Transform Feedback Variable Redeclaration Error on iOS OpenGL ES 3.0 -

I am currently trying to retract the pixel information from the PP so that it can be processed back through the loop / Can be saved. .

To do this, I am trying to implement the conversion feedback, I am facing issues that split the GPU's pipeline. It is different from the top and the piece shadri programs that separation of compilation and shadder program creation too. In implementing this, the compiler is giving me a catch-22 response in which it tells me that if I separate headsets, then I will have to re-gather some Biltin per-vertex variables like gl_Position.

  ERROR: With different shodder objects, the variable 'gl_Position' should be built-in before being used.  

But when I do this, I tell you that I do not have permission to redistribute the Bilton variable:

  Hype vec4 gl_Position;  

Error: 0: 1: Regular non-array variable 'gl_Position' can not be changed again.

I tried to redefine gl_PerVertex, I have found an example, but fails to recognize that gl_PerVertex is an underlying thing:

  // Insin, out, and uniforms in the top verbal shodder: Gl_PerVertex outside {vec4 gl_Position; Float gl_PointSize; Float gl_ClipDistance []; };  

Error: 0: 1: The identifier name 'gl_PerVertex' can not start with 'gl_'

Is there any special Who knows what variables) is effective for reducing gl_Position redeclare effective for iOS again in the top pinnacle? Or is there something wrong with some of the two things that I had already done?

GLES 3.0 says that gl_Position has been declared as

  Highp vec4 gl_Position;  

Perhaps "outside" will help.