[babl] babl: abstract space duplicate detection

[Øyvind Kolås <ok src gnome org>]

commit 633e2dfceb0bd8dae135058eead337395167c55a
Author: Øyvind Kolås <pippin gimp org>
Date:   Sun Sep 3 16:03:13 2017 +0200

    babl: abstract space duplicate detection

 babl/babl-icc.c      |   45 +++++++++++++++++----------------------------
 babl/babl-internal.h |    8 ++++++++
 babl/babl-space.c    |   31 +++++++++++++++++++++++++++++++
 babl/babl.h          |    4 +---
 4 files changed, 57 insertions(+), 31 deletions(-)
---
diff --git a/babl/babl-icc.c b/babl/babl-icc.c
index 3fa24e9..2682fcd 100644
--- a/babl/babl-icc.c
+++ b/babl/babl-icc.c
@@ -635,6 +635,7 @@ babl_space_from_icc (const char  *icc_data,
   const char *int_err;
   char *descr     = NULL;
   char *copyright = NULL;
+  Babl *ret = NULL;
 
   sign_t profile_class, color_space;
 
@@ -748,25 +749,16 @@ babl_space_from_icc (const char  *icc_data,
      wY = icc_read (s15f16, offset + 8 + 4);
      wZ = icc_read (s15f16, offset + 8 + 4 * 2);
 
-     if (trc_red == babl_trc ("sRGB") &&
-         trc_green == babl_trc ("sRGB") &&
-         trc_blue == babl_trc ("sRGB") &&
-         fabs(rx - 0.436042) < 0.001 &&
-         fabs(ry - 0.222492) < 0.001 &&
-         fabs(rz - 0.013916) < 0.001 &&
-         fabs(gx - 0.385122) < 0.001 &&
-         fabs(gy - 0.716915) < 0.001 &&
-         fabs(gz - 0.097063) < 0.001 &&
-         fabs(bx - 0.143053) < 0.001 &&
-         fabs(by - 0.060609) < 0.001 &&
-         fabs(bz - 0.713939) < 0.001)
+     ret = (void*)babl_space_match_trc_matrix (trc_red, trc_green, trc_blue,
+                                        rx, ry, rz, gx, gy, gz, bx, by, bz);
+     if (ret)
      {
         babl_free (state);
-        return babl_space ("sRGB");
+        return ret;
      }
 
      {
-       Babl *ret = (void*)babl_space_from_rgbxyz_matrix (NULL,
+       ret  = (void*)babl_space_from_rgbxyz_matrix (NULL,
                 wX, wY, wZ,
                 rx, gx, bx,
                 ry, gy, by,
@@ -792,7 +784,7 @@ babl_space_from_icc (const char  *icc_data,
 
      if (phosporant != 0)
      {
-       *error = "unhandled phosporants, please report bug";
+       *error = "unhandled phosporants, please report bug against babl with profile";
        return NULL;
      }
      if (channels != 3)
@@ -815,19 +807,16 @@ babl_space_from_icc (const char  *icc_data,
        double wZ = icc_read (s15f16, offset + 8 + 4 * 2);
        babl_free (state);
 
-       {
-         Babl *ret = (void*) babl_space_from_chromaticities (NULL,
-                       wX / (wX + wY + wZ),
-                       wY / (wX + wY + wZ),
-                       red_x, red_y,
-                       green_x, green_y,
-                       blue_x, blue_y,
-                       trc_red, trc_green, trc_blue);
-         ret->space.description = descr;
-         ret->space.copyright = copyright;
-         return ret;
-       }
-
+       ret = (void*) babl_space_from_chromaticities (NULL,
+                     wX / (wX + wY + wZ),
+                     wY / (wX + wY + wZ),
+                     red_x, red_y,
+                     green_x, green_y,
+                     blue_x, blue_y,
+                     trc_red, trc_green, trc_blue);
+       ret->space.description = descr;
+       ret->space.copyright = copyright;
+       return ret;
      }
   }
 
diff --git a/babl/babl-internal.h b/babl/babl-internal.h
index 6593862..ca65279 100644
--- a/babl/babl-internal.h
+++ b/babl/babl-internal.h
@@ -362,4 +362,12 @@ void _babl_space_add_universal_rgb (const Babl *space);
 const Babl *
 babl_trc_formula_srgb (double gamma, double a, double b, double c, double d);
 
+
+const Babl *babl_space_match_trc_matrix (const Babl *trc_red,
+                                         const Babl *trc_green,
+                                         const Babl *trc_blue,
+                                         float rx, float ry, float rz,
+                                         float gx, float gy, float gz,
+                                         float bx, float by, float bz);
+
 #endif
diff --git a/babl/babl-space.c b/babl/babl-space.c
index 8ed8465..20ce40c 100644
--- a/babl/babl-space.c
+++ b/babl/babl-space.c
@@ -772,3 +772,34 @@ void _babl_space_add_universal_rgb (const Babl *space)
   babl_space_class_for_each (add_rgb_adapter, (void*)space);
 }
 
+
+const Babl *babl_space_match_trc_matrix (const Babl *trc_red,
+                                         const Babl *trc_green,
+                                         const Babl *trc_blue,
+                                         float rx, float ry, float rz,
+                                         float gx, float gy, float gz,
+                                         float bx, float by, float bz)
+{
+  // XXX: extend to iteratre through registered spaces and finding
+  //      already registered ones that are close enough duplicates
+  //      first registered space (thus also internal babl ones) wins.
+  //      this makes using babl to get icc meta data difficult, perhaps
+  //      the icc meta data should be passed out-of-band?
+
+  if (trc_red == babl_trc ("sRGB") &&
+      trc_green == babl_trc ("sRGB") &&
+      trc_blue == babl_trc ("sRGB") &&
+      fabs(rx - 0.436042) < 0.001 &&
+      fabs(ry - 0.222492) < 0.001 &&
+      fabs(rz - 0.013916) < 0.001 &&
+      fabs(gx - 0.385122) < 0.001 &&
+      fabs(gy - 0.716915) < 0.001 &&
+      fabs(gz - 0.097063) < 0.001 &&
+      fabs(bx - 0.143053) < 0.001 &&
+      fabs(by - 0.060609) < 0.001 &&
+      fabs(bz - 0.713939) < 0.001)
+   {
+     return babl_space ("sRGB");
+   }
+  return NULL;
+}
diff --git a/babl/babl.h b/babl/babl.h
index 3527a60..01431a0 100644
--- a/babl/babl.h
+++ b/babl/babl.h
@@ -92,12 +92,10 @@ const Babl * babl_trc       (const char *name);
  * babl_trc_gamma:
  *
  * Creates a Babl TRC for a specific gamma value, it will be given
- * a name 
+ * a name that is a short string representation of the value.
  */
 const Babl * babl_trc_gamma (double gamma);
 
-
-
 /**
  * babl_space:
  *