[babl] babl: make babl_space_to_icc internal, for now

[Øyvind Kolås <ok src gnome org>]

commit 056cc862095ed2688c5b1d8d0d38ed4f904032aa
Author: Øyvind Kolås <pippin gimp org>
Date:   Fri Sep 22 14:50:48 2017 +0200

    babl: make babl_space_to_icc internal, for now
    
    Also adds an optimized 26 entry LUT, as used in the creation of
    http://pippin.gimp.org/sRGBz/
     Please enter the commit message for your changes. Lines starting

 babl/babl-icc.c          |   73 ++++++++++++++++++++++++++++++++--------------
 babl/babl-internal.h     |   22 +++++++++++++-
 babl/babl-space.c        |    2 +-
 babl/babl.h              |   11 -------
 tools/babl-icc-rewrite.c |   66 +++++++++++++++++++++++++++++++++++------
 5 files changed, 129 insertions(+), 45 deletions(-)
---
diff --git a/babl/babl-icc.c b/babl/babl-icc.c
index b5e85fc..fe146f6 100644
--- a/babl/babl-icc.c
+++ b/babl/babl-icc.c
@@ -405,8 +405,18 @@ static void icc_duplicate_tag(ICC *state, const char *tag)
     icc_write (u32,  128 + 4 + 4 * state->headpos++, state->psize);
 }
 
-void write_trc (ICC *state, const char *name, const BablTRC *trc);
-void write_trc (ICC *state, const char *name, const BablTRC *trc)
+/* brute force optimized 26 entry sRGB LUT */
+static const uint16_t 
lut_srgb_26[]={0,202,455,864,1423,2154,3060,4156,5454,6960,8689,10637,12821,15247,17920,20855,24042,27501,31233,35247,39549,44132,49018,54208,59695,65535};
+
+
+void write_trc (ICC *state,
+                const char *name,
+                const BablTRC *trc,
+                BablICCFlags flags);
+void write_trc (ICC *state,
+                const char *name,
+                const BablTRC *trc,
+                BablICCFlags flags)
 {
 switch (trc->type)
 {
@@ -436,10 +446,26 @@ switch (trc->type)
     break;
   // this is the case catching things not directly representable in v2
   case BABL_TRC_SRGB:
+    if (flags == BABL_ICC_COMPACT_TRC_LUT)
+    {
+      int lut_size = 26;
+      icc_allocate_tag (state, name, 12 + lut_size * 2);
+      icc_write (sign, state->o, "curv");
+      icc_write (u32, state->o + 4, 0);
+      icc_write (u32, state->o + 8, lut_size);
+      {
+        int j;
+        for (j = 0; j < lut_size; j ++)
+        icc_write (u16, state->o + 12 + j * 2, lut_srgb_26[j]);
+      }
+      break;
+    }
   case BABL_TRC_FORMULA_SRGB:
-//  default:
     {
       int lut_size = 512;
+      if (flags == BABL_ICC_COMPACT_TRC_LUT)
+        lut_size = 128;
+
       icc_allocate_tag (state, name, 12 + lut_size * 2);
       icc_write (sign, state->o, "curv");
       icc_write (u32, state->o + 4, 0);
@@ -456,7 +482,11 @@ switch (trc->type)
 
 static void symmetry_test (ICC *state);
 
-const char *babl_space_to_icc (const Babl *babl, int *ret_length)
+const char *babl_space_to_icc (const Babl  *babl,
+                               const char  *description,
+                               const char  *copyright,
+                               BablICCFlags flags,
+                               int         *ret_length)
 {
   const BablSpace *space = &babl->space;
   static char icc[65536];
@@ -529,8 +559,7 @@ const char *babl_space_to_icc (const Babl *babl, int *ret_length)
     icc_write (s15f16, state->o + 12, space->RGBtoXYZ[5]);
     icc_write (s15f16, state->o + 16, space->RGBtoXYZ[8]);
 
-
-    write_trc (state, "rTRC", &space->trc[0]->trc);
+    write_trc (state, "rTRC", &space->trc[0]->trc, flags);
 
     if (space->trc[0] == space->trc[1] &&
         space->trc[0] == space->trc[2])
@@ -540,33 +569,33 @@ const char *babl_space_to_icc (const Babl *babl, int *ret_length)
     }
     else
     {
-      write_trc (state, "gTRC", &space->trc[1]->trc);
-      write_trc (state, "bTRC", &space->trc[2]->trc);
+      write_trc (state, "gTRC", &space->trc[1]->trc, flags);
+      write_trc (state, "bTRC", &space->trc[2]->trc, flags);
     }
 
     {
-      char str[128];
+      char str[128]="CC0/public domain";
       int i;
-      sprintf (str, "babl");
-      icc_allocate_tag(state, "desc", 90 + strlen (str) + 0);
-      icc_write (sign, state->o,"desc");
+      if (!copyright) copyright = str;
+      icc_allocate_tag(state, "cprt", 8 + strlen (copyright) + 1);
+      icc_write (sign, state->o, "text");
       icc_write (u32, state->o + 4, 0);
-      icc_write (u32, state->o + 8, strlen(str) + 1);
-      for (i = 0; str[i]; i++)
-        icc_write (u8, state->o + 12 + i, str[i]);
+      for (i = 0; copyright[i]; i++)
+        icc_write (u8, state->o + 8 + i, copyright[i]);
     }
-
     {
-      char str[128];
+      char str[128]="babl";
       int i;
-      sprintf (str, "CC0/public domain");
-      icc_allocate_tag(state, "cprt", 8 + strlen (str) + 1);
-      icc_write (sign, state->o, "text");
+      if (!description) description = str;
+      icc_allocate_tag(state, "desc", 90 + strlen (description) + 0);
+      icc_write (sign, state->o,"desc");
       icc_write (u32, state->o + 4, 0);
-      for (i = 0; str[i]; i++)
-        icc_write (u8, state->o + 8 + i, str[i]);
+      icc_write (u32, state->o + 8, strlen(description) + 1);
+      for (i = 0; description[i]; i++)
+        icc_write (u8, state->o + 12 + i, description[i]);
     }
 
+
     icc_write (u32, 0, state->no + 0);
     length = state->no + 0;
   }
diff --git a/babl/babl-internal.h b/babl/babl-internal.h
index efa593c..3a7676e 100644
--- a/babl/babl-internal.h
+++ b/babl/babl-internal.h
@@ -445,6 +445,26 @@ const Babl * babl_trc       (const char *name);
 int _babl_file_get_contents (const char  *path,
                              char       **contents,
                              long        *length,
-                             void        *error);
+                            void        *error);
+
+typedef enum {
+  BABL_ICC_DEFAULTS = 0,
+  BABL_ICC_COMPACT_TRC_LUT = 1,
+} BablICCFlags;
+
+/* babl_space_to_icc:
+ *
+ * Creates an ICCv2 RGB matrix profile for a babl space. The profiles strive to
+ * be as small and compact as possible, TRCs are stored as 1024 entry LUT(s).
+ *
+ * you should make a copy of the profile before making another call to this
+ * function.
+ */
+
+const char *babl_space_to_icc (const Babl  *space,
+                               const char  *description,
+                               const char  *copyright,
+                               BablICCFlags flags,
+                               int         *icc_length);
 
 #endif
diff --git a/babl/babl-space.c b/babl/babl-space.c
index 2ffd1de..a362521 100644
--- a/babl/babl-space.c
+++ b/babl/babl-space.c
@@ -175,7 +175,7 @@ static void babl_space_compute_matrices (BablSpace *space)
   double green_XYZ[3]      = { _ xg / _ yg, 1.0, ( 1.0 - _ xg - _ yg) / _ yg};
   double blue_XYZ[3]       = { _ xb / _ yb, 1.0, ( 1.0 - _ xb - _ yb) / _ yb};
   double whitepoint_XYZ[3] = { _ xw / _ yw, 1.0, ( 1.0 - _ xw - _ yw) / _ yw};
-  double D50_XYZ[3]        = {0.9642,       1.0, 0.8249};
+  double D50_XYZ[3]        = {0.96420288, 1.0, 0.82490540};
 #undef _
 
   double mat[9] = {red_XYZ[0], green_XYZ[0], blue_XYZ[0],
diff --git a/babl/babl.h b/babl/babl.h
index a7d75b5..9ab3881 100644
--- a/babl/babl.h
+++ b/babl/babl.h
@@ -145,17 +145,6 @@ char *babl_icc_get_key (const char *icc_data,
                         const char *language,
                         const char *counter);
 
-
-/* babl_space_to_icc:
- *
- * Creates an ICCv2 RGB matrix profile for a babl space. The profiles strive to
- * be as small and compact as possible, TRCs are stored as 1024 entry LUT(s).
- *
- * you should make a copy of the profile before making another call to this
- * function.
- */
-const char *babl_space_to_icc (const Babl *space, int *icc_length);
-
 /* babl_space_get_rgbtoxyz:
 
    Returns the internal, double-precision 3x3 matrix used to convert linear
diff --git a/tools/babl-icc-rewrite.c b/tools/babl-icc-rewrite.c
index f30b20e..e01994e 100644
--- a/tools/babl-icc-rewrite.c
+++ b/tools/babl-icc-rewrite.c
@@ -25,42 +25,85 @@ file_get_contents (const char  *path,
                    char       **contents,
                    long        *length,
                    void        *error);
+
 void file_set_contents (const char *path, const char *data, long length);
 
 int
 main (int    argc,
       char **argv)
 {
+  BablICCFlags flags = 0;
   const Babl *babl;
   char *icc_data = NULL;
   long  icc_len;
   int genlen;
+  char *description = NULL;
+  char *copyright = NULL;
   const char *error;
   const char *la = NULL;
   const char *co = NULL;
+
+  const char *input = NULL;
+  const char *output = NULL;
+  int i;
+
   babl_init ();
 
-  if (!argv[1] || !argv[2])
+
+  for (i = 1; argv[i]; i++)
+  {
+    if (!strcmp (argv[i], "-d") ||
+        !strcmp (argv[i], "--description"))
+    {
+      description = argv[++i];
+    }
+    else if (!strcmp (argv[i], "-c") ||
+             !strcmp (argv[i], "--copyright"))
+    {
+      copyright = argv[++i];
+    }
+    else if (!strcmp (argv[i], "--compact-trc"))
+    {
+      flags |= BABL_ICC_COMPACT_TRC_LUT;
+    }
+    else if (argv[i][0] == '-')
+    {
+      fprintf (stderr, "unknown option %s\n", argv[i]);
+      return -1;
+    }
+    else
+    {
+      if (!input)       input  = argv[i];
+      else if (!output) output = argv[i];
+    }
+  }
+
+  if (!input || !output)
   {
-    fprintf (stderr, "usage: %s <input.icc> <output.icc>\n", argv[0]);
+    fprintf (stderr, "usage: %s [options] <input.icc> <output.icc>\n", argv[0]);
+    fprintf (stderr, " where recognized options are:  \n");
+    fprintf (stderr, "    -d <description>\n");
+    fprintf (stderr, "    -c <copyright>\n");
+    fprintf (stderr, "    --compact-trc\n");
     return -1;
   }
 
-  if (file_get_contents (argv[1], &icc_data, &icc_len, NULL))
+  if (file_get_contents (input, &icc_data, &icc_len, NULL))
     return -1;
 
+  if (!description)
   {
-    char *description = babl_icc_get_key (icc_data, icc_len, "description", la, co);
+    description = babl_icc_get_key (icc_data, icc_len, "description", la, co);
     if (description)
       fprintf (stderr, "description: %s\n", description);
   }
 
+  if (!copyright)
   {
-    char *str = babl_icc_get_key (icc_data, icc_len, "copyright", la, co);
-    if (str)
+    copyright = babl_icc_get_key (icc_data, icc_len, "copyright", la, co);
+    if (copyright)
     {
-      fprintf (stderr, "copyright: %s\n", str);
-      free (str);
+      fprintf (stderr, "copyright: %s\n", copyright);
     }
   }
   {
@@ -87,11 +130,14 @@ main (int    argc,
     return -1;
   }
 
-  icc_data = (char *)babl_space_to_icc (babl, &genlen);
+  icc_data = (char *)babl_space_to_icc (babl, description,
+                                        copyright, flags,
+                                        &genlen);
   if (icc_data)
   {
-    file_set_contents (argv[2], icc_data, genlen);
+    file_set_contents (output, icc_data, genlen);
   }
+  fprintf (stderr, "[%s]\n", output);
 
   babl_exit ();
   return 0;