math ?

LOL...this has become a quest...my last attempt was pretty buggy...look at this...

http://www.hotgreen3.com/Experiments/zoom2.swf

...main timeline...

Code:

---

MovieClip.prototype.zoom = function () {
if (_root.varZoom) {
this._xscale += 2;
this._yscale += 2;
_parent._xscale += 2;
_parent._yscale += 2;
_parent._x = _parent._x - this._x/25;
} else if (_root.varZoom == false) {
this._xscale -= 2;
this._yscale -= 2;
_parent._xscale -= 2;
_parent._yscale -= 2;
_parent._x = _parent._x + this._x/25;
}
}

---

...on each of the zoomMC's...

Code:

---

onClipEvent (load) {
        startPosX = this._width;
        pstartPosX = _parent._width;
        endPosX = this._width+200;
        pendPosX = _parent._width+200;
}
onClipEvent (enterFrame) {
        if (this.hitTest(_root._xmouse, _root._ymouse) && this._width<endPosX && _parent._width<pendPosX) {
                _root.varZoom = true;
                this.zoom();
        } else if (!this.hitTest(_root._xmouse, _root._ymouse) && this._width>=startPosX && _parent._width>=pstartPosX) {
                _root.varZoom = false;
                this.zoom();
        }
}

---

...I'm sure it could be refined more...but is the what you're trying to achieve?

-pg-

Yes, I would say that the dist_x and aX lines are similar results ...

Notice in the function call how I arrive at 'endx' and 'endy' ... this is similar to appointing a new point object in a localToGlobal code ... look back to my original example on this thread to see similar coding, where you must take into account the parent's position to find the actual stage position:

map.graphs.FloatTo(20,mcPointer._x-map._x,mcPointer._y-map._y);

// endx = mcPointer._x-map._x

this.dist_x = Math.round(endx - this._x);

Math.round is used to create an integer for further use with the decimal value for 'this.speed' in the multiplication to find vel_x, and it's use keeps the multiplication to a reasonable number of significant digits for the result (less processor-intense no doubt).

..edit..

It looks like pigghost's code is getting pretty close to what you need!

Richard
[Edited by Dickee on 08-28-2001 at 02:54 AM]

Dickee...LOL...I posted before I read your last post and I was just going to say yours looks like it's got some of the elements we're missing...need to study that one...

This is a tough one, GD...but I need to bail on you for tonight...good luck...I'll check tomorrow...let us know if you get it....

-pigghost-

BINGO!!!!!!
That is exactly it! You can put that on one zoomMC and change the position of the zoomMC and it scales and scrolls according to the zoomMC position. Nice work pg! It auto updates the _x position instead of manually having to set it with code. What is funny is, I am learning a bit about functions and I was going to use this to try to code it into a function, but you have done that already as well! lol Way cool! Use it with a 3d image to scale and you get a nice effect. I set it to work on mouseover, but you could call it a variety of ways. Put the "zoomMC" in another 2 frame MC(blank first frame) and turn the zoom on and off whenever you wanted, get timer to turn zoom on or off, buttons, position the "zoomMC" dynamically with code,lots of possibilities. Thx again for the brainwork pg and dickee! Thx again dickee for given me some good ideas and some nice codeing tips as well. Man, this post has turned to be really long one, but it was worth it! That is exactly what I had in my head.
Thanks again!!!

Regards!
~GD~

-edit-
Hm, now ya got me thinking about adding the _y position to the function as well. Does it ever end??? lol ;)

Thx again!!!
[Edited by grvdgr on 08-28-2001 at 03:58 AM]

GD...I think the refinement it needs is a reference to the centerpoint of the stage...the first obvious answer to me, is another mc...but a point the zoomMC can always center on...and sure, you need the _y position...

If I get a chance today I'll take another look at it...

...and yes get into functions...and when you're comfortable with them...move into prototypes...I just started playing around with them in the last couple of weeks....they will definitely change the way you look at things...

Take care...and Dickee thanks for sharing the codes...I need to file those away for reference.... ;)

EDIT: I just picked up my handy copy of ASDG by Moock and localToGlobal() is exactly what we need...as Dickee pointed out soooo many posts ago....if there's a hard way, I'll find it...LOL...later.
-pg-
[Edited by pigghost on 08-28-2001 at 10:00 AM]

Hello again,
I have been testing that function with a few different actions(buttons, onclipEvent, mouseover, and conditional if statements) It seems to work quite well. I do see that it could be refined a bit now. It could be centered better on the zoomMC for one thing. I looked up localToGlobal and I understand what your talking about now. That does seem to be the way to go. It looks as if you could achieve the same zoom appearance without the "zoomMC" but with the _xmouse and _ymouse coordinates, that would make it even more dynamic. You would be able to zoom wherever the mousecordinates are. That would save steps over having to place the "zoomMC" as you could specify it to occur when the mouse reached a certain position as opposed to a mouseOver on a MC. That would also deal with the "chopiness" you get if you mouseover the edge of the "zoomMC". I tried using the example in the reference guide for localToGlobal with the code I had before the function was posted with no success. I am unsure of how your function works completly, so I haven't tried adding localToGlobal to that.
Also, I have been studying that function. I know I have asked alot from this post, but could explain "prototype" a bit?

Thx again
~GD~

The basic difference between a regular function and a prototype ... a regular function is a user-defined set of statements that are invoked with a direct call to the function name, with or without arguments, and with attention to the scope ... if the function occupies frame 1 of the main timeline, you need to refer to it through the object heirarchy ( eg. _parent.FunctionName(args1,args2,,,argsN) {//statements}; ).

The following function defines a Circle object:

function Circle(radius) {
this.radius = radius;
}

// usage:
myCircleRadius = _root.Circle(150);

A prototype is a property which is included as a method of the general object ... eg. an anonymous function ... if your prototype is occupying frame 1 of the main timeline, to invoke the function, you call it as a method of the object ... eg. MovieClip.myFunction(); (again, with or without arguments).

The following statement defines an anonymous function that calculates the area of a circle and attaches it to the object Circle as a method:

Circle.prototype.area = function () {return Math.PI * this.radius * this.radius};

// usage:
myCircle.area();

A quote from the Actionscript Reference:

Quote:

---

Creating inheritance

All functions have a prototype property that is created automatically when the function is defined. When you use a constructor function to create a new object, all the properties and methods of the constructor's prototype property become properties and methods of the __proto__ property of the new object. The prototype property indicates the default property values for objects created with that function. Passing values using the __proto__ and prototype properties is called inheritance.

Inheritance proceeds according to a definite hierarchy. When you call an object's property or method, ActionScript looks at the object to see if such an element exists. If it doesn't exist, ActionScript looks at the object's __proto__ property for the information (object.__proto__). If the called property is not a property of the object's __proto__ object, ActionScript looks at object.__proto__.__proto__.

---

Here's Colin Moock's 2 functions that pigghost referred to from his global-local-wrapper.fla, found at the asdg CodeDepot:

http://www.moock.org/asdg/

Code:

---

function toLocal(clip, x, y) {
    var point = new Object();
    point.x = x;
    point.y = y;
    clip.globalToLocal(point);
    return [point.x, point.y];
}

function toGlobal(clip, x, y) {
    var point = new Object();
    point.x = x;
    point.y = y;
    clip.localToGlobal(point);
    return [point.x, point.y];
}

---

I posted these links at were-here some time ago, so I'll just paste it in:

Checkout andya's tutorial ... Functions for Beginners:

http://www.armisteadtanner.ws/functions_beginners.html

... and his advanced tutorial for use of functions ... Recursive Functions:

http://www.armisteadtanner.ws/Recursive_Functions.html

Then checkout this link for using prototype by Branden Hall:

http://chattyfig.figleaf.com/ff2k/sanfran2001/

Checkout this great page on Object Inheritance from Dave Yang of Quantumwave Interactive:

http://quantumwave.com/html/flash5_inheritance.html

Then checkout my example using prototype in a real application ... Matrix Multiplication on page 12 of this thread ... More Flash 5 functions (oh, and don't forget to read everything in the thread ... have you got an extra week?) ... also, page 11 has a download from cyberfunk utilizing the prototypes that he has provided on the thread:

http://www.were-here.com/forums/show...&pagenumber=12

And checkout the multitude of prototype functions at the layer51 database:

http://www.layer51.com/proto/

Richard
[Edited by Dickee on 09-04-2001 at 06:04 PM]

I don't think there's anything I could add...:) Dickee is the man when you need information....

I didn't really get back to the "zoom" thing today...and the "localToGlobal" looks like it will take some serious concentration....I think...

Take care...

-pg-

Thx Richard!

This post just turned into a gold mine! Excellent explanation! Even answered a couple general questions I had about functions. Also, A wealth of information to study!

Thank you very much!

Regards!

~GD~

grvdgr

can you show us what your final looks like, and how you ultimately codded it?? I have been following this post with great attention. . .

thanks
Darin

I post one example for mouse click at any place. This may serve as an example for usage of localToGlobal function.

http://www.geocities.com/~dr_ericlin/aaa/rootZoom2.html
http://www.geocities.com/~dr_ericlin/aaa/rootZoom2.fla

ericlin...the Master! Straight to the heart of the problem...with the least amount of code...I envy your skills, sir.

...but it always takes me a while to figure out exactly what you've done... ;)
Take care...
-pg-

Yes,
that is amazing! Still trying to get my head around the basics of what will make it all work, look up, and you have it done. Although, mine should be worth more, it has about 5 times as much code! Then again, it doesn't work, lol.

Thx to pigghost and dickee for the time you all spent on this and the helpful info you passed on! And to ericlin for the localToGlobal example and to the point codeing.

Darin, I really didn't have any dynamic project for all this. I was just trying to get a better grasp of a horizontal scroll and it snowballed into this, lol. Went from horizontal to vertical to scale to dynamic scale, just followed along as it kind of took me. pigghost posted a function for it, which I have been studying latly as well, and that led me to discover "prototype". Which "dickee" posted some great info! The thread on his site is excellent! 21 pages! But excellent!
Some of the things I picked up from this thread I will be studying for some time, no doubt, but here is a demo of some of the things this thread was about. Well, til the end, I haven't incorporated ericlins version into it all yet, have to study it for awhile first, but most of it is in this demo.
This will eventually be a redesign of my site. Kind of buggy in spots right now, but works well enough for now.
*Keep in mind*
There are no preloaders at work, a couple of the files are around 500k.......
The intro needs redone, got too much stuff flyin around and the actionscript archive gets bogged down when you cycle through the windows too fast. Well, lots of bugs at the moment! lol All just a test right now. Also using another one of ericlins creations there! The textfield in the "virtual cave" that resizes based on input is straight from him!
K, now if any of you big dogs look at this, comments most welcome!!! I would love to get into developing professionally, and after talking with some of the folks here, I realize I have a long way to go.
Demo........
http://caveart.tv/siteredo/Intro.swf

Thx again for all the help and info!!!
Regards!
~GD~

Hi pigghost

Thanks.

I add some comments and changed the names of variables.

Hey thanks, ericlin...there were a couple of things I wasn't sure of...now it all makes perfect sense...thanks for taking the time....

-pg-

Hello again,
Another question. Well, a couple actually. I am trying to understand ericlin's code. I get most of it, but there are a couple things that I don't understand. I tried to break it down a bit, forgive my comments, they might be confusing, they are to me, .....

Code:

---

onClipEvent (mouseDown) {
    if (k>0) {  //  if variable "k" greater than 0
        return;  // return the value of the mouseclick position
    }
    zoom = true;  // set zoom to true
    dir == 1 ? (dir=-1) : (dir=1);// strange conditional statement I can't seem to find out much about.
    if (dir == 1) {// if direction is equal to zoom in
        pt = {x:_root._xmouse, y:_root._ymouse};// variable "pt" is equal to mouse position
    }
}
onClipEvent (enterFrame) {
    if (!zoom) {// if not zooming
        return; // return value
    }
    _root._xscale += dir*k*50/8;// the actual zoom in or out depending on "dir" (set with the conditional statement)  times variable "k" times 50 divided by 8
    _root._yscale += dir*k*50/8; 
    var pt2 = {x:pt.x, y:pt.y};//variable pt2  x  ":" is this another conditional?  x is conditional to pt.x and y is conditional to pt.y?
    _root.localToGlobal(pt2);// taking the arguement of pt2 and assigning it to Global?
    _root._x -= (pt2.x-pt.x);//  assigning _root._x "-"(zoomout) to the Global x mouse position - the clicked _x mouse position
    _root._y -= (pt2.y-pt.y);// assigning the _root._y "-" (zoomout) to the Global y mouse position - the clicked _y mouse position
    k++; // variable k increment
    if (k == 8) {// if...
        zoom = false;// set zoom false
        k = 0;  // reset k
    }
}

---

The main things I am finding confusing is the conditional statements,
dir == 1 ? (dir=-1) : (dir=1);
and the ":" in ...var pt2 = {x:pt.x, y:pt.y};

the actual math involved.....
dir*k*50/8; I understand "dir" sets + or - ( basically zoom in or out) and variable "k" is the incremental value of the scale, that scale is basically in 8 sections (k = 1 thru 8) so it is all divided by 8. Why 50? and what exactly does this number represent? Pigghosts function used 200 and this scales more. 200 doesn't work at 50/8 unless it is the combination of parent.width + this.width? Maybe just getting confused looking at both codes.
Any thoughts?

GD


Also, what about limiting the zoom to a portion of the stage ( only allow zoom on certain coordinates) A basic "if" statement? If _x_mouse = 100 zoom == "true" else zoom == "false" something like that?

P.S. Thx again dickee! that is an incredible thread! and links to things I had never seen before!
[Edited by grvdgr on 08-29-2001 at 07:15 PM]

Hi grvdgr

I add my comments, you can download that new file again.

dir == 1 ? (dir=-1) : (dir=1);

If dir is positive , change it to negative. If dir is negative or not defined, dir is positive.

var pt2 = {x:pt.x, y:pt.y};

{} is an object initializer.
var pt2=new Object;
pt2.x=pt.x;
pt2.y=pt.y;
localToGlobal function will change the parameter value permanently and we will lost the data we stored on click. So I copies one and preserve the original.

dir*k*50/8;

Sorry It's my mistake. The correct codes should be
_root._xscale+=dir*50/8. Omit the k;
I want to zoom from xscale 100 to 150 in 8 steps. So each step should increase the xscale value by 50/8.

About limiting the zoom to a portion of the stage ( only allow zoom on certain coordinates) , you can add coordinate limitation (Math.abs(_xmouse-100)<10) etc or make invisible blank movieClip then use hitTest to define mouse click sensitive region. Then set zoom to true or false.

Thx ericlin!

I understand now. I had not seen that ?: conditional before, plus "I want to zoom from xscale 100 to 150 in 8 steps." helped me understand alot! I'm sure you prob already know of this site that dickee posted, but with your talent, it seems like it would be right in line for you..........

http://www.were-here.com/forums/show...8&pagenumber=1

There is a prototype site from there. I have learned more there in the last couple hours than I have in the last week digging through my books. Thx again for the explanation.

~GD~