Adding direct access to SkMipMap levels.
BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1639693002
Review URL: https://codereview.chromium.org/1639693002
diff --git a/tests/MipMapTest.cpp b/tests/MipMapTest.cpp
index 32fa34f..027c046 100644
--- a/tests/MipMapTest.cpp
+++ b/tests/MipMapTest.cpp
@@ -10,12 +10,8 @@
#include "SkRandom.h"
#include "Test.h"
-static void make_bitmap(SkBitmap* bm, SkRandom& rand) {
- // for now, Build needs a min size of 2, otherwise it will return nullptr.
- // should fix that to support 1 X N, where N > 1 to return non-null.
- int w = 2 + rand.nextU() % 1000;
- int h = 2 + rand.nextU() % 1000;
- bm->allocN32Pixels(w, h);
+static void make_bitmap(SkBitmap* bm, int width, int height) {
+ bm->allocN32Pixels(width, height);
bm->eraseColor(SK_ColorWHITE);
}
@@ -24,9 +20,14 @@
SkRandom rand;
for (int i = 0; i < 500; ++i) {
- make_bitmap(&bm, rand);
+ // for now, Build needs a min size of 2, otherwise it will return nullptr.
+ // should fix that to support 1 X N, where N > 1 to return non-null.
+ int width = 2 + rand.nextU() % 1000;
+ int height = 2 + rand.nextU() % 1000;
+ make_bitmap(&bm, width, height);
SkAutoTUnref<SkMipMap> mm(SkMipMap::Build(bm, nullptr));
+ REPORTER_ASSERT(reporter, mm->countLevels() == SkMipMap::ComputeLevelCount(width, height));
REPORTER_ASSERT(reporter, !mm->extractLevel(SkSize::Make(SK_Scalar1, SK_Scalar1),
nullptr));
REPORTER_ASSERT(reporter, !mm->extractLevel(SkSize::Make(SK_Scalar1 * 2, SK_Scalar1 * 2),
@@ -55,3 +56,99 @@
}
}
}
+
+static void test_mipmap_generation(int width, int height, int expectedMipLevelCount,
+ skiatest::Reporter* reporter) {
+ SkBitmap bm;
+ bm.allocN32Pixels(width, height);
+ 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());
+
+ // + 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) {
+ // create mipmap with invalid size
+ {
+ // SkMipMap current requires the dimensions be greater than 2x2
+ SkBitmap bm;
+ bm.allocN32Pixels(1, 1);
+ bm.eraseColor(SK_ColorWHITE);
+ SkAutoTUnref<SkMipMap> mm(SkMipMap::Build(bm, nullptr));
+
+ REPORTER_ASSERT(reporter, mm == nullptr);
+ }
+
+ // check small mipmap's count and levels
+ // There should be 5 mipmap levels generated:
+ // 16x16, 8x8, 4x4, 2x2, 1x1
+ test_mipmap_generation(32, 32, 5, reporter);
+
+ // check large mipmap's count and levels
+ // There should be 9 mipmap levels generated:
+ // 500x500, 250x250, 125x125, 62x62, 31x31, 15x15, 7x7, 3x3, 1x1
+ test_mipmap_generation(1000, 1000, 9, reporter);
+}
+
+struct LevelCountScenario {
+ int fWidth;
+ int fHeight;
+ int fExpectedLevelCount;
+};
+
+DEF_TEST(MipMap_ComputeLevelCount, reporter) {
+ const LevelCountScenario tests[] = {
+ // Test mipmaps with negative sizes
+ {-100, 100, 0},
+ {100, -100, 0},
+ {-100, -100, 0},
+
+ // Test mipmaps with 0, 1, 2 as dimensions
+ // (SkMipMap::Build requires a min size of 2)
+ //
+ // 0
+ {0, 100, 0},
+ {100, 0, 0},
+ {0, 0, 0},
+ // 1
+ {1, 100, 0},
+ {100, 1, 0},
+ {1, 1, 0},
+ // 2
+ {2, 100, 1},
+ {100, 2, 1},
+ {2, 2, 1},
+
+ // Test a handful of boundaries such as 63x63 and 64x64
+ {63, 63, 5},
+ {64, 64, 6},
+ {127, 127, 6},
+ {128, 128, 7},
+ {255, 255, 7},
+ {256, 256, 8},
+
+ // Test different dimensions, such as 256x64
+ {64, 129, 6},
+ {255, 32, 5},
+ {500, 1000, 8}
+ };
+
+ for (auto& currentTest : tests) {
+ int levelCount = SkMipMap::ComputeLevelCount(currentTest.fWidth, currentTest.fHeight);
+ REPORTER_ASSERT(reporter, currentTest.fExpectedLevelCount == levelCount);
+ }
+}