SkMipMap::ComputeLevelSize should only cover SkMipMap's levels.

tests/MipMapTest.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkMipMap.h"
 #include "SkRandom.h"
@@ skipping 51 matching lines @@
     bm.eraseColor(SK_ColorWHITE);
     SkAutoTUnref<SkMipMap> mm(SkMipMap::Build(bm, nullptr));
 
     const int mipLevelCount = mm->countLevels();
     REPORTER_ASSERT(reporter, mipLevelCount == expectedMipLevelCount);
     for (int i = 0; i < mipLevelCount; ++i) {
         SkMipMap::Level level;
         REPORTER_ASSERT(reporter, mm->getLevel(i, &level));
         // Make sure the mipmaps contain valid data and that the sizes are correct
         REPORTER_ASSERT(reporter, level.fPixmap.addr());
 

[reed1, 2016/06/09 10:31:26]

Here would be an interesting place to call ComputeLevelSize, to assert that it
matches the level returned by getLevel().

[cblume, 2016/06/09 16:23:06]

Done.

         // + 1 because SkMipMap does not include the base mipmap level.
         int twoToTheMipLevel = 1 << (i + 1);
         int currentWidth = width / twoToTheMipLevel;
         int currentHeight = height / twoToTheMipLevel;
         REPORTER_ASSERT(reporter, level.fPixmap.width() == currentWidth);
         REPORTER_ASSERT(reporter, level.fPixmap.height() == currentHeight);
     }
 }
 
 DEF_TEST(MipMap_DirectLevelAccess, reporter) {
@@ skipping 71 matching lines @@
 struct LevelSizeScenario {
     int fBaseWidth;
     int fBaseHeight;
     int fLevel;
     SkISize fExpectedMipMapLevelSize;
 };
 
 DEF_TEST(MipMap_ComputeLevelSize, reporter) {
     const LevelSizeScenario tests[] = {
         // Test mipmaps with negative sizes
-        {-100, 100, 1, SkISize::Make(0, 0)},
-        {100, -100, 1, SkISize::Make(0, 0)},
-        {-100, -100, 1, SkISize::Make(0, 0)},
+        {-100, 100, 0, SkISize::Make(0, 0)},
+        {100, -100, 0, SkISize::Make(0, 0)},
+        {-100, -100, 0, SkISize::Make(0, 0)},
 
         // Test mipmaps with 0, 1, 2 as dimensions
         // (SkMipMap::Build requires a min size of 1)
         //
         // 0
-        {0, 100, 1, SkISize::Make(0, 0)},
-        {100, 0, 1, SkISize::Make(0, 0)},
-        {0, 0, 1, SkISize::Make(0, 0)},
+        {0, 100, 0, SkISize::Make(0, 0)},
+        {100, 0, 0, SkISize::Make(0, 0)},
+        {0, 0, 0, SkISize::Make(0, 0)},
         // 1
 
-        {1, 100, 1, SkISize::Make(1, 50)},
-        {100, 1, 1, SkISize::Make(50, 1)},
-        {1, 1, 1, SkISize::Make(0, 0)},
+        {1, 100, 0, SkISize::Make(1, 50)},
+        {100, 1, 0, SkISize::Make(50, 1)},
+        {1, 1, 0, SkISize::Make(0, 0)},
         // 2
-        {2, 100, 1, SkISize::Make(1, 50)},
-        {100, 2, 2, SkISize::Make(25, 1)},
-        {2, 2, 1, SkISize::Make(1, 1)},
+        {2, 100, 0, SkISize::Make(1, 50)},
+        {100, 2, 1, SkISize::Make(25, 1)},
+        {2, 2, 0, SkISize::Make(1, 1)},
 
         // Test a handful of cases
-        {63, 63, 3, SkISize::Make(7, 7)},
-        {64, 64, 3, SkISize::Make(8, 8)},
-        {127, 127, 3, SkISize::Make(15, 15)},
-        {64, 129, 4, SkISize::Make(4, 8)},
-        {255, 32, 7, SkISize::Make(1, 1)},
-        {500, 1000, 2, SkISize::Make(125, 250)},
+        {63, 63, 2, SkISize::Make(7, 7)},
+        {64, 64, 2, SkISize::Make(8, 8)},
+        {127, 127, 2, SkISize::Make(15, 15)},
+        {64, 129, 3, SkISize::Make(4, 8)},
+        {255, 32, 6, SkISize::Make(1, 1)},
+        {500, 1000, 1, SkISize::Make(125, 250)},
     };
 
     for (auto& currentTest : tests) {
         SkISize levelSize = SkMipMap::ComputeLevelSize(currentTest.fBaseWidth,
                                                        currentTest.fBaseHeight,
                                                        currentTest.fLevel);
         REPORTER_ASSERT(reporter, currentTest.fExpectedMipMapLevelSize == levelSize);
     }
 }