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Codechange: introduce generic ClampTo function to clamp to the range of a type

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Rubidium
2023-04-29 08:54:24 +02:00
committed by rubidium42
parent e33b2afd87
commit 969a3dc0f3
3 changed files with 116 additions and 6 deletions
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45
src/tests/math_func.cpp
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@@ -75,3 +75,48 @@ TEST_CASE("IntSqrtTest - FindSqRt")
CHECK(9 == IntSqrt(88));
CHECK(1696 == IntSqrt(2876278));
}
TEST_CASE("ClampTo")
{
CHECK(0 == ClampTo<uint8_t>(std::numeric_limits<int64_t>::lowest()));
CHECK(0 == ClampTo<uint8_t>(-1));
CHECK(0 == ClampTo<uint8_t>(0));
CHECK(1 == ClampTo<uint8_t>(1));
CHECK(255 == ClampTo<uint8_t>(std::numeric_limits<uint64_t>::max()));
CHECK(255 == ClampTo<uint8_t>(256));
CHECK(255 == ClampTo<uint8_t>(255));
CHECK(254 == ClampTo<uint8_t>(254));
CHECK(-128 == ClampTo<int8_t>(std::numeric_limits<int64_t>::lowest()));
CHECK(-128 == ClampTo<int8_t>(-129));
CHECK(-128 == ClampTo<int8_t>(-128));
CHECK(-127 == ClampTo<int8_t>(-127));
CHECK(127 == ClampTo<int8_t>(std::numeric_limits<uint64_t>::max()));
CHECK(127 == ClampTo<int8_t>(128));
CHECK(127 == ClampTo<int8_t>(127));
CHECK(126 == ClampTo<int8_t>(126));
CHECK(126 == ClampTo<int64_t>(static_cast<uint8>(126)));
CHECK(126 == ClampTo<uint64_t>(static_cast<int8>(126)));
CHECK(0 == ClampTo<uint64_t>(static_cast<int8>(-126)));
CHECK(0 == ClampTo<uint8_t>(static_cast<int8>(-126)));
/* The realm around 64 bits types is tricky as there is not one type/method that works for all. */
/* lowest/max uint64_t does not get clamped when clamping to uint64_t. */
CHECK(std::numeric_limits<uint64_t>::lowest() == ClampTo<uint64_t>(std::numeric_limits<uint64_t>::lowest()));
CHECK(std::numeric_limits<uint64_t>::max() == ClampTo<uint64_t>(std::numeric_limits<uint64_t>::max()));
/* negative int64_t get clamped to 0. */
CHECK(0 == ClampTo<uint64_t>(std::numeric_limits<int64_t>::lowest()));
CHECK(0 == ClampTo<uint64_t>(int64_t(-1)));
/* positive int64_t remain the same. */
CHECK(1 == ClampTo<uint64_t>(int64_t(1)));
CHECK(static_cast<uint64_t>(std::numeric_limits<int64_t>::max()) == ClampTo<uint64_t>(std::numeric_limits<int64_t>::max()));
/* max uint64_t gets clamped to max int64_t. */
CHECK(std::numeric_limits<int64_t>::max() == ClampTo<int64_t>(std::numeric_limits<uint64_t>::max()));
}