Re: why the gl_ClipDistance[] doesn't work?

Sorry for the late reply. Here's how I'm setting clip planes in the vert shader and it's working fine for me on AMD, NVidia and Intel:

#if defined(VERT_SHADER) 

outfloat gl_ClipDistance[MAX_CLIP_PLANES]; 

void setClipPlanes(in vec4 worldSpaceVertex){

#   if MAX_CLIP_PLANES > 0

    gl_ClipDistance[0]= dot(worldSpaceVertex, dvd_clip_plane[0]);

#  endif

#   if MAX_CLIP_PLANES > 1

    gl_ClipDistance[1]= dot(worldSpaceVertex, dvd_clip_plane[1]);

#  endif

.........

}

#endif