[babl/wip/pippin/inverted-cmyk: 5/9] add more proper cmyk extension

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 39b3ae7fd691bb76604c53b867dece05cbfe2d56
Author: Øyvind Kolås <pippin gimp org>
Date:   Fri Aug 24 18:50:20 2018 +0200

    add more proper cmyk extension

 extensions/CMYK.c       | 565 ++++++++++++++++++++++++++++++++++++++++++++++++
 extensions/naive-CMYK.c |  45 ++--
 2 files changed, 587 insertions(+), 23 deletions(-)
---
diff --git a/extensions/CMYK.c b/extensions/CMYK.c
new file mode 100644
index 0000000..c1028ce
--- /dev/null
+++ b/extensions/CMYK.c
@@ -0,0 +1,565 @@
+/* babl - dynamically extendable universal pixel conversion library.
+ * Copyright (C) 2005, 2018 Øyvind Kolås.
+ *
+ * This library 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.
+ *
+ * This library 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 this library; if not, see
+ * <https://www.gnu.org/licenses/>.
+ */
+
+/* This file define the "cmy" and "cmyk" models and related formats these
+ * are CMYK formats withthe components stored so that 0 means full coverage
+ * and 1.0 means no coverage, making additive compositing/blending work
+ * one thep pixel data.
+ */
+
+#include "config.h"
+#include <math.h>
+#include <string.h>
+
+#include "babl.h"
+#include "base/util.h"
+
+static void  rgba_to_cmykA (const Babl *conversion,char *src,
+                            char *dst,
+                            long  n);
+
+static void  cmykA_to_rgba (const Babl *conversion,char *src,
+                            char *dst,
+                            long  n);
+
+static void  rgba_to_cmyka (const Babl *conversion,char *src,
+                            char *dst,
+                            long  n);
+
+static void  cmyka_to_rgba (const Babl *conversion,char *src,
+                            char *dst,
+                            long  n);
+
+static void  rgba_to_cmyk (const Babl *conversion,char *src,
+                           char *dst,
+                           long  n);
+
+static void  cmyk_to_rgba (const Babl *conversion,char *src,
+                           char *dst,
+                           long  n);
+
+static void  rgba_to_cmy  (const Babl *conversion,char *src,
+                           char *dst,
+                           long  n);
+
+static void  cmy_to_rgba  (const Babl *conversion,char *src,
+                           char *dst,
+                           long  n);
+
+int init (void);
+
+int
+init (void)
+{
+
+
+  babl_component_new ("cyan", NULL);
+  babl_component_new ("yellow", NULL);
+  babl_component_new ("magenta", NULL);
+  babl_component_new ("key", NULL);
+
+
+  babl_component_new ("ca", NULL);
+  babl_component_new ("ma", NULL);
+  babl_component_new ("ya", NULL);
+  babl_component_new ("ka", NULL);
+
+
+  babl_model_new (
+    "name", "camayakaA",
+    babl_component ("ca"),
+    babl_component ("ma"),
+    babl_component ("ya"),
+    babl_component ("ka"),
+    babl_component ("A"),
+    NULL
+  );
+
+  babl_model_new (
+    "name", "cmykA",
+    babl_component ("cyan"),
+    babl_component ("magenta"),
+    babl_component ("yellow"),
+    babl_component ("key"),
+    babl_component ("A"),
+    NULL
+  );
+  babl_model_new (
+    "name", "cmyk",
+    babl_component ("cyan"),
+    babl_component ("magenta"),
+    babl_component ("yellow"),
+    babl_component ("key"),
+    NULL
+  );
+  babl_model_new (
+    "name", "cmy",
+    babl_component ("cyan"),
+    babl_component ("magenta"),
+    babl_component ("yellow"),
+    NULL
+  );
+
+  babl_conversion_new (
+    babl_model ("RGBA"),
+    babl_model ("camayakaA"),
+    "linear", rgba_to_cmykA,
+    NULL
+  );
+  babl_conversion_new (
+    babl_model ("camayakaA"),
+    babl_model ("RGBA"),
+    "linear", cmykA_to_rgba,
+    NULL
+  );
+
+  babl_conversion_new (
+    babl_model ("RGBA"),
+    babl_model ("cmykA"),
+    "linear", rgba_to_cmyka,
+    NULL
+  );
+  babl_conversion_new (
+    babl_model ("cmykA"),
+    babl_model ("RGBA"),
+    "linear", cmyka_to_rgba,
+    NULL
+  );
+  babl_conversion_new (
+    babl_model ("RGBA"),
+    babl_model ("cmyk"),
+    "linear", rgba_to_cmyk,
+    NULL
+  );
+  babl_conversion_new (
+    babl_model ("cmyk"),
+    babl_model ("RGBA"),
+    "linear", cmyk_to_rgba,
+    NULL
+  );
+  babl_conversion_new (
+    babl_model ("RGBA"),
+    babl_model ("cmy"),
+    "linear", rgba_to_cmy,
+    NULL
+  );
+  babl_conversion_new (
+    babl_model ("cmy"),
+    babl_model ("RGBA"),
+    "linear", cmy_to_rgba,
+    NULL
+  );
+
+  babl_format_new (
+    "name", "camayakaA float",
+    babl_model ("camayakaA"),
+    babl_type ("float"),
+    babl_component ("ca"),
+    babl_component ("ma"),
+    babl_component ("ya"),
+    babl_component ("ka"),
+    babl_component ("A"),
+    NULL
+  );
+
+  babl_format_new (
+    "name", "cmykA float",
+    babl_model ("cmykA"),
+    babl_type ("float"),
+    babl_component ("cyan"),
+    babl_component ("magenta"),
+    babl_component ("yellow"),
+    babl_component ("key"),
+    babl_component ("A"),
+    NULL
+  );
+  babl_format_new (
+    "name", "cmyk float",
+    babl_model ("cmyk"),
+    babl_type ("float"),
+    babl_component ("cyan"),
+    babl_component ("magenta"),
+    babl_component ("yellow"),
+    babl_component ("key"),
+    NULL
+  );
+  babl_format_new (
+    "name", "cmy float",
+    babl_model ("cmy"),
+    babl_type ("float"),
+    babl_component ("cyan"),
+    babl_component ("magenta"),
+    babl_component ("yellow"),
+    NULL
+  );
+
+  babl_format_new (
+    "name", "cmyk u8",
+    babl_model ("cmyk"),
+    babl_type ("u8"),
+    babl_component ("cyan"),
+    babl_component ("magenta"),
+    babl_component ("yellow"),
+    babl_component ("key"),
+    NULL
+  );
+  babl_format_new (
+    "name", "cmykA u8",
+    babl_model ("cmykA"),
+    babl_type ("u8"),
+    babl_component ("cyan"),
+    babl_component ("magenta"),
+    babl_component ("yellow"),
+    babl_component ("key"),
+    babl_component ("A"),
+    NULL
+  );
+
+  return 0;
+}
+
+static void
+rgba_to_cmykA (const Babl *conversion,char *src,
+               char *dst,
+               long  n)
+{
+  while (n--)
+    {
+      double red   = linear_to_gamma_2_2 (((double *) src)[0]);
+      double green = linear_to_gamma_2_2 (((double *) src)[1]);
+      double blue  = linear_to_gamma_2_2 (((double *) src)[2]);
+      double alpha = ((double *) src)[3];
+
+      double cyan, magenta, yellow, key;
+
+      double pullout = 1.0;
+
+      cyan    = 1.0 - red;
+      magenta = 1.0 - green;
+      yellow  = 1.0 - blue;
+
+      key = 1.0;
+      if (cyan < key) key = cyan;
+      if (magenta < key) key = magenta;
+      if (yellow < key) key = yellow;
+
+      key *= pullout;
+
+      if (key < 1.0)
+        {
+          cyan    = (cyan - key)    / (1.0 - key);
+          magenta = (magenta - key) / (1.0 - key);
+          yellow  = (yellow - key)  / (1.0 - key);
+        }
+      else
+        {
+          cyan    = 0.0;
+          magenta = 0.0;
+          yellow  = 0.0;
+        }
+
+      ((double *) dst)[0] = (1.0-cyan) * alpha;
+      ((double *) dst)[1] = (1.0-magenta) * alpha;
+      ((double *) dst)[2] = (1.0-yellow) * alpha;
+      ((double *) dst)[3] = (1.0-key) * alpha;
+      ((double *) dst)[4] = alpha;
+
+      src += 4 * sizeof (double);
+      dst += 5 * sizeof (double);
+    }
+}
+
+static void
+cmykA_to_rgba (const Babl *conversion,char *src,
+               char *dst,
+               long  n)
+{
+  while (n--)
+    {
+      double alpha   = ((double *) src)[4];
+      double ralpha  = alpha>0.000001?1.0/alpha:0.0;
+      double cyanI   = ((double *) src)[0] * ralpha;
+      double magentaI= ((double *) src)[1] * ralpha;
+      double yellowI = ((double *) src)[2] * ralpha;
+      double keyI    = ((double *) src)[3] * ralpha;
+
+      double cyan    = 1.0-cyanI;
+      double magenta = 1.0-magentaI;
+      double yellow  = 1.0-yellowI;
+      double key     = 1.0-keyI;
+
+      double red, green, blue;
+
+      if (key < 1.0)
+        {
+          cyan    = cyan * (1.0 - key) + key;
+          magenta = magenta * (1.0 - key) + key;
+          yellow  = yellow * (1.0 - key) + key;
+        }
+      else
+        {
+          cyan = magenta = yellow = 1.0;
+        }
+
+      red   = 1.0 - cyan;
+      green = 1.0 - magenta;
+      blue  = 1.0 - yellow;
+
+      ((double *) dst)[0] = gamma_2_2_to_linear (red);
+      ((double *) dst)[1] = gamma_2_2_to_linear (green);
+      ((double *) dst)[2] = gamma_2_2_to_linear (blue);
+      ((double *) dst)[3] = alpha;
+
+      src += 5 * sizeof (double);
+      dst += 4 * sizeof (double);
+    }
+}
+
+static void
+rgba_to_cmyka (const Babl *conversion,char *src,
+               char *dst,
+               long  n)
+{
+  while (n--)
+    {
+      double red   = linear_to_gamma_2_2 (((double *) src)[0]);
+      double green = linear_to_gamma_2_2 (((double *) src)[1]);
+      double blue  = linear_to_gamma_2_2 (((double *) src)[2]);
+      double alpha = ((double *) src)[3];
+
+      double cyan, magenta, yellow, key;
+
+      double pullout = 1.0;
+
+      cyan    = 1.0 - red;
+      magenta = 1.0 - green;
+      yellow  = 1.0 - blue;
+
+      key = 1.0;
+      if (cyan < key) key = cyan;
+      if (magenta < key) key = magenta;
+      if (yellow < key) key = yellow;
+
+      key *= pullout;
+
+      if (key < 1.0)
+        {
+          cyan    = (cyan - key)    / (1.0 - key);
+          magenta = (magenta - key) / (1.0 - key);
+          yellow  = (yellow - key)  / (1.0 - key);
+        }
+      else
+        {
+          cyan    = 0.0;
+          magenta = 0.0;
+          yellow  = 0.0;
+        }
+
+      ((double *) dst)[0] = 1.0-cyan;
+      ((double *) dst)[1] = 1.0-magenta;
+      ((double *) dst)[2] = 1.0-yellow;
+      ((double *) dst)[3] = 1.0-key;
+      ((double *) dst)[4] = alpha;
+
+      src += 4 * sizeof (double);
+      dst += 5 * sizeof (double);
+    }
+}
+
+static void
+cmyka_to_rgba (const Babl *conversion,char *src,
+               char *dst,
+               long  n)
+{
+  while (n--)
+    {
+      double cyan    = 1.0-((double *) src)[0];
+      double magenta = 1.0-((double *) src)[1];
+      double yellow  = 1.0-((double *) src)[2];
+      double key     = 1.0-((double *) src)[3];
+      double alpha   = ((double *) src)[4];
+
+      double red, green, blue;
+
+      if (key < 1.0)
+        {
+          cyan    = cyan * (1.0 - key) + key;
+          magenta = magenta * (1.0 - key) + key;
+          yellow  = yellow * (1.0 - key) + key;
+        }
+      else
+        {
+          cyan = magenta = yellow = 1.0;
+        }
+
+      red   = 1.0 - cyan;
+      green = 1.0 - magenta;
+      blue  = 1.0 - yellow;
+
+      ((double *) dst)[0] = gamma_2_2_to_linear (red);
+      ((double *) dst)[1] = gamma_2_2_to_linear (green);
+      ((double *) dst)[2] = gamma_2_2_to_linear (blue);
+      ((double *) dst)[3] = alpha;
+
+      src += 5 * sizeof (double);
+      dst += 4 * sizeof (double);
+    }
+}
+
+static void
+rgba_to_cmyk (const Babl *conversion,char *src,
+              char *dst,
+              long  n)
+{
+  while (n--)
+    {
+      double red   = linear_to_gamma_2_2 (((double *) src)[0]);
+      double green = linear_to_gamma_2_2 (((double *) src)[1]);
+      double blue  = linear_to_gamma_2_2 (((double *) src)[2]);
+
+      double cyan, magenta, yellow, key;
+
+      double pullout = 1.0;
+
+      cyan    = 1.0 - red;
+      magenta = 1.0 - green;
+      yellow  = 1.0 - blue;
+
+      key = 1.0;
+      if (cyan < key) key = cyan;
+      if (magenta < key) key = magenta;
+      if (yellow < key) key = yellow;
+
+      key *= pullout;
+
+      if (key < 1.0)
+        {
+          cyan    = (cyan - key)    / (1.0 - key);
+          magenta = (magenta - key) / (1.0 - key);
+          yellow  = (yellow - key)  / (1.0 - key);
+        }
+      else
+        {
+          cyan    = 0.0;
+          magenta = 0.0;
+          yellow  = 0.0;
+        }
+
+      ((double *) dst)[0] = 1.0-cyan;
+      ((double *) dst)[1] = 1.0-magenta;
+      ((double *) dst)[2] = 1.0-yellow;
+      ((double *) dst)[3] = 1.0-key;
+
+      src += 4 * sizeof (double);
+      dst += 4 * sizeof (double);
+    }
+}
+
+static void
+cmyk_to_rgba (const Babl *conversion,char *src,
+              char *dst,
+              long  n)
+{
+  while (n--)
+    {
+      double cyan    = 1.0-((double *) src)[0];
+      double magenta = 1.0-((double *) src)[1];
+      double yellow  = 1.0-((double *) src)[2];
+      double key     = 1.0-((double *) src)[3];
+
+      double red, green, blue;
+
+      if (key < 1.0)
+        {
+          cyan    = cyan * (1.0 - key) + key;
+          magenta = magenta * (1.0 - key) + key;
+          yellow  = yellow * (1.0 - key) + key;
+        }
+      else
+        {
+          cyan = magenta = yellow = 1.0;
+        }
+
+      red   = 1.0 - cyan;
+      green = 1.0 - magenta;
+      blue  = 1.0 - yellow;
+
+      ((double *) dst)[0] = gamma_2_2_to_linear (red);
+      ((double *) dst)[1] = gamma_2_2_to_linear (green);
+      ((double *) dst)[2] = gamma_2_2_to_linear (blue);
+
+      ((double *) dst)[3] = 1.0;
+
+      src += 4 * sizeof (double);
+      dst += 4 * sizeof (double);
+    }
+}
+
+static void
+rgba_to_cmy (const Babl *conversion,char *src,
+             char *dst,
+             long  n)
+{
+  while (n--)
+    {
+      double red   = linear_to_gamma_2_2 (((double *) src)[0]);
+      double green = linear_to_gamma_2_2 (((double *) src)[1]);
+      double blue  = linear_to_gamma_2_2 (((double *) src)[2]);
+
+      double cyan, magenta, yellow;
+
+      cyan    = 1.0 - red;
+      magenta = 1.0 - green;
+      yellow  = 1.0 - blue;
+
+      ((double *) dst)[0] = 1.0-cyan;
+      ((double *) dst)[1] = 1.0-magenta;
+      ((double *) dst)[2] = 1.0-yellow;
+
+      src += 4 * sizeof (double);
+      dst += 3 * sizeof (double);
+    }
+}
+
+static void
+cmy_to_rgba (const Babl *conversion,char *src,
+              char *dst,
+              long  n)
+{
+  while (n--)
+    {
+      double cyan    = 1.0-((double *) src)[0];
+      double magenta = 1.0-((double *) src)[1];
+      double yellow  = 1.0-((double *) src)[2];
+
+      double red, green, blue;
+
+      red   = 1.0 - cyan;
+      green = 1.0 - magenta;
+      blue  = 1.0 - yellow;
+
+      ((double *) dst)[0] = gamma_2_2_to_linear (red);
+      ((double *) dst)[1] = gamma_2_2_to_linear (green);
+      ((double *) dst)[2] = gamma_2_2_to_linear (blue);
+
+      ((double *) dst)[3] = 1.0;
+
+      src += 3 * sizeof (double);
+      dst += 4 * sizeof (double);
+    }
+}
diff --git a/extensions/naive-CMYK.c b/extensions/naive-CMYK.c
index c2d3071..371599f 100644
--- a/extensions/naive-CMYK.c
+++ b/extensions/naive-CMYK.c
@@ -45,25 +45,24 @@ int init (void);
 int
 init (void)
 {
-  return 0; // use the CMYK extension instead
-  babl_component_new ("cyan", NULL);
-  babl_component_new ("yellow", NULL);
-  babl_component_new ("magenta", NULL);
-  babl_component_new ("key", NULL);
+  babl_component_new ("Cyan", NULL);
+  babl_component_new ("Yellow", NULL);
+  babl_component_new ("Magenta", NULL);
+  babl_component_new ("Key", NULL);
 
   babl_model_new (
     "name", "CMYK",
-    babl_component ("cyan"),
-    babl_component ("magenta"),
-    babl_component ("yellow"),
-    babl_component ("key"),
+    babl_component ("Cyan"),
+    babl_component ("Magenta"),
+    babl_component ("Yellow"),
+    babl_component ("Key"),
     NULL
   );
   babl_model_new (
     "name", "CMY",
-    babl_component ("cyan"),
-    babl_component ("magenta"),
-    babl_component ("yellow"),
+    babl_component ("Cyan"),
+    babl_component ("Magenta"),
+    babl_component ("Yellow"),
     NULL
   );
 
@@ -96,19 +95,19 @@ init (void)
     "name", "CMYK float",
     babl_model ("CMYK"),
     babl_type ("float"),
-    babl_component ("cyan"),
-    babl_component ("magenta"),
-    babl_component ("yellow"),
-    babl_component ("key"),
+    babl_component ("Cyan"),
+    babl_component ("Magenta"),
+    babl_component ("Yellow"),
+    babl_component ("Key"),
     NULL
   );
   babl_format_new (
     "name", "CMY float",
     babl_model ("CMY"),
     babl_type ("float"),
-    babl_component ("cyan"),
-    babl_component ("magenta"),
-    babl_component ("yellow"),
+    babl_component ("Cyan"),
+    babl_component ("Magenta"),
+    babl_component ("Yellow"),
     NULL
   );
 
@@ -116,10 +115,10 @@ init (void)
     "name", "CMYK u8",
     babl_model ("CMYK"),
     babl_type ("u8"),
-    babl_component ("cyan"),
-    babl_component ("magenta"),
-    babl_component ("yellow"),
-    babl_component ("key"),
+    babl_component ("Cyan"),
+    babl_component ("Magenta"),
+    babl_component ("Yellow"),
+    babl_component ("Key"),
     NULL
   );