Android GLSurfaceView transparent background without setZOrderonTop

Question

Sorry for my English.

My work is based on https://github.com/harism/android_page_curl/

After many hours of research, I have found a few solutions, but not for all the issues what I have in my application. I've some trouble with a GLSurfaceView. I've got a background with a relativeLayout, a GLSurfaceView, and an overlay on top.

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/background"
    android:layout_width="match_parent"
    android:background="@layout/backgroundrepeat"
    android:layout_height="match_parent">
<com.m2y.foxprez.view.CurlView
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/openglview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
<RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/overlay"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
</RelativeLayout>

When I init my view :

setEGLConfigChooser(8,8,8,8,16,0);
setRenderer(renderer);
getHolder().setFormat(PixelFormat.TRANSLUCENT);
setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
setZOrderMediaOverlay(true);

In my renderer:

public void onSurfaceCreated(GL10 gl, EGLConfig config) {
    gl.glClearColor(0f, 0f, 0f, 0f);
    gl.glShadeModel(GL10.GL_SMOOTH);
    gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
    gl.glHint(GL10.GL_LINE_SMOOTH_HINT, GL10.GL_NICEST);
    gl.glHint(GL10.GL_POLYGON_SMOOTH_HINT, GL10.GL_NICEST);
    gl.glEnable(GL10.GL_LINE_SMOOTH);
    gl.glDisable(GL10.GL_DEPTH_TEST);
    gl.glDisable(GL10.GL_CULL_FACE);
}

public synchronized void onDrawFrame(GL10 gl) {
    gl.glClearColor(0f,0f,0f,0f);
    gl.glClear(GL10.GL_COLOR_BUFFER_BIT);
    gl.glLoadIdentity();
}

After multiple research, I am currently blocked with this result:
with setZOrderOnTop, i've got background, but the overlay is under the view.
with setZOrderMediaOverlay, i've got the overlay, but the background is black.

Someone can help me?

Answer 1

This worked for me:

final GLSurfaceView glView = (GLSurfaceView) findViewById(R.id.glView);

glView.setZOrderOnTop(true);
glView.setEGLConfigChooser(8, 8, 8, 8, 16, 0);
glView.getHolder().setFormat(PixelFormat.RGBA_8888);
glView.setRenderer(new MyRenderer());
glView.setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);

Found here: http://andrewhague.wordpress.com/2011/05/24/how-to-set-a-transparent-glsurfaceview/

Answer 2

I would like to accomplish the same thing with a view on top of a GLSurfaceView and I have not found a solution without limitations. First, glView.setZOrderOnTop(true) gives the correct transparent background but the view is alway on top no matter what the sequence of ordering views. Second, without ZOrderOnTop the view hierarchy is maintained but the GLSurface background is black or the color that is set with glClearColor(red, green, blue, alpha) in the renderer. Unfortunately, the alpha argument has no effect when using this method unless

android:windowIsTranslucent="true"

and the problem with this is that you may not want to punch a hole into the OS view. There should be a way to accomplish this easily for a more animated UI using openGL. I have searched this site and others without finding a solution.