From 0271047b26d75bb2dfe808ebda7704ae2f757b2b Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <seth@kipro-pcb.com>
Date: Sun, 27 Jul 2025 17:22:02 -0700
Subject: [PATCH] Add a method to force KiCad to software rendering

There are enough cases of problematic OpenGL implementations to need a
way to avoid calling OpenGL in the first place.  This provides a
temporary method for people experiencing crashing KiCad or starting
KiCad over a remote terminal to temporarily enforce software rendering
---
 common/eda_draw_frame.cpp | 19 +++++++++++++++++++
 kicad/kicad.cpp           |  9 +++++++++
 2 files changed, 28 insertions(+)

diff --git a/common/eda_draw_frame.cpp b/common/eda_draw_frame.cpp
index debd608e63..d15525c812 100644
--- a/common/eda_draw_frame.cpp
+++ b/common/eda_draw_frame.cpp
@@ -944,6 +944,19 @@ EDA_DRAW_PANEL_GAL::GAL_TYPE EDA_DRAW_FRAME::loadCanvasTypeSetting(  APP_SETTING
     if( canvasType == EDA_DRAW_PANEL_GAL::GAL_TYPE_NONE )
         canvasType = EDA_DRAW_PANEL_GAL::GAL_TYPE_OPENGL;
 
+    wxString envCanvasType;
+
+    if( wxGetEnv( "KICAD_SOFTWARE_RENDERING", &envCanvasType ) )
+    {
+        if( envCanvasType.CmpNoCase( "1" ) == 0
+            || envCanvasType.CmpNoCase( "true" ) == 0
+            || envCanvasType.CmpNoCase( "yes" ) == 0 )
+        {
+            // Force software rendering if the environment variable is set
+            canvasType = EDA_DRAW_PANEL_GAL::GAL_TYPE_CAIRO;
+        }
+    }
+
     return canvasType;
 }
 
@@ -964,6 +977,12 @@ bool EDA_DRAW_FRAME::saveCanvasTypeSetting( EDA_DRAW_PANEL_GAL::GAL_TYPE aCanvas
     if( !alg::contains( s_allowedFrames, m_ident ) )
         return false;
 
+    if( wxGetEnv( "KICAD_SOFTWARE_RENDERING", nullptr ) )
+    {
+        // If the environment variable is set, don't save the canvas type.
+        return false;
+    }
+
     if( aCanvasType < EDA_DRAW_PANEL_GAL::GAL_TYPE_NONE
             || aCanvasType >= EDA_DRAW_PANEL_GAL::GAL_TYPE_LAST )
     {
diff --git a/kicad/kicad.cpp b/kicad/kicad.cpp
index 4ff6a7e78f..dc98263a2a 100644
--- a/kicad/kicad.cpp
+++ b/kicad/kicad.cpp
@@ -104,6 +104,10 @@ bool PGM_KICAD::OnPgmInit()
         { wxCMD_LINE_OPTION, "f", "frame", "Frame to load", wxCMD_LINE_VAL_STRING, 0 },
         { wxCMD_LINE_SWITCH, "n", "new", "New instance of KiCad, does not attempt to load previously open files",
           wxCMD_LINE_VAL_NONE, 0 },
+#ifndef __WXOSX__
+        { wxCMD_LINE_SWITCH, nullptr, "software-rendering", "Use software rendering instead of OpenGL",
+          wxCMD_LINE_VAL_NONE, 0 },
+#endif
         { wxCMD_LINE_PARAM, nullptr, nullptr, "File to load", wxCMD_LINE_VAL_STRING,
           wxCMD_LINE_PARAM_MULTIPLE | wxCMD_LINE_PARAM_OPTIONAL },
         { wxCMD_LINE_NONE, nullptr, nullptr, nullptr, wxCMD_LINE_VAL_NONE, 0 }
@@ -158,6 +162,11 @@ bool PGM_KICAD::OnPgmInit()
         Kiway.SetCtlBits( KFCTL_STANDALONE );
     }
 
+    if( parser.Found( "software-rendering" ) )
+    {
+        wxSetEnv( "KICAD_SOFTWARE_RENDERING", "1" );
+    }
+
     bool skipPythonInit = false;
 
     if( appType == FRAME_BM2CMP || appType == FRAME_PL_EDITOR || appType == FRAME_GERBER