Support :transform-smoothing on images (MS-Windows) (bug#57166)

* src/dispextern.h (struct image): Add field 'smoothing' for
NTGUI.
* src/image.c (image_set_transform): Assign the 'smoothing'
field of the image struct.
* src/w32gdiplus.h: Add references to more GDI+ functions.
* src/w32image.c (gdiplus_init): Add references to more GDI+
functions.
* src/w32term.c (w32_draw_image_foreground): If the image is
marked for smoothing and GDI+ is available, draw it with GDI+
bilinear interpolation.
* etc/NEWS: New entry for this change.

1 files changed, 6 insertions, 4 deletions

diff --git a/src/image.c b/src/image.c
index 34936977a40..db7f6acd171 100644
--- a/src/image.c
+++ b/src/image.c
@@ -3049,12 +3049,10 @@ image_set_transform (struct frame *f, struct image *img)
   flip = !NILP (image_spec_value (img->spec, QCflip, NULL));
 
 # if defined USE_CAIRO || defined HAVE_XRENDER || defined HAVE_NS || defined HAVE_HAIKU \
-  || defined HAVE_ANDROID
+  || defined HAVE_ANDROID || defined HAVE_NTGUI
   /* We want scale up operations to use a nearest neighbor filter to
      show real pixels instead of munging them, but scale down
-     operations to use a blended filter, to avoid aliasing and the like.
-
-     TODO: implement for Windows.  */
+     operations to use a blended filter, to avoid aliasing and the like.  */
   bool smoothing;
   Lisp_Object s = image_spec_value (img->spec, QCtransform_smoothing, NULL);
   if (NILP (s))
@@ -3067,6 +3065,10 @@ image_set_transform (struct frame *f, struct image *img)
   img->use_bilinear_filtering = smoothing;
 #endif
 
+#ifdef HAVE_NTGUI
+  img->smoothing = smoothing;
+#endif
+
   /* Perform scale transformation.  */
 
   matrix3x3 matrix