[gnome-desktop] thumbnail: Deprecate gnome_desktop_thumbnail_scale_down_pixbuf()

[Bastien Nocera <hadess src gnome org>]

commit cb64228291842ac73d6bf64d93e35070aab88de1
Author: Bastien Nocera <hadess hadess net>
Date:   Fri Jan 6 17:36:20 2017 +0100

    thumbnail: Deprecate gnome_desktop_thumbnail_scale_down_pixbuf()
    
    As scaling down by huge factors is now fixed in gdk-pixbuf. Require the
    newer gdk-pixbuf as well, to avoid running into a pre-fix version.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=775991

 configure.ac                                    |    2 +-
 libgnome-desktop/gnome-desktop-thumbnail.h      |    7 ++
 libgnome-desktop/gnome-thumbnail-pixbuf-utils.c |  129 ++--------------------
 3 files changed, 20 insertions(+), 118 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 5baf1a2..2174a46 100644
--- a/configure.ac
+++ b/configure.ac
@@ -103,7 +103,7 @@ GLIB_TESTS
 dnl If you add a version number here, you *must* add an AC_SUBST line for
 dnl it too, or it will never make it into the spec file!
 
-GDK_PIXBUF_REQUIRED=2.36.1
+GDK_PIXBUF_REQUIRED=2.36.5
 GTK_REQUIRED=3.3.6
 GLIB_REQUIRED=2.44.0
 XRANDR_REQUIRED=1.3
diff --git a/libgnome-desktop/gnome-desktop-thumbnail.h b/libgnome-desktop/gnome-desktop-thumbnail.h
index 424f6cc..9ad36ca 100644
--- a/libgnome-desktop/gnome-desktop-thumbnail.h
+++ b/libgnome-desktop/gnome-desktop-thumbnail.h
@@ -103,6 +103,13 @@ char *     gnome_desktop_thumbnail_path_for_uri      (const char         *uri,
 
 /* Pixbuf utils */
 
+#ifndef __GTK_DOC_IGNORE__
+#define GNOME_DESKTOP_DEPRECATED_IN_3_24_FOR(f) G_DEPRECATED_FOR(f) extern
+#else
+#define GNOME_DESKTOP_DEPRECATED_IN_3_24_FOR(f) extern
+#endif
+
+GNOME_DESKTOP_DEPRECATED_IN_3_24_FOR(gdk_pixbuf_scale_simple)
 GdkPixbuf *gnome_desktop_thumbnail_scale_down_pixbuf (GdkPixbuf          *pixbuf,
                                                      int                 dest_width,
                                                      int                 dest_height);
diff --git a/libgnome-desktop/gnome-thumbnail-pixbuf-utils.c b/libgnome-desktop/gnome-thumbnail-pixbuf-utils.c
index f704bb6..fcd88c0 100644
--- a/libgnome-desktop/gnome-thumbnail-pixbuf-utils.c
+++ b/libgnome-desktop/gnome-thumbnail-pixbuf-utils.c
@@ -39,8 +39,11 @@
  * @dest_height: the desired new height
  *
  * Scales the pixbuf to the desired size. This function
- * is a lot faster than gdk-pixbuf when scaling down by
- * large amounts.
+ * used to be a lot faster than gdk-pixbuf when scaling
+ * down by large amounts. This is not true anymore since
+ * gdk-pixbuf UNRELEASED. You should use
+ * gdk_pixbuf_scale_simple() instead, which this function
+ * now does internally.
  *
  * Return value: (transfer full): a scaled pixbuf
  * 
@@ -48,123 +51,15 @@
  **/
 GdkPixbuf *
 gnome_desktop_thumbnail_scale_down_pixbuf (GdkPixbuf *pixbuf,
-                                          int dest_width,
-                                          int dest_height)
+                                          int        dest_width,
+                                          int        dest_height)
 {
-       int source_width, source_height;
-       int s_x1, s_y1, s_x2, s_y2;
-       int s_xfrac, s_yfrac;
-       int dx, dx_frac, dy, dy_frac;
-       div_t ddx, ddy;
-       int x, y;
-       int r, g, b, a;
-       int n_pixels;
-       gboolean has_alpha;
-       guchar *dest, *src, *xsrc, *src_pixels;
-       GdkPixbuf *dest_pixbuf;
-       int pixel_stride;
-       int source_rowstride, dest_rowstride;
+       g_return_val_if_fail (GDK_IS_PIXBUF (pixbuf), NULL);
+       g_return_val_if_fail (gdk_pixbuf_get_width (pixbuf) >= dest_width, NULL);
+       g_return_val_if_fail (gdk_pixbuf_get_height (pixbuf) >= dest_height, NULL);
 
-       if (dest_width == 0 || dest_height == 0) {
+       if (dest_width == 0 || dest_height == 0)
                return NULL;
-       }
-       
-       source_width = gdk_pixbuf_get_width (pixbuf);
-       source_height = gdk_pixbuf_get_height (pixbuf);
 
-       g_assert (source_width >= dest_width);
-       g_assert (source_height >= dest_height);
-
-       ddx = div (source_width, dest_width);
-       dx = ddx.quot;
-       dx_frac = ddx.rem;
-       
-       ddy = div (source_height, dest_height);
-       dy = ddy.quot;
-       dy_frac = ddy.rem;
-
-       has_alpha = gdk_pixbuf_get_has_alpha (pixbuf);
-       source_rowstride = gdk_pixbuf_get_rowstride (pixbuf);
-       src_pixels = gdk_pixbuf_get_pixels (pixbuf);
-
-       dest_pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, has_alpha, 8,
-                                     dest_width, dest_height);
-       dest = gdk_pixbuf_get_pixels (dest_pixbuf);
-       dest_rowstride = gdk_pixbuf_get_rowstride (dest_pixbuf);
-
-       pixel_stride = (has_alpha)?4:3;
-       
-       s_y1 = 0;
-       s_yfrac = -dest_height/2;
-       while (s_y1 < source_height) {
-               s_y2 = s_y1 + dy;
-               s_yfrac += dy_frac;
-               if (s_yfrac > 0) {
-                       s_y2++;
-                       s_yfrac -= dest_height;
-               }
-
-               s_x1 = 0;
-               s_xfrac = -dest_width/2;
-               while (s_x1 < source_width) {
-                       s_x2 = s_x1 + dx;
-                       s_xfrac += dx_frac;
-                       if (s_xfrac > 0) {
-                               s_x2++;
-                               s_xfrac -= dest_width;
-                       }
-
-                       /* Average block of [x1,x2[ x [y1,y2[ and store in dest */
-                       r = g = b = a = 0;
-                       n_pixels = 0;
-
-                       src = src_pixels + s_y1 * source_rowstride + s_x1 * pixel_stride;
-                       for (y = s_y1; y < s_y2; y++) {
-                               xsrc = src;
-                               if (has_alpha) {
-                                       for (x = 0; x < s_x2-s_x1; x++) {
-                                               n_pixels++;
-                                               
-                                               r += xsrc[3] * xsrc[0];
-                                               g += xsrc[3] * xsrc[1];
-                                               b += xsrc[3] * xsrc[2];
-                                               a += xsrc[3];
-                                               xsrc += 4;
-                                       }
-                               } else {
-                                       for (x = 0; x < s_x2-s_x1; x++) {
-                                               n_pixels++;
-                                               r += *xsrc++;
-                                               g += *xsrc++;
-                                               b += *xsrc++;
-                                       }
-                               }
-                               src += source_rowstride;
-                       }
-                       
-                       if (has_alpha) {
-                               if (a != 0) {
-                                       *dest++ = r / a;
-                                       *dest++ = g / a;
-                                       *dest++ = b / a;
-                                       *dest++ = a / n_pixels;
-                               } else {
-                                       *dest++ = 0;
-                                       *dest++ = 0;
-                                       *dest++ = 0;
-                                       *dest++ = 0;
-                               }
-                       } else {
-                               *dest++ = r / n_pixels;
-                               *dest++ = g / n_pixels;
-                               *dest++ = b / n_pixels;
-                       }
-                       
-                       s_x1 = s_x2;
-               }
-               s_y1 = s_y2;
-               dest += dest_rowstride - dest_width * pixel_stride;
-       }
-       
-       return dest_pixbuf;
+       return gdk_pixbuf_scale_simple (pixbuf, dest_width, dest_height, GDK_INTERP_HYPER);
 }