cc: Implement IndexRect for encapsulating tile indices.

cc/base/index_rect_unittest.cc

Index: cc/base/index_rect_unittest.cc
diff --git a/cc/base/index_rect_unittest.cc b/cc/base/index_rect_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..aff41ee97595b0dcbc1d1af0544569ffdda92b4e
--- /dev/null
+++ b/cc/base/index_rect_unittest.cc
@@ -0,0 +1,99 @@
+// 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 "base/macros.h"
+#include "cc/base/index_rect.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+
+TEST(IndexRectTest, NumIndices) {
+  struct NumIndicesCase {
+    int left;
+    int right;
+    int top;
+    int bottom;
+    int num_indices_x;
+    int num_indices_y;
+  } num_indices_cases[] = {{-10, 10, -10, 10, 21, 21},
+                           {0, 5, 0, 10, 6, 11},
+                           {1, 2, 3, 4, 2, 2},
+                           {0, 0, 0, 0, 1, 1},
+                           {10, 10, 10, 10, 1, 1}};
+
+  for (size_t i = 0; i < arraysize(num_indices_cases); ++i) {
+    const NumIndicesCase& value = num_indices_cases[i];
+    IndexRect rect(value.left, value.right, value.top, value.bottom);
+    EXPECT_EQ(value.num_indices_x, rect.num_indices_x());
+    EXPECT_EQ(value.num_indices_y, rect.num_indices_y());
+  }
+}
+
+TEST(IndexRectTest, ClampTo) {
+  struct Indices {
+    int left;
+    int right;
+    int top;
+    int bottom;
+  };
+
+  struct ClampToCase {
+    Indices first;
+    Indices second;
+    Indices expected;
+    bool valid;
+  } clamp_to_cases[] = {{{0, 5, 0, 5}, {0, 5, 0, 5}, {0, 5, 0, 5}, true},
+                        {{0, 10, 0, 10}, {0, 5, 0, 5}, {0, 5, 0, 5}, true},
+                        {{0, 5, 0, 5}, {0, 10, 0, 10}, {0, 5, 0, 5}, true},
+                        {{-10, 5, -10, 5}, {0, 10, 0, 10}, {0, 5, 0, 5}, true},
+                        {{0, 5, 0, 5}, {10, 20, 10, 20}, {0, 0, 0, 0}, false}};
+
+  for (size_t i = 0; i < arraysize(clamp_to_cases); ++i) {
+    const ClampToCase& value = clamp_to_cases[i];
+    IndexRect first(value.first.left, value.first.right, value.first.top,
+                    value.first.bottom);
+    IndexRect second(value.second.left, value.second.right, value.second.top,
+                     value.second.bottom);
+    IndexRect expected(value.expected.left, value.expected.right,
+                       value.expected.top, value.expected.bottom);
+
+    first.ClampTo(second);
+    EXPECT_EQ(value.valid, first.is_valid());
+
+    if (value.valid)
+      EXPECT_EQ(expected, first);
+  }
+}
+
+TEST(IndexRectTest, Contains) {
+  struct ContainsCase {
+    int left;
+    int right;
+    int top;
+    int bottom;
+    int index_x;
+    int index_y;
+    bool contained;
+  } contains_cases[] = {
+      {-10, 10, -10, 10, -10, -10, true}, {-10, 10, -10, 10, 0, 0, true},
+      {-10, 10, -10, 10, 10, 10, true},   {-10, 10, -10, 10, 5, 5, true},
+      {-10, 10, -10, 10, -5, -5, true},   {-10, 10, -10, 10, -20, -20, false},
+      {-10, 10, -10, 10, 20, 20, false},  {-10, 10, -10, 10, 20, 5, false},
+      {-10, 10, -10, 10, 5, 20, false}};
+
+  for (size_t i = 0; i < arraysize(contains_cases); ++i) {
+    const ContainsCase& value = contains_cases[i];
+    IndexRect rect(value.left, value.right, value.top, value.bottom);
+    EXPECT_EQ(value.contained, rect.Contains(value.index_x, value.index_y));
+  }
+}
+
+TEST(IndexRectTest, Equals) {
+  EXPECT_TRUE(IndexRect(0, 0, 0, 0) == IndexRect(0, 0, 0, 0));
+  EXPECT_FALSE(IndexRect(0, 0, 0, 0) == IndexRect(0, 0, 0, 1));
+  EXPECT_TRUE(IndexRect(0, 0, 0, 0) != IndexRect(0, 0, 0, 1));
+  EXPECT_FALSE(IndexRect(0, 0, 0, 0) != IndexRect(0, 0, 0, 0));
+}
+
+}  // namespace cc