xserver: Branch 'master'

[GitLab Mirror]

 hw/xwayland/xwayland-output.c |   41 ++---------------------------------------
 hw/xwayland/xwayland-screen.c |    7 ++++++-
 2 files changed, 8 insertions(+), 40 deletions(-)

New commits:
commit b0413b6e99c6b5fbc04229ce64ddf1f41b08e63e
Author: Olivier Fourdan <ofourdan at redhat.com>
Date:   Tue Jun 2 11:23:46 2020 +0200

    xwayland: Use a fixed DPI value for core protocol
    
    The way Xwayland works (like all Wayland clients), it first queries the
    Wayland registry, set up all relevant protocols and then initializes its
    own structures.
    
    That means Xwayland will get the Wayland outputs from the Wayland
    compositor, compute the physical size of the combined outputs and set
    the corresponding Xwayland screen properties accordingly.
    
    Then it creates the X11 screen using fbScreenInit() but does so by using
    a default DPI value of 96. That value is used to set the physical size
    of the X11 screen, hence overriding the value computed from the actual
    physical size provided by the Wayland compositor.
    
    As a result, the DPI computed by tools such as xdpyinfo will always be
    96 regardless of the actual screen size and resolution.
    
    However, if the Wayland outputs get reconfigured, or new outputs added,
    or existing outputs removed, Xwayland will recompute and update the
    physical size of the screen, leading to an unexpected change of DPI.
    
    To avoid that discrepancy, use a fixed size DPI (defaults to 96, and can
    be set using the standard command lime option "-dpi") and compute a
    physical screen size to match that DPI setting.
    
    Note that only affects legacy core protocols, X11 clients can still get
    the actual physical output size as reported by the Wayland compositor
    using the RandR protocol, which also allows for the size to be 0 if the
    size is unknown or meaningless.
    
    Signed-off-by: Olivier Fourdan <ofourdan at redhat.com>
    Reviewed-by: Simon Ser <contact at emersion.fr>
    Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/731

diff --git a/hw/xwayland/xwayland-output.c b/hw/xwayland/xwayland-output.c
index 04eb42e8e..f94aa0d35 100644
--- a/hw/xwayland/xwayland-output.c
+++ b/hw/xwayland/xwayland-output.c
@@ -35,7 +35,6 @@
 
 #include "xdg-output-unstable-v1-client-protocol.h"
 
-#define DEFAULT_DPI 96
 #define ALL_ROTATIONS (RR_Rotate_0   | \
                        RR_Rotate_90  | \
                        RR_Rotate_180 | \
@@ -148,34 +147,6 @@ output_get_new_size(struct xwl_output *xwl_output,
         *height = xwl_output->y + output_height;
 }
 
-/* Approximate some kind of mmpd (m.m. per dot) of the screen given the outputs
- * associated with it.
- *
- * It either calculates the mean mmpd of all the outputs or, if no reasonable
- * value could be calculated, defaults to the mmpd of a screen with a DPI value
- * of DEFAULT_DPI.
- */
-static double
-approximate_mmpd(struct xwl_screen *xwl_screen)
-{
-    struct xwl_output *it;
-    int total_width_mm = 0;
-    int total_width = 0;
-
-    xorg_list_for_each_entry(it, &xwl_screen->output_list, link) {
-        if (it->randr_output->mmWidth == 0)
-            continue;
-
-        total_width_mm += it->randr_output->mmWidth;
-        total_width += it->width;
-    }
-
-    if (total_width_mm != 0)
-        return (double)total_width_mm / total_width;
-    else
-        return 25.4 / DEFAULT_DPI;
-}
-
 static int
 xwl_set_pixmap_visit_window(WindowPtr window, void *data)
 {
@@ -214,7 +185,6 @@ static void
 update_screen_size(struct xwl_output *xwl_output, int width, int height)
 {
     struct xwl_screen *xwl_screen = xwl_output->xwl_screen;
-    double mmpd;
 
     if (xwl_screen->root_clip_mode == ROOT_CLIP_FULL)
         SetRootClip(xwl_screen->screen, ROOT_CLIP_NONE);
@@ -226,15 +196,8 @@ update_screen_size(struct xwl_output *xwl_output, int width, int height)
     xwl_screen->height = height;
     xwl_screen->screen->width = width;
     xwl_screen->screen->height = height;
-
-    if (xwl_output->width == width && xwl_output->height == height) {
-        xwl_screen->screen->mmWidth = xwl_output->randr_output->mmWidth;
-        xwl_screen->screen->mmHeight = xwl_output->randr_output->mmHeight;
-    } else {
-        mmpd = approximate_mmpd(xwl_screen);
-        xwl_screen->screen->mmWidth = width * mmpd;
-        xwl_screen->screen->mmHeight = height * mmpd;
-    }
+    xwl_screen->screen->mmWidth = (width * 25.4) / monitorResolution;
+    xwl_screen->screen->mmHeight = (height * 25.4) / monitorResolution;
 
     SetRootClip(xwl_screen->screen, xwl_screen->root_clip_mode);
 
diff --git a/hw/xwayland/xwayland-screen.c b/hw/xwayland/xwayland-screen.c
index 4e523fec1..18d8968c7 100644
--- a/hw/xwayland/xwayland-screen.c
+++ b/hw/xwayland/xwayland-screen.c
@@ -59,6 +59,8 @@
 static DevPrivateKeyRec xwl_screen_private_key;
 static DevPrivateKeyRec xwl_client_private_key;
 
+#define DEFAULT_DPI 96
+
 _X_NORETURN
 static void _X_ATTRIBUTE_PRINTF(1, 2)
 xwl_give_up(const char *f, ...)
@@ -594,6 +596,9 @@ xwl_screen_init(ScreenPtr pScreen, int argc, char **argv)
     xorg_list_init(&xwl_screen->window_list);
     xwl_screen->depth = 24;
 
+    if (!monitorResolution)
+        monitorResolution = DEFAULT_DPI;
+
     xwl_screen->display = wl_display_connect(NULL);
     if (xwl_screen->display == NULL) {
         ErrorF("could not connect to wayland server\n");
@@ -624,7 +629,7 @@ xwl_screen_init(ScreenPtr pScreen, int argc, char **argv)
 
     ret = fbScreenInit(pScreen, NULL,
                        xwl_screen->width, xwl_screen->height,
-                       96, 96, 0,
+                       monitorResolution, monitorResolution, 0,
                        BitsPerPixel(xwl_screen->depth));
     if (!ret)
         return FALSE;