Mozart: Move frame lag compensation to new class.

mojo/services/gfx/composition/cpp/frame_tracker_apptest.cc

Index: mojo/services/gfx/composition/cpp/frame_tracker_apptest.cc
diff --git a/mojo/services/gfx/composition/cpp/frame_tracker_apptest.cc b/mojo/services/gfx/composition/cpp/frame_tracker_apptest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0591ed028199bd1881a2a1b251e8c6e101f5e760
--- /dev/null
+++ b/mojo/services/gfx/composition/cpp/frame_tracker_apptest.cc
@@ -0,0 +1,186 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "mojo/services/gfx/composition/cpp/frame_tracker.h"
+
+#include "mojo/public/cpp/application/application_impl.h"
+#include "mojo/public/cpp/application/application_test_base.h"
+#include "mojo/public/cpp/system/macros.h"
+
+namespace test {
+
+class FrameTrackerTest : public mojo::test::ApplicationTestBase {
+ public:
+  FrameTrackerTest() {}
+  ~FrameTrackerTest() override {}
+
+ protected:
+  mojo::gfx::composition::FrameTracker frame_tracker_;
+
+  uint64_t Update(int64_t frame_time,
+                  uint64_t frame_interval,
+                  int64_t frame_deadline,
+                  int64_t presentation_time,
+                  MojoTimeTicks now) {
+    mojo::gfx::composition::FrameInfo frame_info;
+    frame_info.frame_time = frame_time;
+    frame_info.frame_interval = frame_interval;
+    frame_info.frame_deadline = frame_deadline;
+    frame_info.presentation_time = presentation_time;
+    return frame_tracker_.Update(frame_info, now);
+  }
+
+ private:
+  MOJO_DISALLOW_COPY_AND_ASSIGN(FrameTrackerTest);
+};
+
+namespace {
+
+TEST_F(FrameTrackerTest, InitialState) {
+  EXPECT_EQ(0u, frame_tracker_.frame_count());
+  EXPECT_EQ(0, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(0u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(0, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(0, frame_tracker_.frame_info().presentation_time);
+}
+
+TEST_F(FrameTrackerTest, ClearResetsEverything) {
+  Update(10, 10u, 10, 10, 10);
+
+  frame_tracker_.Clear();
+  EXPECT_EQ(0u, frame_tracker_.frame_count());
+  EXPECT_EQ(0, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(0u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(0, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(0, frame_tracker_.frame_info().presentation_time);
+}
+
+TEST_F(FrameTrackerTest, TypicalUpdate) {
+  // Signalled right at frame time.
+  // No corrections.
+  EXPECT_EQ(0u, Update(12, 10u, 24, 28, 12));
+  EXPECT_EQ(1u, frame_tracker_.frame_count());
+  EXPECT_EQ(12, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(24, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(28, frame_tracker_.frame_info().presentation_time);
+
+  // Signalled 1 ms after frame time.
+  // No corrections.
+  EXPECT_EQ(10u, Update(22, 10u, 34, 38, 22 + 1));
+  EXPECT_EQ(2u, frame_tracker_.frame_count());
+  EXPECT_EQ(22, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(34, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(38, frame_tracker_.frame_info().presentation_time);
+
+  // Signalled 9 ms after frame time (frame interval is 10 ms).
+  // No corrections.
+  EXPECT_EQ(10u, Update(32, 10u, 44, 48, 32 + 9));
+  EXPECT_EQ(3u, frame_tracker_.frame_count());
+  EXPECT_EQ(32, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(44, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(48, frame_tracker_.frame_info().presentation_time);
+
+  // Frame interval changed.
+  // No corrections.
+  EXPECT_EQ(14u, Update(46, 15u, 59, 62, 46 + 2));
+  EXPECT_EQ(4u, frame_tracker_.frame_count());
+  EXPECT_EQ(46, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(15u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(59, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(62, frame_tracker_.frame_info().presentation_time);
+}
+
+TEST_F(FrameTrackerTest, LagCompensation) {
+  // Received signal exactly when next frame should begin.
+  // Skip 1 frame.
+  EXPECT_EQ(0u, Update(12, 10u, 24, 28, 12 + 10));
+  EXPECT_EQ(1u, frame_tracker_.frame_count());
+  EXPECT_EQ(22, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(34, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(38, frame_tracker_.frame_info().presentation_time);
+
+  // Received signal 2 ms after next frame should begin.
+  // Skip 1 frame.
+  EXPECT_EQ(20u, Update(32, 10u, 44, 48, 32 + 10 + 2));
+  EXPECT_EQ(2u, frame_tracker_.frame_count());
+  EXPECT_EQ(42, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(54, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(58, frame_tracker_.frame_info().presentation_time);
+
+  // Received signal 35 ms after next frame should begin.
+  // Skip 4 frames.
+  EXPECT_EQ(50u, Update(52, 10u, 64, 68, 52 + 10 + 35));
+  EXPECT_EQ(3u, frame_tracker_.frame_count());
+  EXPECT_EQ(92, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(104, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(108, frame_tracker_.frame_info().presentation_time);
+}
+
+TEST_F(FrameTrackerTest, FrameTimeInPast) {
+  // Frame time is in the future.
+  // Clamp frame time to present.
+  EXPECT_EQ(0u, Update(12, 10u, 24, 28, 12 - 1));
+  EXPECT_EQ(1u, frame_tracker_.frame_count());
+  EXPECT_EQ(11, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(24, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(28, frame_tracker_.frame_info().presentation_time);
+}
+
+TEST_F(FrameTrackerTest, FrameDeadlineBehindFrameTime) {
+  // Frame deadline is earlier than frame time.
+  // Clamp frame deadline time to frame time.
+  EXPECT_EQ(0u, Update(12, 10u, 12 - 1, 28, 12));
+  EXPECT_EQ(1u, frame_tracker_.frame_count());
+  EXPECT_EQ(12, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(12, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(28, frame_tracker_.frame_info().presentation_time);
+}
+
+TEST_F(FrameTrackerTest, PresentationTimeBehindFrameDeadline) {
+  // Presentation time is earlier than frame deadline.
+  // Clamp presentation time to frame deadline.
+  EXPECT_EQ(0u, Update(12, 10u, 24, 24 - 1, 12));
+  EXPECT_EQ(1u, frame_tracker_.frame_count());
+  EXPECT_EQ(12, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(24, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(24, frame_tracker_.frame_info().presentation_time);
+}
+
+TEST_F(FrameTrackerTest, NonMonotonicFrameTime) {
+  Update(12, 10u, 24, 28, 12);
+
+  // Frame time is going backwards.
+  // Clamp frame time to old frame time.
+  EXPECT_EQ(0u, Update(10, 10u, 24, 28, 13));
+  EXPECT_EQ(2u, frame_tracker_.frame_count());
+  EXPECT_EQ(12, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(24, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(28, frame_tracker_.frame_info().presentation_time);
+}
+
+TEST_F(FrameTrackerTest, NonMonotonicPresentationTime) {
+  Update(12, 10u, 24, 28, 12);
+
+  // Presentation time is going backwards.
+  // Clamp presentation time to old presentation time.
+  EXPECT_EQ(10u, Update(22, 10u, 26, 27, 22));
+  EXPECT_EQ(2u, frame_tracker_.frame_count());
+  EXPECT_EQ(22, frame_tracker_.frame_info().frame_time);
+  EXPECT_EQ(10u, frame_tracker_.frame_info().frame_interval);
+  EXPECT_EQ(26, frame_tracker_.frame_info().frame_deadline);
+  EXPECT_EQ(28, frame_tracker_.frame_info().presentation_time);
+}
+
+}  // namespace
+}  // namespace mojo