Scale up and down layer

[Bruto]

Hi all,

a bit late on the boat! I'm going to port 3 commercial games to iphone/ipad so hopefully this will give more to show on Clickteam's iphone portfolio.

So I've spent the past few days doing the homework, reading past discussions, bugs, fixes, iOS documentation available on Apple and on the installer and also playing with files uploaded here. However I could not find answer to this:

How to I scale up and down an entire layer with "pinching" gesture? I've found a nice example but it was using an object only. Is it currently possible?

Thanks

[Francois]

There is no easy way of doing this. You have to detect the gesture using the Multiple touch object, and then set the zoom factor of all the objects of the layer manually.

[RhysD]

Might be able to use the viewport object if it ever gets ported

[Anders]

Viewport object is a software-only effect (though it could work in compatibility mode with HWA but very slow)

It would not benefit iOS games at all.

[Bruto]

I see a few problems with a non automatic way of zooming an entire layer.. perhaps we can work it out.

1)No background image, just actives.. perhaps this will give performance issue (a big active object as background)?

1) the biggest problem is that objects always scale up in their own axis (hot spot). See image attached. The zoom would look very messed up this way. So, would be at all possible to select a group.good (like all objects to be scaled in a layer) and center their hotspot so the zoom in happens as it should? I'm open to suggestions because there is no way to release hidden object games in iphone if people can't zoom in to see it.

Thanks

[Bruto]

An idea... would be possible an extension, action or anything that pick up all objects in a group and set their hotspot according to an object? Just the way set position relative to another object works, but with hotspots and automatic?

edit: no I don't think this would work the way I thought. hopefully this image will clear it out.


Uploaded with ImageShack.us

edit2: If Francois or Andos could check out this game:

PuppetShow: Mystery of Joyville

when you enter a hidden object scene it shows you can zoom in certain areas back and forth.

[Bruto]

Here is my reference.. as you can see, user can pinch specific areas, zoom in and out
http://youtu.be/5W4ZS5AJW9g

This is the best I could achieve so far... with original file from AndyH and drag and drop help from Andos

http://www.brutomemo.com/temp/pinch_scale_TEST_group.mfa

I'm having trouble to keep background image and grouped images as whole and centered while navigating/pinching back and forth.. anyone can please help?

Many thanks


edit: Andos, by the way.. the compatibility mode between Viweport object and HWA, on iOS would be terribly slow? Even slower than scaling up a huge background images and about 30 small objects attached to it?

[UrbanMonk]

Yes you'll have to move the objects too.

You'll need some trig.

When the user places their 2nd finger on the screen calculate the distance between their fingers and calculate the mid-point between.

Then calculate the distance and angle between all the objects to be scaled and the mid-point.

Then just use trig to reposition the objects as the screen is scaled.

so the X of each object would be: cos(angleFromMidpoint)*scaleFactor
the Y: sin(angleFromMidpoint)*scaleFactor


This method will unfortunately lag if you have too many objects, but it's the best I could come up with.

[Bruto]

Thanks Urbanmonk.. I'm trying this with a fresh start.. I'll let you know if a doubt arises

[Bruto]

apparently the red object is stuck in the upper left corner with this formula. I had an example of angle between objects, still trying to find it but tests with fixed angle is making the object stuck. Would you mind tweaking that file uploaded?