[babl] add file missing from last commit

[Ãyvind KolÃs <ok src gnome org>]

commit 11d4a44ebbee10d62064b516e8946025ea045f76
Author: Ãyvind KolÃs <pippin gimp org>
Date:   Sat Mar 17 12:32:47 2012 +0000

    add file missing from last commit

 babl/babl-palette.c |  254 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 254 insertions(+), 0 deletions(-)
---
diff --git a/babl/babl-palette.c b/babl/babl-palette.c
new file mode 100644
index 0000000..c8f10d0
--- /dev/null
+++ b/babl/babl-palette.c
@@ -0,0 +1,254 @@
+/* babl - dynamically extendable universal pixel conversion library.
+ * Copyright (C) 2005, Ãyvind KolÃs.
+ *
+ * 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
+ * <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+#include <stdlib.h>
+
+#include "babl-internal.h"
+#include "babl-classes.h"
+#include "babl.h"
+#include "babl-ids.h"
+#include "util.h"
+#include "rgb-constants.h"
+#include "math.h"
+#include "babl-base.h"
+
+typedef struct BablPalette
+{
+  int         count; /* number of palette entries */
+  const Babl *format;/* the pixel format the palette is stored in */
+  void       *data;  /* one linear segment of all the pixels representing the palette, in   order */
+} BablPalette;
+
+
+static BablPalette *make_pal (Babl *format, void *data, int count)
+{
+  BablPalette *pal = NULL;
+  int bpp = babl_format_get_bytes_per_pixel (format);
+  pal = babl_malloc (sizeof (BablPalette));
+  pal->count = count;
+  pal->format = format;
+  pal->data = babl_malloc (bpp * count);
+  memcpy (pal->data, data, bpp * count);
+  return pal;
+}
+
+static unsigned char defpal_data[4*16] = 
+{  
+0  ,0  ,0  ,255,
+127,0  ,0  ,255,
+0  ,127,0  ,255,
+127,127,0  ,255,
+0  ,0  ,127,255,
+127,0  ,127,255,
+0  ,127,127,255,
+127,127,127,255,
+63 ,63 ,63 ,255,
+255,0  ,0  ,255,
+0  ,255,0  ,255,
+255,255,0  ,255,
+0  ,0  ,255,255,
+255,0  ,255,255,
+0  ,255,255,255,
+255,255,255,255,
+};
+
+static BablPalette *default_palette (void)
+{
+  static BablPalette pal;
+  static int inited = 0;
+  if (inited)
+    return &pal;
+  inited = 1;
+  pal.count = 16;
+  pal.format = babl_format ("RGBA u8");
+  pal.data = defpal_data;
+  return &pal;
+}
+
+static long
+rgba_to_pal (char *src,
+             char *dst,
+             long  n,
+             void *foo,
+             void *dst_model_data)
+{
+  BablPalette *pal = dst_model_data;
+  Babl        *fish;
+  int bpp;
+  
+  if (babl_in_fish_path)
+    babl_mutex_unlock (babl_format_mutex);
+  fish = babl_fish (
+      pal->format,
+      babl_format_from_id (BABL_RGBA_DOUBLE));
+  if (babl_in_fish_path)
+    babl_mutex_lock (babl_format_mutex);
+
+  bpp = babl_format_get_bytes_per_pixel (pal->format);
+  while (n--)
+    {
+      int idx;
+
+      int best_idx = 0;
+      double best_diff = 100000;
+      double *srcf;
+
+      srcf = ((double *) src);
+
+      for (idx = 0; idx<pal->count; idx++)
+        {
+          double diff;
+          double palpx[4];
+
+          /* oh horror, at least cache the format */
+          babl_process (fish, ((char*)pal->data) + idx * bpp,
+                palpx, 1);
+
+          diff = (palpx[0] - srcf[0]) * (palpx[0] - srcf[0]) +
+                 (palpx[1] - srcf[1]) * (palpx[1] - srcf[1]) +
+                 (palpx[2] - srcf[2]) * (palpx[2] - srcf[2]) +
+                 (palpx[3] - srcf[3]) * (palpx[3] - srcf[3]);
+          if (diff < best_diff)
+            {
+              best_diff = diff;
+              best_idx = idx;
+            }
+        }
+
+      ((double *) dst)[0] = best_idx / 256.0;
+
+      src += sizeof (double) * 4;
+      dst += sizeof (double) * 1;
+    }
+  return n;
+}
+
+static long
+pal_to_rgba (char *src,
+             char *dst,
+             long  n,
+             void *src_model_data,
+             void *foo)
+{
+  BablPalette *pal = src_model_data;
+  Babl        *fish = babl_fish (
+      pal->format,
+      babl_format_from_id (BABL_RGBA_DOUBLE));
+  int bpp = babl_format_get_bytes_per_pixel (pal->format);
+
+  while (n--)
+    {
+      int    idx;
+
+      idx       = (((double *) src)[0]) * 256.0;
+
+      if (idx < 0) idx = 0;
+      if (idx >= pal->count) idx = pal->count-1;
+
+      babl_process (fish, 
+            ((char*)pal->data) + idx * bpp,
+            dst, 1);
+
+      src += sizeof (double) * 1;
+      dst += sizeof (double) * 4;
+    }
+  return n;
+}
+
+Babl *babl_new_palette (const char *name)
+{
+  Babl *model;
+  Babl *format;
+  char  cname[64];
+
+  if (!name)
+    {
+      static int cnt = 0;
+      sprintf (cname, "pal-%i", cnt++);
+      name = cname;
+    }
+
+  babl_component_new (
+    "I",
+    "id", BABL_PAL,
+    "luma",
+    "chroma",
+    "alpha",
+    NULL);
+  
+  model = babl_model_new (
+    "name", name,
+    babl_component_from_id (BABL_PAL),
+    NULL);
+  
+  model->model.data = (void*) 0x012;
+
+  babl_conversion_new (
+    model,
+    babl_model_from_id (BABL_RGBA),
+    "linear", pal_to_rgba,
+    NULL
+  );
+
+  babl_conversion_new (
+    babl_model_from_id (BABL_RGBA),
+    model,
+    "linear", rgba_to_pal,
+    NULL
+  );
+
+  format = babl_format_new ("name", name, model,
+                            babl_type ("u8"),
+                            babl_component ("I"), NULL);
+
+  format->format.model_data = default_palette ();
+  format->format.model->data = format->format.model_data;
+
+  babl_sanity ();
+  return format;
+}
+
+void
+babl_palette_set_palette (Babl *babl,
+                          Babl *format,
+                          void *data,
+                          int   count)
+{
+  if (babl->format.model->data != default_palette ())
+    {
+      BablPalette *pal = babl->format.model->data;
+      babl_free (pal->data);
+      babl_free (pal);
+    }
+  babl->format.model_data = make_pal (format, data, count);
+  babl->format.model->data = babl->format.model_data;
+}
+
+void
+babl_palette_reset (Babl *babl)
+{
+  if (babl->format.model->data != default_palette ())
+    {
+      BablPalette *pal = babl->format.model->data;
+      babl_free (pal->data);
+      babl_free (pal);
+    }
+  babl->format.model_data = default_palette ();
+  babl->format.model->data = babl->format.model_data;
+}