Using gl_ViewID_OVR in fragment shader - strange bugs

[kwuerl]

I am experiencing some very strange bugs while trying to use gl_ViewID_OVR in an opengl es 3 fragment shader.
As soon as I use more than one input (in) and gl_ViewID_OVR in the fragment shader the glLinkProgram() function simply deadlocks !?!

When i try to work around this by setting gl_ViewID_OVR in the vertex shader as an flat uint out, the shader compiles but the screen just flickers and produces strange artifacts....
One can reproduce this by simply adding a few lines to the VrCubeWorld NativeSurface example:
Just replace the shade code in the example by the one provided by shaders_bug.txt
My test devices where S7 Edge and S7.

Does anybody see if I'm doing something wrong here or if this is a bug in the driver?
And if it is - is there a better place to report this than in this forum?

[deftware]

According to: https://www.khronos.org/registry/OpenGL/extensions/OVR/OVR_multiview.txt

It's only supposed to be used in the vertex shader.

It's also likely that it's not exactly a variable that you can copy out to the fragment shader as well. Although this seems like it would be an implementation-specific thing that some hardware vendors and/or drivers have just hacked in there.

[deftware]

Ah:

In this mode there are several restrictions:

        - in vertex shader gl_Position is the only output that can depend on
          gl_ViewID_OVR (see Section 7.1 of the OpenGL ES Shading Language
          specification)

This would imply that nowhere else would you be able to set any variables using its value.

[kwuerl]

Maybe i should mention that i use the OVR_multiview2 extension, so at least passing the variable from vertex to fragment shader should work:
https://www.khronos.org/registry/OpenGL/extensions/OVR/OVR_multiview2.txt

This extension relaxes the restriction in OVR_multiview that only gl_Position
can depend on ViewID in the vertex shader.  With this change, view-dependent
outputs like reflection vectors and similar are allowed.

Nevertheless  gl_ViewID_OVR should be visible in fragment shader also:
https://www.khronos.org/registry/OpenGL/extensions/OVR/OVR_multiview.txt

(6) Is gl_ViewID_OVR visible at every pipeline stage?

    Resolved: To make integration simple for app developers, the intent is for
    gl_ViewID_OVR to be visible as a built-in at each programmable pipeline stage.

It is not quite clear if fragment shader output can be dependent on gl_ViewID_OVR or not - i gess it should be in multiview2, as it lifts the dependency restriction...
https://www.khronos.org/registry/OpenGL/extensions/OVR/OVR_multiview.txt

For non-VTG stages (eg compute and fragment) which don't have a
    gl_Position output variable this means that no outputs can depend
    on the gl_VIewID_OVR. It is still possible that shader side effects
    (such as image or buffer stores) could be view-dependent.

Btw: i found a really really ugly workaround that allows me to pass the viewid to the fragment shader:
This is the only way this seems to work reliable without random artifacts or strange flickering.
In vertex shader:

...
flat out float V_VIEW_ID;
....
void main() {
...
V_VIEW_ID = (float(VIEW_ID) > 0.5 ? 1.0 : 0.0);
...
}

In fragment shader:

...
flat in float V_VIEW_ID;
...
void main() {
...
int VIEW_ID = V_VIEW_ID > 0.5 ? 1 : 0;
...
}

The thing is: At least some of this does not work as intended. I was hoping some Oculus guy could maybe look over this.

[deftware]

 [ DELETED ]
 Doh, I just repeated what you already found.

[kwuerl]

Thank you for your support so far!
All our test devices have Android N - 7.0.
But we use SDK version 23 to build.

[WadeWatts]

Did this get resolved? We are running into the same problem?