=== modified file 'Makefile.am'
--- Makefile.am	2012-09-17 13:31:13 +0000
+++ Makefile.am	2014-11-28 09:12:39 +0000
@@ -1,6 +1,6 @@
 # -*- Mode: Automake; indent-tabs-mode: t; tab-width: 4 -*-
 
-SUBDIRS = data po src tests
+SUBDIRS = data po vapi src tests
 
 EXTRA_DIST = \
 	autogen.sh \

=== modified file 'configure.ac'
--- configure.ac	2014-04-30 15:33:19 +0000
+++ configure.ac	2014-11-28 09:33:49 +0000
@@ -29,6 +29,7 @@
     libcanberra
     pixman-1
     x11
+    xrandr
 ])
 
 AC_DEFINE_UNQUOTED([INDICATOR_FILE_DIR], ["${prefix}/share/unity/indicators"], [Indicator files are searched for in this directory])
@@ -59,6 +60,7 @@
 Makefile
 data/Makefile
 po/Makefile.in
+vapi/Makefile
 src/Makefile
 tests/Makefile
 ])

=== modified file 'debian/changelog'
--- debian/changelog	2014-04-30 15:33:19 +0000
+++ debian/changelog	2014-12-01 08:58:30 +0000
@@ -1,3 +1,9 @@
+unity-greeter (14.04.10-0ubuntu1.1) trusty; urgency=medium
+
+  * Support HiDPI display.
+
+ -- Shih-Yuan Lee (FourDollars) <sylee@canonical.com>  Thu, 20 Nov 2014 17:45:04 +0800
+
 unity-greeter (14.04.10-0ubuntu1) trusty; urgency=medium
 
   * New upstream release:

=== modified file 'debian/control'
--- debian/control	2014-04-08 07:57:42 +0000
+++ debian/control	2014-11-28 09:39:31 +0000
@@ -18,6 +18,7 @@
                libido3-0.1-dev (>= 13.10.0),
                liblightdm-gobject-1-dev (>= 1.4.0),
                libpixman-1-dev,
+               libxrandr-dev,
                valac (>= 0.20.0),
                xvfb,
 Homepage: https://launchpad.net/unity-greeter

=== modified file 'src/Makefile.am'
--- src/Makefile.am	2014-04-08 07:57:42 +0000
+++ src/Makefile.am	2014-11-28 09:20:26 +0000
@@ -2,6 +2,7 @@
 
 sbin_PROGRAMS = unity-greeter
 noinst_PROGRAMS = logo-generator
+noinst_HEADERS = hidpi_check.h
 
 unity_greeter_SOURCES = \
 	config.vapi \
@@ -33,7 +34,8 @@
 	toggle-box.vala \
 	unity-greeter.vala \
 	user-list.vala \
-	user-prompt-box.vala
+	user-prompt-box.vala \
+	hidpi_check.c
 
 logo_generator_SOURCES = logo-generator.vala
 
@@ -51,6 +53,8 @@
 logo_generator_CFLAGS = $(unity_greeter_CFLAGS)
 
 unity_greeter_VALAFLAGS = \
+	--vapidir=$(top_srcdir)/vapi \
+	--pkg hidpi-check \
 	--pkg posix \
 	--pkg gtk+-3.0 \
 	--pkg gdk-x11-3.0 \

=== added file 'src/hidpi_check.c'
--- src/hidpi_check.c	1970-01-01 00:00:00 +0000
+++ src/hidpi_check.c	2014-11-28 11:03:18 +0000
@@ -0,0 +1,49 @@
+#include "hidpi_check.h"
+
+#include <math.h>
+
+#include <X11/extensions/Xrandr.h>
+
+int check_hidpi (void)
+{
+	int result = 0;
+	int i;
+	Display *display = XOpenDisplay (NULL);
+
+	if (!display)
+		return 0;
+
+	Window window = RootWindow (display, XDefaultScreen (display));
+
+	XRRScreenResources *resources = XRRGetScreenResourcesCurrent (display, window);
+
+	if (!resources)
+		return 0;
+
+	for (i = 0; i < resources->noutput; ++i) {
+		XRROutputInfo *output = XRRGetOutputInfo (display, resources, resources->outputs[i]);
+
+		if (output->connection == RR_Disconnected) {
+			XRRFreeOutputInfo (output);
+			continue;
+		}
+
+		if (output->crtc) {
+			XRRCrtcInfo *crtc = XRRGetCrtcInfo (display, resources, output->crtc);
+			double diagonal = sqrt (crtc->width * crtc->width + crtc->height * crtc->height);
+			double diagonal_mm = sqrt (output->mm_width * output->mm_width + output->mm_height * output->mm_height);
+			int ppi = (int) floor (diagonal * 25.4 / diagonal_mm);
+
+			if (ppi >= 192 && crtc->height >= 1200)
+				result = 1;
+
+			XRRFreeCrtcInfo (crtc);
+		}
+		XRRFreeOutputInfo (output);
+	}
+
+	XRRFreeScreenResources (resources);
+	XCloseDisplay (display);
+
+	return result;
+}

=== added file 'src/hidpi_check.h'
--- src/hidpi_check.h	1970-01-01 00:00:00 +0000
+++ src/hidpi_check.h	2014-11-28 08:01:56 +0000
@@ -0,0 +1,12 @@
+#ifndef _HIDPI_CHECK_H
+#define _HIDPI_CHECK_H 1
+
+#include <features.h>
+
+__BEGIN_DECLS
+
+extern int check_hidpi (void);
+
+__END_DECLS
+
+#endif

=== modified file 'src/unity-greeter.vala'
--- src/unity-greeter.vala	2014-04-08 15:57:59 +0000
+++ src/unity-greeter.vala	2014-11-28 11:21:06 +0000
@@ -487,6 +487,10 @@
             warning ("Error starting the at-spi registry: %s", e.message);
         }
 
+        /* GDK_SCALE needs to be set before Gtk.init () */
+        if (HiDPI.check_hidpi ())
+            Environment.set_variable ("GDK_SCALE", "2", true);
+
         Gtk.init (ref args);
         Ido.init ();
 

=== added directory 'vapi'
=== added file 'vapi/Makefile.am'
--- vapi/Makefile.am	1970-01-01 00:00:00 +0000
+++ vapi/Makefile.am	2014-11-28 09:06:33 +0000
@@ -0,0 +1,3 @@
+noinst_DATA = hidpi-check.vapi
+
+EXTRA_DIST = $(noinst_DATA)

=== added file 'vapi/hidpi-check.vapi'
--- vapi/hidpi-check.vapi	1970-01-01 00:00:00 +0000
+++ vapi/hidpi-check.vapi	2014-11-28 07:55:37 +0000
@@ -0,0 +1,6 @@
+[CCode (prefix = "", lower_case_cprefix = "")]
+namespace HiDPI
+{
+    [CCode (cheader_filename = "hidpi_check.h")]
+    public bool check_hidpi();
+}