BARKS IN THE WIND: Symbolics Lisp Machine demo Jan 2013 by kalman reti notes

last in the series of guru narrations by kalman reti on genera use. he rehashes a lot of subjects he previously covered, but the core of video is loading an image and then manipulating it through indirect arrays

https://www.youtube.com/watch?v=o4-YnLpLgtk

(si:login-to-sys-host)

(setq fs::*remember-passwords* t)

(defun kr-prompt (stream ignore)
  (prog1
    (if *use-date-prompt*
	(format stream "~\\datime\\ ~A command: " neti:*local-host*)
	(format stream "Command: "))
    (let ((window *terminal-io*))
      (let* ((pos (setq *current-position*
			(cons window
			      (multiple-value-list (send window :viewport-position)))))
	     (lastpos *last-position*)
	     (q-reg #\z))
	(unless (equalp pos lastpos)
	  (setf (gethash #\X cp::*POSITION-Q-REGS*)(gethash #\Y cp::*POSITION-Q-REGS*))
	  (setf (gethash #\Y cp::*POSITION-Q-REGS*) (gethash Q-REG cp::*POSITION-Q-REGS*))
	  (setf (gethash Q-REG cp::*POSITION-Q-REGS*) lastpos))
	(setq *last-position* *current-position*)))))

(defun gp ()
  (terpri)
  (terpri)
  (scl::present (list 'a "B" 123) 'sys::expression) (terpri)
  (dw::with-output-as-presentation (:type 'string :object "circle")
    (graphics::with-room-for-graphics (nil 80) (graphics::draw-circle 40 40 20 :filled nil))))

(defvar part)

(defun part ()
  (let ((imd (scl::send (images::find-image-named :wallpaper-402118) :data-array)))
    (setq part (color::make-image
		 'color::32b-image
		 :name "part" :width 200 :height 200
		 :daata-array (si:make-raster-array
				200 200
				:type 'si:art-fixnum
				:displaced-to imd
				:displaced-conformally t
				:displaced-index-offset
				(si:array-row-major-index imd 300 560))))))

(defun redline (&optional (pixel #x0000ff))
  (loop with array = (scl::send (images::find-image-named "part") :data-array)
	for i below 200
	do (setf (si:raster-aref array i i) pixel)))

Help Commands
looks like he's using libjpeg-turbo, but probably some older version for C compatibility?
images:read-images-from-file-in-format→fcl::jpeg-image-from-file→read-jfif-to-image→read-jpeg→read-jpeg-stream→c-sys:execute→read_jfif_to_iman (doesn't exist elsewhere)→read_JPEG_file
C-x e Set Trap On Exit
Show Source Code foo
Function-Refresh (doesn't work on his machine without fixing keyboard, not sure how to do on mine)