ladybird/Tests/AK/TestFixedPoint.cpp
Nico Weber b898a46d7f AK: Make FixedPoint(FloatingPoint) ctor round instead of truncating
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.
2023-03-03 09:23:02 +00:00

172 lines
6.4 KiB
C++

/*
* Copyright (c) 2021, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibTest/TestCase.h>
#include <AK/FixedPoint.h>
#include <AK/NumericLimits.h>
using Type = FixedPoint<4>;
TEST_CASE(arithmetic)
{
EXPECT_EQ(
Type(0.5) + Type(0.5),
Type(1));
EXPECT_EQ(
Type(1) + Type(0.5),
Type(1.5));
EXPECT_EQ(
(float)(Type(1) + Type(0.5)),
1.5f);
// FIXME: Test for rounded multiply
EXPECT_EQ(
Type((int)1) * Type(0.5),
Type(0.5));
EXPECT_EQ(
Type((int)1) / Type(0.5),
Type(2));
}
TEST_CASE(rounding)
{
EXPECT_EQ(Type(0.5).round(), Type(0));
EXPECT_EQ(Type(0.5).floor(), Type(0));
EXPECT_EQ(Type(0.5).ceil(), Type(1));
EXPECT_EQ(Type(0.75).trunk(), Type(0));
EXPECT_EQ(Type(1.5).round(), Type(2));
EXPECT_EQ(Type(1.5).floor(), Type(1));
EXPECT_EQ(Type(1.5).ceil(), Type(2));
EXPECT_EQ(Type(1.25).trunk(), Type(1));
EXPECT_EQ(Type(-0.5).round(), Type(0));
EXPECT_EQ(Type(-0.5).floor(), Type(-1));
EXPECT_EQ(Type(-0.5).ceil(), Type(0));
EXPECT_EQ(Type(-0.75).trunk(), Type(0));
EXPECT_EQ(Type(-1.5).round(), Type(-2));
EXPECT_EQ(Type(-1.5).floor(), Type(-2));
EXPECT_EQ(Type(-1.5).ceil(), Type(-1));
EXPECT_EQ(Type(-1.25).trunk(), Type(-1));
EXPECT_EQ(Type(0.5).lround(), 0);
EXPECT_EQ(Type(0.5).lfloor(), 0);
EXPECT_EQ(Type(0.5).lceil(), 1);
EXPECT_EQ(Type(0.5).ltrunk(), 0);
EXPECT_EQ(Type(1.5).lround(), 2);
EXPECT_EQ(Type(1.5).lfloor(), 1);
EXPECT_EQ(Type(1.5).lceil(), 2);
EXPECT_EQ(Type(1.5).ltrunk(), 1);
EXPECT_EQ(Type(-0.5).lround(), 0);
EXPECT_EQ(Type(-0.5).lfloor(), -1);
EXPECT_EQ(Type(-0.5).lceil(), 0);
EXPECT_EQ(Type(-0.5).ltrunk(), 0);
EXPECT_EQ(Type(-1.5).lround(), -2);
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)
{
EXPECT_EQ(Type(0).log2().raw(), NumericLimits<int>::min());
EXPECT_EQ(Type(1).log2(), Type(0));
EXPECT_EQ(Type(2).log2(), Type(1));
EXPECT_EQ(Type(8).log2(), Type(3));
EXPECT_EQ(Type(0.5).log2(), Type(-1));
EXPECT_EQ(Type(22.627416997969520780827019587355).log2(), Type(4.4375));
EXPECT_EQ(Type(3088).log2(), Type(11.592457037268080419637304576833));
}
TEST_CASE(comparison)
{
EXPECT(Type(0) < 1);
EXPECT(Type(0) <= 1);
EXPECT(Type(0) <= 0);
EXPECT(Type(-10) <= -10);
EXPECT(Type(4.25) > 4);
EXPECT(Type(4.25) >= 4);
EXPECT(Type(4.25) <= 5);
EXPECT(Type(4.25) < 5);
EXPECT(Type(1.5) > 1);
EXPECT(!(FixedPoint<4, u8>(2) > 128));
EXPECT(!(FixedPoint<4, u8>(2) >= 128));
EXPECT(Type(-6.25) < -6);
EXPECT(Type(-6.25) <= -6);
EXPECT(Type(-6.75) > -7);
EXPECT(Type(-6.75) >= -7);
EXPECT(Type(17) == 17);
EXPECT(Type(-8) != -9);
}
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 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));
EXPECT((double)downcast_value2 >= 4567.1 && (double)downcast_value2 <= 4567.2);
downcast_value2 = FixedPoint<32, u64>(7654.654321);
EXPECT((double)downcast_value2 >= 7654.64 && (double)downcast_value2 <= 7654.66);
EXPECT((double)downcast_value2 >= 7654.64 && (double)downcast_value2 <= 7654.66);
FixedPoint<6, u32> downcast_value3(FixedPoint<32, u64>(4567.987654));
EXPECT((double)downcast_value3 >= 4567.9 && (double)downcast_value3 <= 4567.99);
downcast_value3 = FixedPoint<32, u64>(7654.456789);
EXPECT((double)downcast_value3 >= 7654.45 && (double)downcast_value3 <= 7654.46);
FixedPoint<32, u64> upcast_value1(FixedPoint<16, u32>(123.4567));
EXPECT((double)upcast_value1 >= 123.4566 && (double)upcast_value1 <= 123.4568);
upcast_value1 = FixedPoint<16, u32>(321.7654);
EXPECT((double)upcast_value1 >= 321.7653 && (double)upcast_value1 <= 321.7655);
FixedPoint<32, u64> upcast_value2(FixedPoint<6, u32>(4567.123456));
EXPECT((double)upcast_value2 >= 4567.1 && (double)upcast_value2 <= 4567.2);
upcast_value2 = FixedPoint<6, u32>(7654.654321);
EXPECT((double)upcast_value2 >= 7654.64 && (double)upcast_value2 <= 7654.66);
FixedPoint<32, u64> upcast_value3(FixedPoint<6, u32>(4567.987654));
EXPECT((double)upcast_value3 >= 4567.9 && (double)upcast_value3 <= 4567.99);
upcast_value3 = FixedPoint<6, u32>(7654.456789);
EXPECT((double)upcast_value3 >= 7654.45 && (double)upcast_value3 <= 7654.46);
}
TEST_CASE(formatter)
{
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(123.456)), "123.455993"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(-123.456)), "-123.455994"sv);
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)), "0.100006"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)), "-0.100007"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(-0.02)), "-0.020005"sv);
EXPECT_EQ(DeprecatedString::formatted("{}", FixedPoint<16>(-0.0000000005)), "0"sv);
}