From a65ada2a5ec1466fa2d17567b0220af7750fff42 Mon Sep 17 00:00:00 2001
From: Paul Cornett <paulcor@users.noreply.github.com>
Date: Mon, 1 Jan 2024 13:52:10 -0800
Subject: [PATCH] Simplify mm-to-pixel conversion

wxDisplay can already tell us the PPI, just convert it to mm.
---
 src/common/dcbase.cpp | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/common/dcbase.cpp b/src/common/dcbase.cpp
index e1060ae402..e11e10176f 100644
--- a/src/common/dcbase.cpp
+++ b/src/common/dcbase.cpp
@@ -1397,13 +1397,17 @@ float wxDCImpl::GetFontPointSizeAdjustment(float dpi)
     return float(wxDisplay::GetStdPPIValue()) / dpi;
 }
 
+static void mmToPx(wxWindow* win, double& x, double& y)
+{
+    const wxSize ppi(win ? wxDisplay(win).GetPPI() : wxGetDisplayPPI());
+    x = ppi.x * mm2inches;
+    y = ppi.y * mm2inches;
+}
+
 double wxDCImpl::GetMMToPXx() const
 {
     if ( wxIsNullDouble(m_mm_to_pix_x) )
-    {
-        m_mm_to_pix_x = (double)wxGetDisplaySize().GetWidth() /
-                        (double)wxGetDisplaySizeMM().GetWidth();
-    }
+        mmToPx(m_window, m_mm_to_pix_x, m_mm_to_pix_y);
 
     return m_mm_to_pix_x;
 }
@@ -1411,10 +1415,7 @@ double wxDCImpl::GetMMToPXx() const
 double wxDCImpl::GetMMToPXy() const
 {
     if ( wxIsNullDouble(m_mm_to_pix_y) )
-    {
-        m_mm_to_pix_y = (double)wxGetDisplaySize().GetHeight() /
-                        (double)wxGetDisplaySizeMM().GetHeight();
-    }
+        mmToPx(m_window, m_mm_to_pix_x, m_mm_to_pix_y);
 
     return m_mm_to_pix_y;
 }