AS3 : Scaling Sprite with Matrix on slider change? - actionscript-3

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;
}

Related

as3 - converting bitmap back to vector in view

So I found a V-CAM source, I am now using it and quite happy however, is it possible to untoggled bitmap when the objects that are bitmapped are viewed by the cam? For instance, lets say I have a vector movieclip with a bunch of vector art, I toggle export as bitmap on the movieclip from my IDE, now would it be possible to add on to my VCAM, that everything in its view (it resizes stage) untoggles or redraws back to vector, while the rest of map/movieclip is still in bitmap? And as the VCAM moves away, what was shifted from bitmap to vector gets shifted back to bitmap?
var camColor: ColorTransform = new ColorTransform();
var parentColor: ColorTransform = new ColorTransform();
var cX: Number;
var cY: Number;
var sX: Number;
var sY: Number;
this.visible = false;
var oldMode: String = stage.scaleMode;
stage.scaleMode = StageScaleMode.EXACT_FIT;
cX = stage.stageWidth / 2;
cY = stage.stageHeight / 2;
sX = stage.stageWidth;
sY = stage.stageHeight;
stage.scaleMode = oldMode;
camColor = this.transform.colorTransform;
parentColor = this.parent.transform.colorTransform;
camControl(new Event(Event.ENTER_FRAME));
addEventListener(Event.ENTER_FRAME, camControl);
addEventListener(Event.REMOVED, resetStage);
function camControl(event: Event): void {
camColor = this.transform.colorTransform;
parent.transform.colorTransform = camColor;
var xScale: Number = sX / this.width;
var yScale: Number = sY / this.height;
parent.x = cX - (this.x * xScale);
parent.y = cY - (this.y * yScale);
parent.scaleX = xScale;
parent.scaleY = yScale;
}
function resetStage(event: Event): void {
removeEventListener(Event.ENTER_FRAME, camControl);
parent.transform.colorTransform = parentColor;
parent.scaleX = 1;
parent.scaleY = 1;
parent.x = 0;
parent.y = 0;
}
I think you'd better use another camera with higher bitmap dimensions (2x-4x) to render those scenes from vector that you feel are too pixelized. In terms of export, just export the character's bitmaps 2x-4x larger, or you can just have it as a vector somewhere in your app, maybe hidden, and do realtime render when needed, or plain have it in your display list as a vector and not a bitmap.
In case you need to have some complex vector form into a bitmap-based engine, you can use realtime bitmap drawing of a single source in various postures/rotations, then use those rendered bitmaps to get performance. Check the game "Enigmata: Stellar War" for this technique, how does it look in the process (hint: when it says "Loading boss" it does all the render behind the scenes).
Getting a vectorized source form bitmaps is a lot more processor consuming than having a ready-made vectorized source stored somewhere. Also you won't get your original vector restored in exact form, as converting a vector to a bitmap is a lossy transformation.

How to create smooth motion for a mouse follower along a predefined path?

I want to make a tracing game. I want my circle to follow the path as the user traces the letter (path of the letter). The user can not go back to the area which is already traced
import flash.events.Event;
import flash.geom.Point;
var i: Number;
var size: int = 80;
var down: Boolean = false;
var up: Boolean = true;
var inside: Boolean = true;
var outside: Boolean = true;
var circle: Shape = new Shape();
stage.addEventListener(Event.ENTER_FRAME, loop);
stage.addEventListener(MouseEvent.MOUSE_UP, mouseup);
char.addEventListener(MouseEvent.MOUSE_DOWN, mousedown);
function loop(e: Event) {
if (down == true) {
// Checks if mouse pointer is on path i.e 'S' alphabet
if (s.hitTestPoint(stage.mouseX, stage.mouseY, true)) {
inside = true;
outside = true;
var point: Point = maskobj.globalToLocal(new Point(stage.mouseX, stage.mouseY));
var point2: Point = new Point();
//Checks if mouse pointer is completely outside of drawn area
for (i = 0; i < 2 * Math.PI; i += (2 * Math.PI) / 10) {
point2.x = stage.mouseX + (size / 3) * Math.cos(i);
point2.y = stage.mouseY + (size / 3) * Math.sin(i);
if ((maskobj.hitTestPoint(point2.x, point2.y, true))) {
outside = false;
break;
}
}
//Checks if mouse pointer is completely inside drawn area
for (i = 0; i < 2 * Math.PI; i += (2 * Math.PI) / 10) {
point2.x = stage.mouseX + (size / 3) * Math.cos(i);
point2.y = stage.mouseY + (size / 3) * Math.sin(i);
if (!(maskobj.hitTestPoint(point2.x, point2.y, true))) {
inside = false;
break;
}
}
//Character will be moved only if mouse position not to far from current position
if (outside == false) {
if (inside == false) {
//Increases drawn area by drawing a circle shape in 'maskobj' MovieClip
circle.graphics.beginFill(0x0000ff);
circle.graphics.drawCircle(point.x, point.y, size);
circle.graphics.endFill();
maskobj.addChild(circle);
//Moves character to new position
char.x = stage.mouseX;
char.y = stage.mouseY;
}
}
}
}
}
function mouseup(e: MouseEvent): void {
up = true;
down = false;
}
function mousedown(e: MouseEvent): void {
down = true;
up = false;
}
When I trace the path,the motion is not smooth. Can someone please suggest a way to make the motion smooth OR suggest another way to achieve the same. Thank you in advance.
I've created a drawing game before that allowed the user to draw a path.
Not sure why Wicked's answer was down-voted, as the first thing you need to do is to use the highest frame rate that you can get away with. The higher the frame rate, the smoother your curve.
I see that your code draws a circle at the current position if the conditions are met. It might be better to draw a line from the last point.x/point.y to the current one instead of just a circle, so that you don't have any holes in your path.
I couldn't get around the fact that the line was jagged (a series of straight lines) as it was being drawn, but as soon as the user lifted their finger I was able to take the points along the line they had drawn and replace them with a smooth bezier Path (a series of simple bezier curves), which worked well. You could also do this on-the-fly once you have 3 points (you need 3 points to draw a curve).
Here is a good reference on how to achieve this, with theory and code samples. See further down the page for bezier paths. You'll need to convert to AS3, but it shouldn't be difficult.
Another tip is to do as little calculation as possible within the ENTER_FRAME. You could pre-calculate the two values used by your loops (2 * Math.PI) and ((2 * Math.PI) / 10) as these are constants. You could also calculate (size/3) once at the top of the function, and especially pre-calculate the 10 values for Math.sin(i) and Math.cos(i) and store them in an Array (basically a LUT - Look Up Table) as these are the heaviest math ops you're doing.
My final tip is that your code doesn't check if the point being drawn is very close to the last point that was drawn. I would recommend you do this, and only draw a point after the mouse has moved a minimum distance (e.g. 2 pixels). Otherwise you could get the mouse sitting still in one spot and your code is drawing circle upon circle on top of itself needlessly.
Try increasing the FPS in your document to atleast double what you currently have
Modify>Document...>Frame Rate

Actionscript 3: Rotate multiple shapes around internal point

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;
}
}

over drawn the circle when input angle in actionscript?

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();

How to rotate a rectangle around centroid in flex 3

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