cc: Create a Region class that wraps SkRegion, to replace use of WebCore::Region.

cc/region_unittest.cc

+// Copyright 2012 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 "config.h"
+
+#include "cc/region.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+using namespace cc;
+
+namespace {
+
+#define TEST_INSIDE_RECT(r, x, y, w, h)                      \
+  EXPECT_TRUE(r.Contains(gfx::Point(x, y)));                 \
+  EXPECT_TRUE(r.Contains(gfx::Point(x + w - 1, y)));         \
+  EXPECT_TRUE(r.Contains(gfx::Point(x, y + h - 1)));         \
+  EXPECT_TRUE(r.Contains(gfx::Point(x + w - 1, y + h - 1))); \
+  EXPECT_TRUE(r.Contains(gfx::Point(x, y + h / 2)));         \
+  EXPECT_TRUE(r.Contains(gfx::Point(x + w - 1, y + h / 2))); \
+  EXPECT_TRUE(r.Contains(gfx::Point(x + w / 2, y)));         \
+  EXPECT_TRUE(r.Contains(gfx::Point(x + w / 2, y + h - 1))); \
+  EXPECT_TRUE(r.Contains(gfx::Point(x + w / 2, y + h / 2))); \
+
+#define TEST_LEFT_OF_RECT(r, x, y, w, h)                  \
+  EXPECT_FALSE(r.Contains(gfx::Point(x - 1, y)));         \
+  EXPECT_FALSE(r.Contains(gfx::Point(x - 1, y + h - 1))); \
+
+#define TEST_RIGHT_OF_RECT(r, x, y, w, h)                 \
+  EXPECT_FALSE(r.Contains(gfx::Point(x + w, y)));         \
+  EXPECT_FALSE(r.Contains(gfx::Point(x + w, y + h - 1))); \
+
+#define TEST_TOP_OF_RECT(r, x, y, w, h)                   \
+  EXPECT_FALSE(r.Contains(gfx::Point(x, y - 1)));         \
+  EXPECT_FALSE(r.Contains(gfx::Point(x + w - 1, y - 1))); \
+
+#define TEST_BOTTOM_OF_RECT(r, x, y, w, h)                \
+  EXPECT_FALSE(r.Contains(gfx::Point(x, y + h)));         \
+  EXPECT_FALSE(r.Contains(gfx::Point(x + w - 1, y + h))); \
+
+TEST(RegionTest, ContainsPoint) {
+  Region r;
+
+  EXPECT_FALSE(r.Contains(gfx::Point(0, 0)));
+
+  r.Union(gfx::Rect(35, 35, 1, 1));
+  TEST_INSIDE_RECT(r, 35, 35, 1, 1);
+  TEST_LEFT_OF_RECT(r, 35, 35, 1, 1);
+  TEST_RIGHT_OF_RECT(r, 35, 35, 1, 1);
+  TEST_TOP_OF_RECT(r, 35, 35, 1, 1);
+  TEST_BOTTOM_OF_RECT(r, 35, 35, 1, 1);
+
+  r.Union(gfx::Rect(30, 30, 10, 10));
+  TEST_INSIDE_RECT(r, 30, 30, 10, 10);
+  TEST_LEFT_OF_RECT(r, 30, 30, 10, 10);
+  TEST_RIGHT_OF_RECT(r, 30, 30, 10, 10);
+  TEST_TOP_OF_RECT(r, 30, 30, 10, 10);
+  TEST_BOTTOM_OF_RECT(r, 30, 30, 10, 10);
+
+  r.Union(gfx::Rect(31, 40, 10, 10));
+  EXPECT_FALSE(r.Contains(gfx::Point(30, 40)));
+  EXPECT_TRUE(r.Contains(gfx::Point(31, 40)));
+  EXPECT_FALSE(r.Contains(gfx::Point(40, 39)));
+  EXPECT_TRUE(r.Contains(gfx::Point(40, 40)));
+
+  TEST_INSIDE_RECT(r, 30, 30, 10, 10);
+  TEST_LEFT_OF_RECT(r, 30, 30, 10, 10);
+  TEST_RIGHT_OF_RECT(r, 30, 30, 10, 10);
+  TEST_TOP_OF_RECT(r, 30, 30, 10, 10);
+  TEST_INSIDE_RECT(r, 31, 40, 10, 10);
+  TEST_LEFT_OF_RECT(r, 31, 40, 10, 10);
+  TEST_RIGHT_OF_RECT(r, 31, 40, 10, 10);
+  TEST_BOTTOM_OF_RECT(r, 31, 40, 10, 10);
+
+  r.Union(gfx::Rect(42, 40, 10, 10));
+  
+  TEST_INSIDE_RECT(r, 42, 40, 10, 10);
+  TEST_LEFT_OF_RECT(r, 42, 40, 10, 10);
+  TEST_RIGHT_OF_RECT(r, 42, 40, 10, 10);
+  TEST_TOP_OF_RECT(r, 42, 40, 10, 10);
+  TEST_BOTTOM_OF_RECT(r, 42, 40, 10, 10);
+
+  TEST_INSIDE_RECT(r, 30, 30, 10, 10);
+  TEST_LEFT_OF_RECT(r, 30, 30, 10, 10);
+  TEST_RIGHT_OF_RECT(r, 30, 30, 10, 10);
+  TEST_TOP_OF_RECT(r, 30, 30, 10, 10);
+  TEST_INSIDE_RECT(r, 31, 40, 10, 10);
+  TEST_LEFT_OF_RECT(r, 31, 40, 10, 10);
+  TEST_RIGHT_OF_RECT(r, 31, 40, 10, 10);
+  TEST_BOTTOM_OF_RECT(r, 31, 40, 10, 10);
+}
+
+TEST(RegionTest, EmptySpan) {
+  Region r;
+  r.Union(gfx::Rect(5, 0, 10, 10));
+  r.Union(gfx::Rect(0, 5, 10, 10));
+  r.Subtract(gfx::Rect(7, 7, 10, 0));
+
+  for (Region::Iterator it(r); it.has_rect(); it.next())
+    EXPECT_FALSE(it.rect().IsEmpty());
+}
+
+#define TEST_NO_INTERSECT(a, b) {  \
+  Region ar = a;                   \
+  Region br = b;                   \
+  EXPECT_FALSE(ar.Intersects(br)); \
+  EXPECT_FALSE(br.Intersects(ar)); \
+  EXPECT_FALSE(ar.Intersects(b));  \
+  EXPECT_FALSE(br.Intersects(a));  \
+}
+
+#define TEST_INTERSECT(a, b) {    \
+  Region ar = a;                  \
+  Region br = b;                  \
+  EXPECT_TRUE(ar.Intersects(br)); \
+  EXPECT_TRUE(br.Intersects(ar)); \
+  EXPECT_TRUE(ar.Intersects(b));  \
+  EXPECT_TRUE(br.Intersects(a));  \
+}
+
+TEST(RegionTest, IntersectsRegion) {
+  Region r;
+
+  TEST_NO_INTERSECT(gfx::Rect(), gfx::Rect());
+  TEST_NO_INTERSECT(gfx::Rect(), gfx::Rect(0, 0, 1, 1));
+  TEST_NO_INTERSECT(gfx::Rect(), gfx::Rect(1, 1, 1, 1));
+
+  TEST_NO_INTERSECT(gfx::Rect(-1, -1, 2, 2), gfx::Rect());
+
+  r.Union(gfx::Rect(0, 0, 1, 1));
+  TEST_NO_INTERSECT(r, gfx::Rect());
+  TEST_INTERSECT(r, gfx::Rect(0, 0, 1, 1));
+  TEST_INTERSECT(r, gfx::Rect(0, 0, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(-1, 0, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(-1, -1, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(0, -1, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(-1, -1, 3, 3));
+
+  r.Union(gfx::Rect(0, 0, 3, 3));
+  r.Union(gfx::Rect(10, 0, 3, 3));
+  r.Union(gfx::Rect(0, 10, 13, 3));
+  TEST_NO_INTERSECT(r, gfx::Rect());
+  TEST_INTERSECT(r, gfx::Rect(1, 1, 1, 1));
+  TEST_INTERSECT(r, gfx::Rect(0, 0, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(1, 0, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(1, 1, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(0, 1, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(0, 0, 3, 3));
+  TEST_INTERSECT(r, gfx::Rect(-1, -1, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(2, -1, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(2, 2, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(-1, 2, 2, 2));
+
+  TEST_INTERSECT(r, gfx::Rect(11, 1, 1, 1));
+  TEST_INTERSECT(r, gfx::Rect(10, 0, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(11, 0, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(11, 1, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(10, 1, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(10, 0, 3, 3));
+  TEST_INTERSECT(r, gfx::Rect(9, -1, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(12, -1, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(12, 2, 2, 2));
+  TEST_INTERSECT(r, gfx::Rect(9, 2, 2, 2));
+
+  TEST_INTERSECT(r, gfx::Rect(0, -1, 13, 5));
+  TEST_INTERSECT(r, gfx::Rect(1, -1, 11, 5));
+  TEST_INTERSECT(r, gfx::Rect(2, -1, 9, 5));
+  TEST_INTERSECT(r, gfx::Rect(2, -1, 8, 5));
+  TEST_INTERSECT(r, gfx::Rect(3, -1, 8, 5));
+  TEST_NO_INTERSECT(r, gfx::Rect(3, -1, 7, 5));
+
+  TEST_INTERSECT(r, gfx::Rect(0, 1, 13, 1));
+  TEST_INTERSECT(r, gfx::Rect(1, 1, 11, 1));
+  TEST_INTERSECT(r, gfx::Rect(2, 1, 9, 1));
+  TEST_INTERSECT(r, gfx::Rect(2, 1, 8, 1));
+  TEST_INTERSECT(r, gfx::Rect(3, 1, 8, 1));
+  TEST_NO_INTERSECT(r, gfx::Rect(3, 1, 7, 1));
+
+  TEST_INTERSECT(r, gfx::Rect(0, 0, 13, 13));
+  TEST_INTERSECT(r, gfx::Rect(0, 1, 13, 11));
+  TEST_INTERSECT(r, gfx::Rect(0, 2, 13, 9));
+  TEST_INTERSECT(r, gfx::Rect(0, 2, 13, 8));
+  TEST_INTERSECT(r, gfx::Rect(0, 3, 13, 8));
+  TEST_NO_INTERSECT(r, gfx::Rect(0, 3, 13, 7));
+}
+
+TEST(RegionTest, ReadPastFullSpanVectorInIntersectsTest) {
+  Region r;
+
+  // This region has enough spans to fill its allocated Vector exactly.
+  r.Union(gfx::Rect(400, 300, 1, 800));
+  r.Union(gfx::Rect(785, 585, 1, 1));
+  r.Union(gfx::Rect(787, 585, 1, 1));
+  r.Union(gfx::Rect(0, 587, 16, 162));
+  r.Union(gfx::Rect(26, 590, 300, 150));
+  r.Union(gfx::Rect(196, 750, 1, 1));
+  r.Union(gfx::Rect(0, 766, 1, 1));
+  r.Union(gfx::Rect(0, 782, 1, 1));
+  r.Union(gfx::Rect(745, 798, 1, 1));
+  r.Union(gfx::Rect(795, 882, 10, 585));
+  r.Union(gfx::Rect(100, 1499, 586, 1));
+  r.Union(gfx::Rect(100, 1500, 585, 784));
+  // This query rect goes past the bottom of the Region, causing the
+  // test to reach the last span and try go past it. It should not read
+  // memory off the end of the span Vector.
+  TEST_NO_INTERSECT(r, gfx::Rect(0, 2184, 1, 150));
+}
+
+#define TEST_NO_CONTAINS(a, b)                  \
+  {                                             \
+    Region ar = a;                              \
+    Region br = b;                              \
+    EXPECT_FALSE(ar.Contains(br));              \
+    EXPECT_FALSE(ar.Contains(b));               \
+  }
+
+#define TEST_CONTAINS(a, b)                     \
+  {                                             \
+    Region ar = a;                              \
+    Region br = b;                              \
+    EXPECT_TRUE(ar.Contains(br));               \
+    EXPECT_TRUE(ar.Contains(b));                \
+  }
+
+TEST(RegionTest, ContainsRegion) {
+  TEST_NO_CONTAINS(gfx::Rect(), gfx::Rect());
+  TEST_NO_CONTAINS(gfx::Rect(), gfx::Rect(0, 0, 1, 1));
+  TEST_NO_CONTAINS(gfx::Rect(), gfx::Rect(1, 1, 1, 1));
+
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(11, 10, 1, 1));
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(10, 11, 1, 1));
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(9, 10, 1, 1));
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(10, 9, 1, 1));
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(9, 9, 2, 2));
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(10, 9, 2, 2));
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(9, 10, 2, 2));
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(10, 10, 2, 2));
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(9, 9, 3, 3));
+
+  Region hLines;
+  for (int i = 10; i < 20; i += 2)
+    hLines.Union(gfx::Rect(i, 10, 1, 10));
+
+  TEST_CONTAINS(gfx::Rect(10, 10, 9, 10), hLines);
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 9, 9), hLines);
+  TEST_NO_CONTAINS(gfx::Rect(10, 11, 9, 9), hLines);
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 8, 10), hLines);
+  TEST_NO_CONTAINS(gfx::Rect(11, 10, 8, 10), hLines);
+
+  Region vLines;
+  for (int i = 10; i < 20; i += 2)
+    vLines.Union(gfx::Rect(10, i, 10, 1));
+
+  TEST_CONTAINS(gfx::Rect(10, 10, 10, 9), vLines);
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 9, 9), vLines);
+  TEST_NO_CONTAINS(gfx::Rect(11, 10, 9, 9), vLines);
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 10, 8), vLines);
+  TEST_NO_CONTAINS(gfx::Rect(10, 11, 10, 8), vLines);
+
+  Region grid;
+  for (int i = 10; i < 20; i += 2)
+    for (int j = 10; j < 20; j += 2)
+      grid.Union(gfx::Rect(i, j, 1, 1));
+
+  TEST_CONTAINS(gfx::Rect(10, 10, 9, 9), grid);
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 9, 8), grid);
+  TEST_NO_CONTAINS(gfx::Rect(10, 11, 9, 8), grid);
+  TEST_NO_CONTAINS(gfx::Rect(10, 10, 8, 9), grid);
+  TEST_NO_CONTAINS(gfx::Rect(11, 10, 8, 9), grid);
+
+  TEST_CONTAINS(hLines, hLines);
+  TEST_CONTAINS(vLines, vLines);
+  TEST_NO_CONTAINS(vLines, hLines);
+  TEST_NO_CONTAINS(hLines, vLines);
+  TEST_CONTAINS(grid, grid);
+  TEST_CONTAINS(hLines, grid);
+  TEST_CONTAINS(vLines, grid);
+  TEST_NO_CONTAINS(grid, hLines);
+  TEST_NO_CONTAINS(grid, vLines);
+
+  for (int i = 10; i < 20; i += 2)
+    TEST_CONTAINS(hLines, gfx::Rect(i, 10, 1, 10));
+
+  for (int i = 10; i < 20; i += 2)
+    TEST_CONTAINS(vLines, gfx::Rect(10, i, 10, 1));
+
+  for (int i = 10; i < 20; i += 2)
+    for (int j = 10; j < 20; j += 2)
+      TEST_CONTAINS(grid, gfx::Rect(i, j, 1, 1));
+
+  Region container;
+  container.Union(gfx::Rect(0, 0, 40, 20));
+  container.Union(gfx::Rect(0, 20, 41, 20));
+  TEST_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
+
+  container = Region();
+  container.Union(gfx::Rect(0, 0, 10, 10));
+  container.Union(gfx::Rect(0, 30, 10, 10));
+  container.Union(gfx::Rect(30, 30, 10, 10));
+  container.Union(gfx::Rect(30, 0, 10, 10));
+  TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
+
+  container = Region();
+  container.Union(gfx::Rect(0, 0, 10, 10));
+  container.Union(gfx::Rect(0, 30, 10, 10));
+  container.Union(gfx::Rect(30, 0, 10, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
+
+  container = Region();
+  container.Union(gfx::Rect(30, 0, 10, 10));
+  container.Union(gfx::Rect(30, 30, 10, 10));
+  container.Union(gfx::Rect(0, 0, 10, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
+
+  container = Region();
+  container.Union(gfx::Rect(0, 0, 10, 40));
+  container.Union(gfx::Rect(30, 0, 10, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
+
+  container = Region();
+  container.Union(gfx::Rect(0, 0, 40, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(10, -1, 20, 10));
+
+  container = Region();
+  container.Union(gfx::Rect(0, 0, 40, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(10, 31, 20, 10));
+
+  container = Region();
+  container.Union(gfx::Rect(0, 0, 40, 20));
+  container.Union(gfx::Rect(0, 20, 41, 20));
+  TEST_NO_CONTAINS(container, gfx::Rect(-1, 10, 10, 20));
+
+  container = Region();
+  container.Union(gfx::Rect(0, 0, 40, 20));
+  container.Union(gfx::Rect(0, 20, 41, 20));
+  TEST_NO_CONTAINS(container, gfx::Rect(31, 10, 10, 20));
+
+  container = Region();
+  container.Union(gfx::Rect(0, 0, 40, 40));
+  container.Subtract(gfx::Rect(0, 20, 60, 0));
+  TEST_NO_CONTAINS(container, gfx::Rect(31, 10, 10, 20));
+
+  container = Region();
+  container.Union(gfx::Rect(0, 0, 60, 20));
+  container.Union(gfx::Rect(30, 20, 10, 20));
+  TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 39));
+  TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 41));
+  TEST_NO_CONTAINS(container, gfx::Rect(29, 0, 10, 39));
+  TEST_CONTAINS(container, gfx::Rect(30, 0, 10, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(31, 0, 10, 41));
+  TEST_NO_CONTAINS(container, gfx::Rect(49, 0, 10, 39));
+  TEST_NO_CONTAINS(container, gfx::Rect(50, 0, 10, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(51, 0, 10, 41));
+
+  container = Region();
+  container.Union(gfx::Rect(30, 0, 10, 20));
+  container.Union(gfx::Rect(0, 20, 60, 20));
+  TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 39));
+  TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 41));
+  TEST_NO_CONTAINS(container, gfx::Rect(29, 0, 10, 39));
+  TEST_CONTAINS(container, gfx::Rect(30, 0, 10, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(31, 0, 10, 41));
+  TEST_NO_CONTAINS(container, gfx::Rect(49, 0, 10, 39));
+  TEST_NO_CONTAINS(container, gfx::Rect(50, 0, 10, 40));
+  TEST_NO_CONTAINS(container, gfx::Rect(51, 0, 10, 41));
+}
+
+TEST(RegionTest, Union) {
+  Region r;
+  Region r2;
+
+  // A rect uniting a contained rect does not change the region.
+  r2 = r = gfx::Rect(0, 0, 50, 50);
+  r2.Union(gfx::Rect(20, 20, 10, 10));
+  EXPECT_EQ(r, r2);
+
+  // A rect uniting a containing rect gives back the containing rect.
+  r = gfx::Rect(0, 0, 50, 50);
+  r.Union(gfx::Rect(0, 0, 100, 100));
+  EXPECT_EQ(Region(gfx::Rect(0, 0, 100, 100)), r);
+
+  // A complex region uniting a contained rect does not change the region.
+  r = gfx::Rect(0, 0, 50, 50);
+  r.Union(gfx::Rect(100, 0, 50, 50));
+  r2 = r;
+  r2.Union(gfx::Rect(20, 20, 10, 10));
+  EXPECT_EQ(r, r2);
+
+  // A complex region uniting a containing rect gives back the containing rect.
+  r = gfx::Rect(0, 0, 50, 50);
+  r.Union(gfx::Rect(100, 0, 50, 50));
+  r.Union(gfx::Rect(0, 0, 500, 500));
+  EXPECT_EQ(Region(gfx::Rect(0, 0, 500, 500)), r);
+}
+
+TEST(RegionTest, IsEmpty) {
+  EXPECT_TRUE(Region().IsEmpty());
+  EXPECT_TRUE(Region(gfx::Rect()).IsEmpty());
+  EXPECT_TRUE(Region(Region()).IsEmpty());
+  EXPECT_TRUE(Region(gfx::Rect(10, 10, 10, 0)).IsEmpty());
+  EXPECT_TRUE(Region(gfx::Rect(10, 10, 0, 10)).IsEmpty());
+  EXPECT_TRUE(Region(gfx::Rect(-10, 10, 10, 0)).IsEmpty());
+  EXPECT_TRUE(Region(gfx::Rect(-10, 10, 0, 10)).IsEmpty());
+  EXPECT_FALSE(Region(gfx::Rect(-1, -1, 1, 1)).IsEmpty());
+  EXPECT_FALSE(Region(gfx::Rect(0, 0, 1, 1)).IsEmpty());
+  EXPECT_FALSE(Region(gfx::Rect(0, 0, 2, 2)).IsEmpty());
+
+  EXPECT_TRUE(SkIRect::MakeXYWH(10, 10, 10, 0).isEmpty());
+  EXPECT_TRUE(SkIRect::MakeXYWH(10, 10, 0, 10).isEmpty());
+  EXPECT_TRUE(SkIRect::MakeXYWH(-10, 10, 10, 0).isEmpty());
+  EXPECT_TRUE(SkIRect::MakeXYWH(-10, 10, 0, 10).isEmpty());
+  EXPECT_FALSE(SkIRect::MakeXYWH(-1, -1, 1, 1).isEmpty());
+  EXPECT_FALSE(SkIRect::MakeXYWH(0, 0, 1, 1).isEmpty());
+  EXPECT_FALSE(SkIRect::MakeXYWH(0, 0, 2, 2).isEmpty());
+}
+
+}  // namespace