Add native image scaling (bug#33587)

* configure.ac: Test for XRender outside of xft checks.
* src/Makefile.in (XRENDER_LIBS): List XRender libs separately from
xft libs.
* lisp/image.el (image--get-imagemagick-and-warn): Allow resizing if
native scaling is available.
* src/dispextern.h: Add XRender and image scaling stuff.
(struct image): Add XRender Pictures.
* src/image.c (x_create_bitmap_mask):
(image_create_x_image_and_pixmap): Handle XRender Picture.
(scale_image_size):
(compute_image_size): Make available when any form of scaling is
enabled.
(x_set_image_size): New function.
(lookup_image): Set image size.
(x_create_x_image_and_pixmap): Create XRender Picture when necessary.
(x_put_x_image): Handle the case where desired size != actual size.
(free_image): Free XRender Pictures.
(Fimage_scaling_p): New function.
(syms_of_image): Add image-scaling-p.
* src/nsimage.m (ns_load_image): Remove NS specific resizing.
([EmacsImage setSizeFromSpec:]): Remove method.
(ns_image_set_size): New function.
* src/nsterm.m (ns_draw_fringe_bitmap): Cocoa and GNUstep both have
the same compositing functions, so remove unnecessary difference.
* src/xterm.c (x_composite_image): New function.
(x_draw_image_foreground): Use new x_composite_image function.
* doc/lispref/display.texi (Image Descriptors): Document
image-scaling-p and add resizing descriptors.
(ImageMagick Images): Remove resizing descriptors.

1 files changed, 6 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index a3aa5a29381..a96ec781b4e 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1461,6 +1461,12 @@ that is non-nil, it will look for a file name handler for the current
 buffer's 'default-directory' and invoke that file name handler to make
 the process.  That way 'make-process' can start remote processes.
 
++++
+** Emacs now supports resizing images without ImageMagick on X window
+systems where the XRender extension is available, and on the NS port.
+The new function 'image-scaling-p' can be used to test whether any
+given frame supports resizing.
+
 
 * Changes in Emacs 27.1 on Non-Free Operating Systems