From 6f5cb1f97d95ad893744cdcb47115ca0fb1db438 Mon Sep 17 00:00:00 2001
From: Jeff Young <jeff@rokeby.ie>
Date: Thu, 3 Jun 2021 22:42:07 +0100
Subject: [PATCH] Fix printing of hidden refs and/or values.

IsLayerVisible() is patched to always return true when printing
(even when "print according to appearance settings" is checked, and
that's too risky to change at this point.  So we also look to see
if the layer colour is set to the background colour.

Fixes https://gitlab.com/kicad/code/kicad/issues/8548
---
 pcbnew/fp_text.cpp | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/pcbnew/fp_text.cpp b/pcbnew/fp_text.cpp
index bbf967c63e..503e6c4afd 100644
--- a/pcbnew/fp_text.cpp
+++ b/pcbnew/fp_text.cpp
@@ -32,6 +32,7 @@
 #include <settings/settings_manager.h>
 #include <trigo.h>
 #include <kicad_string.h>
+#include <painter.h>
 
 FP_TEXT::FP_TEXT( FOOTPRINT* aParentFootprint, TEXT_TYPE text_type ) :
     BOARD_ITEM( aParentFootprint, PCB_FP_TEXT_T ),
@@ -360,6 +361,8 @@ void FP_TEXT::ViewGetLayers( int aLayers[], int& aCount ) const
 double FP_TEXT::ViewGetLOD( int aLayer, KIGFX::VIEW* aView ) const
 {
     constexpr double HIDE = (double)std::numeric_limits<double>::max();
+    RENDER_SETTINGS* renderSettings = aView->GetPainter()->GetSettings();
+    COLOR4D          backgroundColor = renderSettings->GetLayerColor( LAYER_PCB_BACKGROUND );
 
     if( !aView )
         return 0.0;
@@ -370,13 +373,23 @@ double FP_TEXT::ViewGetLOD( int aLayer, KIGFX::VIEW* aView ) const
         return HIDE;
 
     // Handle Render tab switches
-    if( ( m_Type == TEXT_is_VALUE || GetText() == wxT( "${VALUE}" ) )
-            && !aView->IsLayerVisible( LAYER_MOD_VALUES ) )
-        return HIDE;
+    if( m_Type == TEXT_is_VALUE || GetText() == wxT( "${VALUE}" ) )
+    {
+        if( !aView->IsLayerVisible( LAYER_MOD_VALUES )
+                || renderSettings->GetLayerColor( LAYER_MOD_VALUES ) == backgroundColor )
+        {
+            return HIDE;
+        }
+    }
 
-    if( ( m_Type == TEXT_is_REFERENCE || GetText() == wxT( "${REFERENCE}" ) )
-            && !aView->IsLayerVisible( LAYER_MOD_REFERENCES ) )
-        return HIDE;
+    if( m_Type == TEXT_is_REFERENCE || GetText() == wxT( "${REFERENCE}" ) )
+    {
+        if( !aView->IsLayerVisible( LAYER_MOD_REFERENCES )
+                || renderSettings->GetLayerColor( LAYER_MOD_REFERENCES ) == backgroundColor )
+        {
+            return HIDE;
+        }
+    }
 
     if( !IsParentFlipped() && !aView->IsLayerVisible( LAYER_MOD_FR ) )
         return HIDE;