tests: Add tests for HDR Static Metadata encoding/decoding and equality

We have the drm/InfoFrame encoding and our MetaOutputHdrMetadata
encoding. Check that we can correctly convert between each other by
doing a encode/decode and decode/encode roundtrip and then checking for
equality.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2879>

src/backends/native/meta-kms-connector-private.h

@@ -142,7 +142,16 @@ MetaKmsConnector * meta_kms_connector_new (MetaKmsImplDevice *impl_device,
 gboolean meta_kms_connector_is_same_as (MetaKmsConnector *connector,
                                         drmModeConnector *drm_connector);
 
+META_EXPORT_TEST
 void meta_set_drm_hdr_metadata (MetaOutputHdrMetadata      *metadata,
                                 struct hdr_output_metadata *drm_metadata);
 
+META_EXPORT_TEST
+gboolean set_output_hdr_metadata (struct hdr_output_metadata *drm_metadata,
+                                  MetaOutputHdrMetadata      *metadata);
+
+META_EXPORT_TEST
+gboolean hdr_metadata_equal (MetaOutputHdrMetadata *metadata,
+                             MetaOutputHdrMetadata *other_metadata);
+
 #endif /* META_KMS_CONNECTOR_PRIVATE_H */

src/backends/native/meta-kms-connector.c

@@ -504,7 +504,7 @@ decode_u16_min_luminance (uint16_t value)
   return value * 0.0001;
 }
 
-static gboolean
+gboolean
 set_output_hdr_metadata (struct hdr_output_metadata *drm_metadata,
                          MetaOutputHdrMetadata      *metadata)
 {
@@ -887,7 +887,7 @@ hdr_min_luminance_equal (double x1, double x2)
   return fabs (x1 - x2) < (0.0001 - DBL_EPSILON);
 }
 
-static gboolean
+gboolean
 hdr_metadata_equal (MetaOutputHdrMetadata *metadata,
                     MetaOutputHdrMetadata *other_metadata)
 {

src/tests/hdr-metadata-unit-tests.c

@@ -0,0 +1,107 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+/*
+ * Copyright (C) 2023 Red Hat Inc.
+ *
+ * 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/>.
+ *
+ * Author: Sebastian Wick <sebastian.wick@redhat.com>
+ */
+
+#include "hdr-metadata-unit-tests.h"
+
+#include "tests/meta-monitor-test-utils.h"
+
+#include "backends/native/meta-kms-connector-private.h"
+
+static void
+meta_test_hdr_metadata_equality1 (void)
+{
+  struct hdr_output_metadata drm_metadata_in, drm_metadata_out;
+  MetaOutputHdrMetadata metadata;
+
+  memset (&drm_metadata_in, 0, sizeof (drm_metadata_in));
+  memset (&drm_metadata_out, 0, sizeof (drm_metadata_out));
+
+  drm_metadata_in = (struct hdr_output_metadata) {
+    .metadata_type = 0,
+    .hdmi_metadata_type1 = {
+      .eotf = 2,
+      .metadata_type = 0,
+      .display_primaries[0].x = 27,
+      .display_primaries[0].y = 53,
+      .display_primaries[1].x = 111,
+      .display_primaries[1].y = 43,
+      .display_primaries[2].x = 633,
+      .display_primaries[2].y = 2,
+      .white_point.x = 27,
+      .white_point.y = 53,
+      .max_display_mastering_luminance = 3333,
+      .min_display_mastering_luminance = 1000,
+      .max_cll = 392,
+      .max_fall = 2,
+    },
+  };
+
+  g_assert_true (set_output_hdr_metadata (&drm_metadata_in, &metadata));
+  meta_set_drm_hdr_metadata (&metadata, &drm_metadata_out);
+
+  g_assert_cmpint (memcmp (&drm_metadata_in,
+                           &drm_metadata_out,
+                           sizeof (struct hdr_output_metadata)), ==, 0);
+}
+
+static void
+meta_test_hdr_metadata_equality2 (void)
+{
+  struct hdr_output_metadata drm_metadata;
+  MetaOutputHdrMetadata metadata_in, metadata_out;
+
+  memset (&metadata_in, 0, sizeof (metadata_in));
+  memset (&metadata_out, 0, sizeof (metadata_out));
+
+  metadata_in = (MetaOutputHdrMetadata) {
+    .active = true,
+    .eotf = META_OUTPUT_HDR_METADATA_EOTF_PQ,
+    .mastering_display_primaries[0].x = 0.2384,
+    .mastering_display_primaries[0].y = 1.0000,
+    .mastering_display_primaries[1].x = 0.4,
+    .mastering_display_primaries[1].y = 0.002,
+    .mastering_display_primaries[2].x = 0.3,
+    .mastering_display_primaries[2].y = 0.333,
+    .mastering_display_white_point.x = 0.0001,
+    .mastering_display_white_point.y = 0.999,
+    .mastering_display_max_luminance = 22.22,
+    .max_cll = 50.5,
+    .max_fall = 12.0,
+  };
+
+  meta_set_drm_hdr_metadata (&metadata_in, &drm_metadata);
+  g_assert_true (set_output_hdr_metadata (&drm_metadata, &metadata_out));
+  metadata_out.active = TRUE;
+
+  g_assert_cmpint (memcmp (&metadata_in,
+                           &metadata_out,
+                           sizeof (MetaOutputHdrMetadata)), !=, 0);
+
+  g_assert_true (hdr_metadata_equal (&metadata_in, &metadata_out));
+}
+
+void
+init_hdr_metadata_tests (void)
+{
+  g_test_add_func ("/backends/native/hdr-metadata-equality1",
+                   meta_test_hdr_metadata_equality1);
+  g_test_add_func ("/backends/native/hdr-metadata-equality2",
+                   meta_test_hdr_metadata_equality2);
+}

src/tests/hdr-metadata-unit-tests.h

@@ -0,0 +1,26 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+/*
+ * Copyright (C) 2023 Red Hat Inc.
+ *
+ * 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/>.
+ *
+ * Author: Sebastian Wick <sebastian.wick@redhat.com>
+ */
+
+#ifndef HDR_METADATA_UNIT_TESTS_H
+#define HDR_METADATA_UNIT_TESTS_H
+
+void init_hdr_metadata_tests (void);
+
+#endif /* HDR_METADATA_UNIT_TESTS_H */

src/tests/meson.build

@@ -235,6 +235,7 @@ test_cases += [
       'monitor-transform-tests.c',
       'monitor-transform-tests.h',
       'orientation-manager-unit-tests.c',
+      'hdr-metadata-unit-tests.c',
     ],
   },
   {

src/tests/unit-tests.c

@@ -38,6 +38,7 @@
 #include "tests/monitor-transform-tests.h"
 #include "tests/meta-test-utils.h"
 #include "tests/orientation-manager-unit-tests.h"
+#include "tests/hdr-metadata-unit-tests.h"
 
 MetaContext *test_context;
 
@@ -242,6 +243,7 @@ init_tests (void)
   init_boxes_tests ();
   init_monitor_transform_tests ();
   init_orientation_manager_tests ();
+  init_hdr_metadata_tests ();
 }
 
 int