anchor.diff:     (technique)
      (vertex-count
       :initarg :vertex-count
  -    :initform 64)))
  +    :initform 64)
  +   (contour
  +    :initarg :contour
  +    :initform nil
  +    :accessor contour)))
   
   (defgeneric circle-render (circle projection-transform model-view-transform color))
   
  
positive.code:     (gl:vertex-attrib-pointer 1 2 :float nil (* (cffi:foreign-type-size :float) 8) (cffi:make-pointer (* (cffi:foreign-type-size :float) 3)))
      (gl:vertex-attrib-pointer 2 3 :float nil (* (cffi:foreign-type-size :float) 8) (cffi:make-pointer (* (cffi:foreign-type-size :float) 5)))
      
      (gl:draw-arrays :triangle-fan 0 vertex-count)
        
      (gl:disable-vertex-attrib-array 0)
      (gl:disable-vertex-attrib-array 1)
  
negative.code:     (setf technique (make-instance 'color-technique :vs-path "/home/quicklisp/local-projects/battleship/shaders/shader.vertexshader" :fs-path "/home/quicklisp/local-projects/battleship/shaders/shader.fragmentshader"))))
  
  (defmethod circle-render ((self circle) projection-transform model-view-transform color)
      (with-slots (vertex-buffer technique vertex-count contour) self
  
      (technique-enable technique)
  
  