Function: strokes-get-stroke-extent

strokes-get-stroke-extent is a byte-compiled function defined in strokes.el.gz.

Signature

(strokes-get-stroke-extent PIXEL-POSITIONS)

Documentation

From a list of absolute PIXEL-POSITIONS, return absolute spatial extent.

The return value is a list ((XMIN . YMIN) (XMAX . YMAX)).

Source Code

;; Defined in /usr/src/emacs/lisp/strokes.el.gz
(defun strokes-get-stroke-extent (pixel-positions)
  "From a list of absolute PIXEL-POSITIONS, return absolute spatial extent.
The return value is a list ((XMIN . YMIN) (XMAX . YMAX))."
  (if pixel-positions
      (let ((xmin (caar pixel-positions))
	    (xmax (caar pixel-positions))
	    (ymin (cdar pixel-positions))
	    (ymax (cdar pixel-positions))
	    (rest (cdr pixel-positions)))
	(while rest
	  (if (consp (car rest))
	      (let ((x (caar rest))
		    (y (cdar rest)))
		(if (< x xmin)
		    (setq xmin x))
		(if (> x xmax)
		    (setq xmax x))
		(if (< y ymin)
		    (setq ymin y))
		(if (> y ymax)
		    (setq ymax y))))
	  (setq rest (cdr rest)))
	(let ((delta-x (- xmax xmin))
	      (delta-y (- ymax ymin)))
	  (if (> delta-x delta-y)
	      (setq ymin (- ymin
			    (/ (- delta-x delta-y)
			       2))
		    ymax (+ ymax
			    (/ (- delta-x delta-y)
			       2)))
	    (setq xmin (- xmin
			  (/ (- delta-y delta-x)
			     2))
		  xmax (+ xmax
			  (/ (- delta-y delta-x)
			     2))))
	  (list (cons xmin ymin)
		(cons xmax ymax))))
    nil))