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, 208 insertions, 104 deletions

diff --git a/src/image.c b/src/image.c
index 87e0c071eef..84c31dcfc3c 100644
--- a/src/image.c
+++ b/src/image.c
@@ -408,8 +408,13 @@ x_destroy_all_bitmaps (Display_Info *dpyinfo)
   dpyinfo->bitmaps_last = 0;
 }
 
+#ifndef HAVE_XRENDER
+/* Required for the definition of x_create_x_image_and_pixmap below.  */
+typedef void Picture;
+#endif
+
 static bool x_create_x_image_and_pixmap (struct frame *, int, int, int,
-                                         XImagePtr *, Pixmap *);
+                                         XImagePtr *, Pixmap *, Picture *);
 static void x_destroy_x_image (XImagePtr ximg);
 
 #ifdef HAVE_NTGUI
@@ -472,7 +477,8 @@ x_create_bitmap_mask (struct frame *f, ptrdiff_t id)
       return;
     }
 
-  result = x_create_x_image_and_pixmap (f, width, height, 1, &mask_img, &mask);
+  result = x_create_x_image_and_pixmap (f, width, height, 1,
+                                        &mask_img, &mask, NULL);
 
   unblock_input ();
   if (!result)
@@ -1011,6 +1017,13 @@ free_image (struct frame *f, struct image *img)
 
       c->images[img->id] = NULL;
 
+#ifdef HAVE_XRENDER
+      if (img->picture)
+        XRenderFreePicture (FRAME_X_DISPLAY (f), img->picture);
+      if (img->mask_picture)
+        XRenderFreePicture (FRAME_X_DISPLAY (f), img->mask_picture);
+#endif
+
       /* Windows NT redefines 'free', but in this file, we need to
          avoid the redefinition.  */
 #ifdef WINDOWSNT
@@ -1747,6 +1760,147 @@ postprocess_image (struct frame *f, struct image *img)
     }
 }
 
+#if defined (HAVE_IMAGEMAGICK) || defined (HAVE_NATIVE_SCALING)
+/* Scale an image size by returning SIZE / DIVISOR * MULTIPLIER,
+   safely rounded and clipped to int range.  */
+
+static int
+scale_image_size (int size, size_t divisor, size_t multiplier)
+{
+  if (divisor != 0)
+    {
+      double s = size;
+      double scaled = s * multiplier / divisor + 0.5;
+      if (scaled < INT_MAX)
+        return scaled;
+    }
+  return INT_MAX;
+}
+
+/* Compute the desired size of an image with native size WIDTH x HEIGHT.
+   Use SPEC to deduce the size.  Store the desired size into
+   *D_WIDTH x *D_HEIGHT.  Store -1 x -1 if the native size is OK.  */
+static void
+compute_image_size (size_t width, size_t height,
+                    Lisp_Object spec,
+                    int *d_width, int *d_height)
+{
+  Lisp_Object value;
+  int desired_width = -1, desired_height = -1, max_width = -1, max_height = -1;
+  double scale = 1;
+
+  value = image_spec_value (spec, QCscale, NULL);
+  if (NUMBERP (value))
+    scale = XFLOATINT (value);
+
+  value = image_spec_value (spec, QCmax_width, NULL);
+  if (FIXNATP (value))
+    max_width = min (XFIXNAT (value), INT_MAX);
+
+  value = image_spec_value (spec, QCmax_height, NULL);
+  if (FIXNATP (value))
+    max_height = min (XFIXNAT (value), INT_MAX);
+
+  /* If width and/or height is set in the display spec assume we want
+     to scale to those values.  If either h or w is unspecified, the
+     unspecified should be calculated from the specified to preserve
+     aspect ratio.  */
+  value = image_spec_value (spec, QCwidth, NULL);
+  if (FIXNATP (value))
+    {
+      desired_width = min (XFIXNAT (value) * scale, INT_MAX);
+      /* :width overrides :max-width. */
+      max_width = -1;
+    }
+
+  value = image_spec_value (spec, QCheight, NULL);
+  if (FIXNATP (value))
+    {
+      desired_height = min (XFIXNAT (value) * scale, INT_MAX);
+      /* :height overrides :max-height. */
+      max_height = -1;
+    }
+
+  /* If we have both width/height set explicitly, we skip past all the
+     aspect ratio-preserving computations below. */
+  if (desired_width != -1 && desired_height != -1)
+    goto out;
+
+  width = width * scale;
+  height = height * scale;
+
+  if (desired_width != -1)
+    /* Width known, calculate height. */
+    desired_height = scale_image_size (desired_width, width, height);
+  else if (desired_height != -1)
+    /* Height known, calculate width. */
+    desired_width = scale_image_size (desired_height, height, width);
+  else
+    {
+      desired_width = width;
+      desired_height = height;
+    }
+
+  if (max_width != -1 && desired_width > max_width)
+    {
+      /* The image is wider than :max-width. */
+      desired_width = max_width;
+      desired_height = scale_image_size (desired_width, width, height);
+    }
+
+  if (max_height != -1 && desired_height > max_height)
+    {
+      /* The image is higher than :max-height. */
+      desired_height = max_height;
+      desired_width = scale_image_size (desired_height, height, width);
+    }
+
+ out:
+  *d_width = desired_width;
+  *d_height = desired_height;
+}
+
+#ifdef HAVE_NATIVE_SCALING
+static void
+x_set_image_size (struct frame *f, struct image *img)
+{
+#ifdef HAVE_IMAGEMAGICK
+  /* ImageMagick images are already the correct size.  */
+  if (!EQ (image_spec_value (img->spec, QCtype, NULL), Qimagemagick))
+#endif
+    {
+      int width, height;
+
+      compute_image_size (img->width, img->height, img->spec, &width, &height);
+
+#ifdef HAVE_NS
+      ns_image_set_size (img->pixmap, width, height);
+      img->width = width;
+      img->height = height;
+#endif
+
+#ifdef HAVE_XRENDER
+      if (img->picture)
+      {
+        double xscale = (double) img->width/width;
+        double yscale = (double) img->height/height;
+
+        XTransform tmat = {{{XDoubleToFixed (xscale), XDoubleToFixed (0), XDoubleToFixed (0)},
+                            {XDoubleToFixed (0), XDoubleToFixed (yscale), XDoubleToFixed (0)},
+                            {XDoubleToFixed (0), XDoubleToFixed (0), XDoubleToFixed (1)}}};
+
+        XRenderSetPictureFilter (FRAME_X_DISPLAY (f), img->picture, FilterBest, 0, 0);
+        XRenderSetPictureTransform (FRAME_X_DISPLAY (f), img->picture, &tmat);
+
+        img->width = width;
+        img->height = height;
+      }
+#endif
+    }
+}
+#endif
+#endif /* HAVE_IMAGEMAGICK || HAVE_XRENDER || HAVE_NS  */
+
 
 /* Return the id of image with Lisp specification SPEC on frame F.
    SPEC must be a valid Lisp image specification (see valid_image_p).  */
@@ -1802,6 +1956,9 @@ lookup_image (struct frame *f, Lisp_Object spec)
              `:background COLOR'.  */
           Lisp_Object ascent, margin, relief, bg;
           int relief_bound;
+#ifdef HAVE_NATIVE_SCALING
+          x_set_image_size (f, img);
+#endif
 
           ascent = image_spec_value (spec, QCascent, NULL);
           if (FIXNUMP (ascent))
@@ -1976,12 +2133,15 @@ x_check_image_size (XImagePtr ximg, int width, int height)
 
 static bool
 x_create_x_image_and_pixmap (struct frame *f, int width, int height, int depth,
-                             XImagePtr *ximg, Pixmap *pixmap)
+                             XImagePtr *ximg, Pixmap *pixmap, Picture *picture)
 {
 #ifdef HAVE_X_WINDOWS
   Display *display = FRAME_X_DISPLAY (f);
   Drawable drawable = FRAME_X_DRAWABLE (f);
   Screen *screen = FRAME_X_SCREEN (f);
+#ifdef HAVE_XRENDER
+  int event_basep, error_basep;
+#endif
 
   eassert (input_blocked_p ());
 
@@ -2018,6 +2178,21 @@ x_create_x_image_and_pixmap (struct frame *f, int width, int height, int depth,
       return 0;
     }
 
+#ifdef HAVE_XRENDER
+  if (picture && XRenderQueryExtension (display, &event_basep, &error_basep))
+    {
+      XRenderPictFormat *format;
+      XRenderPictureAttributes attr;
+
+      /* FIXME: Do we need to handle all possible bit depths?  */
+      format = XRenderFindStandardFormat (display,
+                                          depth > 24 ? PictStandardARGB32
+                                          : depth > 8 ? PictStandardRGB24
+                                          : PictStandardA8);
+      *picture = XRenderCreatePicture (display, *pixmap, format, 0, &attr);
+    }
+#endif
+
   return 1;
 #endif /* HAVE_X_WINDOWS */
 
@@ -2163,7 +2338,8 @@ x_put_x_image (struct frame *f, XImagePtr ximg, Pixmap pixmap, int width, int he
 
   eassert (input_blocked_p ());
   gc = XCreateGC (FRAME_X_DISPLAY (f), pixmap, 0, NULL);
-  XPutImage (FRAME_X_DISPLAY (f), pixmap, gc, ximg, 0, 0, 0, 0, width, height);
+  XPutImage (FRAME_X_DISPLAY (f), pixmap, gc, ximg, 0, 0, 0, 0,
+             ximg->width, ximg->height);
   XFreeGC (FRAME_X_DISPLAY (f), gc);
 #endif /* HAVE_X_WINDOWS */
 
@@ -2192,7 +2368,13 @@ image_create_x_image_and_pixmap (struct frame *f, struct image *img,
   eassert ((!mask_p ? img->pixmap : img->mask) == NO_PIXMAP);
 
   return x_create_x_image_and_pixmap (f, width, height, depth, ximg,
-                                      !mask_p ? &img->pixmap : &img->mask);
+                                      !mask_p ? &img->pixmap : &img->mask,
+#ifdef HAVE_XRENDER
+                                      !mask_p ? &img->picture : &img->mask_picture
+#else
+                                      NULL
+#endif
+                                      );
 }
 
 /* Put X image XIMG into image IMG on frame F, as a mask if and only
@@ -8101,105 +8283,6 @@ gif_load (struct frame *f, struct image *img)
                                  ImageMagick
 ***********************************************************************/
 
-/* Scale an image size by returning SIZE / DIVISOR * MULTIPLIER,
-   safely rounded and clipped to int range.  */
-
-static int
-scale_image_size (int size, size_t divisor, size_t multiplier)
-{
-  if (divisor != 0)
-    {
-      double s = size;
-      double scaled = s * multiplier / divisor + 0.5;
-      if (scaled < INT_MAX)
-        return scaled;
-    }
-  return INT_MAX;
-}
-
-/* Compute the desired size of an image with native size WIDTH x HEIGHT.
-   Use SPEC to deduce the size.  Store the desired size into
-   *D_WIDTH x *D_HEIGHT.  Store -1 x -1 if the native size is OK.  */
-static void
-compute_image_size (size_t width, size_t height,
-                    Lisp_Object spec,
-                    int *d_width, int *d_height)
-{
-  Lisp_Object value;
-  int desired_width = -1, desired_height = -1, max_width = -1, max_height = -1;
-  double scale = 1;
-
-  value = image_spec_value (spec, QCscale, NULL);
-  if (NUMBERP (value))
-    scale = XFLOATINT (value);
-
-  value = image_spec_value (spec, QCmax_width, NULL);
-  if (FIXNATP (value))
-    max_width = min (XFIXNAT (value), INT_MAX);
-
-  value = image_spec_value (spec, QCmax_height, NULL);
-  if (FIXNATP (value))
-    max_height = min (XFIXNAT (value), INT_MAX);
-
-  /* If width and/or height is set in the display spec assume we want
-     to scale to those values.  If either h or w is unspecified, the
-     unspecified should be calculated from the specified to preserve
-     aspect ratio.  */
-  value = image_spec_value (spec, QCwidth, NULL);
-  if (FIXNATP (value))
-    {
-      desired_width = min (XFIXNAT (value) * scale, INT_MAX);
-      /* :width overrides :max-width. */
-      max_width = -1;
-    }
-
-  value = image_spec_value (spec, QCheight, NULL);
-  if (FIXNATP (value))
-    {
-      desired_height = min (XFIXNAT (value) * scale, INT_MAX);
-      /* :height overrides :max-height. */
-      max_height = -1;
-    }
-
-  /* If we have both width/height set explicitly, we skip past all the
-     aspect ratio-preserving computations below. */
-  if (desired_width != -1 && desired_height != -1)
-    goto out;
-
-  width = width * scale;
-  height = height * scale;
-
-  if (desired_width != -1)
-    /* Width known, calculate height. */
-    desired_height = scale_image_size (desired_width, width, height);
-  else if (desired_height != -1)
-    /* Height known, calculate width. */
-    desired_width = scale_image_size (desired_height, height, width);
-  else
-    {
-      desired_width = width;
-      desired_height = height;
-    }
-
-  if (max_width != -1 && desired_width > max_width)
-    {
-      /* The image is wider than :max-width. */
-      desired_width = max_width;
-      desired_height = scale_image_size (desired_width, width, height);
-    }
-
-  if (max_height != -1 && desired_height > max_height)
-    {
-      /* The image is higher than :max-height. */
-      desired_height = max_height;
-      desired_width = scale_image_size (desired_height, height, width);
-    }
-
- out:
-  *d_width = desired_width;
-  *d_height = desired_height;
-}
-
 static bool imagemagick_image_p (Lisp_Object);
 static bool imagemagick_load (struct frame *, struct image *);
 static void imagemagick_clear_image (struct frame *, struct image *);
@@ -9816,6 +9899,25 @@ DEFUN ("lookup-image", Flookup_image, Slookup_image, 1, 1, 0,
                             Initialization
  ***********************************************************************/
 
+DEFUN ("image-scaling-p", Fimage_scaling_p, Simage_scaling_p, 0, 1, 0,
+       doc: /* Test whether FRAME supports resizing images.
+Return t if FRAME supports native scaling, nil otherwise.  */)
+     (Lisp_Object frame)
+{
+#ifdef HAVE_NS
+  return Qt;
+#elif defined (HAVE_X_WINDOWS) && defined (HAVE_XRENDER)
+  int event_basep, error_basep;
+
+  if (XRenderQueryExtension
+      (FRAME_X_DISPLAY (decode_window_system_frame (frame)),
+       &event_basep, &error_basep))
+    return Qt;
+#endif
+
+  return Qnil;
+}
+
 DEFUN ("init-image-library", Finit_image_library, Sinit_image_library, 1, 1, 0,
        doc: /* Initialize image library implementing image type TYPE.
 Return non-nil if TYPE is a supported image type.
@@ -10058,6 +10160,8 @@ non-numeric, there is no explicit limit on the size of images.  */);
   defsubr (&Slookup_image);
 #endif
 
+  defsubr (&Simage_scaling_p);
+
   DEFVAR_BOOL ("cross-disabled-images", cross_disabled_images,
     doc: /* Non-nil means always draw a cross over disabled images.
 Disabled images are those having a `:conversion disabled' property.