anchor.diff:              result
   
       type [<NoEquality; NoComparison>] private Pool =
  -        { mutable ContextCurrent : int
  +        { mutable ContextIndex : int
             Contexts : Context List
             SpriteMax : int }
   
           static member create spriteMax prealloc =
               let contexts = Seq.init (max 1 prealloc) (fun _ -> OpenGL.Hl.Assert (Context.create spriteMax)) |> List
  -            { ContextCurrent = 0
  +            { ContextIndex = 0
                 Contexts = contexts
                 SpriteMax = spriteMax }
   
  
positive.code:         OpenGL.Hl.Assert ()
  
          // next pool
          Pool.next env.Pool
          env.SpriteIndex <- 0
  
      let CreateEnv () =
          let (texUniform, shader) = CreateShader ()
  
negative.code:               Pool : Pool
                mutable State : State }
  
      /// Create a batched sprite shader with uniforms:
      ///     0: sampler2D tex
      /// and attributes:
      ///     0: vec2 position
  