[gimp] Bug 720045 - Add black point compensation to Preferences/Color Management

[Michael Natterer <mitch src gnome org>]

commit a4821914d355afc2f45a7491cc7746cd39ac6846
Author: Elle Stone <ellestone ninedegreesbelow com>
Date:   Sat Dec 7 13:42:11 2013 -0500

    Bug 720045 - Add black point compensation to Preferences/Color Management
    
    Make black point compensation configurable separately for both proof
    and display.

 app/dialogs/preferences-dialog.c |   24 ++++++++++++++++-
 libgimpconfig/gimpcolorconfig.c  |   53 ++++++++++++++++++++++++++++++-------
 libgimpconfig/gimpcolorconfig.h  |    6 +++-
 modules/display-filter-lcms.c    |   29 +++++++++++++--------
 4 files changed, 89 insertions(+), 23 deletions(-)
---
diff --git a/app/dialogs/preferences-dialog.c b/app/dialogs/preferences-dialog.c
index 7a9c118..be14267 100644
--- a/app/dialogs/preferences-dialog.c
+++ b/app/dialogs/preferences-dialog.c
@@ -2342,7 +2342,18 @@ prefs_dialog_new (Gimp       *gimp,
                                       "display-rendering-intent", 0, 0,
                                       _("_Display rendering intent:"),
                                       GTK_TABLE (table), row++, NULL);
-            gtk_table_set_row_spacing (GTK_TABLE (table), row - 1, 12);
+
+            button =
+              gimp_prop_check_button_new (color_config,
+                                          "display-use-black-point-compensation",
+                                          _("Use _black point compensation for "
+                                            "the display"));
+
+            gtk_table_attach_defaults (GTK_TABLE (table),
+                                       button, 1, 2, row, row + 1);
+            gtk_widget_show (button);
+            gtk_table_set_row_spacing (GTK_TABLE (table), row, 12);
+            row++;
           }
 
         if (i == 3) /* printer profile */
@@ -2351,6 +2362,17 @@ prefs_dialog_new (Gimp       *gimp,
                                       "simulation-rendering-intent", 0, 0,
                                       _("_Softproof rendering intent:"),
                                       GTK_TABLE (table), row++, NULL);
+
+            button =
+              gimp_prop_check_button_new (color_config,
+                                          "simulation-use-black-point-compensation",
+                                          _("Use black _point compensation "
+                                            "for softproofing"));
+
+            gtk_table_attach_defaults (GTK_TABLE (table),
+                                       button, 1, 2, row, row + 1);
+            gtk_widget_show (button);
+            row++;
           }
       }
 
diff --git a/libgimpconfig/gimpcolorconfig.c b/libgimpconfig/gimpcolorconfig.c
index 1277941..7698337 100644
--- a/libgimpconfig/gimpcolorconfig.c
+++ b/libgimpconfig/gimpcolorconfig.c
@@ -62,19 +62,31 @@
 #define CMYK_PROFILE_BLURB \
   N_("The CMYK color profile used to convert between RGB and CMYK.")
 #define PRINTER_PROFILE_BLURB \
-  N_("The color profile used for simulating a printed version (softproof).")
+  N_("The color profile to use for soft proofing from your image's " \
+     "color space to some other color space, including " \
+     "soft proofing to a printer or other output device profile. ")
 #define DISPLAY_RENDERING_INTENT_BLURB \
-  N_("Sets how colors are mapped for your display.")
+  N_("How colors are converted from your image's color space to your display device. " \
+     "Relative colorimetric is usually the best choice. " \
+     "Unless you use a LUT monitor profile (most monitor profiles are matrix), " \
+     "choosing perceptual intent really gives you relative colorimetric." )
+#define DISPLAY_USE_BPC_BLURB \
+  N_("Do use black point compensation (unless you know you have a reason not to). ")
 #define SIMULATION_RENDERING_INTENT_BLURB \
-  N_("Sets how colors are converted from RGB working space to the " \
-     "print simulation device.")
+  N_("How colors are converted from your image's color space to the " \
+     "output simulation device (usually your monitor). " \
+     "Try them all and choose what looks the best. ")
+#define SIMULATION_USE_BPC_BLURB \
+  N_("Try with and without black point compensation "\
+     "and choose what looks best. ")
 #define SIMULATION_GAMUT_CHECK_BLURB \
-  N_("When enabled, the print simulation will mark colors which can not be " \
-     "represented in the target color space.")
+  N_("When enabled, the print simulation will mark colors " \
+     "which can not be represented in the target color space.")
 #define OUT_OF_GAMUT_COLOR_BLURB \
   N_("The color to use for marking colors which are out of gamut.")
 
 
+
 enum
 {
   PROP_0,
@@ -85,7 +97,9 @@ enum
   PROP_DISPLAY_PROFILE_FROM_GDK,
   PROP_PRINTER_PROFILE,
   PROP_DISPLAY_RENDERING_INTENT,
+  PROP_DISPLAY_USE_BPC,
   PROP_SIMULATION_RENDERING_INTENT,
+  PROP_SIMULATION_USE_BPC,
   PROP_SIMULATION_GAMUT_CHECK,
   PROP_OUT_OF_GAMUT_COLOR,
   PROP_DISPLAY_MODULE
@@ -153,14 +167,24 @@ gimp_color_config_class_init (GimpColorConfigClass *klass)
                                  "display-rendering-intent",
                                  DISPLAY_RENDERING_INTENT_BLURB,
                                  GIMP_TYPE_COLOR_RENDERING_INTENT,
-                                 GIMP_COLOR_RENDERING_INTENT_PERCEPTUAL,
+                                 GIMP_COLOR_RENDERING_INTENT_RELATIVE_COLORIMETRIC,
                                  GIMP_PARAM_STATIC_STRINGS);
+  GIMP_CONFIG_INSTALL_PROP_BOOLEAN (object_class, PROP_DISPLAY_USE_BPC,
+                                    "display-use-black-point-compensation",
+                                    DISPLAY_USE_BPC_BLURB,
+                                    TRUE,
+                                    GIMP_PARAM_STATIC_STRINGS);
   GIMP_CONFIG_INSTALL_PROP_ENUM (object_class, PROP_SIMULATION_RENDERING_INTENT,
                                  "simulation-rendering-intent",
                                  SIMULATION_RENDERING_INTENT_BLURB,
                                  GIMP_TYPE_COLOR_RENDERING_INTENT,
                                  GIMP_COLOR_RENDERING_INTENT_PERCEPTUAL,
                                  GIMP_PARAM_STATIC_STRINGS);
+  GIMP_CONFIG_INSTALL_PROP_BOOLEAN (object_class, PROP_SIMULATION_USE_BPC,
+                                    "simulation-use-black-point-compensation",
+                                    SIMULATION_USE_BPC_BLURB,
+                                    FALSE,
+                                    GIMP_PARAM_STATIC_STRINGS);
   GIMP_CONFIG_INSTALL_PROP_BOOLEAN (object_class, PROP_SIMULATION_GAMUT_CHECK,
                                     "simulation-gamut-check",
                                     SIMULATION_GAMUT_CHECK_BLURB,
@@ -171,7 +195,6 @@ gimp_color_config_class_init (GimpColorConfigClass *klass)
                                 OUT_OF_GAMUT_COLOR_BLURB,
                                 FALSE, &color,
                                 GIMP_PARAM_STATIC_STRINGS);
-
   GIMP_CONFIG_INSTALL_PROP_STRING (object_class, PROP_DISPLAY_MODULE,
                                    "display-module", NULL,
                                    "CdisplayLcms",
@@ -241,9 +264,15 @@ gimp_color_config_set_property (GObject      *object,
     case PROP_DISPLAY_RENDERING_INTENT:
       color_config->display_intent = g_value_get_enum (value);
       break;
+    case PROP_DISPLAY_USE_BPC:
+      color_config->display_use_black_point_compensation = g_value_get_boolean (value);
+      break;
     case PROP_SIMULATION_RENDERING_INTENT:
       color_config->simulation_intent = g_value_get_enum (value);
       break;
+    case PROP_SIMULATION_USE_BPC:
+      color_config->simulation_use_black_point_compensation = g_value_get_boolean (value);
+      break;
     case PROP_SIMULATION_GAMUT_CHECK:
       color_config->simulation_gamut_check = g_value_get_boolean (value);
       break;
@@ -254,7 +283,6 @@ gimp_color_config_set_property (GObject      *object,
       g_free (color_config->display_module);
       color_config->display_module = g_value_dup_string (value);
       break;
-
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
       break;
@@ -292,9 +320,15 @@ gimp_color_config_get_property (GObject    *object,
     case PROP_DISPLAY_RENDERING_INTENT:
       g_value_set_enum (value, color_config->display_intent);
       break;
+    case PROP_DISPLAY_USE_BPC:
+      g_value_set_boolean (value, color_config->display_use_black_point_compensation);
+      break;
     case PROP_SIMULATION_RENDERING_INTENT:
       g_value_set_enum (value, color_config->simulation_intent);
       break;
+    case PROP_SIMULATION_USE_BPC:
+      g_value_set_boolean (value, color_config->simulation_use_black_point_compensation);
+      break;
     case PROP_SIMULATION_GAMUT_CHECK:
       g_value_set_boolean (value, color_config->simulation_gamut_check);
       break;
@@ -304,7 +338,6 @@ gimp_color_config_get_property (GObject    *object,
     case PROP_DISPLAY_MODULE:
       g_value_set_string (value, color_config->display_module);
       break;
-
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
       break;
diff --git a/libgimpconfig/gimpcolorconfig.h b/libgimpconfig/gimpcolorconfig.h
index 22cf17b..9d99428 100644
--- a/libgimpconfig/gimpcolorconfig.h
+++ b/libgimpconfig/gimpcolorconfig.h
@@ -55,10 +55,14 @@ struct _GimpColorConfig
   gboolean                    simulation_gamut_check;
   GimpRGB                     out_of_gamut_color;
 
+  gboolean                    display_use_black_point_compensation;
+  gboolean                    simulation_use_black_point_compensation;
+
   /*< private >*/
   /* Padding for future expansion */
-  void (* _gimp_reserved1) (void);
+#if (GLIB_SIZEOF_VOID_P == 8)
   void (* _gimp_reserved2) (void);
+#endif
   void (* _gimp_reserved3) (void);
   void (* _gimp_reserved4) (void);
   void (* _gimp_reserved5) (void);
diff --git a/modules/display-filter-lcms.c b/modules/display-filter-lcms.c
index 7510360..17966b7 100644
--- a/modules/display-filter-lcms.c
+++ b/modules/display-filter-lcms.c
@@ -338,7 +338,6 @@ cdisplay_lcms_changed (GimpColorDisplay *display)
   cmsHPROFILE      src_profile   = NULL;
   cmsHPROFILE      dest_profile  = NULL;
   cmsHPROFILE      proof_profile = NULL;
-  cmsUInt32Number  flags         = 0;
   cmsUInt16Number  alarmCodes[cmsMAXCHANNELS] = { 0, };
 
   if (lcms->transform)
@@ -365,27 +364,28 @@ cdisplay_lcms_changed (GimpColorDisplay *display)
       break;
     }
 
-  if (config->display_intent ==
-      GIMP_COLOR_RENDERING_INTENT_RELATIVE_COLORIMETRIC)
-    {
-      flags |= cmsFLAGS_BLACKPOINTCOMPENSATION;
-    }
-
   if (proof_profile)
     {
+      cmsUInt32Number softproof_flags = 0;
+
       if (! src_profile)
         src_profile = cmsCreate_sRGBProfile ();
 
       if (! dest_profile)
         dest_profile = cmsCreate_sRGBProfile ();
 
-      flags |= cmsFLAGS_SOFTPROOFING;
+      softproof_flags |= cmsFLAGS_SOFTPROOFING;
+
+      if (config->simulation_use_black_point_compensation)
+        {
+          softproof_flags |= cmsFLAGS_BLACKPOINTCOMPENSATION;
+        }
 
       if (config->simulation_gamut_check)
         {
           guchar r, g, b;
 
-          flags |= cmsFLAGS_GAMUTCHECK;
+          softproof_flags |= cmsFLAGS_GAMUTCHECK;
 
           gimp_rgb_get_uchar (&config->out_of_gamut_color, &r, &g, &b);
 
@@ -401,21 +401,28 @@ cdisplay_lcms_changed (GimpColorDisplay *display)
                                                     proof_profile,
                                                     config->simulation_intent,
                                                     config->display_intent,
-                                                    flags);
+                                                    softproof_flags);
       cmsCloseProfile (proof_profile);
     }
   else if (src_profile || dest_profile)
     {
+      cmsUInt32Number display_flags = 0;
+
       if (! src_profile)
         src_profile = cmsCreate_sRGBProfile ();
 
       if (! dest_profile)
         dest_profile = cmsCreate_sRGBProfile ();
 
+      if (config->display_use_black_point_compensation)
+        {
+          display_flags |= cmsFLAGS_BLACKPOINTCOMPENSATION;
+        }
+
       lcms->transform = cmsCreateTransform (src_profile,  TYPE_RGBA_FLT,
                                             dest_profile, TYPE_RGBA_FLT,
                                             config->display_intent,
-                                            flags);
+                                            display_flags);
     }
 
   if (dest_profile)