From 2e9c554f2c044cb34758139375203e2fdf3296c1 Mon Sep 17 00:00:00 2001
From: Tim Edwards <tim@opencircuitdesign.com>
Date: Sat, 20 Feb 2021 13:24:02 -0500
Subject: [PATCH] Revised the wrapper script to use the Tk command "font
 measure" to get the pixel size of the default font, and scale the window
 glyphs and scrollbars to match, so that the display is automatically adjusted
 for screen resolution and does not require manual intervention to correct for
 high resolution displays.

---
 VERSION           |  2 +-
 tcltk/wrapper.tcl | 11 ++++++++++-
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/VERSION b/VERSION
index a82d6cf7..c11794e5 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-8.3.130
+8.3.131
diff --git a/tcltk/wrapper.tcl b/tcltk/wrapper.tcl
index 5bba211a..4b327c80 100644
--- a/tcltk/wrapper.tcl
+++ b/tcltk/wrapper.tcl
@@ -554,7 +554,6 @@ set Opts(crosshair) 0
 set Opts(hidelocked) 0
 set Opts(hidespecial) 0
 set Opts(toolbar) 0
-set Opts(scale) 1.0
 set Opts(toolscale) 1.0
 set Opts(drc) 1
 set Opts(autobuttontext) 1
@@ -1135,6 +1134,16 @@ proc magic::openwrapper {{cell ""} {framename ""}} {
    toplevel $framename
    tkwait visibility $framename
 
+   # Get scale from the TkDefaultFont size, unless Opts(scale) is already
+   # set.  On standard displays, an "M" in the Sans font is usually 10
+   # pixels wide, and 22 on high resolution displays, so this maps to
+   # a scale of 1 on standard displays and a scale of 2 on high resolution
+   # displays.
+ 
+   if [catch {set Opts(scale)}] {
+	set Opts(scale) [expr {int([font measure TkDefaultFont M] / 10)}]
+   }
+
    # Resize the window
    if {[catch {wm geometry ${framename} $Winopts(${framename},geometry)}]} {
       catch {wm geometry ${framename} $Opts(geometry)}