cc/region_unittest.cc

   1 // Copyright 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "cc/region.h"
   6
   7 #include "testing/gtest/include/gtest/gtest.h"
   8
   9 namespace cc {
  10 namespace {
  11
  12 #define TEST_INSIDE_RECT(r, x, y, w, h)                      \
  13   EXPECT_TRUE(r.Contains(gfx::Point(x, y)));                 \
  14   EXPECT_TRUE(r.Contains(gfx::Point(x + w - 1, y)));         \
  15   EXPECT_TRUE(r.Contains(gfx::Point(x, y + h - 1)));         \
  16   EXPECT_TRUE(r.Contains(gfx::Point(x + w - 1, y + h - 1))); \
  17   EXPECT_TRUE(r.Contains(gfx::Point(x, y + h / 2)));         \
  18   EXPECT_TRUE(r.Contains(gfx::Point(x + w - 1, y + h / 2))); \
  19   EXPECT_TRUE(r.Contains(gfx::Point(x + w / 2, y)));         \
  20   EXPECT_TRUE(r.Contains(gfx::Point(x + w / 2, y + h - 1))); \
  21   EXPECT_TRUE(r.Contains(gfx::Point(x + w / 2, y + h / 2))); \
  22
  23 #define TEST_LEFT_OF_RECT(r, x, y, w, h)                  \
  24   EXPECT_FALSE(r.Contains(gfx::Point(x - 1, y)));         \
  25   EXPECT_FALSE(r.Contains(gfx::Point(x - 1, y + h - 1))); \
  26
  27 #define TEST_RIGHT_OF_RECT(r, x, y, w, h)                 \
  28   EXPECT_FALSE(r.Contains(gfx::Point(x + w, y)));         \
  29   EXPECT_FALSE(r.Contains(gfx::Point(x + w, y + h - 1))); \
  30
  31 #define TEST_TOP_OF_RECT(r, x, y, w, h)                   \
  32   EXPECT_FALSE(r.Contains(gfx::Point(x, y - 1)));         \
  33   EXPECT_FALSE(r.Contains(gfx::Point(x + w - 1, y - 1))); \
  34
  35 #define TEST_BOTTOM_OF_RECT(r, x, y, w, h)                \
  36   EXPECT_FALSE(r.Contains(gfx::Point(x, y + h)));         \
  37   EXPECT_FALSE(r.Contains(gfx::Point(x + w - 1, y + h))); \
  38
  39 TEST(RegionTest, ContainsPoint) {
  40   Region r;
  41
  42   EXPECT_FALSE(r.Contains(gfx::Point(0, 0)));
  43
  44   r.Union(gfx::Rect(35, 35, 1, 1));
  45   TEST_INSIDE_RECT(r, 35, 35, 1, 1);
  46   TEST_LEFT_OF_RECT(r, 35, 35, 1, 1);
  47   TEST_RIGHT_OF_RECT(r, 35, 35, 1, 1);
  48   TEST_TOP_OF_RECT(r, 35, 35, 1, 1);
  49   TEST_BOTTOM_OF_RECT(r, 35, 35, 1, 1);
  50
  51   r.Union(gfx::Rect(30, 30, 10, 10));
  52   TEST_INSIDE_RECT(r, 30, 30, 10, 10);
  53   TEST_LEFT_OF_RECT(r, 30, 30, 10, 10);
  54   TEST_RIGHT_OF_RECT(r, 30, 30, 10, 10);
  55   TEST_TOP_OF_RECT(r, 30, 30, 10, 10);
  56   TEST_BOTTOM_OF_RECT(r, 30, 30, 10, 10);
  57
  58   r.Union(gfx::Rect(31, 40, 10, 10));
  59   EXPECT_FALSE(r.Contains(gfx::Point(30, 40)));
  60   EXPECT_TRUE(r.Contains(gfx::Point(31, 40)));
  61   EXPECT_FALSE(r.Contains(gfx::Point(40, 39)));
  62   EXPECT_TRUE(r.Contains(gfx::Point(40, 40)));
  63
  64   TEST_INSIDE_RECT(r, 30, 30, 10, 10);
  65   TEST_LEFT_OF_RECT(r, 30, 30, 10, 10);
  66   TEST_RIGHT_OF_RECT(r, 30, 30, 10, 10);
  67   TEST_TOP_OF_RECT(r, 30, 30, 10, 10);
  68   TEST_INSIDE_RECT(r, 31, 40, 10, 10);
  69   TEST_LEFT_OF_RECT(r, 31, 40, 10, 10);
  70   TEST_RIGHT_OF_RECT(r, 31, 40, 10, 10);
  71   TEST_BOTTOM_OF_RECT(r, 31, 40, 10, 10);
  72
  73   r.Union(gfx::Rect(42, 40, 10, 10));
  74
  75   TEST_INSIDE_RECT(r, 42, 40, 10, 10);
  76   TEST_LEFT_OF_RECT(r, 42, 40, 10, 10);
  77   TEST_RIGHT_OF_RECT(r, 42, 40, 10, 10);
  78   TEST_TOP_OF_RECT(r, 42, 40, 10, 10);
  79   TEST_BOTTOM_OF_RECT(r, 42, 40, 10, 10);
  80
  81   TEST_INSIDE_RECT(r, 30, 30, 10, 10);
  82   TEST_LEFT_OF_RECT(r, 30, 30, 10, 10);
  83   TEST_RIGHT_OF_RECT(r, 30, 30, 10, 10);
  84   TEST_TOP_OF_RECT(r, 30, 30, 10, 10);
  85   TEST_INSIDE_RECT(r, 31, 40, 10, 10);
  86   TEST_LEFT_OF_RECT(r, 31, 40, 10, 10);
  87   TEST_RIGHT_OF_RECT(r, 31, 40, 10, 10);
  88   TEST_BOTTOM_OF_RECT(r, 31, 40, 10, 10);
  89 }
  90
  91 TEST(RegionTest, EmptySpan) {
  92   Region r;
  93   r.Union(gfx::Rect(5, 0, 10, 10));
  94   r.Union(gfx::Rect(0, 5, 10, 10));
  95   r.Subtract(gfx::Rect(7, 7, 10, 0));
  96
  97   for (Region::Iterator it(r); it.has_rect(); it.next())
  98     EXPECT_FALSE(it.rect().IsEmpty());
  99 }
 100
 101 #define TEST_NO_INTERSECT(a, b) {  \
 102   Region ar = a;                   \
 103   Region br = b;                   \
 104   EXPECT_FALSE(ar.Intersects(br)); \
 105   EXPECT_FALSE(br.Intersects(ar)); \
 106   EXPECT_FALSE(ar.Intersects(b));  \
 107   EXPECT_FALSE(br.Intersects(a));  \
 108 }
 109
 110 #define TEST_INTERSECT(a, b) {    \
 111   Region ar = a;                  \
 112   Region br = b;                  \
 113   EXPECT_TRUE(ar.Intersects(br)); \
 114   EXPECT_TRUE(br.Intersects(ar)); \
 115   EXPECT_TRUE(ar.Intersects(b));  \
 116   EXPECT_TRUE(br.Intersects(a));  \
 117 }
 118
 119 TEST(RegionTest, IntersectsRegion) {
 120   Region r;
 121
 122   TEST_NO_INTERSECT(gfx::Rect(), gfx::Rect());
 123   TEST_NO_INTERSECT(gfx::Rect(), gfx::Rect(0, 0, 1, 1));
 124   TEST_NO_INTERSECT(gfx::Rect(), gfx::Rect(1, 1, 1, 1));
 125
 126   TEST_NO_INTERSECT(gfx::Rect(-1, -1, 2, 2), gfx::Rect());
 127
 128   r.Union(gfx::Rect(0, 0, 1, 1));
 129   TEST_NO_INTERSECT(r, gfx::Rect());
 130   TEST_INTERSECT(r, gfx::Rect(0, 0, 1, 1));
 131   TEST_INTERSECT(r, gfx::Rect(0, 0, 2, 2));
 132   TEST_INTERSECT(r, gfx::Rect(-1, 0, 2, 2));
 133   TEST_INTERSECT(r, gfx::Rect(-1, -1, 2, 2));
 134   TEST_INTERSECT(r, gfx::Rect(0, -1, 2, 2));
 135   TEST_INTERSECT(r, gfx::Rect(-1, -1, 3, 3));
 136
 137   r.Union(gfx::Rect(0, 0, 3, 3));
 138   r.Union(gfx::Rect(10, 0, 3, 3));
 139   r.Union(gfx::Rect(0, 10, 13, 3));
 140   TEST_NO_INTERSECT(r, gfx::Rect());
 141   TEST_INTERSECT(r, gfx::Rect(1, 1, 1, 1));
 142   TEST_INTERSECT(r, gfx::Rect(0, 0, 2, 2));
 143   TEST_INTERSECT(r, gfx::Rect(1, 0, 2, 2));
 144   TEST_INTERSECT(r, gfx::Rect(1, 1, 2, 2));
 145   TEST_INTERSECT(r, gfx::Rect(0, 1, 2, 2));
 146   TEST_INTERSECT(r, gfx::Rect(0, 0, 3, 3));
 147   TEST_INTERSECT(r, gfx::Rect(-1, -1, 2, 2));
 148   TEST_INTERSECT(r, gfx::Rect(2, -1, 2, 2));
 149   TEST_INTERSECT(r, gfx::Rect(2, 2, 2, 2));
 150   TEST_INTERSECT(r, gfx::Rect(-1, 2, 2, 2));
 151
 152   TEST_INTERSECT(r, gfx::Rect(11, 1, 1, 1));
 153   TEST_INTERSECT(r, gfx::Rect(10, 0, 2, 2));
 154   TEST_INTERSECT(r, gfx::Rect(11, 0, 2, 2));
 155   TEST_INTERSECT(r, gfx::Rect(11, 1, 2, 2));
 156   TEST_INTERSECT(r, gfx::Rect(10, 1, 2, 2));
 157   TEST_INTERSECT(r, gfx::Rect(10, 0, 3, 3));
 158   TEST_INTERSECT(r, gfx::Rect(9, -1, 2, 2));
 159   TEST_INTERSECT(r, gfx::Rect(12, -1, 2, 2));
 160   TEST_INTERSECT(r, gfx::Rect(12, 2, 2, 2));
 161   TEST_INTERSECT(r, gfx::Rect(9, 2, 2, 2));
 162
 163   TEST_INTERSECT(r, gfx::Rect(0, -1, 13, 5));
 164   TEST_INTERSECT(r, gfx::Rect(1, -1, 11, 5));
 165   TEST_INTERSECT(r, gfx::Rect(2, -1, 9, 5));
 166   TEST_INTERSECT(r, gfx::Rect(2, -1, 8, 5));
 167   TEST_INTERSECT(r, gfx::Rect(3, -1, 8, 5));
 168   TEST_NO_INTERSECT(r, gfx::Rect(3, -1, 7, 5));
 169
 170   TEST_INTERSECT(r, gfx::Rect(0, 1, 13, 1));
 171   TEST_INTERSECT(r, gfx::Rect(1, 1, 11, 1));
 172   TEST_INTERSECT(r, gfx::Rect(2, 1, 9, 1));
 173   TEST_INTERSECT(r, gfx::Rect(2, 1, 8, 1));
 174   TEST_INTERSECT(r, gfx::Rect(3, 1, 8, 1));
 175   TEST_NO_INTERSECT(r, gfx::Rect(3, 1, 7, 1));
 176
 177   TEST_INTERSECT(r, gfx::Rect(0, 0, 13, 13));
 178   TEST_INTERSECT(r, gfx::Rect(0, 1, 13, 11));
 179   TEST_INTERSECT(r, gfx::Rect(0, 2, 13, 9));
 180   TEST_INTERSECT(r, gfx::Rect(0, 2, 13, 8));
 181   TEST_INTERSECT(r, gfx::Rect(0, 3, 13, 8));
 182   TEST_NO_INTERSECT(r, gfx::Rect(0, 3, 13, 7));
 183 }
 184
 185 TEST(RegionTest, ReadPastFullSpanVectorInIntersectsTest) {
 186   Region r;
 187
 188   // This region has enough spans to fill its allocated Vector exactly.
 189   r.Union(gfx::Rect(400, 300, 1, 800));
 190   r.Union(gfx::Rect(785, 585, 1, 1));
 191   r.Union(gfx::Rect(787, 585, 1, 1));
 192   r.Union(gfx::Rect(0, 587, 16, 162));
 193   r.Union(gfx::Rect(26, 590, 300, 150));
 194   r.Union(gfx::Rect(196, 750, 1, 1));
 195   r.Union(gfx::Rect(0, 766, 1, 1));
 196   r.Union(gfx::Rect(0, 782, 1, 1));
 197   r.Union(gfx::Rect(745, 798, 1, 1));
 198   r.Union(gfx::Rect(795, 882, 10, 585));
 199   r.Union(gfx::Rect(100, 1499, 586, 1));
 200   r.Union(gfx::Rect(100, 1500, 585, 784));
 201   // This query rect goes past the bottom of the Region, causing the
 202   // test to reach the last span and try go past it. It should not read
 203   // memory off the end of the span Vector.
 204   TEST_NO_INTERSECT(r, gfx::Rect(0, 2184, 1, 150));
 205 }
 206
 207 #define TEST_NO_CONTAINS(a, b)                  \
 208   {                                             \
 209     Region ar = a;                              \
 210     Region br = b;                              \
 211     EXPECT_FALSE(ar.Contains(br));              \
 212     EXPECT_FALSE(ar.Contains(b));               \
 213   }
 214
 215 #define TEST_CONTAINS(a, b)                     \
 216   {                                             \
 217     Region ar = a;                              \
 218     Region br = b;                              \
 219     EXPECT_TRUE(ar.Contains(br));               \
 220     EXPECT_TRUE(ar.Contains(b));                \
 221   }
 222
 223 TEST(RegionTest, ContainsRegion) {
 224   TEST_CONTAINS(gfx::Rect(), gfx::Rect());
 225   TEST_CONTAINS(gfx::Rect(0, 0, 1, 1), gfx::Rect());
 226   TEST_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect());
 227
 228   TEST_NO_CONTAINS(gfx::Rect(), gfx::Rect(0, 0, 1, 1));
 229   TEST_NO_CONTAINS(gfx::Rect(), gfx::Rect(1, 1, 1, 1));
 230
 231   TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(11, 10, 1, 1));
 232   TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(10, 11, 1, 1));
 233   TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(9, 10, 1, 1));
 234   TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(10, 9, 1, 1));
 235   TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(9, 9, 2, 2));
 236   TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(10, 9, 2, 2));
 237   TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(9, 10, 2, 2));
 238   TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(10, 10, 2, 2));
 239   TEST_NO_CONTAINS(gfx::Rect(10, 10, 1, 1), gfx::Rect(9, 9, 3, 3));
 240
 241   Region hLines;
 242   for (int i = 10; i < 20; i += 2)
 243     hLines.Union(gfx::Rect(i, 10, 1, 10));
 244
 245   TEST_CONTAINS(gfx::Rect(10, 10, 9, 10), hLines);
 246   TEST_NO_CONTAINS(gfx::Rect(10, 10, 9, 9), hLines);
 247   TEST_NO_CONTAINS(gfx::Rect(10, 11, 9, 9), hLines);
 248   TEST_NO_CONTAINS(gfx::Rect(10, 10, 8, 10), hLines);
 249   TEST_NO_CONTAINS(gfx::Rect(11, 10, 8, 10), hLines);
 250
 251   Region vLines;
 252   for (int i = 10; i < 20; i += 2)
 253     vLines.Union(gfx::Rect(10, i, 10, 1));
 254
 255   TEST_CONTAINS(gfx::Rect(10, 10, 10, 9), vLines);
 256   TEST_NO_CONTAINS(gfx::Rect(10, 10, 9, 9), vLines);
 257   TEST_NO_CONTAINS(gfx::Rect(11, 10, 9, 9), vLines);
 258   TEST_NO_CONTAINS(gfx::Rect(10, 10, 10, 8), vLines);
 259   TEST_NO_CONTAINS(gfx::Rect(10, 11, 10, 8), vLines);
 260
 261   Region grid;
 262   for (int i = 10; i < 20; i += 2)
 263     for (int j = 10; j < 20; j += 2)
 264       grid.Union(gfx::Rect(i, j, 1, 1));
 265
 266   TEST_CONTAINS(gfx::Rect(10, 10, 9, 9), grid);
 267   TEST_NO_CONTAINS(gfx::Rect(10, 10, 9, 8), grid);
 268   TEST_NO_CONTAINS(gfx::Rect(10, 11, 9, 8), grid);
 269   TEST_NO_CONTAINS(gfx::Rect(10, 10, 8, 9), grid);
 270   TEST_NO_CONTAINS(gfx::Rect(11, 10, 8, 9), grid);
 271
 272   TEST_CONTAINS(hLines, hLines);
 273   TEST_CONTAINS(vLines, vLines);
 274   TEST_NO_CONTAINS(vLines, hLines);
 275   TEST_NO_CONTAINS(hLines, vLines);
 276   TEST_CONTAINS(grid, grid);
 277   TEST_CONTAINS(hLines, grid);
 278   TEST_CONTAINS(vLines, grid);
 279   TEST_NO_CONTAINS(grid, hLines);
 280   TEST_NO_CONTAINS(grid, vLines);
 281
 282   for (int i = 10; i < 20; i += 2)
 283     TEST_CONTAINS(hLines, gfx::Rect(i, 10, 1, 10));
 284
 285   for (int i = 10; i < 20; i += 2)
 286     TEST_CONTAINS(vLines, gfx::Rect(10, i, 10, 1));
 287
 288   for (int i = 10; i < 20; i += 2)
 289     for (int j = 10; j < 20; j += 2)
 290       TEST_CONTAINS(grid, gfx::Rect(i, j, 1, 1));
 291
 292   Region container;
 293   container.Union(gfx::Rect(0, 0, 40, 20));
 294   container.Union(gfx::Rect(0, 20, 41, 20));
 295   TEST_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
 296
 297   container.Clear();
 298   container.Union(gfx::Rect(0, 0, 10, 10));
 299   container.Union(gfx::Rect(0, 30, 10, 10));
 300   container.Union(gfx::Rect(30, 30, 10, 10));
 301   container.Union(gfx::Rect(30, 0, 10, 10));
 302   TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
 303
 304   container.Clear();
 305   container.Union(gfx::Rect(0, 0, 10, 10));
 306   container.Union(gfx::Rect(0, 30, 10, 10));
 307   container.Union(gfx::Rect(30, 0, 10, 40));
 308   TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
 309
 310   container.Clear();
 311   container.Union(gfx::Rect(30, 0, 10, 10));
 312   container.Union(gfx::Rect(30, 30, 10, 10));
 313   container.Union(gfx::Rect(0, 0, 10, 40));
 314   TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
 315
 316   container.Clear();
 317   container.Union(gfx::Rect(0, 0, 10, 40));
 318   container.Union(gfx::Rect(30, 0, 10, 40));
 319   TEST_NO_CONTAINS(container, gfx::Rect(5, 5, 30, 30));
 320
 321   container.Clear();
 322   container.Union(gfx::Rect(0, 0, 40, 40));
 323   TEST_NO_CONTAINS(container, gfx::Rect(10, -1, 20, 10));
 324
 325   container.Clear();
 326   container.Union(gfx::Rect(0, 0, 40, 40));
 327   TEST_NO_CONTAINS(container, gfx::Rect(10, 31, 20, 10));
 328
 329   container.Clear();
 330   container.Union(gfx::Rect(0, 0, 40, 20));
 331   container.Union(gfx::Rect(0, 20, 41, 20));
 332   TEST_NO_CONTAINS(container, gfx::Rect(-1, 10, 10, 20));
 333
 334   container.Clear();
 335   container.Union(gfx::Rect(0, 0, 40, 20));
 336   container.Union(gfx::Rect(0, 20, 41, 20));
 337   TEST_NO_CONTAINS(container, gfx::Rect(31, 10, 10, 20));
 338
 339   container.Clear();
 340   container.Union(gfx::Rect(0, 0, 40, 40));
 341   container.Subtract(gfx::Rect(0, 20, 60, 0));
 342   TEST_NO_CONTAINS(container, gfx::Rect(31, 10, 10, 20));
 343
 344   container.Clear();
 345   container.Union(gfx::Rect(0, 0, 60, 20));
 346   container.Union(gfx::Rect(30, 20, 10, 20));
 347   TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 39));
 348   TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 40));
 349   TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 41));
 350   TEST_NO_CONTAINS(container, gfx::Rect(29, 0, 10, 39));
 351   TEST_CONTAINS(container, gfx::Rect(30, 0, 10, 40));
 352   TEST_NO_CONTAINS(container, gfx::Rect(31, 0, 10, 41));
 353   TEST_NO_CONTAINS(container, gfx::Rect(49, 0, 10, 39));
 354   TEST_NO_CONTAINS(container, gfx::Rect(50, 0, 10, 40));
 355   TEST_NO_CONTAINS(container, gfx::Rect(51, 0, 10, 41));
 356
 357   container.Clear();
 358   container.Union(gfx::Rect(30, 0, 10, 20));
 359   container.Union(gfx::Rect(0, 20, 60, 20));
 360   TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 39));
 361   TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 40));
 362   TEST_NO_CONTAINS(container, gfx::Rect(0, 0, 10, 41));
 363   TEST_NO_CONTAINS(container, gfx::Rect(29, 0, 10, 39));
 364   TEST_CONTAINS(container, gfx::Rect(30, 0, 10, 40));
 365   TEST_NO_CONTAINS(container, gfx::Rect(31, 0, 10, 41));
 366   TEST_NO_CONTAINS(container, gfx::Rect(49, 0, 10, 39));
 367   TEST_NO_CONTAINS(container, gfx::Rect(50, 0, 10, 40));
 368   TEST_NO_CONTAINS(container, gfx::Rect(51, 0, 10, 41));
 369 }
 370
 371 TEST(RegionTest, Union) {
 372   Region r;
 373   Region r2;
 374
 375   // A rect uniting a contained rect does not change the region.
 376   r2 = r = gfx::Rect(0, 0, 50, 50);
 377   r2.Union(gfx::Rect(20, 20, 10, 10));
 378   EXPECT_EQ(r, r2);
 379
 380   // A rect uniting a containing rect gives back the containing rect.
 381   r = gfx::Rect(0, 0, 50, 50);
 382   r.Union(gfx::Rect(0, 0, 100, 100));
 383   EXPECT_EQ(Region(gfx::Rect(0, 0, 100, 100)), r);
 384
 385   // A complex region uniting a contained rect does not change the region.
 386   r = gfx::Rect(0, 0, 50, 50);
 387   r.Union(gfx::Rect(100, 0, 50, 50));
 388   r2 = r;
 389   r2.Union(gfx::Rect(20, 20, 10, 10));
 390   EXPECT_EQ(r, r2);
 391
 392   // A complex region uniting a containing rect gives back the containing rect.
 393   r = gfx::Rect(0, 0, 50, 50);
 394   r.Union(gfx::Rect(100, 0, 50, 50));
 395   r.Union(gfx::Rect(0, 0, 500, 500));
 396   EXPECT_EQ(Region(gfx::Rect(0, 0, 500, 500)), r);
 397 }
 398
 399 TEST(RegionTest, IsEmpty) {
 400   EXPECT_TRUE(Region().IsEmpty());
 401   EXPECT_TRUE(Region(gfx::Rect()).IsEmpty());
 402   EXPECT_TRUE(Region(Region()).IsEmpty());
 403   EXPECT_TRUE(Region(gfx::Rect(10, 10, 10, 0)).IsEmpty());
 404   EXPECT_TRUE(Region(gfx::Rect(10, 10, 0, 10)).IsEmpty());
 405   EXPECT_TRUE(Region(gfx::Rect(-10, 10, 10, 0)).IsEmpty());
 406   EXPECT_TRUE(Region(gfx::Rect(-10, 10, 0, 10)).IsEmpty());
 407   EXPECT_FALSE(Region(gfx::Rect(-1, -1, 1, 1)).IsEmpty());
 408   EXPECT_FALSE(Region(gfx::Rect(0, 0, 1, 1)).IsEmpty());
 409   EXPECT_FALSE(Region(gfx::Rect(0, 0, 2, 2)).IsEmpty());
 410
 411   EXPECT_TRUE(SkIRect::MakeXYWH(10, 10, 10, 0).isEmpty());
 412   EXPECT_TRUE(SkIRect::MakeXYWH(10, 10, 0, 10).isEmpty());
 413   EXPECT_TRUE(SkIRect::MakeXYWH(-10, 10, 10, 0).isEmpty());
 414   EXPECT_TRUE(SkIRect::MakeXYWH(-10, 10, 0, 10).isEmpty());
 415   EXPECT_FALSE(SkIRect::MakeXYWH(-1, -1, 1, 1).isEmpty());
 416   EXPECT_FALSE(SkIRect::MakeXYWH(0, 0, 1, 1).isEmpty());
 417   EXPECT_FALSE(SkIRect::MakeXYWH(0, 0, 2, 2).isEmpty());
 418 }
 419
 420 TEST(RegionTest, Clear) {
 421   Region r;
 422
 423   r = gfx::Rect(0, 0, 50, 50);
 424   EXPECT_FALSE(r.IsEmpty());
 425   r.Clear();
 426   EXPECT_TRUE(r.IsEmpty());
 427
 428   r = gfx::Rect(0, 0, 50, 50);
 429   r.Union(gfx::Rect(100, 0, 50, 50));
 430   r.Union(gfx::Rect(0, 0, 500, 500));
 431   EXPECT_FALSE(r.IsEmpty());
 432   r.Clear();
 433   EXPECT_TRUE(r.IsEmpty());
 434 }
 435
 436 TEST(RegionSwap, Swap) {
 437   Region r1, r2, r3;
 438
 439   r1 = gfx::Rect(0, 0, 50, 50);
 440   r1.Swap(r2);
 441   EXPECT_TRUE(r1.IsEmpty());
 442   EXPECT_EQ(r2.ToString(), Region(gfx::Rect(0, 0, 50, 50)).ToString());
 443
 444   r1 = gfx::Rect(0, 0, 50, 50);
 445   r1.Union(gfx::Rect(100, 0, 50, 50));
 446   r1.Union(gfx::Rect(0, 0, 500, 500));
 447   r3 = r1;
 448   r1.Swap(r2);
 449   EXPECT_EQ(r1.ToString(), Region(gfx::Rect(0, 0, 50, 50)).ToString());
 450   EXPECT_EQ(r2.ToString(), r3.ToString());
 451 }
 452
 453 }  // namespace
 454 }  // namespace cc