BARKS IN THE WIND: Genera emulator demo of smooth scrolling by kalman reti notes

this is another guru narration by kalman repi of lisp machine use, this time the goal is produce a cute hack to autoscroll a sheet of music

https://www.youtube.com/watch?v=sfgjL7EUHZ8

(si:login-to-sys-host)
c-?
Set X Keyboard Mapping
+ gives you previous repl input,  but for commands it'll return lisp equivalent of command input
  (elsewhere reti uses + to set a variable after exploring its value, as in ,foo followed by (set + 'bar))
c-s-a arglist
(storage:open-disk-stream (fs:parse-pathname"host:/disk1/VLM/fep0") :direction :block) ;block is r/w, lets you dynamically attach a fep
a section on presentation system

(defun foo0 ()
  (graphics::with-room-for-graphics (nil 6201)
    (graphics::draw-image kr2 0 0 :alu :flip))) ;alu flip draw b-on-w

(defun scroll (&optional start limit increment)
  (loop for i from (or start 0)
	      below (- (or limit (fourth (multiple-value-list (scl::send *terminal-io* :visible-cursorpos-limits))))
		       (scl::send *terminal-io* :height)) by (or increment 1)
	do (scl::send *terminal-io* :set-viewport-position 0 i)))

(defun top-down-flip (bit-array)
  (let* ((dims (si:array-dimensions bit-array))
	 (height (first dims))
	 (width (second dims))
	 (new-bit-array
	   (si:make-array dims :type (si::array-type bit-array))))
    (loop for j below height
	  for jj downfrom (1- height)
	  do (loop for i below width
		   do (setf (aref new-bit-array jj i)
			    (aref bit-array j i))))
    new-bit-array))

(defun playit1 (array &optional increment before-sleep after-sleep)
  (tv::with-notification-mode (:ignore)
    (cp::com-clear-output-history *terminal-io*)
    (graphics::with-room-for-graphics (nil (first (si:array-dimensions array)))
      (graphics::draw-image array 0 0 :alu :flip))
    (loop repeat 14 do (terpri))
    (let ((end (fourth (multiple-value-list (scl:send *terminal-io* :visible-cursor-limits)))))
      (time (progn
	      (scl:send *terminal-io* :set-viewport-position 0 0)
	      (sleep (or before-sleep 12))
	      (scroll 0 end (or increment 3))
	      (sleep (or after-sleep 35)))))))

(defun foo1 ()
  ;; preserves operations in history, so scrolling around will replay&block
  (graphics::with-room-for-graphics (nil 800)
    (loop for i below 500
	  do (send *standard-output* :bitblt tv:alu-seta 1300 800 kr32 0 i 0
		   (- (car (last (graphics::stream-transform *standard-output*))) 800)))))

(defun foo2 ()
  (graphics::with-room-for-graphics (nil 900)
    (loop repeat (or 200 (- 8192 900))
	  for i downfrom (- 8192 900)
	  do (graphics::draw-image kr2 0 0 :image-top i :image-bottom (min 8192 (+ i 900))))))

C-S-a arglist on (scl:send ... :method) give arglist for method
Read Image File
C-mouse-l mark region m-w copy to kill ring
(describe (accept'images::named-image))
(setq kr #|he clicks on color:data-array from describe, which is an array bit type|#)
(setq kr2 (top-down-flip kr))
from debugger can :Load File ...
he then loads a file called sddt-flattened, which lets him call an memory inspection function (si:sdddt). there's a definition for sddt in sys/in-house/sddt.lisp. gives help on Ü
C-l in debugger show frame :detailed no :clear screen yes
, in both repl and debugger is a way to enter individual value. no more (progn ...)!
Start GC :Ephemeral No :Dynamic No  stops gc
(tv:notify nil "Hi!")
time's storage system is always 0s on vlm, because there are shortcuts, storage is handled in vlm