anchor.diff:                          OpenGL.Hl.FlipSurface &textSurface
   
                           // construct mvp matrix
  -                        let translation = position // + offset
  -                        let modelTranslation = Matrix4x4.CreateTranslation translation.V3
  +                        let positionOffset = position + v2 offset.X -offset.Y
  +                        let sizeOffset = v2 (single textSurface.w) (single textSurface.h)
  +                        let modelTranslation = Matrix4x4.CreateTranslation (position + size * 0.5f).V3
                           let modelScale = Matrix4x4.CreateScale (v3 size.X size.Y 1.0f)
                           let modelMatrix = modelScale * modelTranslation
                           let modelViewProjection = modelMatrix * viewProjection
  
positive.code:                     colorSdl.a <- color.A8
  
                      // NOTE: the resource implications (throughput and fragmentation?) of creating and destroying a
                      // texture one or more times a frame must be understood! Although, maybe it all happens in software
                      // and vram fragmentation would not be a concern in the first place... perf could still be, however.
                      let (offset, textSurface) =
                          match justification with
                          | Unjustified wrapped ->
  
negative.code:          eyeSize : Vector2,
           eyeMargin : Vector2,
           renderer : GlRenderer2d) =
          let (transform, color) = (transform, color) // make visible from lambda
          flip OpenGL.SpriteBatch.InterruptFrame renderer.RenderSpriteBatchEnv $ fun () ->
              let mutable transform = transform
              let absolute = transform.Absolute
              let perimeter = transform.Perimeter
              let position = perimeter.Position.V2 * Constants.Render.VirtualScalar2
              let size = perimeter.Size.V2 * Constants.Render.VirtualScalar2
              let viewport = GlRenderer2d.computeViewport renderer
              let viewAbsolute = GlRenderer2d.computeViewAbsolute eyePosition eyeSize eyeMargin
              let viewRelative = GlRenderer2d.computeViewRelative eyePosition eyeSize eyeMargin
  