From 66e87956563a8863736ad6cfc0f29aacb60e02de Mon Sep 17 00:00:00 2001
From: Seth Hillbrand <hillbrand@ucdavis.edu>
Date: Sun, 16 Jun 2019 13:27:58 -0700
Subject: [PATCH] Plotting: Handle mask transparency

This handles images with transparent colors by mapping the transparent
color to white.  This only works when plotted into the background.

(cherry picked from commit b32439a69433f50f93b489050854b438a24c1a1a)
---
 common/plotters/PDF_plotter.cpp | 16 +++++++++++++---
 common/plotters/PS_plotter.cpp  | 11 +++++++++++
 2 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/common/plotters/PDF_plotter.cpp b/common/plotters/PDF_plotter.cpp
index cde9f51795..6286bc83e6 100644
--- a/common/plotters/PDF_plotter.cpp
+++ b/common/plotters/PDF_plotter.cpp
@@ -405,12 +405,22 @@ void PDF_PLOTTER::PlotImage( const wxImage & aImage, const wxPoint& aPos,
                 }
             }
 
+            if( aImage.HasMask() )
+            {
+                if( r == aImage.GetMaskRed() && g == aImage.GetMaskGreen() && b == aImage.GetMaskBlue() )
+                {
+                    r = 0xFF;
+                    g = 0xFF;
+                    b = 0xFF;
+                }
+            }
+
             // As usual these days, stdio buffering has to suffeeeeerrrr
             if( colorMode )
             {
-            putc( r, workFile );
-            putc( g, workFile );
-            putc( b, workFile );
+                putc( r, workFile );
+                putc( g, workFile );
+                putc( b, workFile );
             }
             else
             {
diff --git a/common/plotters/PS_plotter.cpp b/common/plotters/PS_plotter.cpp
index 46f7fc174a..7b2425814d 100644
--- a/common/plotters/PS_plotter.cpp
+++ b/common/plotters/PS_plotter.cpp
@@ -723,6 +723,17 @@ void PS_PLOTTER::PlotImage( const wxImage & aImage, const wxPoint& aPos,
                 }
             }
 
+            if( aImage.HasMask() )
+            {
+                if( red == aImage.GetMaskRed() && green == aImage.GetMaskGreen()
+                        && blue == aImage.GetMaskBlue() )
+                {
+                    red = 0xFF;
+                    green = 0xFF;
+                    blue = 0xFF;
+                }
+            }
+
             if( colorMode )
                 fprintf( outputFile, "%2.2X%2.2X%2.2X", red, green, blue );
             else