From 80f79e0cc7509b79b38193a006b0d98d03432044 Mon Sep 17 00:00:00 2001

From: Ray Strode <rstrode@redhat.com>

Date: Mon, 5 Aug 2019 14:39:21 -0400

Subject: [PATCH] iconcache: Avoid xrender picture formats when creating cairo

 surface

If an application provides its window icon via wmhints, then mutter

loads the pixmap specified by the application into a cairo xlib surface. When

creating the surface it specifies the visual, indirectly, via an XRender

picture format.

This is suboptimal, since XRender picture formats don't have a way to specify

16bpp depth, which an application may be using.

In particular, applications are likely to use 16bpp depth pixmaps for their

icons, if the video card offers a 16bpp framebuffer/root window.

This commit drops the XRender middleman, and just tells cairo a visual to use

directly.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/715

---

 src/x11/iconcache.c | 31 ++++++-------------------------

 1 file changed, 6 insertions(+), 25 deletions(-)

diff --git a/src/x11/iconcache.c b/src/x11/iconcache.c

index 15d72da65..521c77b8d 100644

--- a/src/x11/iconcache.c

+++ b/src/x11/iconcache.c

@@ -261,97 +261,78 @@ get_pixmap_geometry (MetaX11Display *x11_display,

                      Pixmap          pixmap,

                      int            *w,

                      int            *h,

                      int            *d)

 {

   Window root_ignored;

   int x_ignored, y_ignored;

   guint width, height;

   guint border_width_ignored;

   guint depth;

   if (w)

     *w = 1;

   if (h)

     *h = 1;

   if (d)

     *d = 1;

   XGetGeometry (x11_display->xdisplay,

                 pixmap, &root_ignored, &x_ignored, &y_ignored,

                 &width, &height, &border_width_ignored, &depth);

   if (w)

     *w = width;

   if (h)

     *h = height;

   if (d)

     *d = depth;

 }

-static int

-standard_pict_format_for_depth (int depth)

-{

-  switch (depth)

-    {

-    case 1:

-      return PictStandardA1;

-    case 24:

-      return PictStandardRGB24;

-    case 32:

-      return PictStandardARGB32;

-    default:

-      g_assert_not_reached ();

-    }

-  return 0;

-}

-

-static XRenderPictFormat *

-pict_format_for_depth (Display *xdisplay, int depth)

-{

-  return XRenderFindStandardFormat (xdisplay, standard_pict_format_for_depth (depth));

-}

-

 static cairo_surface_t *

 surface_from_pixmap (Display *xdisplay, Pixmap xpixmap,

                      int width, int height)

 {

   Window root_return;

+  XVisualInfo visual_info;

   int x_ret, y_ret;

   unsigned int w_ret, h_ret, bw_ret, depth_ret;

   if (!XGetGeometry (xdisplay, xpixmap, &root_return,

                      &x_ret, &y_ret, &w_ret, &h_ret, &bw_ret, &depth_ret))

     return NULL;

-  return cairo_xlib_surface_create_with_xrender_format (xdisplay, xpixmap, DefaultScreenOfDisplay (xdisplay),

-                                                        pict_format_for_depth (xdisplay, depth_ret), w_ret, h_ret);

+  if (!XMatchVisualInfo (xdisplay, DefaultScreen (xdisplay),

+                         depth_ret, TrueColor, &visual_info))

+    return NULL;

+

+  return cairo_xlib_surface_create (xdisplay, xpixmap, visual_info.visual, w_ret, h_ret);

 }

 static gboolean

 try_pixmap_and_mask (MetaX11Display   *x11_display,

                      Pixmap            src_pixmap,

                      Pixmap            src_mask,

                      cairo_surface_t **iconp)

 {

   Display *xdisplay = x11_display->xdisplay;

   cairo_surface_t *icon, *mask = NULL;

   int w, h, d;

   if (src_pixmap == None)

     return FALSE;

   meta_x11_error_trap_push (x11_display);

   get_pixmap_geometry (x11_display, src_pixmap, &w, &h, &d);

   icon = surface_from_pixmap (xdisplay, src_pixmap, w, h);

   if (icon && src_mask != None)

     {

       get_pixmap_geometry (x11_display, src_mask, &w, &h, &d);

       if (d == 1)

         mask = surface_from_pixmap (xdisplay, src_mask, w, h);

     }

   meta_x11_error_trap_pop (x11_display);

-- 

2.21.0