tests/wayland: Add test for fractional-scale protocol

For now test that a simple fullscreen client on a FullHD screen selects
the expected values.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2394>

8 files changed, 411 insertions, 2 deletions

diff --git a/src/tests/meson.build b/src/tests/meson.build
index 3dd8a59b9..3768b83da 100644
--- a/src/tests/meson.build
+++ b/src/tests/meson.build
@@ -431,10 +431,11 @@ if have_native_tests
       ],
     },
     {
-      'name': 'wayland-client-tests',
+      'name': 'wayland-fractional-scale',
       'suite': 'wayland',
       'sources': [
-        'wayland-client-tests.c',
+        'wayland-fractional-scale-test.c',
+        wayland_test_utils,
       ],
     },
     {
diff --git a/src/tests/monitor-configs/full-hd-fractional-scale-1.25.xml b/src/tests/monitor-configs/full-hd-fractional-scale-1.25.xml
new file mode 100644
index 000000000..11b37d18b
--- /dev/null
+++ b/src/tests/monitor-configs/full-hd-fractional-scale-1.25.xml
@@ -0,0 +1,23 @@
+<monitors version="2">
+  <configuration>
+    <logicalmonitor>
+      <x>0</x>
+      <y>0</y>
+      <primary>yes</primary>
+      <scale>1.25</scale>
+      <monitor>
+       <monitorspec>
+         <connector>Meta-0</connector>
+         <vendor>MetaTestVendor</vendor>
+         <product>MetaVirtualMonitor</product>
+         <serial>0x10000</serial>
+       </monitorspec>
+       <mode>
+         <width>1920</width>
+         <height>1080</height>
+         <rate>60</rate>
+       </mode>
+      </monitor>
+    </logicalmonitor>
+  </configuration>
+</monitors>
diff --git a/src/tests/monitor-configs/full-hd-fractional-scale-1.5.xml b/src/tests/monitor-configs/full-hd-fractional-scale-1.5.xml
new file mode 100644
index 000000000..125d9f7e3
--- /dev/null
+++ b/src/tests/monitor-configs/full-hd-fractional-scale-1.5.xml
@@ -0,0 +1,23 @@
+<monitors version="2">
+  <configuration>
+    <logicalmonitor>
+      <x>0</x>
+      <y>0</y>
+      <primary>yes</primary>
+      <scale>1.5</scale>
+      <monitor>
+       <monitorspec>
+         <connector>Meta-0</connector>
+         <vendor>MetaTestVendor</vendor>
+         <product>MetaVirtualMonitor</product>
+         <serial>0x10000</serial>
+       </monitorspec>
+       <mode>
+         <width>1920</width>
+         <height>1080</height>
+         <rate>60</rate>
+       </mode>
+      </monitor>
+    </logicalmonitor>
+  </configuration>
+</monitors>
diff --git a/src/tests/wayland-fractional-scale-test.c b/src/tests/wayland-fractional-scale-test.c
new file mode 100644
index 000000000..77b6d217d
--- /dev/null
+++ b/src/tests/wayland-fractional-scale-test.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright (C) 2022 Red Hat, Inc.
+ * Copyright (C) 2023 Collabora, Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include "backends/meta-virtual-monitor.h"
+#include "core/window-private.h"
+#include "meta-test/meta-context-test.h"
+#include "tests/meta-test-utils.h"
+#include "tests/meta-wayland-test-driver.h"
+#include "tests/meta-wayland-test-utils.h"
+#include "wayland/meta-wayland-surface.h"
+
+static MetaContext *test_context;
+static MetaVirtualMonitor *virtual_monitor;
+static MetaWaylandTestClient *wayland_test_client;
+static MetaWaylandTestDriver *test_driver;
+static MetaWindow *test_window = NULL;
+
+#define assert_wayland_surface_size(window, width, height) \
+{ \
+  g_assert_cmpint (meta_wayland_surface_get_width (meta_window_get_wayland_surface (window)), \
+                   ==, \
+                   width); \
+  g_assert_cmpint (meta_wayland_surface_get_height (meta_window_get_wayland_surface (window)), \
+                   ==, \
+                   height); \
+}
+
+#define assert_wayland_buffer_size(window, width, height) \
+{ \
+  g_assert_cmpint (meta_wayland_surface_get_buffer_width (meta_window_get_wayland_surface (window)), \
+                   ==, \
+                   width); \
+  g_assert_cmpint (meta_wayland_surface_get_buffer_height (meta_window_get_wayland_surface (window)), \
+                   ==, \
+                   height); \
+}
+
+static void
+wait_for_sync_point (unsigned int sync_point)
+{
+  meta_wayland_test_driver_wait_for_sync_point (test_driver, sync_point);
+}
+
+static void
+fractional_scale (void)
+{
+  MetaBackend *backend = meta_context_get_backend (test_context);
+  MetaMonitorManager *monitor_manager =
+    meta_backend_get_monitor_manager (backend);
+  MetaLogicalMonitor *logical_monitor;
+  MetaRectangle layout;
+
+  wait_for_sync_point (0);
+  assert_wayland_surface_size (test_window, 1920, 1080);
+  assert_wayland_buffer_size (test_window, 1920, 1080);
+
+  meta_set_custom_monitor_config_full (backend,
+                                       "full-hd-fractional-scale-1.25.xml",
+                                       META_MONITORS_CONFIG_FLAG_NONE);
+  meta_monitor_manager_reload (monitor_manager);
+  logical_monitor =
+    meta_monitor_manager_get_logical_monitors (monitor_manager)->data;
+  layout = meta_logical_monitor_get_layout (logical_monitor);
+  g_assert_cmpint (layout.x, ==, 0);
+  g_assert_cmpint (layout.y, ==, 0);
+  g_assert_cmpint (layout.width, ==, 1536);
+  g_assert_cmpint (layout.height, ==, 864);
+
+  wait_for_sync_point (1);
+  assert_wayland_surface_size (test_window, 1536, 864);
+  assert_wayland_buffer_size (test_window, 1920, 1080);
+
+  meta_set_custom_monitor_config_full (backend,
+                                       "full-hd-fractional-scale-1.5.xml",
+                                       META_MONITORS_CONFIG_FLAG_NONE);
+  meta_monitor_manager_reload (monitor_manager);
+  logical_monitor =
+    meta_monitor_manager_get_logical_monitors (monitor_manager)->data;
+  layout = meta_logical_monitor_get_layout (logical_monitor);
+  g_assert_cmpint (layout.x, ==, 0);
+  g_assert_cmpint (layout.y, ==, 0);
+  g_assert_cmpint (layout.width, ==, 1280);
+  g_assert_cmpint (layout.height, ==, 720);
+
+  wait_for_sync_point (2);
+  assert_wayland_surface_size (test_window, 1280, 720);
+  assert_wayland_buffer_size (test_window, 1920, 1080);
+}
+
+static void
+on_before_tests (void)
+{
+  MetaWaylandCompositor *compositor =
+    meta_context_get_wayland_compositor (test_context);
+
+  test_driver = meta_wayland_test_driver_new (compositor);
+
+  virtual_monitor = meta_create_test_monitor (test_context,
+                                              1920, 1080, 60.0);
+
+  wayland_test_client = meta_wayland_test_client_new (test_context,
+                                                      "fractional-scale");
+
+  while (!test_window)
+    {
+      g_main_context_iteration (NULL, TRUE);
+      test_window =
+        meta_find_window_from_title (test_context, "fractional-scale");
+    }
+}
+
+static void
+on_after_tests (void)
+{
+  meta_window_delete (test_window, g_get_monotonic_time ());
+
+  meta_wayland_test_client_finish (wayland_test_client);
+
+  g_clear_object (&virtual_monitor);
+
+  g_clear_object (&test_driver);
+}
+
+static void
+init_tests (void)
+{
+  g_test_add_func ("/wayland/fractional-scale",
+                   fractional_scale);
+}
+
+int
+main (int   argc,
+      char *argv[])
+{
+  g_autoptr (MetaContext) context = NULL;
+
+  context = meta_create_test_context (META_CONTEXT_TEST_TYPE_HEADLESS,
+                                      META_CONTEXT_TEST_FLAG_NO_X11);
+  g_assert (meta_context_configure (context, &argc, &argv, NULL));
+
+  test_context = context;
+
+  init_tests ();
+
+  g_signal_connect (context, "before-tests",
+                    G_CALLBACK (on_before_tests), NULL);
+  g_signal_connect (context, "after-tests",
+                    G_CALLBACK (on_after_tests), NULL);
+
+  return meta_context_test_run_tests (META_CONTEXT_TEST (context),
+                                      META_TEST_RUN_FLAG_NONE);
+}
diff --git a/src/tests/wayland-test-clients/fractional-scale.c b/src/tests/wayland-test-clients/fractional-scale.c
new file mode 100644
index 000000000..b46e63f31
--- /dev/null
+++ b/src/tests/wayland-test-clients/fractional-scale.c
@@ -0,0 +1,182 @@
+/*
+ * Copyright (C) 2023 Collabora, Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <glib.h>
+#include <wayland-client.h>
+
+#include "wayland-test-client-utils.h"
+
+static WaylandDisplay *display;
+static struct wl_surface *surface;
+static struct xdg_surface *xdg_surface;
+static struct xdg_toplevel *xdg_toplevel;
+static struct wp_viewport *viewport;
+static struct wp_fractional_scale_v1 *fractional_scale_obj;
+
+static gboolean running;
+static gboolean waiting_for_configure;
+static gboolean waiting_for_scale;
+static uint32_t logical_width = 0;
+static uint32_t logical_height = 0;
+static float fractional_buffer_scale = 1.0;
+static int sync_point = 0;
+
+static void
+handle_frame_callback (void               *data,
+                       struct wl_callback *callback,
+                       uint32_t            time)
+{
+  wl_callback_destroy (callback);
+  test_driver_sync_point (display->test_driver, sync_point++, NULL);
+}
+
+static const struct wl_callback_listener frame_listener = {
+  handle_frame_callback,
+};
+
+static void
+maybe_redraw (void)
+{
+  struct wl_callback *callback;
+  uint32_t buffer_width;
+  uint32_t buffer_height;
+
+  if (waiting_for_configure || waiting_for_scale)
+    return;
+
+  g_assert_cmpint (logical_width, >, 0);
+  g_assert_cmpint (logical_height, >, 0);
+  g_assert_cmpfloat (fractional_buffer_scale, >, 0.0);
+
+  buffer_width = ceilf (logical_width * fractional_buffer_scale);
+  buffer_height = ceilf (logical_height * fractional_buffer_scale);
+
+  draw_surface (display, surface, buffer_width, buffer_height, 0x1f109f20);
+  wp_viewport_set_destination (viewport, logical_width, logical_height);
+
+  callback = wl_surface_frame (surface);
+  wl_callback_add_listener (callback, &frame_listener, NULL);
+
+  wl_surface_commit (surface);
+
+  waiting_for_configure = TRUE;
+  waiting_for_scale = TRUE;
+}
+
+static void
+handle_xdg_toplevel_configure (void                *data,
+                               struct xdg_toplevel *xdg_toplevel,
+                               int32_t              width,
+                               int32_t              height,
+                               struct wl_array     *states)
+{
+  if (width > 0 && height > 0)
+    {
+      logical_width = width;
+      logical_height = height;
+      waiting_for_configure = TRUE;
+    }
+}
+
+static void
+handle_xdg_toplevel_close (void                *data,
+                           struct xdg_toplevel *xdg_toplevel)
+{
+  running = FALSE;
+}
+
+static const struct xdg_toplevel_listener xdg_toplevel_listener = {
+  handle_xdg_toplevel_configure,
+  handle_xdg_toplevel_close,
+};
+
+static void
+handle_xdg_surface_configure (void               *data,
+                              struct xdg_surface *xdg_surface,
+                              uint32_t            serial)
+{
+  xdg_surface_ack_configure (xdg_surface, serial);
+  waiting_for_configure = FALSE;
+
+  maybe_redraw ();
+}
+
+static const struct xdg_surface_listener xdg_surface_listener = {
+  handle_xdg_surface_configure,
+};
+
+static void handle_preferred_scale (void                          *data,
+                                    struct wp_fractional_scale_v1 *fractional_scale_obj,
+                                    uint32_t                       wire_scale)
+{
+  float new_fractional_buffer_scale;
+
+  new_fractional_buffer_scale = wire_scale / 120.0;
+  if (G_APPROX_VALUE (new_fractional_buffer_scale,
+                      fractional_buffer_scale,
+                      FLT_EPSILON))
+    return;
+
+  fractional_buffer_scale = new_fractional_buffer_scale;
+  waiting_for_scale = FALSE;
+  maybe_redraw ();
+}
+
+static const struct wp_fractional_scale_v1_listener fractional_scale_listener = {
+  .preferred_scale = handle_preferred_scale,
+};
+
+int
+main (int    argc,
+      char **argv)
+{
+  display = wayland_display_new (WAYLAND_DISPLAY_CAPABILITY_TEST_DRIVER);
+
+  surface = wl_compositor_create_surface (display->compositor);
+  xdg_surface = xdg_wm_base_get_xdg_surface (display->xdg_wm_base, surface);
+  xdg_surface_add_listener (xdg_surface, &xdg_surface_listener, NULL);
+  xdg_toplevel = xdg_surface_get_toplevel (xdg_surface);
+  xdg_toplevel_add_listener (xdg_toplevel, &xdg_toplevel_listener, NULL);
+  xdg_toplevel_set_title (xdg_toplevel, "fractional-scale");
+  xdg_toplevel_set_fullscreen (xdg_toplevel, NULL);
+
+  viewport = wp_viewporter_get_viewport (display->viewporter, surface);
+  fractional_scale_obj =
+    wp_fractional_scale_manager_v1_get_fractional_scale (display->fractional_scale_mgr,
+                                                         surface);
+  wp_fractional_scale_v1_add_listener (fractional_scale_obj,
+                                       &fractional_scale_listener,
+                                       NULL);
+
+  wl_surface_commit (surface);
+
+  waiting_for_configure = TRUE;
+  waiting_for_scale = FALSE;
+
+  running = TRUE;
+  while (running)
+    {
+      if (wl_display_dispatch (display->display) == -1)
+        return EXIT_FAILURE;
+    }
+
+  wl_display_roundtrip (display->display);
+
+  return EXIT_SUCCESS;
+}
diff --git a/src/tests/wayland-test-clients/meson.build b/src/tests/wayland-test-clients/meson.build
index 572e07bd0..e61781ba2 100644
--- a/src/tests/wayland-test-clients/meson.build
+++ b/src/tests/wayland-test-clients/meson.build
@@ -21,6 +21,9 @@ wayland_test_clients = [
     'name': 'buffer-transform',
   },
   {
+    'name': 'fractional-scale',
+  },
+  {
     'name': 'single-pixel-buffer',
   },
   {
diff --git a/src/tests/wayland-test-clients/wayland-test-client-utils.c b/src/tests/wayland-test-clients/wayland-test-client-utils.c
index 9e044c003..97d28b8e1 100644
--- a/src/tests/wayland-test-clients/wayland-test-client-utils.c
+++ b/src/tests/wayland-test-clients/wayland-test-client-utils.c
@@ -166,6 +166,12 @@ handle_registry_global (void               *user_data,
       display->shm = wl_registry_bind (registry,
                                        id, &wl_shm_interface, 1);
     }
+  else if (strcmp (interface, wp_fractional_scale_manager_v1_interface.name) == 0)
+    {
+      display->fractional_scale_mgr =
+        wl_registry_bind (registry, id,
+                          &wp_fractional_scale_manager_v1_interface, 1);
+    }
   else if (strcmp (interface, wp_single_pixel_buffer_manager_v1_interface.name) == 0)
     {
       display->single_pixel_mgr =
diff --git a/src/tests/wayland-test-clients/wayland-test-client-utils.h b/src/tests/wayland-test-clients/wayland-test-client-utils.h
index 8508ae5a5..af5eb0e54 100644
--- a/src/tests/wayland-test-clients/wayland-test-client-utils.h
+++ b/src/tests/wayland-test-clients/wayland-test-client-utils.h
@@ -5,6 +5,7 @@
 #include <stdio.h>
 #include <wayland-client.h>
 
+#include "fractional-scale-v1-client-protocol.h"
 #include "single-pixel-buffer-v1-client-protocol.h"
 #include "test-driver-client-protocol.h"
 #include "viewporter-client-protocol.h"
@@ -28,6 +29,7 @@ typedef struct _WaylandDisplay
   struct wl_compositor *compositor;
   struct wl_subcompositor *subcompositor;
   struct wl_shm *shm;
+  struct wp_fractional_scale_manager_v1 *fractional_scale_mgr;
   struct wp_single_pixel_buffer_manager_v1 *single_pixel_mgr;
   struct wp_viewporter *viewporter;
   struct xdg_wm_base *xdg_wm_base;