dolphin/Source/UnitTests/Common/MathUtilTest.cpp
Scott Mansell b8695a57da Fix incorrect clamping in SWRenderer.
A previous PR changed a whole lot of min/maxes to std::min/std::max
but made a mistake here and used a templated min which cast it's
arguments to unsigned instead of casting return value.

This resulted in glitchy artifacts in bright areas (See issue 7439)

I rewrote the code to use a proper clamping function so it's cleaner
to read.
2014-07-15 21:15:49 +12:00

99 lines
3.2 KiB
C++

// Copyright 2014 Dolphin Emulator Project
// Licensed under GPLv2
// Refer to the license.txt file included.
#include <gtest/gtest.h>
#include <limits>
#include <random>
#include "Common/MathUtil.h"
TEST(MathUtil, Clamp)
{
EXPECT_EQ(1, MathUtil::Clamp(1, 0, 2));
EXPECT_EQ(1.0, MathUtil::Clamp(1.0, 0.0, 2.0));
EXPECT_EQ(2, MathUtil::Clamp(4, 0, 2));
EXPECT_EQ(2.0, MathUtil::Clamp(4.0, 0.0, 2.0));
EXPECT_EQ(0, MathUtil::Clamp(-1, 0, 2));
EXPECT_EQ(0.0, MathUtil::Clamp(-1.0, 0.0, 2.0));
}
TEST(MathUtil, IsINF)
{
EXPECT_TRUE(MathUtil::IsINF(+std::numeric_limits<double>::infinity()));
EXPECT_TRUE(MathUtil::IsINF(-std::numeric_limits<double>::infinity()));
}
TEST(MathUtil, IsNAN)
{
EXPECT_TRUE(MathUtil::IsNAN(std::numeric_limits<double>::quiet_NaN()));
EXPECT_TRUE(MathUtil::IsNAN(std::numeric_limits<double>::signaling_NaN()));
}
TEST(MathUtil, IsQNAN)
{
EXPECT_TRUE(MathUtil::IsQNAN(std::numeric_limits<double>::quiet_NaN()));
EXPECT_FALSE(MathUtil::IsQNAN(std::numeric_limits<double>::signaling_NaN()));
}
TEST(MathUtil, IsSNAN)
{
EXPECT_FALSE(MathUtil::IsSNAN(std::numeric_limits<double>::quiet_NaN()));
EXPECT_TRUE(MathUtil::IsSNAN(std::numeric_limits<double>::signaling_NaN()));
}
TEST(MathUtil, Log2)
{
EXPECT_EQ(0, Log2(1));
EXPECT_EQ(1, Log2(2));
EXPECT_EQ(2, Log2(4));
EXPECT_EQ(3, Log2(8));
EXPECT_EQ(63, Log2(0x8000000000000000ull));
// Rounding behavior.
EXPECT_EQ(3, Log2(15));
EXPECT_EQ(63, Log2(0xFFFFFFFFFFFFFFFFull));
}
TEST(MathUtil, FlushToZero)
{
// To test the software implementation we need to make sure FTZ and DAZ are disabled.
// Using volatile here to ensure the compiler doesn't constant-fold it,
// we want the multiplication to occur at test runtime.
volatile float s = std::numeric_limits<float>::denorm_min();
volatile double d = std::numeric_limits<double>::denorm_min();
EXPECT_LT(0, s * 2);
EXPECT_LT(0, d * 2);
EXPECT_EQ(+0, MathUtil::FlushToZero(+std::numeric_limits<double>::denorm_min()));
EXPECT_EQ(-0, MathUtil::FlushToZero(-std::numeric_limits<double>::denorm_min()));
EXPECT_EQ(+0, MathUtil::FlushToZero(+std::numeric_limits<double>::min() / 2));
EXPECT_EQ(-0, MathUtil::FlushToZero(-std::numeric_limits<double>::min() / 2));
EXPECT_EQ(std::numeric_limits<double>::min(), MathUtil::FlushToZero(std::numeric_limits<double>::min()));
EXPECT_EQ(std::numeric_limits<double>::max(), MathUtil::FlushToZero(std::numeric_limits<double>::max()));
EXPECT_EQ(+std::numeric_limits<double>::infinity(), MathUtil::FlushToZero(+std::numeric_limits<double>::infinity()));
EXPECT_EQ(-std::numeric_limits<double>::infinity(), MathUtil::FlushToZero(-std::numeric_limits<double>::infinity()));
// Test all subnormals as well as an equally large set of random normal floats.
std::default_random_engine engine(0);
std::uniform_int_distribution<u32> dist(0x00800000u, 0x7fffffffu);
for (u32 i = 0; i <= 0x007fffffu; ++i)
{
MathUtil::IntFloat x(i);
EXPECT_EQ(+0, MathUtil::FlushToZero(x.f));
x.i = i | 0x80000000u;
EXPECT_EQ(-0, MathUtil::FlushToZero(x.f));
x.i = dist(engine);
MathUtil::IntFloat y(MathUtil::FlushToZero(x.f));
EXPECT_EQ(x.i, y.i);
x.i |= 0x80000000u;
y.f = MathUtil::FlushToZero(x.f);
EXPECT_EQ(x.i, y.i);
}
}