Reland of [WebRTC] A real ScreenCapturer test

webrtc/modules/desktop_capture/screen_capturer_unittest.cc

Index: webrtc/modules/desktop_capture/screen_capturer_unittest.cc
diff --git a/webrtc/modules/desktop_capture/screen_capturer_unittest.cc b/webrtc/modules/desktop_capture/screen_capturer_unittest.cc
index 6d2c0eb0658221f98ebb4f34d18a22076de8521a..a9297584d93def2cd9ffaf7979b81fbc3c26b241 100644
--- a/webrtc/modules/desktop_capture/screen_capturer_unittest.cc
+++ b/webrtc/modules/desktop_capture/screen_capturer_unittest.cc
@@ -8,6 +8,10 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include <string.h>
+
+#include <algorithm>
+#include <initializer_list>
 #include <memory>
 #include <utility>
 
@@ -15,12 +19,16 @@
 
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/checks.h"
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/logging.h"
+#include "webrtc/modules/desktop_capture/rgba_color.h"
 #include "webrtc/modules/desktop_capture/desktop_capture_options.h"
 #include "webrtc/modules/desktop_capture/desktop_frame.h"
 #include "webrtc/modules/desktop_capture/desktop_region.h"
 #include "webrtc/modules/desktop_capture/screen_capturer_mock_objects.h"
+#include "webrtc/modules/desktop_capture/screen_drawer.h"
+#include "webrtc/system_wrappers/include/sleep.h"
 
 #if defined(WEBRTC_WIN)
 #include "webrtc/modules/desktop_capture/win/screen_capturer_win_directx.h"
@@ -34,6 +42,53 @@ const int kTestSharedMemoryId = 123;
 
 namespace webrtc {
 
+namespace {
+
+ACTION_P(SaveUniquePtrArg, dest) {
+  *dest = std::move(*arg1);
+}
+
+// Expects |capturer| to successfully capture a frame, and returns it.
+std::unique_ptr<DesktopFrame> CaptureFrame(
+    ScreenCapturer* capturer,
+    MockScreenCapturerCallback* callback) {
+  std::unique_ptr<DesktopFrame> frame;
+  EXPECT_CALL(*callback,
+              OnCaptureResultPtr(DesktopCapturer::Result::SUCCESS, _))
+      .WillOnce(SaveUniquePtrArg(&frame));
+  capturer->Capture(DesktopRegion());
+  EXPECT_TRUE(frame);
+  return frame;
+}
+
+// Returns true if color in |rect| of |frame| is |color|.
+bool ArePixelsColoredBy(const DesktopFrame& frame,
+                        DesktopRect rect,
+                        RgbaColor color) {
+  // updated_region() should cover the painted area.
+  DesktopRegion updated_region(frame.updated_region());
+  updated_region.IntersectWith(rect);
+  if (!updated_region.Equals(DesktopRegion(rect))) {
+    return false;
+  }
+
+  // Color in the |rect| should be |color|.
+  uint8_t* row = frame.GetFrameDataAtPos(rect.top_left());
+  for (int i = 0; i < rect.height(); i++) {
+    uint8_t* column = row;
+    for (int j = 0; j < rect.width(); j++) {
+      if (color != RgbaColor(column)) {
+        return false;
+      }
+      column += DesktopFrame::kBytesPerPixel;
+    }
+    row += frame.stride();
+  }
+  return true;
+}
+
+}  // namespace
+
 class ScreenCapturerTest : public testing::Test {
  public:
   void SetUp() override {
@@ -42,6 +97,93 @@ class ScreenCapturerTest : public testing::Test {
   }
 
  protected:
+  void TestCaptureUpdatedRegion(
+      std::initializer_list<ScreenCapturer*> capturers) {
+    RTC_DCHECK(capturers.size() > 0);
+    // A large enough area for the tests, which should be able to fulfill by
+    // most of systems.
+    const int kTestArea = 512;
+    const int kRectSize = 32;
+    std::unique_ptr<ScreenDrawer> drawer = ScreenDrawer::Create();
+    if (!drawer || drawer->DrawableRegion().is_empty()) {
+      LOG(LS_WARNING) << "No ScreenDrawer implementation for current platform.";
+      return;
+    }
+    if (drawer->DrawableRegion().width() < kTestArea ||
+        drawer->DrawableRegion().height() < kTestArea) {
+      LOG(LS_WARNING) << "ScreenDrawer::DrawableRegion() is too small for the "
+                         "CaptureUpdatedRegion tests.";
+      return;
+    }
+
+    for (ScreenCapturer* capturer : capturers) {
+      capturer->Start(&callback_);
+    }
+
+    for (int c = 0; c < 3; c++) {
+      for (int i = 0; i < kTestArea - kRectSize; i += 16) {
+        DesktopRect rect = DesktopRect::MakeXYWH(i, i, kRectSize, kRectSize);
+        rect.Translate(drawer->DrawableRegion().top_left());
+        RgbaColor color((c == 0 ? (i & 0xff) : 0x7f),
+                        (c == 1 ? (i & 0xff) : 0x7f),
+                        (c == 2 ? (i & 0xff) : 0x7f));
+        drawer->Clear();
+        drawer->DrawRectangle(rect, color);
+
+        const int wait_first_capture_round = 20;
+        for (int j = 0; j < wait_first_capture_round; j++) {
+          drawer->WaitForPendingDraws();
+          std::unique_ptr<DesktopFrame> frame =
+              CaptureFrame(*capturers.begin(), &callback_);
+          if (!frame) {
+            return;
+          }
+
+          if (ArePixelsColoredBy(*frame, rect, color)) {
+            // The first capturer successfully captured the frame we expected.
+            // So the others should also be able to capture it.
+            break;
+          } else {
+            ASSERT_LT(j, wait_first_capture_round);
+          }
+        }
+
+        for (ScreenCapturer* capturer : capturers) {
+          if (capturer == *capturers.begin()) {
+            // TODO(zijiehe): ScreenCapturerX11 and ScreenCapturerWinGdi cannot
+            // capture a correct frame again if screen does not update.
+            continue;
+          }
+          std::unique_ptr<DesktopFrame> frame =
+              CaptureFrame(capturer, &callback_);
+          if (!frame) {
+            return;
+          }
+
+          ASSERT_TRUE(ArePixelsColoredBy(*frame, rect, color));
+        }
+      }
+    }
+  }
+
+  void TestCaptureUpdatedRegion() {
+    TestCaptureUpdatedRegion({capturer_.get()});
+  }
+
+#if defined(WEBRTC_WIN)
+  bool SetDirectxCapturerMode() {
+    if (!ScreenCapturerWinDirectx::IsSupported()) {
+      LOG(LS_WARNING) << "Directx capturer is not supported";
+      return false;
+    }
+
+    DesktopCaptureOptions options(DesktopCaptureOptions::CreateDefault());
+    options.set_allow_directx_capturer(true);
+    capturer_.reset(ScreenCapturer::Create(options));
+    return true;
+  }
+#endif  // defined(WEBRTC_WIN)
+
   std::unique_ptr<ScreenCapturer> capturer_;
   MockScreenCapturerCallback callback_;
 };
@@ -74,10 +216,6 @@ class FakeSharedMemoryFactory : public SharedMemoryFactory {
   RTC_DISALLOW_COPY_AND_ASSIGN(FakeSharedMemoryFactory);
 };
 
-ACTION_P(SaveUniquePtrArg, dest) {
-  *dest = std::move(*arg1);
-}
-
 TEST_F(ScreenCapturerTest, GetScreenListAndSelectScreen) {
   webrtc::ScreenCapturer::ScreenList screens;
   EXPECT_TRUE(capturer_->GetScreenList(&screens));
@@ -117,6 +255,10 @@ TEST_F(ScreenCapturerTest, Capture) {
   EXPECT_TRUE(it.IsAtEnd());
 }
 
+TEST_F(ScreenCapturerTest, CaptureUpdatedRegion) {
+  TestCaptureUpdatedRegion();
+}

[stefan-webrtc, 2016/09/14 15:37:09]

I'm not sure we want to add tests to modules_unittests which render things on
the screen. If nothing else, it's annoying when you run tests locally, but it
also seems to run for a longer time than what I think is acceptible for a
unittest (10 seconds on my machine). Can we at least move it to modules_tests?

+
 #if defined(WEBRTC_WIN)
 
 TEST_F(ScreenCapturerTest, UseSharedBuffers) {
@@ -151,15 +293,10 @@ TEST_F(ScreenCapturerTest, UseMagnifier) {
 }
 
 TEST_F(ScreenCapturerTest, UseDirectxCapturer) {
-  if (!ScreenCapturerWinDirectx::IsSupported()) {
-    LOG(LS_WARNING) << "Directx capturer is not supported";
+  if (!SetDirectxCapturerMode()) {
     return;
   }
 
-  DesktopCaptureOptions options(DesktopCaptureOptions::CreateDefault());
-  options.set_allow_directx_capturer(true);
-  capturer_.reset(ScreenCapturer::Create(options));
-
   std::unique_ptr<DesktopFrame> frame;
   EXPECT_CALL(callback_,
               OnCaptureResultPtr(DesktopCapturer::Result::SUCCESS, _))
@@ -171,15 +308,10 @@ TEST_F(ScreenCapturerTest, UseDirectxCapturer) {
 }
 
 TEST_F(ScreenCapturerTest, UseDirectxCapturerWithSharedBuffers) {
-  if (!ScreenCapturerWinDirectx::IsSupported()) {
-    LOG(LS_WARNING) << "Directx capturer is not supported";
+  if (!SetDirectxCapturerMode()) {
     return;
   }
 
-  DesktopCaptureOptions options(DesktopCaptureOptions::CreateDefault());
-  options.set_allow_directx_capturer(true);
-  capturer_.reset(ScreenCapturer::Create(options));
-
   std::unique_ptr<DesktopFrame> frame;
   EXPECT_CALL(callback_,
               OnCaptureResultPtr(DesktopCapturer::Result::SUCCESS, _))
@@ -194,6 +326,24 @@ TEST_F(ScreenCapturerTest, UseDirectxCapturerWithSharedBuffers) {
   EXPECT_EQ(frame->shared_memory()->id(), kTestSharedMemoryId);
 }
 
+TEST_F(ScreenCapturerTest, CaptureUpdatedRegionWithDirectxCapturer) {
+  if (!SetDirectxCapturerMode()) {
+    return;
+  }
+
+  TestCaptureUpdatedRegion();
+}
+
+TEST_F(ScreenCapturerTest, TwoDirectxCapturers) {
+  if (!SetDirectxCapturerMode()) {
+    return;
+  }
+
+  std::unique_ptr<ScreenCapturer> capturer2(capturer_.release());
+  RTC_CHECK(SetDirectxCapturerMode());
+  TestCaptureUpdatedRegion({capturer_.get(), capturer2.get()});
+}
+
 #endif  // defined(WEBRTC_WIN)
 
 }  // namespace webrtc