[gimp] app: add code to read/write XCF tile data as big-endian

[Michael Natterer <mitch src gnome org>]

commit a735ba0daac4ca3024b1b1a5f42123c0c9a2ddf1
Author: Michael Natterer <mitch gimp org>
Date:   Sat Sep 16 19:03:20 2017 +0200

    app: add code to read/write XCF tile data as big-endian
    
    It was always supposed to be like that, but simply forgotten.
    Fortunately, big-endian machines are almost extinct...
    
    The new code is triggered with XCF version >= 12, but we will start
    using that only after code review.

 app/xcf/xcf-load.c  |   29 ++++++++++++++++++++++++++++-
 app/xcf/xcf-read.c  |   41 +++++++++++++++++++++++++++++++++++++++++
 app/xcf/xcf-read.h  |    4 ++++
 app/xcf/xcf-save.c  |   37 ++++++++++++++++++++++++++++++++++++-
 app/xcf/xcf-write.c |   41 +++++++++++++++++++++++++++++++++++++++++
 app/xcf/xcf-write.h |    4 ++++
 app/xcf/xcf.c       |    3 ++-
 7 files changed, 156 insertions(+), 3 deletions(-)
---
diff --git a/app/xcf/xcf-load.c b/app/xcf/xcf-load.c
index 846648e..f6d468c 100644
--- a/app/xcf/xcf-load.c
+++ b/app/xcf/xcf-load.c
@@ -2052,7 +2052,17 @@ xcf_load_tile (XcfInfo       *info,
   gint    tile_size = bpp * tile_rect->width * tile_rect->height;
   guchar *tile_data = g_alloca (tile_size);
 
-  xcf_read_int8 (info, tile_data, tile_size);
+  if (info->file_version <= 11)
+    {
+      xcf_read_int8 (info, tile_data, tile_size);
+    }
+  else
+    {
+      gint n_components = babl_format_get_n_components (format);
+
+      xcf_read_component (info, bpp / n_components, tile_data,
+                          tile_size / n_components);
+    }
 
   gegl_buffer_set (buffer, tile_rect, 0, format, tile_data,
                    GEGL_AUTO_ROWSTRIDE);
@@ -2189,6 +2199,14 @@ xcf_load_tile_rle (XcfInfo       *info,
         }
     }
 
+  if (info->file_version >= 12)
+    {
+      gint n_components = babl_format_get_n_components (format);
+
+      xcf_read_from_be (bpp / n_components, tile_data,
+                        tile_size / n_components);
+    }
+
   gegl_buffer_set (buffer, tile_rect, 0, format, tile_data,
                    GEGL_AUTO_ROWSTRIDE);
 
@@ -2279,10 +2297,19 @@ xcf_load_tile_zlib (XcfInfo       *info,
         }
     }
 
+  if (info->file_version >= 12)
+    {
+      gint n_components = babl_format_get_n_components (format);
+
+      xcf_read_from_be (bpp / n_components, tile_data,
+                        tile_size / n_components);
+    }
+
   gegl_buffer_set (buffer, tile_rect, 0, format, tile_data,
                    GEGL_AUTO_ROWSTRIDE);
 
   inflateEnd (&strm);
+
   return TRUE;
 }
 
diff --git a/app/xcf/xcf-read.c b/app/xcf/xcf-read.c
index 51c1b8f..46b80a7 100644
--- a/app/xcf/xcf-read.c
+++ b/app/xcf/xcf-read.c
@@ -225,3 +225,44 @@ xcf_read_component (XcfInfo *info,
 
   return 0;
 }
+
+void
+xcf_read_from_be (gint    bpc,
+                  guint8 *data,
+                  gint    count)
+{
+  gint i;
+
+  switch (bpc)
+    {
+    case 8:
+      break;
+
+    case 16:
+      {
+        guint16 *d = (guint16 *) data;
+
+        for (i = 0; i < count; i++)
+          d[i] = g_ntohs (d[i]);
+      }
+      break;
+
+    case 32:
+      {
+        guint32 *d = (guint32 *) data;
+
+        for (i = 0; i < count; i++)
+          d[i] = g_ntohl (d[i]);
+      }
+      break;
+
+    case 64:
+      {
+        guint64 *d = (guint64 *) data;
+
+        for (i = 0; i < count; i++)
+          d[i] = GINT64_FROM_BE (d[i]);
+      }
+      break;
+    }
+}
diff --git a/app/xcf/xcf-read.h b/app/xcf/xcf-read.h
index 6a95859..e15afb4 100644
--- a/app/xcf/xcf-read.h
+++ b/app/xcf/xcf-read.h
@@ -45,5 +45,9 @@ guint   xcf_read_component (XcfInfo  *info,
                             guint8   *data,
                             gint      count);
 
+void    xcf_read_from_be   (gint      bpc,
+                            guint8   *data,
+                            gint      count);
+
 
 #endif  /* __XCF_READ_H__ */
diff --git a/app/xcf/xcf-save.c b/app/xcf/xcf-save.c
index 42ced1f..8162fe2 100644
--- a/app/xcf/xcf-save.c
+++ b/app/xcf/xcf-save.c
@@ -186,6 +186,15 @@ static gboolean xcf_save_vectors       (XcfInfo           *info,
     }                                                                  \
   } G_STMT_END
 
+#define xcf_write_component_check_error(info, bpc, data, count) G_STMT_START { \
+  xcf_write_component (info, bpc, data, count, &tmp_error);          \
+  if (tmp_error)                                                     \
+    {                                                                \
+      g_propagate_error (error, tmp_error);                          \
+      return FALSE;                                                  \
+    }                                                                \
+  } G_STMT_END
+
 #define xcf_write_prop_type_check_error(info, prop_type) G_STMT_START { \
   guint32 _prop_int32 = prop_type;                                      \
   xcf_write_int32_check_error (info, &_prop_int32, 1);                  \
@@ -1628,7 +1637,17 @@ xcf_save_tile (XcfInfo        *info,
   gegl_buffer_get (buffer, tile_rect, 1.0, format, tile_data,
                    GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
 
-  xcf_write_int8_check_error (info, tile_data, tile_size);
+  if (info->file_version <= 11)
+    {
+      xcf_write_int8_check_error (info, tile_data, tile_size);
+    }
+  else
+    {
+      gint n_components = babl_format_get_n_components (format);
+
+      xcf_write_component_check_error (info, bpp / n_components, tile_data,
+                                       tile_size / n_components);
+    }
 
   return TRUE;
 }
@@ -1651,6 +1670,14 @@ xcf_save_tile_rle (XcfInfo        *info,
   gegl_buffer_get (buffer, tile_rect, 1.0, format, tile_data,
                    GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
 
+  if (info->file_version >= 12)
+    {
+      gint n_components = babl_format_get_n_components (format);
+
+      xcf_write_to_be (bpp / n_components, tile_data,
+                       tile_size / n_components);
+    }
+
   for (i = 0; i < bpp; i++)
     {
       const guchar *data   = tile_data + i;
@@ -1779,6 +1806,14 @@ xcf_save_tile_zlib (XcfInfo        *info,
   gegl_buffer_get (buffer, tile_rect, 1.0, format, tile_data,
                    GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
 
+  if (info->file_version >= 12)
+    {
+      gint n_components = babl_format_get_n_components (format);
+
+      xcf_write_to_be (bpp / n_components, tile_data,
+                       tile_size / n_components);
+    }
+
   /* allocate deflate state */
   strm.zalloc = Z_NULL;
   strm.zfree  = Z_NULL;
diff --git a/app/xcf/xcf-write.c b/app/xcf/xcf-write.c
index 113ad5a..023722d 100644
--- a/app/xcf/xcf-write.c
+++ b/app/xcf/xcf-write.c
@@ -276,3 +276,44 @@ xcf_write_component (XcfInfo       *info,
 
   return 0;
 }
+
+void
+xcf_write_to_be (gint    bpc,
+                 guint8 *data,
+                 gint    count)
+{
+  gint i;
+
+  switch (bpc)
+    {
+    case 8:
+      break;
+
+    case 16:
+      {
+        guint16 *d = (guint16 *) data;
+
+        for (i = 0; i < count; i++)
+          d[i] = g_htons (d[i]);
+      }
+      break;
+
+    case 32:
+      {
+        guint32 *d = (guint32 *) data;
+
+        for (i = 0; i < count; i++)
+          d[i] = g_htonl (d[i]);
+      }
+      break;
+
+    case 64:
+      {
+        guint64 *d = (guint64 *) data;
+
+        for (i = 0; i < count; i++)
+          d[i] = GINT64_TO_BE (d[i]);
+      }
+      break;
+    }
+}
diff --git a/app/xcf/xcf-write.h b/app/xcf/xcf-write.h
index b456df3..21769ec 100644
--- a/app/xcf/xcf-write.h
+++ b/app/xcf/xcf-write.h
@@ -56,5 +56,9 @@ guint   xcf_write_component   (XcfInfo        *info,
                                gint            count,
                                GError        **error);
 
+void    xcf_write_to_be       (gint            bpc,
+                               guint8         *data,
+                               gint            count);
+
 
 #endif  /* __XCF_WRITE_H__ */
diff --git a/app/xcf/xcf.c b/app/xcf/xcf.c
index f336c33..620c92d 100644
--- a/app/xcf/xcf.c
+++ b/app/xcf/xcf.c
@@ -78,7 +78,8 @@ static GimpXcfLoaderFunc * const xcf_loaders[] =
   xcf_load_image,   /* version  8 */
   xcf_load_image,   /* version  9 */
   xcf_load_image,   /* version 10 */
-  xcf_load_image    /* version 11 */
+  xcf_load_image,   /* version 11 */
+  xcf_load_image    /* version 12 */
 };