diff options
Diffstat (limited to 'tests/MathTest.cpp')
| -rw-r--r-- | tests/MathTest.cpp | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/tests/MathTest.cpp b/tests/MathTest.cpp index 105a3e4bdf..372b41c793 100644 --- a/tests/MathTest.cpp +++ b/tests/MathTest.cpp @@ -48,6 +48,32 @@ static void test_floor(skiatest::Reporter* reporter) { /////////////////////////////////////////////////////////////////////////////// +// test that SkMul16ShiftRound and SkMulDiv255Round return the same result +static void test_muldivround(skiatest::Reporter* reporter) { +#if 0 + // this "complete" test is too slow, so we test a random sampling of it + + for (int a = 0; a <= 32767; ++a) { + for (int b = 0; b <= 32767; ++b) { + unsigned prod0 = SkMul16ShiftRound(a, b, 8); + unsigned prod1 = SkMulDiv255Round(a, b); + SkASSERT(prod0 == prod1); + } + } +#endif + + SkRandom rand; + for (int i = 0; i < 10000; ++i) { + unsigned a = rand.nextU() & 0x7FFF; + unsigned b = rand.nextU() & 0x7FFF; + + unsigned prod0 = SkMul16ShiftRound(a, b, 8); + unsigned prod1 = SkMulDiv255Round(a, b); + + REPORTER_ASSERT(reporter, prod0 == prod1); + } +} + static float float_blend(int src, int dst, float unit) { return dst + (src - dst) * unit; } @@ -595,6 +621,8 @@ static void TestMath(skiatest::Reporter* reporter) { // disable for now if (false) test_blend31(); // avoid bit rot, suppress warning + + test_muldivround(reporter); } #include "TestClassDef.h" |