From: Carl Worth <cworth@cworth.org>
Date: Thu, 7 Nov 2013 04:34:43 +0000 (-0800)
Subject: Zoom and pan a bit less with each keypress
X-Git-Url: https://git.cworth.org/git?p=acre;a=commitdiff_plain;h=12b6b0f6a439c7838daac5e2a1e5764bd0218936

Zoom and pan a bit less with each keypress

This makes it a bit smoother and less jumpy for better control.
---

diff --git a/acre-x.c b/acre-x.c
index c1f7c41..e89c7fc 100644
--- a/acre-x.c
+++ b/acre-x.c
@@ -120,6 +120,8 @@ handle_events(Display *dpy, Window window, Visual *visual,
 			draw (dpy, window, visual, acre,
 			      width, height, x_min, x_max);
 
+#define PAN  0.05
+#define ZOOM PAN
 		XNextEvent (dpy, &xev);
                 switch (xev.type) {
                 case KeyPress:
@@ -130,26 +132,26 @@ handle_events(Display *dpy, Window window, Visual *visual,
 			}
 			else if (keycode == left_code)
 			{
-				shift = 0.25 * (x_max - x_min);
+				shift = PAN * (x_max - x_min);
 				x_min += shift;
 				x_max += shift;
 			}
 			else if (keycode == right_code)
 			{
-				shift = 0.25 * (x_max - x_min);
+				shift = PAN * (x_max - x_min);
 				x_min -= shift;
 				x_max -= shift;
 			}
 			else if (keycode == plus_code ||
 				   keycode == equal_code)
 			{
-				shift = 0.25 * (x_max - x_min);
+				shift = ZOOM * (x_max - x_min);
 				x_min += shift;
 				x_max -= shift;
 			}
 			else if (keycode == minus_code)
 			{
-				shift = 0.5 * (x_max - x_min);
+				shift = (1- 2*ZOOM) * (x_max - x_min);
 				x_min -= shift;
 				x_max += shift;
 			}