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Diffstat (limited to 'skia/ext/image_operations_unittest.cc')
| -rw-r--r-- | skia/ext/image_operations_unittest.cc | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/skia/ext/image_operations_unittest.cc b/skia/ext/image_operations_unittest.cc index 06bd4fc..3699685 100644 --- a/skia/ext/image_operations_unittest.cc +++ b/skia/ext/image_operations_unittest.cc @@ -399,3 +399,116 @@ TEST(ImageOperations, CreateCroppedBitmapWrapping) { } } +TEST(ImageOperations, DownsampleByTwo) { + // Use an odd-sized bitmap to make sure the edge cases where there isn't a + // 2x2 block of pixels is handled correctly. + // Here's the ARGB example + // + // 50% transparent green opaque 50% blue white + // 80008000 FF000080 FFFFFFFF + // + // 50% transparent red opaque 50% gray black + // 80800000 80808080 FF000000 + // + // black white 50% gray + // FF000000 FFFFFFFF FF808080 + // + // The result of this computation should be: + // A0404040 FF808080 + // FF808080 FF808080 + SkBitmap input; + input.setConfig(SkBitmap::kARGB_8888_Config, 3, 3); + input.allocPixels(); + + // The color order may be different, but we don't care (the channels are + // trated the same). + *input.getAddr32(0, 0) = 0x80008000; + *input.getAddr32(1, 0) = 0xFF000080; + *input.getAddr32(2, 0) = 0xFFFFFFFF; + *input.getAddr32(0, 1) = 0x80800000; + *input.getAddr32(1, 1) = 0x80808080; + *input.getAddr32(2, 1) = 0xFF000000; + *input.getAddr32(0, 2) = 0xFF000000; + *input.getAddr32(1, 2) = 0xFFFFFFFF; + *input.getAddr32(2, 2) = 0xFF808080; + + SkBitmap result = skia::ImageOperations::DownsampleByTwo(input); + EXPECT_EQ(2, result.width()); + EXPECT_EQ(2, result.height()); + + // Some of the values are off-by-one due to rounding. + SkAutoLockPixels lock(result); + EXPECT_EQ(0x9f404040, *result.getAddr32(0, 0)); + EXPECT_EQ(0xFF7f7f7f, *result.getAddr32(1, 0)); + EXPECT_EQ(0xFF7f7f7f, *result.getAddr32(0, 1)); + EXPECT_EQ(0xFF808080, *result.getAddr32(1, 1)); +} + +// Test edge cases for DownsampleByTwo. +TEST(ImageOperations, DownsampleByTwoSmall) { + SkPMColor reference = 0xFF4080FF; + + // Test a 1x1 bitmap. + SkBitmap one_by_one; + one_by_one.setConfig(SkBitmap::kARGB_8888_Config, 1, 1); + one_by_one.allocPixels(); + *one_by_one.getAddr32(0, 0) = reference; + SkBitmap result = skia::ImageOperations::DownsampleByTwo(one_by_one); + SkAutoLockPixels lock1(result); + EXPECT_EQ(1, result.width()); + EXPECT_EQ(1, result.height()); + EXPECT_EQ(reference, *result.getAddr32(0, 0)); + + // Test an n by 1 bitmap. + SkBitmap one_by_n; + one_by_n.setConfig(SkBitmap::kARGB_8888_Config, 300, 1); + one_by_n.allocPixels(); + result = skia::ImageOperations::DownsampleByTwo(one_by_n); + SkAutoLockPixels lock2(result); + EXPECT_EQ(300, result.width()); + EXPECT_EQ(1, result.height()); + + // Test a 1 by n bitmap. + SkBitmap n_by_one; + n_by_one.setConfig(SkBitmap::kARGB_8888_Config, 1, 300); + n_by_one.allocPixels(); + result = skia::ImageOperations::DownsampleByTwo(n_by_one); + SkAutoLockPixels lock3(result); + EXPECT_EQ(1, result.width()); + EXPECT_EQ(300, result.height()); + + // Test an empty bitmap + SkBitmap empty; + result = skia::ImageOperations::DownsampleByTwo(empty); + EXPECT_TRUE(result.isNull()); + EXPECT_EQ(0, result.width()); + EXPECT_EQ(0, result.height()); +} + +// Here we assume DownsampleByTwo works correctly (it's tested above) and +// just make sure that the +TEST(ImageOperations, DownsampleByTwoUntilSize) { + // First make sure a "too small" bitmap doesn't get modified at all. + SkBitmap too_small; + too_small.setConfig(SkBitmap::kARGB_8888_Config, 10, 10); + too_small.allocPixels(); + SkBitmap result = skia::ImageOperations::DownsampleByTwoUntilSize( + too_small, 16, 16); + EXPECT_EQ(10, result.width()); + EXPECT_EQ(10, result.height()); + + // Now make sure giving it a 0x0 target returns something reasonable. + result = skia::ImageOperations::DownsampleByTwoUntilSize(too_small, 0, 0); + EXPECT_EQ(1, result.width()); + EXPECT_EQ(1, result.height()); + + // Test multiple steps of downsampling. + SkBitmap large; + large.setConfig(SkBitmap::kARGB_8888_Config, 100, 43); + large.allocPixels(); + result = skia::ImageOperations::DownsampleByTwoUntilSize(large, 6, 6); + + // The result should be divided in half 100x43 -> 50x22 -> 25x11 + EXPECT_EQ(25, result.width()); + EXPECT_EQ(11, result.height()); +}
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