RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-07-26 16:27:43 +00:00
Code Issues Activity Actions

AK: Make FixedPoint(FloatingPoint) ctor round instead of truncating

Browse source 
This is needed to have code for creating an in-memory sRGB profile using
the (floating-ppoint) numbers from the sRGB spec and having the
fixed-point values in the profile match what they are in other software
(such as GIMP).

It has the side effect of making the FixedPoint ctor no longer constexpr
(which seems fine; nothing was currently relying on that).

Some of FixedPoint's member functions don't round yet, which requires
tweaking a test.
This commit is contained in:
Nico Weber 2023-03-01 18:34:01 -05:00 • committed by Linus Groh
parent 62f2f0a081
commit b898a46d7f
3 changed files with 33 additions and 12 deletions
Download patch file Download diff file Expand all files Collapse all files

22
Tests/AK/TestFixedPoint.cpp
View file

@ -72,6 +72,16 @@ TEST_CASE(rounding)
EXPECT_EQ(Type(-1.5).lfloor(), -2);
EXPECT_EQ(Type(-1.5).lceil(), -1);
EXPECT_EQ(Type(-1.5).ltrunk(), -1);
// Check that sRGB TRC curve parameters match the s15fixed16 values stored in Gimp's built-in profile.
// (This only requires that the FixedPoint<> constructor rounds before truncating to the fixed-point value,
// as it should anyways.)
using S15Fixed16 = FixedPoint<16, i32>;
EXPECT_EQ(S15Fixed16(2.4).raw(), 0x26666);
EXPECT_EQ(S15Fixed16(1 / 1.055).raw(), 0xf2a7);
EXPECT_EQ(S15Fixed16(0.055 / 1.055).raw(), 0xd59);
EXPECT_EQ(S15Fixed16(1 / 12.92).raw(), 0x13d0);
EXPECT_EQ(S15Fixed16(0.04045).raw(), 0xa5b);
}
TEST_CASE(logarithm)
@ -115,7 +125,7 @@ TEST_CASE(cast)
{
FixedPoint<16, u32> downcast_value1(FixedPoint<32, u64>(123.4567));
EXPECT((double)downcast_value1 >= 123.4566 && (double)downcast_value1 <= 123.4568);
static constexpr FixedPoint<32, u64> value1(321.7654);
static FixedPoint<32, u64> const value1(321.7654);
downcast_value1 = value1;
EXPECT((double)downcast_value1 >= 321.7653 && (double)downcast_value1 <= 321.7655);
FixedPoint<6, u32> downcast_value2(FixedPoint<32, u64>(4567.123456));
@ -150,12 +160,12 @@ TEST_CASE(formatter)
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<4>(123.456)), "123.4375"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<4>(-123.456)), "-123.4375"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16> {}), "0"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(0.1)), "0.09999"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(0.02)), "0.019989"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(0.003)), "0.00299"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(0.1)), "0.100006"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(0.02)), "0.020004"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(0.003)), "0.003005"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(0.0004)), "0.000396"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(0.0000000005)), "0"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(-0.1)), "-0.099991"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(-0.02)), "-0.01999"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(-0.1)), "-0.100007"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(-0.02)), "-0.020005"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(-0.0000000005)), "0"sv);
}