList();
}
}
The Matrix.transform method calls matrix.rotate method
public static function transform(sourceMatrix:Matrix,
rotation:Number=0 ):Matrix
{
sourceMatrix = MatrixTransformer.rotate(sourceMatrix, rotation, "degrees");
return sourceMatrix;
}
/**
* Rotates a matrix and returns the result. The unit parameter lets the user specify "degrees",
* "gradients", or "radians".
*/
public static function rotate(sourceMatrix:Matrix, angle:Number, unit:String = "radians"):Matrix {
if (unit == "degrees")
{
angle = Math.PI * 2 *( angle / 360);
}
sourceMatrix. rotate(angle)
return sourceMatrix;
}
The issue is that x and y are left corener of the box and hence it is rotating around left corner. However, if I try to give temp.x and temp.y as centroid value it does not rotate around centroid?
Can any one suggest what am I doing wrong here?
Thanks
Akshay
If you really want or have to use matrices directly, you can do this more conveniently using a built-in flash class: fl.motion.MatrixTransformer:
MatrixTransformer.rotateAroundInternalPoint(matrix, centroidX, centroidY, angleInDegrees);
See the Adobe docs on MatrixTransformer for more information.
However, if you don't need to use the transformation matrix, the simpler solution would be to:
have your objects drawn in such a way that (0, 0) is their centroid
use the simple rotation property from DisplayObject which achieves the same goal in a much simpler manner
Figured it out. It appears that I was not translating them to appropriate coordinate positions before and after rotation
//Step 1 Fix the co-ordinates of rectangle . I added them to an event so that they remain static
if (TransformEvent.X == 0 && TransformEvent.Y == 0)
{
TransformEvent.X = chld.x;
TransformEvent.Y = chld.y;
}
//next get the centroid of rectangle
tempx = TransformEvent.X + width/2;
tempy= TransformEvent.Y +height/2;
// Step 3: translate before rotation
tempMatrix.translate(-1*tempx,-1*tempy);
//Rotate the rectangle
tempMatrix = MatrixTransformer.transform(tempMatrix,transformEvent.angle);
//translate to centroid after rotation
tempMatrix.translate(tempx,tempy);
//assign back the matrix to the rectangle
chld.transform.matrix = tempMatrix;
Thanks for all your help. Also the this site helped me with translation bit
http://www.foxarc.com/blog/article/66.htm
I have a sprite that holds a bitmap data.
I want to give the user the ability to resize the image with a slider.
I am using the code beneath, as you can see the problem is that the scaling is additive so very quickly the image is gone totally.
I understand that i have to scale it in non additive way, just can not figure out how?
I tried to pass :
var m:Matrix = userImageCopy.transform.matrix;
when userImageCopy holds the original image. that helped for the scaling but then, each time the scaling started the userImage jumped to the position of the userImageCopy.
Any help?
function onSliderChange(evt:Event):void
{
trace( evt.target.value);
//this will create a point object at the center of the display object
var ptRotationPoint:Point = new Point(userImage.x + userImage.width / 2,userImage.y + userImage.height / 2);
//call the function and pass in the object to be rotated, the amount to scale X and Y (sx, sy), and the point object we created
scaleFromCenter(userImage, evt.target.value, evt.target.value, ptRotationPoint);
}
private function scaleFromCenter(ob:*, sx:Number, sy:Number, ptScalePoint:Point)
{
var m:Matrix = userImage.transform.matrix;
m.tx -= ptScalePoint.x;
m.ty -= ptScalePoint.y;
m.scale(sx, sy);
m.tx += ptScalePoint.x;
m.ty += ptScalePoint.y;
ob.transform.matrix = m;
}
Rather than combining your center values with the current tx and ty, just set them directly with the Matrix.translate method:
private function scaleFromCenter(ob:*, sx:Number, sy:Number, ptScalePoint:Point)
{
var m:Matrix = new Matrix();
m.translate(-ptScalePoint.x,-ptScalePoint.y);
m.scale(sx, sy);
m.translate(ptScalePoint.x,ptScalePoint.y);
ob.transform.matrix = m;
}