[babl] babl: add babl_space_rgb_matrix

[Øyvind Kolås <ok src gnome org>]

commit 245de756393f82f8bc909b368eb6d89bf9361b6f
Author: Øyvind Kolås <pippin gimp org>
Date:   Sat Aug 19 04:19:37 2017 +0200

    babl: add babl_space_rgb_matrix

 babl/babl-space.c |   64 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 babl/babl-space.h |    2 +
 babl/babl.h       |   17 +++++++++++++-
 3 files changed, 82 insertions(+), 1 deletions(-)
---
diff --git a/babl/babl-space.c b/babl/babl-space.c
index 37c40ad..a4d695c 100644
--- a/babl/babl-space.c
+++ b/babl/babl-space.c
@@ -144,6 +144,70 @@ babl_space (const char *name)
 }
 
 const Babl *
+babl_space_rgb_matrix (const char *name,
+                       double rx, double gx, double bx,
+                       double ry, double gy, double by,
+                       double rz, double gz, double bz,
+                       const Babl *trc_red,
+                       const Babl *trc_green,
+                       const Babl *trc_blue)
+{
+  int i=0;
+  static BablSpace space;
+  space.instance.class_type = BABL_SPACE;
+  space.instance.id         = 0;
+
+  space.xr = rx;
+  space.yr = gx;
+  space.xg = bx;
+  space.yg = ry;
+  space.xb = gy;
+  space.yb = by;
+  space.xw = rz;
+  space.yw = gz;
+  space.pad = bz;
+  space.trc[0] = trc_red;
+  space.trc[1] = trc_green?trc_green:trc_red;
+  space.trc[2] = trc_blue?trc_blue:trc_red;
+
+  for (i = 0; space_db[i].instance.class_type; i++)
+  {
+    int offset = ((char*)&space_db[i].xr) - (char*)(&space_db[i]);
+    int size   = ((char*)&space_db[i].trc) + sizeof(space_db[i].trc) - ((char*)&space_db[i].xr);
+
+    if (memcmp ((char*)(&space_db[i]) + offset, ((char*)&space) + offset, size)==0)
+      {
+        return (void*)&space_db[i];
+      }
+  }
+  if (i >= MAX_SPACES-1)
+  {
+    babl_log ("too many BablSpaces");
+    return NULL;
+  }
+  /* transplany matrixes */
+  babl_space_compute_matrices (&space_db[i]);
+  memcpy (space.RGBtoXYZ, &space.xr, sizeof (space.RGBtoXYZ));
+  babl_matrix_invert (space.RGBtoXYZ, space.XYZtoRGB);
+
+  space_db[i]=space;
+  space_db[i].instance.name = space_db[i].name;
+  if (name)
+    sprintf (space_db[i].name, "%s", name);
+  else
+    sprintf (space_db[i].name, "space-%.4f,%.4f_%.4f,%.4f_%.4f_%.4f,%.4f_%.4f,%.4f_%s,%s,%s",
+                       rx, gx, bx,
+                       ry, gy, by,
+                       rz, gz, bz,
+             babl_get_name (space.trc[0]),
+             babl_get_name(space.trc[1]), babl_get_name(space.trc[2]));
+
+
+  return (Babl*)&space_db[i];
+}
+
+
+const Babl *
 babl_space_rgb_chromaticities (const char *name,
                                double wx, double wy,
                                double rx, double ry,
diff --git a/babl/babl-space.h b/babl/babl-space.h
index e387d4f..2b2a883 100644
--- a/babl/babl-space.h
+++ b/babl/babl-space.h
@@ -40,6 +40,8 @@ typedef struct
   double           xb;  // blue primary chromaticity
   double           yb;
 
+  double           pad; // for when the numbers represent a matrix
+
   const Babl      *trc[3];
   char             name[128];
 
diff --git a/babl/babl.h b/babl/babl.h
index b635c00..31d58dc 100644
--- a/babl/babl.h
+++ b/babl/babl.h
@@ -106,7 +106,7 @@ const Babl * babl_trc_gamma (double gamma);
 const Babl * babl_space (const char *name);
 
 /**
- * babl_space_new:
+ * babl_space_rgb_chromaticities:
  *
  * Creates a new RGB matrix color space definition with the specified
  * white point wx, wy, primary chromaticities rx,ry,gx,gy,bx,by and
@@ -122,6 +122,21 @@ const Babl * babl_space_rgb_chromaticities (const char *name,
                                             const Babl *trc_green,
                                             const Babl *trc_blue);
 
+/**
+ * babl_space_rgb_chromaticities:
+ *
+ * Creates a new RGB matrix color space definition using a precomputed
+ * D50 adapted 3x3 matrix, as possibly read from an ICC profile.
+ */
+const Babl *
+babl_space_rgb_matrix (const char *name,
+                       double rx, double gx, double bx,
+                       double ry, double gy, double by,
+                       double rz, double gz, double bz,
+                       const Babl *trc_red,
+                       const Babl *trc_green,
+                       const Babl *trc_blue);
+
 const double * babl_space_get_rgbtoxyz (const Babl *space);
 void babl_space_to_xyz   (const Babl *space, const double *rgb, double *xyz);
 void babl_space_from_xyz (const Babl *space, const double *xyz, double *rgb);