anchor.diff:  	    (sb-cga:matrix*
   	     (sb-cga:translate (vec3 0.0 0.0 *zoom-z*))
   	     (sb-cga:rotate (vec3 *rotate-x* *rotate-y* 0.0))
  -	     ;; (sb-cga:rotate (vec3 0.0 (mod (/ (sdl2:get-ticks) 250.0) (* 2 3.14159)) 0.0))
  +	     ;;(sb-cga:rotate (vec3 0.0 (mod (/ (sdl2:get-ticks) 5000.0) (* 2 3.14159)) 0.0))
   	     )))
     ;; projection matrix
     (uniform :mat :perspective-matrix
  
positive.code: 			      #'(lambda (str char n)
  				  (declare (ignore char n))
  				  (list 'sdl2:in-main-thread () (read str t nil t))))
  
  
  ;;; HOW TO USE:
  
negative.code: 	 -0.5 0.5 0.5 -0.5 0.5)))
  
  
  (defvar *tex-coord*
    (cffi:foreign-alloc
     :float
     :initial-contents
     '(20.0 0.0   20.0 20.0   0.0 20.0   0.0 20.0   0.0 0.0   20.0 0.0 ;; to show of *sampler* :repeat
       1.0 0.0   1.0 1.0   0.0 1.0   0.0 1.0   0.0 0.0   1.0 0.0
       1.0 0.0   1.0 1.0   0.0 1.0   0.0 1.0   0.0 0.0   1.0 0.0
       1.0 0.0   1.0 1.0   0.0 1.0   0.0 1.0   0.0 0.0   1.0 0.0
  