[Remoting Client] DesktopViewport Implementation

remoting/client/desktop_viewport_unittest.cc

Index: remoting/client/desktop_viewport_unittest.cc
diff --git a/remoting/client/desktop_viewport_unittest.cc b/remoting/client/desktop_viewport_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..8e12230233e591171c310d9e0941e4b2ba06966e
--- /dev/null
+++ b/remoting/client/desktop_viewport_unittest.cc
@@ -0,0 +1,254 @@
+// Copyright 2017 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 "remoting/client/desktop_viewport.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/strings/stringprintf.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace remoting {
+
+namespace {
+
+const float EPSILON = 0.001f;
+
+}  // namespace
+
+class DesktopViewportTest : public testing::Test {
+ public:
+  void SetUp() override;
+  void TearDown() override;
+
+ protected:
+  void AssertTransformationReceived(const tracked_objects::Location& from_here,
+                                    float scale,
+                                    float offset_x,
+                                    float offset_y);
+
+  DesktopViewport viewport_;
+
+ private:
+  void OnTransformationChanged(const ViewMatrix& matrix);
+
+  ViewMatrix received_transformation_;
+};
+
+void DesktopViewportTest::SetUp() {
+  viewport_.RegisterOnTransformationChangedCallback(
+      base::Bind(&DesktopViewportTest::OnTransformationChanged,
+                 base::Unretained(this)),
+      true);
+}
+
+void DesktopViewportTest::TearDown() {
+  ASSERT_TRUE(received_transformation_.IsEmpty());
+}
+
+void DesktopViewportTest::AssertTransformationReceived(
+    const tracked_objects::Location& from_here,
+    float scale,
+    float offset_x,
+    float offset_y) {
+  ASSERT_FALSE(received_transformation_.IsEmpty())
+      << "Matrix has not been received yet."
+      << "Location: " << from_here.ToString();
+  ViewMatrix expected(scale, {offset_x, offset_y});
+  std::array<float, 9> expected_array = expected.ToMatrixArray();
+  std::array<float, 9> actual_array = received_transformation_.ToMatrixArray();
+
+  for (int i = 0; i < 9; i++) {
+    float diff = expected_array[i] - actual_array[i];
+    ASSERT_TRUE(diff > -EPSILON && diff < EPSILON)
+        << "Matrix doesn't match. \n"
+        << base::StringPrintf("Expected scale: %f, offset: (%f, %f)\n",
+                              expected_array[0], expected_array[2],
+                              expected_array[5])
+        << base::StringPrintf("Actual scale: %f, offset: (%f, %f)\n",
+                              actual_array[0], actual_array[2], actual_array[5])
+        << "Location: " << from_here.ToString();
+  }
+
+  received_transformation_ = ViewMatrix();
+}
+
+void DesktopViewportTest::OnTransformationChanged(const ViewMatrix& matrix) {
+  ASSERT_TRUE(received_transformation_.IsEmpty())
+      << "Previous matrix has not been asserted.";
+  received_transformation_ = matrix;
+}
+
+TEST_F(DesktopViewportTest, TestViewportInitialization1) {
+  // VP < DP. Desktop shrinks to fit.
+  // +====+------+
+  // | VP | DP   |
+  // |    |      |
+  // +====+------+
+  viewport_.SetDesktopSize(8, 6);
+  viewport_.SetSurfaceSize(2, 3);
+  AssertTransformationReceived(FROM_HERE, 0.5f, 0.f, 0.f);
+}
+
+TEST_F(DesktopViewportTest, TestViewportInitialization2) {
+  // VP < DP. Desktop shrinks to fit.
+  // +-----------------+
+  // |       DP        |
+  // |                 |
+  // +=================+
+  // |       VP        |
+  // +=================+
+  viewport_.SetDesktopSize(8, 6);
+  viewport_.SetSurfaceSize(3, 2);
+  AssertTransformationReceived(FROM_HERE, 0.375, 0.f, 0.f);
+}
+
+TEST_F(DesktopViewportTest, TestViewportInitialization3) {
+  // VP < DP. Desktop shrinks to fit.
+  // +========+----+
+  // |  VP    | DP |
+  // +========+----+
+  viewport_.SetDesktopSize(9, 3);
+  viewport_.SetSurfaceSize(2, 1);
+  AssertTransformationReceived(FROM_HERE, 0.333f, 0.f, 0.f);
+}
+
+TEST_F(DesktopViewportTest, TestViewportInitialization4) {
+  // VP > DP. Desktop grows to fit.
+  // +====+------+
+  // | VP | DP   |
+  // |    |      |
+  // +====+------+
+  viewport_.SetDesktopSize(2, 1);
+  viewport_.SetSurfaceSize(3, 4);
+  AssertTransformationReceived(FROM_HERE, 4.f, 0.f, 0.f);
+}
+
+TEST_F(DesktopViewportTest, TestMoveDesktop) {
+  // +====+------+
+  // | VP | DP   |
+  // |    |      |
+  // +====+------+
+  viewport_.SetDesktopSize(8, 6);
+  viewport_.SetSurfaceSize(2, 3);
+  AssertTransformationReceived(FROM_HERE, 0.5f, 0.f, 0.f);
+
+  // <--- DP
+  // +------+====+
+  // | DP   | VP |
+  // |      |    |
+  // +------+====+
+  viewport_.MoveDesktop(-2.f, 0.f);
+  AssertTransformationReceived(FROM_HERE, 0.5f, -2.f, 0.f);
+
+  //      +====+
+  // +----| VP |
+  // | DP |    |
+  // |    +====+
+  // +--------+
+  // Bounces back.
+  viewport_.MoveDesktop(-1.f, 1.f);
+  AssertTransformationReceived(FROM_HERE, 0.5f, -2.f, 0.f);
+}
+
+TEST_F(DesktopViewportTest, TestMoveAndScaleDesktop) {
+  // Number in surface coordinate.
+  //
+  // +====+------+
+  // | VP | DP   |
+  // |    |      | 3
+  // +====+------+
+  //        4
+  viewport_.SetDesktopSize(8, 6);
+  viewport_.SetSurfaceSize(2, 3);
+  AssertTransformationReceived(FROM_HERE, 0.5f, 0.f, 0.f);
+
+  // Scale at pivot point (2, 3) by 1.5x.
+  // +------------------+
+  // |                  |
+  // |   +====+   DP    | 4.5
+  // |   | VP |         |
+  // |   |    |         |
+  // +---+====+---------+
+  //       2     6
+  viewport_.ScaleDesktop(2.f, 3.f, 1.5f);
+  AssertTransformationReceived(FROM_HERE, 0.75f, -1.f, -1.5f);
+
+  // Move VP to the top-right.
+  // +-------------+====+
+  // |             | VP |
+  // |     DP      |    |
+  // |             +====+ 4.5
+  // |               2  |
+  // +------------------+
+  //         6
+  viewport_.MoveDesktop(-10000.f, 10000.f);
+  AssertTransformationReceived(FROM_HERE, 0.75f, -4.f, 0.f);
+
+  // Scale at (2, 0) by 0.5x.
+  //      VP
+  //       +====+
+  //    +--+----+
+  // DP |  |    |
+  //    +--+----+
+  //       +====+
+  viewport_.ScaleDesktop(2.f, 0.f, 0.5f);
+  AssertTransformationReceived(FROM_HERE, 0.375, -1.f, 0.375f);
+
+  // Scale all the way down.
+  // +========+
+  // |   VP   |
+  // +--------+
+  // |   DP   |
+  // +--------+
+  // |        |
+  // +========+
+  viewport_.ScaleDesktop(20.f, 0.f, 0.0001f);
+  AssertTransformationReceived(FROM_HERE, 0.25f, 0.f, 0.75f);
+}
+
+TEST_F(DesktopViewportTest, TestSetViewportCenter) {
+  // Numbers in desktop coordinates.
+  //
+  // +====+------+
+  // | VP | DP   |
+  // |    |      | 6
+  // +====+------+
+  //        8
+  viewport_.SetDesktopSize(8, 6);
+  viewport_.SetSurfaceSize(2, 3);
+  AssertTransformationReceived(FROM_HERE, 0.5f, 0.f, 0.f);
+
+  //  1.6
+  // +==+--------+
+  // |VP|2.4  DP |
+  // +==+        | 6
+  // +-----------+
+  //       8
+  viewport_.ScaleDesktop(0.f, 0.f, 2.5f);
+  AssertTransformationReceived(FROM_HERE, 1.25f, 0.f, 0.f);
+
+  // Move VP to center of the desktop.
+  // +------------------+
+  // |      +1.6=+      |
+  // |      | VP |2.4   | 6
+  // |      +====+      |
+  // +------------------+
+  //          8
+  viewport_.SetViewportCenter(4.f, 3.f);
+  AssertTransformationReceived(FROM_HERE, 1.25f, -4.f, -2.25f);
+
+  // Move it out of bound and bounce it back.
+  // +------------------+
+  // |                  |
+  // |     DP           |
+  // |               +====+
+  // |               | VP |
+  // +---------------|    |
+  //                 +====+
+  viewport_.SetViewportCenter(1000.f, 1000.f);
+  AssertTransformationReceived(FROM_HERE, 1.25f, -8.f, -4.5f);
+}
+
+}  // namespace remoting