app, libgimpbase: allow to select colors by CIE L, C, and H

Add the additional enum values to enum GimpSelectCriterion, and
the few needed lines to gimppickable-contiguous-region.c.

It's horribly slow, but works.

app/core/gimppickable-contiguous-region.c

@@ -285,6 +285,12 @@ choose_format (GeglBuffer          *buffer,
       format = babl_format ("HSVA float");
       break;
 
+    case GIMP_SELECT_CRITERION_LCH_L:
+    case GIMP_SELECT_CRITERION_LCH_C:
+    case GIMP_SELECT_CRITERION_LCH_H:
+      format = babl_format ("CIE LCH(ab) alpha float");
+      break;
+
     default:
       g_return_val_if_reached (NULL);
       break;
@@ -362,6 +368,19 @@ pixel_difference (const gfloat        *col1,
         case GIMP_SELECT_CRITERION_V:
           max = fabs (col1[2] - col2[2]);
           break;
+
+        case GIMP_SELECT_CRITERION_LCH_L:
+          max = fabs (col1[0] - col2[0]) / 100.0;
+          break;
+
+        case GIMP_SELECT_CRITERION_LCH_C:
+          max = fabs (col1[1] - col2[1]) / 100.0;
+          break;
+
+        case GIMP_SELECT_CRITERION_LCH_H:
+          max = fabs (col1[2] - col2[2]) / 360.0;
+          max = MIN (max, 1.0 - max);
+          break;
         }
     }
 

libgimpbase/gimpbaseenums.c

@@ -1581,6 +1581,9 @@ gimp_select_criterion_get_type (void)
     { GIMP_SELECT_CRITERION_S, "GIMP_SELECT_CRITERION_S", "s" },
     { GIMP_SELECT_CRITERION_V, "GIMP_SELECT_CRITERION_V", "v" },
     { GIMP_SELECT_CRITERION_A, "GIMP_SELECT_CRITERION_A", "a" },
+    { GIMP_SELECT_CRITERION_LCH_L, "GIMP_SELECT_CRITERION_LCH_L", "lch-l" },
+    { GIMP_SELECT_CRITERION_LCH_C, "GIMP_SELECT_CRITERION_LCH_C", "lch-c" },
+    { GIMP_SELECT_CRITERION_LCH_H, "GIMP_SELECT_CRITERION_LCH_H", "lch-h" },
     { 0, NULL, NULL }
   };
 
@@ -1594,6 +1597,9 @@ gimp_select_criterion_get_type (void)
     { GIMP_SELECT_CRITERION_S, NC_("select-criterion", "Saturation"), NULL },
     { GIMP_SELECT_CRITERION_V, NC_("select-criterion", "Value"), NULL },
     { GIMP_SELECT_CRITERION_A, NC_("select-criterion", "Alpha"), NULL },
+    { GIMP_SELECT_CRITERION_LCH_L, NC_("select-criterion", "LCH Lightness"), NULL },
+    { GIMP_SELECT_CRITERION_LCH_C, NC_("select-criterion", "LCH Chroma"), NULL },
+    { GIMP_SELECT_CRITERION_LCH_H, NC_("select-criterion", "LCH Hue"), NULL },
     { 0, NULL, NULL }
   };
 

libgimpbase/gimpbaseenums.h

@@ -743,7 +743,10 @@ typedef enum
   GIMP_SELECT_CRITERION_H,          /*< desc="Hue"           >*/
   GIMP_SELECT_CRITERION_S,          /*< desc="Saturation"    >*/
   GIMP_SELECT_CRITERION_V,          /*< desc="Value"         >*/
-  GIMP_SELECT_CRITERION_A           /*< desc="Alpha"      >*/
+  GIMP_SELECT_CRITERION_A,          /*< desc="Alpha"         >*/
+  GIMP_SELECT_CRITERION_LCH_L,      /*< desc="LCH Lightness" >*/
+  GIMP_SELECT_CRITERION_LCH_C,      /*< desc="LCH Chroma"    >*/
+  GIMP_SELECT_CRITERION_LCH_H,      /*< desc="LCH Hue"       >*/
 } GimpSelectCriterion;
 
 

tools/pdbgen/enums.pl

@@ -522,7 +522,10 @@ package Gimp::CodeGen::enums;
 			  GIMP_SELECT_CRITERION_R GIMP_SELECT_CRITERION_G
 			  GIMP_SELECT_CRITERION_B GIMP_SELECT_CRITERION_H
 			  GIMP_SELECT_CRITERION_S GIMP_SELECT_CRITERION_V
-			  GIMP_SELECT_CRITERION_A) ],
+			  GIMP_SELECT_CRITERION_A
+			  GIMP_SELECT_CRITERION_LCH_L
+			  GIMP_SELECT_CRITERION_LCH_C
+			  GIMP_SELECT_CRITERION_LCH_H) ],
 	  mapping => { GIMP_SELECT_CRITERION_COMPOSITE => '0',
 		       GIMP_SELECT_CRITERION_R => '1',
 		       GIMP_SELECT_CRITERION_G => '2',
@@ -530,7 +533,10 @@ package Gimp::CodeGen::enums;
 		       GIMP_SELECT_CRITERION_H => '4',
 		       GIMP_SELECT_CRITERION_S => '5',
 		       GIMP_SELECT_CRITERION_V => '6',
-		       GIMP_SELECT_CRITERION_A => '7' }
+		       GIMP_SELECT_CRITERION_A => '7',
+		       GIMP_SELECT_CRITERION_LCH_L => '8',
+		       GIMP_SELECT_CRITERION_LCH_C => '9',
+		       GIMP_SELECT_CRITERION_LCH_H => '10' }
 	},
     GimpSizeType =>
 	{ contig => 1,