From: Carl Worth <cworth@cworth.org>
Date: Thu, 7 Nov 2013 21:14:56 +0000 (-0800)
Subject: acre-x: Fix zooming so that zoom-in and zoom-out use the same amounts
X-Git-Url: https://git.cworth.org/git?p=acre;a=commitdiff_plain;h=bacc5e501df0d3615dbe0aa8ef54b91ee3377b6e

acre-x: Fix zooming so that zoom-in and zoom-out use the same amounts

The intent was always that one zoom-in followed by one zoom-out, (or
vice versa) would lead to the original zoom level. But the zoom-out
code had some incorrect arithmetic in it such that zooming out was
much faster than zooming in.
---

diff --git a/acre-x.c b/acre-x.c
index 194926a..c375c36 100644
--- a/acre-x.c
+++ b/acre-x.c
@@ -154,7 +154,7 @@ handle_events(Display *dpy, Window window, Visual *visual,
 			}
 			else if (keycode == minus_code)
 			{
-				shift = (1- 2*ZOOM) * (x_max - x_min);
+				shift = (ZOOM/(1 - 2 * ZOOM)) * (x_max - x_min);
 				x_min -= shift;
 				x_max += shift;
 			}