layout (vertices = 3) out;

in vec4 pos_cs_in[];
out vec4 pos_es_in[];

void main()
{   
  // Calculate the tess levels
  if(gl_InvocationID == 0) 
  {
    gl_TessLevelOuter[0] = 1;
    gl_TessLevelOuter[1] = 1;
    gl_TessLevelOuter[2] = 1;
    gl_TessLevelInner[0] = 1;
  }
  pos_es_in[gl_InvocationID] = pos_cs_in[gl_InvocationID];
}