From 7aefad850d8b895969f3f6f412d9bfe9455b10f1 Mon Sep 17 00:00:00 2001
From: Yves Rizoud <yrizoud@gmail.com>
Date: Sun, 12 Dec 2010 18:09:11 +0000
Subject: [PATCH] Fix issue 396: increasing Saturation makes greyscale red

git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1658 416bcca6-2ee7-4201-b75f-2eb2f807beb1
---
 src/palette.c | 50 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 43 insertions(+), 7 deletions(-)

diff --git a/src/palette.c b/src/palette.c
index a0fd545a..253856ec 100644
--- a/src/palette.c
+++ b/src/palette.c
@@ -1366,15 +1366,27 @@ void Button_Palette(void)
           }
           else
           {
+            byte greys=0;
+            byte non_greys=0;
+            // Check if the range contains both greys and non-greys
             for (i=block_start; i<=block_end; i++)
+              if (temp_palette[i].R==temp_palette[i].G && temp_palette[i].R == temp_palette[i].B)
+                non_greys=1;
+              else
+                greys=1;
+            
+            for (i=block_start; i<=block_end; i++)
+            {
+              byte is_grey = temp_palette[i].R==temp_palette[i].G && temp_palette[i].R == temp_palette[i].B;
               Set_HSL(
                 temp_palette,
                 working_palette,
                 i,
-                Color_max-red_slider->Position,
-                Color_max-green_slider->Position,
+                is_grey && greys && non_greys ? 0 : Color_max-red_slider->Position,
+                is_grey && greys && non_greys ? 0 : Color_max-green_slider->Position,
                 Color_max-blue_slider->Position
                 );
+            }
           }
 
           if (red_slider->Position>Color_max)
@@ -1434,15 +1446,27 @@ void Button_Palette(void)
           }
           else
           {
-          for (i=block_start; i<=block_end; i++)
+            byte greys=0;
+            byte non_greys=0;
+            // Check if the range contains both greys and non-greys
+            for (i=block_start; i<=block_end; i++)
+              if (temp_palette[i].R==temp_palette[i].G && temp_palette[i].R == temp_palette[i].B)
+                non_greys=1;
+              else
+                greys=1;
+            
+            for (i=block_start; i<=block_end; i++)
+            {
+              byte is_grey = temp_palette[i].R==temp_palette[i].G && temp_palette[i].R == temp_palette[i].B;
               Set_HSL(
                 temp_palette,
                 working_palette,
                 i,
-                Color_max-red_slider->Position,
-                Color_max-green_slider->Position,
+                is_grey && greys && non_greys ? 0 : Color_max-red_slider->Position,
+                is_grey && greys && non_greys ? 0 : Color_max-green_slider->Position,
                 Color_max-blue_slider->Position
                 );
+            }
           }
 
           if (green_slider->Position>Color_max)
@@ -1502,15 +1526,27 @@ void Button_Palette(void)
           }
           else
           {
+            byte greys=0;
+            byte non_greys=0;
+            // Check if the range contains both greys and non-greys
             for (i=block_start; i<=block_end; i++)
+              if (temp_palette[i].R==temp_palette[i].G && temp_palette[i].R == temp_palette[i].B)
+                non_greys=1;
+              else
+                greys=1;
+            
+            for (i=block_start; i<=block_end; i++)
+            {
+              byte is_grey = temp_palette[i].R==temp_palette[i].G && temp_palette[i].R == temp_palette[i].B;
               Set_HSL(
                 temp_palette,
                 working_palette,
                 i,
-                Color_max-red_slider->Position,
-                Color_max-green_slider->Position,
+                is_grey && greys && non_greys ? 0 : Color_max-red_slider->Position,
+                is_grey && greys && non_greys ? 0 : Color_max-green_slider->Position,
                 Color_max-blue_slider->Position
                 );
+            }
           }
 
           if (blue_slider->Position>Color_max)