From 6494befb2f54cc6312d1569e47a5441d56d67890 Mon Sep 17 00:00:00 2001
From: Giles Atkinson <“gatk555@gmail.com”>
Date: Wed, 26 Jan 2022 19:01:50 +0000
Subject: [PATCH] Request backing store for X11 plot windows.  When supported
 by the X server windows are redrawn vey quickly without replotting.

---
 src/frontend/plotting/x11.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/frontend/plotting/x11.c b/src/frontend/plotting/x11.c
index d4671c6cb..590db2dd2 100644
--- a/src/frontend/plotting/x11.c
+++ b/src/frontend/plotting/x11.c
@@ -572,8 +572,9 @@ X11_NewViewport(GRAPH *graph)
     DEVDEP(graph).window = XtWindow(DEVDEP(graph).view);
     DEVDEP(graph).isopen = 0;
     w_attrs.bit_gravity = ForgetGravity;
-    XChangeWindowAttributes(display, DEVDEP(graph).window, CWBitGravity,
-                            &w_attrs);
+    w_attrs.backing_store = Always;
+    XChangeWindowAttributes(display, DEVDEP(graph).window,
+                            CWBitGravity | CWBackingStore, &w_attrs);
 
     int linewidth, gridlinewidth;
     /* If we had a previous graph, e.g. after zooming, we