Android Question LibGDX TransparentView vs. BringToFront

[wonder]

Bonjour!!

Here's the situation, if I have a regular button / label / textbox at (for example) the center on the screen and non-visible LibGDX surface below, the behavior is as follows:

Sub myButton_Click
    'Toggle LibGDX visibility on and off
    lGdxSurface.Visible = (lGdxSurface.Visible == False)
    'Display the button on top
    myButton.BringToFront
End Sub

With a non-transparent view lGdxSurface.InitializeView2(Config, "LG")
- No problem, it behaves as expected

With a transparent view lGdxSurface.InitializeTransparentView(Config, "LG")
- The button will stay behind, BringToFront just doesn't work.

Additional notes:
- I tried myButton.BringToFront with CallSubUI as well, no success.
- Initializing in a certain order (libGDX before Button) doesn't work either, plus even if it did, it's not the solution I'm looking for.

Attached, the best solution I could come-up with.

 

[Informatix]

You should read the help text of the InitializeTransparentView function:

This function has to be called in Activity_Create. It sets up all the things necessary to get input, render via OpenGL and so on, with the specified configuration. It returns the created view.
The created view is always over the activity contents and may be transparent if glClearColor has alpha < 1.

 

[wonder]

Ahh.. Sorry, I've missed it.
Anyway, is it possible to override that "always on top" characteristic?

 

[Informatix]

Ahh.. Sorry, I've missed it.
Anyway, is it possible to override that "always on top" characteristic?

The goal of InitializeTransparentView is to create a transparent surface above the other views, so trying to move it behind is a bit strange. If you want the libGDX surface to be behind, call InitializeView not InitializeTransparentView.

 

[wonder]

so trying to move it behind is a bit strange

Not at all.

Take this picture, for example:

The vase is opaque, the window is transparent and the background is opaque.
If I took a black marker, I could draw a smiley on the window glass.

Imagining the LibGDX transparent view as this window's glass surface, it does make perfect sense to have a transparent view between 2 others (opaque or not).

 

[Informatix]

Not at all.

Take this picture, for example:

The vase is opaque, the window is transparent and the background is opaque.
If I took a black marker, I could draw a smiley on the window glass.

Imagining the LibGDX transparent view as this window's glass surface, it does make perfect sense to have a transparent view between 2 others (opaque or not).

AFAIK, a surface is always behind or above the window holding the views, so what you want is not possible.
Anyway, why don't you draw everything on the libGDX surface? What views are supposed to be in PanelA and PanelB?

 

[wonder]

I'm trying to emulate the iOS blur effect with LibGDX shaders... I got some positive results already....

 

[Informatix]

I'm trying to emulate the iOS blur effect with LibGDX shaders... I got some positive results already....

There's a simpler way with RenderScript and someone posted the code to do that if I remember well.

 

[wonder]

Oh well, if it's already done, there's no point in perusing this project any further.

Nevertheless, it was a very nice learning experience!
Plus, in the end, I got it working with a non-transparent surface.

My algo goes like this:
- Create a screenshot (bitmap) in memory (no saving)
- Bitmap --> Byte() --> Pixmap --> lgTexture
- Apply the Blur shadder and display the LibGDX surface (w/ continuous rendering: OFF)

Thanks for everything!

 

[Informatix]

Oh well, if it's already done, there's no point in perusing this project any further.

Nevertheless, it was a very nice learning experience!
Plus, in the end, I got it working with a non-transparent surface.

My algo goes like this:
- Create a screenshot (bitmap) in memory (no saving)
- Bitmap --> Byte() --> Pixmap --> lgTexture
- Apply the Blur shadder and display the LibGDX surface (w/ continuous rendering: OFF)

Thanks for everything!

Do you agree to share your code? It may be instructive.

 

[wonder]

Sure, I'll just need to do some clean-up before.
Right now it's really just "quick and dirty".

 

[wonder]

As promised, I've attached the project to the first post.

With LibGDX opaque view:
- I'm unable to eliminate the "flickering" that sometimes happens during the split-second the transition occurs.
- I'm able to use .BringToFront on the Blur button.

With LibGDX transparent view:
- I'm able to eliminate the "flickering" that sometimes happens during the split-second the transition occurs.
- I'm unable to use .BringToFront on the Blur button.

As a practical solution already exists, I won't be working on this anymore.
Nevertheless, please consider my request of allowing the LibGDX transparent surface to sit between views.

 

[Informatix]

As promised, I've attached the project to the first post.

With LibGDX opaque view:
- I'm unable to eliminate the "flickering" that sometimes happens during the split-second the transition occurs.
- I'm able to use .BringToFront on the Blur button.

With LibGDX transparent view:
- I'm able to eliminate the "flickering" that sometimes happens during the split-second the transition occurs.
- I'm unable to use .BringToFront on the Blur button.

As a practical solution already exists, I won't be working on this anymore.
Nevertheless, please consider my request of allowing the LibGDX transparent surface to sit between views.

Some files are missing (vertex, fragment, ...).

 

[wonder]

Sorry. Fixed and re-uploaded.

 

[Informatix]

Sorry. Fixed and re-uploaded.

I'm not sure to understand what I see. When I click on the Blur button, I get a black screen behind.

 

[wonder]

Really? This is how it looks when I try it:

 

[wonder]

Are we using the same versions?

 

[Informatix]

Really? This is how it looks when I try it:

By taping the screen many times, sometimes I get a blurred image, sometimes the screen goes black (the first time, it's always black).

 

[wonder]

Yeah, mine always blurs, but it flickers sometimes... It is possible that the resize event is being fired before the screenshot is ready...
I'm not experienced with multithreaded apps, I'm almost sure I messed it up...

I guess that, at least as a proof of concept, it kinda works.

If you're into it, you could try fixing it and/or experimenting with the Transparent surface, which doesn't need the trickery of moving the surface up and down from 0%y to 100%y in order to hide/unhide.

By the way, here's the whole thing, apk included:
http://www113.zippyshare.com/v/NoYdXIwK/file.html

 

[Informatix]

Nevertheless, please consider my request of allowing the LibGDX transparent surface to sit between views.

It's not possible. A surface has only two positions set by the setZOrderOnTop function, either on top or behind, and only the "on top" position allows the surface view to be transparent.

In brief:
With InitializeView, the created view is always opaque. There's no way to see anything through it, whatever you set with GL.glClearColor. SendToBack and BringToFront work as expected.
With InitializeTransparentView, the created view is always transparent, but you can hide what's behind by setting an opaque color with GL.glClearColor (you change the background color of the drawing surface). SendToBack and BringToFront do not work because the surface is always above.