Add getting the size of a given mipmap level.
When allocating memory for mipmaps, it would be very handy to know the
dimensions of a given mipmap level.
R=bsalomon@google.com
BUG=578304
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2018283002
Review-Url: https://codereview.chromium.org/2018283002
diff --git a/tests/MipMapTest.cpp b/tests/MipMapTest.cpp
index 467fd34..5070d04 100644
--- a/tests/MipMapTest.cpp
+++ b/tests/MipMapTest.cpp
@@ -150,3 +150,50 @@
REPORTER_ASSERT(reporter, currentTest.fExpectedLevelCount == levelCount);
}
}
+
+struct LevelSizeScenario {
+ int fBaseWidth;
+ int fBaseHeight;
+ int fLevel;
+ SkSize fExpectedMipMapLevelSize;
+};
+
+DEF_TEST(MipMap_ComputeLevelSize, reporter) {
+ const LevelSizeScenario tests[] = {
+ // Test mipmaps with negative sizes
+ {-100, 100, 1, SkSize::Make(0, 0)},
+ {100, -100, 1, SkSize::Make(0, 0)},
+ {-100, -100, 1, SkSize::Make(0, 0)},
+
+ // Test mipmaps with 0, 1, 2 as dimensions
+ // (SkMipMap::Build requires a min size of 1)
+ //
+ // 0
+ {0, 100, 1, SkSize::Make(0, 0)},
+ {100, 0, 1, SkSize::Make(0, 0)},
+ {0, 0, 1, SkSize::Make(0, 0)},
+ // 1
+
+ {1, 100, 1, SkSize::Make(1, 50)},
+ {100, 1, 1, SkSize::Make(50, 1)},
+ {1, 1, 1, SkSize::Make(0, 0)},
+ // 2
+ {2, 100, 1, SkSize::Make(1, 50)},
+ {100, 2, 2, SkSize::Make(25, 1)},
+ {2, 2, 1, SkSize::Make(1, 1)},
+
+ // Test a handful of cases
+ {63, 63, 3, SkSize::Make(7, 7)},
+ {64, 64, 3, SkSize::Make(8, 8)},
+ {127, 127, 3, SkSize::Make(15, 15)},
+ {64, 129, 4, SkSize::Make(4, 8)},
+ {255, 32, 7, SkSize::Make(1, 1)},
+ {500, 1000, 2, SkSize::Make(125, 250)},
+ };
+
+ for (auto& currentTest : tests) {
+ SkSize levelSize = SkMipMap::ComputeLevelSize(currentTest.fBaseWidth,
+ currentTest.fBaseHeight, currentTest.fLevel);
+ REPORTER_ASSERT(reporter, currentTest.fExpectedMipMapLevelSize == levelSize);
+ }
+}