[gegl] Bug 749902 - Add Hue-Chroma operation/tool and LCH color selector

[Michael Natterer <mitch src gnome org>]

commit 78c84f94a6633c5d79503d2c1de8125b307c705f
Author: Michael Natterer <mitch gimp org>
Date:   Sun May 7 18:26:35 2017 +0200

    Bug 749902 - Add Hue-Chroma operation/tool and LCH color selector
    
    Add hue-chroma operation.

 operations/common/Makefile.am  |    3 +-
 operations/common/hue-chroma.c |  114 ++++++++++++++++++++++++++++++++++++++++
 po/POTFILES.in                 |    1 +
 3 files changed, 117 insertions(+), 1 deletions(-)
---
diff --git a/operations/common/Makefile.am b/operations/common/Makefile.am
index 74e42ec..5b0a655 100644
--- a/operations/common/Makefile.am
+++ b/operations/common/Makefile.am
@@ -14,7 +14,7 @@ LIBS = $(op_libs)
 opdir = $(ext_dir)
 op_LTLIBRARIES = \
        gegl-common.la 
-    
+
 gegl_common_la_SOURCES =\
     alien-map.c \
     module.c \
@@ -70,6 +70,7 @@ gegl_common_la_SOURCES =\
        grey.c \
        grid.c \
        high-pass.c \
+       hue-chroma.c \
        illusion.c \
        image-compare.c \
        image-gradient.c \
diff --git a/operations/common/hue-chroma.c b/operations/common/hue-chroma.c
new file mode 100644
index 0000000..b6712ec
--- /dev/null
+++ b/operations/common/hue-chroma.c
@@ -0,0 +1,114 @@
+/* This file is an image processing operation for GEGL
+ *
+ * GEGL is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or (at your option) any later version.
+ *
+ * GEGL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with GEGL; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright 2017 Elle Stone <ellestone ninedegreesbelow com>
+ *                Michael Natterer <mitch gimp org>
+ */
+
+#include "config.h"
+#include <glib/gi18n-lib.h>
+
+#ifdef GEGL_PROPERTIES
+
+property_double (hue, _("Hue"),  0.0)
+   description  (_("Hue adjustment"))
+   value_range  (-180.0, 180.0)
+
+property_double (chroma, _("Chroma"), 0.0)
+   description  (_("Chroma adjustment"))
+   value_range  (-100.0, 100.0)
+
+property_double (lightness, _("Lightness"), 0.0)
+   description  (_("Lightness adjustment"))
+   value_range  (-100.0, 100.0)
+
+#else
+
+#define GEGL_OP_POINT_FILTER
+
+#define GEGL_OP_NAME     hue_chroma
+#define GEGL_OP_C_SOURCE hue-chroma.c
+
+#include "gegl-op.h"
+
+static void
+prepare (GeglOperation *operation)
+{
+  gegl_operation_set_format (operation, "input",
+                             babl_format ("CIE LCH(ab) alpha float"));
+  gegl_operation_set_format (operation, "output",
+                             babl_format ("CIE LCH(ab) alpha float"));
+}
+
+static gboolean
+process (GeglOperation       *op,
+         void                *in_buf,
+         void                *out_buf,
+         glong                n_pixels,
+         const GeglRectangle *roi,
+         gint                 level)
+{
+  GeglProperties *o = GEGL_PROPERTIES (op);
+  gfloat         *GEGL_ALIGNED in_pixel;
+  gfloat         *GEGL_ALIGNED out_pixel;
+  gfloat          hue;
+  gfloat          chroma;
+  gfloat          lightness;
+
+  in_pixel   = in_buf;
+  out_pixel  = out_buf;
+
+  hue       = o->hue;
+  chroma    = o->chroma;
+  lightness = o->lightness;
+
+  while (n_pixels--)
+    {
+      out_pixel[0] = in_pixel[0] + lightness;
+      out_pixel[1] = in_pixel[1] + chroma;
+      out_pixel[2] = in_pixel[2] + hue;
+
+      out_pixel[1] = CLAMP (out_pixel[1], 0, 200.0);
+
+      out_pixel[3] = in_pixel[3];
+
+      in_pixel  += 4;
+      out_pixel += 4;
+    }
+
+  return TRUE;
+}
+
+static void
+gegl_op_class_init (GeglOpClass *klass)
+{
+  GeglOperationClass            *operation_class;
+  GeglOperationPointFilterClass *point_filter_class;
+
+  operation_class    = GEGL_OPERATION_CLASS (klass);
+  point_filter_class = GEGL_OPERATION_POINT_FILTER_CLASS (klass);
+
+  operation_class->prepare    = prepare;
+  point_filter_class->process = process;
+
+  gegl_operation_class_set_keys (operation_class,
+      "name",       "gegl:hue-chroma",
+      "title",      _("Hue-Chroma"),
+      "categories", "color",
+      "description", _("Adjust LCH Hue, Chroma, and Lightness"),
+      NULL);
+}
+
+#endif
diff --git a/po/POTFILES.in b/po/POTFILES.in
index e95a8f7..c05c747 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -59,6 +59,7 @@ operations/common/gegl.c
 operations/common/grey.c
 operations/common/grid.c
 operations/common/high-pass.c
+operations/common/hue-chroma.c
 operations/common/illusion.c
 operations/common/image-compare.c
 operations/common/image-gradient.c