Commit 84df0b37 authored by Jim Blandy's avatar Jim Blandy
Browse files

Tue Dec 1 22:34:42 1992 Jim Blandy (

	* hanoi.el (hanoi): If pole-spacing is odd, round down, not up.
	To see if the window is wide enough, just check if one half of a
	ring will fit inside pole-spacing.
parent bc254115
......@@ -29,26 +29,40 @@
(prefix-numeric-value current-prefix-arg))))
(if (<= nrings 0) (error "Negative number of rings"))
(let (pole-spacing
(window-height (window-height (selected-window)))
(window-width (window-width (selected-window))))
(let ((h (+ nrings 2))
(w (+ (* (1- nrings) 6) 2 5)))
(if (not (and (>= window-width h)
(> window-width w)))
(let* (floor-row
(window-height (window-height (selected-window)))
(window-width (window-width (selected-window)))
;; This is the unit of spacing to use between poles. It
;; must be even. We round down, since rounding up might
;; cause us to draw off the edge of the window.
(pole-spacing (logand (/ window-width 6) (lognot 1))))
(let (
;; The poles are (1+ NRINGS) rows high; we also want an
;; empty row at the top for the flying rings, a base, and a
;; blank line underneath that.
(h (+ nrings 4))
;; If we have NRINGS rings, we label them with the numbers 0
;; through NRINGS-1. The width of ring i is 2i+3; it pokes
;; out i spaces on either side of the pole. Rather than
;; checking if the window is wide enough to accomodate this,
;; we make sure pole-spacing is large enough, since that
;; works even when we have decremented pole-spacing to make
;; it even.
(w (1+ nrings)))
(if (not (and (>= window-height h)
(> pole-spacing w)))
(if (not (and (>= (setq window-height
(window-height (selected-window))) h)
(> (setq window-width
(window-width (selected-window))) w)))
(window-height (selected-window)))
(> (setq pole-spacing
(logand (/ window-width 6) (lognot 1)))
(error "Screen is too small (need at least %dx%d)" w h))))
(setq pole-spacing (/ window-width 6))
(if (not (zerop (logand pole-spacing 1)))
;; must be even
(setq pole-spacing (1+ pole-spacing)))
(setq floor-row (if (> (- window-height 3) h)
(- window-height 3) window-height)))
(let ((fly-row (- floor-row nrings 1))
......@@ -197,4 +211,4 @@
(backward-char (/ (+ len 1) 2))
(delete-char 1) (insert ?\|))))))
;;; hanoi.el
\ No newline at end of file
;;; hanoi.el
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