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/*
* Copyright (c) 2012, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <limits.h>
#include <limits>
#include <math.h>
#include <stdlib.h>
#include <wtf/HashTraits.h>
#include <wtf/MathExtras.h>
#include <wtf/SaturatedArithmetic.h>
namespace WTF {
class TextStream;
}
namespace WebCore {
#ifdef NDEBUG
#define REPORT_OVERFLOW(doesOverflow) ((void)0)
#else
#define REPORT_OVERFLOW(doesOverflow) do \
if (!(doesOverflow)) { \
WTFReportError(__FILE__, __LINE__, WTF_PRETTY_FUNCTION, "!(%s)", #doesOverflow); \
} \
while (0)
#endif
static const int kFixedPointDenominator = 64;
const int intMaxForLayoutUnit = INT_MAX / kFixedPointDenominator;
const int intMinForLayoutUnit = INT_MIN / kFixedPointDenominator;
class LayoutUnit {
public:
LayoutUnit() : m_value(0) { }
LayoutUnit(const LayoutUnit&) = default;
LayoutUnit(int value) { setValue(value); }
LayoutUnit(unsigned short value) { setValue(value); }
LayoutUnit(unsigned value) { setValue(value); }
explicit LayoutUnit(unsigned long value)
{
m_value = clampTo<int>(value * kFixedPointDenominator);
}
explicit LayoutUnit(unsigned long long value)
{
m_value = clampTo<int>(value * kFixedPointDenominator);
}
explicit LayoutUnit(float value)
{
m_value = clampToInteger(value * kFixedPointDenominator);
}
explicit LayoutUnit(double value)
{
m_value = clampToInteger(value * kFixedPointDenominator);
}
LayoutUnit& operator=(const LayoutUnit&) = default;
LayoutUnit& operator=(const float& other) { return *this = LayoutUnit(other); }
static LayoutUnit fromFloatCeil(float value)
{
LayoutUnit v;
v.m_value = clampToInteger(ceilf(value * kFixedPointDenominator));
return v;
}
static LayoutUnit fromFloatFloor(float value)
{
LayoutUnit v;
v.m_value = clampToInteger(floorf(value * kFixedPointDenominator));
return v;
}
static LayoutUnit fromFloatRound(float value)
{
if (value >= 0)
return clamp(value + epsilon() / 2.0f);
return clamp(value - epsilon() / 2.0f);
}
int toInt() const { return m_value / kFixedPointDenominator; }
float toFloat() const { return static_cast<float>(m_value) / kFixedPointDenominator; }
double toDouble() const { return static_cast<double>(m_value) / kFixedPointDenominator; }
unsigned toUnsigned() const { REPORT_OVERFLOW(m_value >= 0); return toInt(); }
operator int() const { return toInt(); }
operator float() const { return toFloat(); }
operator double() const { return toDouble(); }
explicit operator bool() const { return m_value; }
LayoutUnit& operator++()
{
m_value += kFixedPointDenominator;
return *this;
}
inline int rawValue() const { return m_value; }
inline void setRawValue(int value) { m_value = value; }
void setRawValue(long long value)
{
REPORT_OVERFLOW(value > std::numeric_limits<int>::min() && value < std::numeric_limits<int>::max());
m_value = static_cast<int>(value);
}
LayoutUnit abs() const
{
LayoutUnit returnValue;
returnValue.setRawValue(::abs(m_value));
return returnValue;
}
int ceil() const
{
if (UNLIKELY(m_value >= INT_MAX - kFixedPointDenominator + 1))
return intMaxForLayoutUnit;
if (m_value >= 0)
return (m_value + kFixedPointDenominator - 1) / kFixedPointDenominator;
return toInt();
}
int round() const
{
if (m_value > 0)
return saturatedSum<int>(rawValue(), kFixedPointDenominator / 2) / kFixedPointDenominator;
return saturatedDifference<int>(rawValue(), (kFixedPointDenominator / 2) - 1) / kFixedPointDenominator;
}
int floor() const
{
if (UNLIKELY(m_value <= INT_MIN + kFixedPointDenominator - 1))
return intMinForLayoutUnit;
if (m_value >= 0)
return toInt();
return (m_value - kFixedPointDenominator + 1) / kFixedPointDenominator;
}
float ceilToFloat() const
{
float floatValue = toFloat();
if (static_cast<int>(floatValue * kFixedPointDenominator) == m_value)
return floatValue;
if (floatValue > 0)
return nextafterf(floatValue, std::numeric_limits<float>::max());
return nextafterf(floatValue, std::numeric_limits<float>::min());
}
LayoutUnit fraction() const
{
// Add the fraction to the size (as opposed to the full location) to avoid overflows.
// Compute fraction using the mod operator to preserve the sign of the value as it may affect rounding.
LayoutUnit fraction;
fraction.setRawValue(rawValue() % kFixedPointDenominator);
return fraction;
}
bool mightBeSaturated() const
{
return rawValue() == std::numeric_limits<int>::max()
|| rawValue() == std::numeric_limits<int>::min();
}
static float epsilon() { return 1.0f / kFixedPointDenominator; }
static const LayoutUnit max()
{
LayoutUnit m;
m.m_value = std::numeric_limits<int>::max();
return m;
}
static const LayoutUnit min()
{
LayoutUnit m;
m.m_value = std::numeric_limits<int>::min();
return m;
}
// Versions of max/min that are slightly smaller/larger than max/min() to allow for roinding without overflowing.
static const LayoutUnit nearlyMax()
{
LayoutUnit m;
m.m_value = std::numeric_limits<int>::max() - kFixedPointDenominator / 2;
return m;
}
static const LayoutUnit nearlyMin()
{
LayoutUnit m;
m.m_value = std::numeric_limits<int>::min() + kFixedPointDenominator / 2;
return m;
}
static LayoutUnit clamp(double value)
{
return clampTo<LayoutUnit>(value, LayoutUnit::min(), LayoutUnit::max());
}
private:
static bool isInBounds(int value)
{
return ::abs(value) <= std::numeric_limits<int>::max() / kFixedPointDenominator;
}
static bool isInBounds(unsigned value)
{
return value <= static_cast<unsigned>(std::numeric_limits<int>::max()) / kFixedPointDenominator;
}
static bool isInBounds(double value)
{
return ::fabs(value) <= std::numeric_limits<int>::max() / kFixedPointDenominator;
}
inline void setValue(int value)
{
if (value > intMaxForLayoutUnit)
m_value = std::numeric_limits<int>::max();
else if (value < intMinForLayoutUnit)
m_value = std::numeric_limits<int>::min();
else
m_value = value * kFixedPointDenominator;
}
inline void setValue(unsigned value)
{
if (value >= static_cast<unsigned>(intMaxForLayoutUnit))
m_value = std::numeric_limits<int>::max();
else
m_value = value * kFixedPointDenominator;
}
int m_value;
};
inline bool operator<=(const LayoutUnit& a, const LayoutUnit& b)
{
return a.rawValue() <= b.rawValue();
}
inline bool operator<=(const LayoutUnit& a, float b)
{
return a.toFloat() <= b;
}
inline bool operator<=(const LayoutUnit& a, int b)
{
return a <= LayoutUnit(b);
}
inline bool operator<=(const float a, const LayoutUnit& b)
{
return a <= b.toFloat();
}
inline bool operator<=(const int a, const LayoutUnit& b)
{
return LayoutUnit(a) <= b;
}
inline bool operator>=(const LayoutUnit& a, const LayoutUnit& b)
{
return a.rawValue() >= b.rawValue();
}
inline bool operator>=(const LayoutUnit& a, int b)
{
return a >= LayoutUnit(b);
}
inline bool operator>=(const float a, const LayoutUnit& b)
{
return a >= b.toFloat();
}
inline bool operator>=(const LayoutUnit& a, float b)
{
return a.toFloat() >= b;
}
inline bool operator>=(const int a, const LayoutUnit& b)
{
return LayoutUnit(a) >= b;
}
inline bool operator<(const LayoutUnit& a, const LayoutUnit& b)
{
return a.rawValue() < b.rawValue();
}
inline bool operator<(const LayoutUnit& a, int b)
{
return a < LayoutUnit(b);
}
inline bool operator<(const LayoutUnit& a, float b)
{
return a.toFloat() < b;
}
inline bool operator<(const LayoutUnit& a, double b)
{
return a.toDouble() < b;
}
inline bool operator<(const int a, const LayoutUnit& b)
{
return LayoutUnit(a) < b;
}
inline bool operator<(const float a, const LayoutUnit& b)
{
return a < b.toFloat();
}
inline bool operator>(const LayoutUnit& a, const LayoutUnit& b)
{
return a.rawValue() > b.rawValue();
}
inline bool operator>(const LayoutUnit& a, double b)
{
return a.toDouble() > b;
}
inline bool operator>(const LayoutUnit& a, float b)
{
return a.toFloat() > b;
}
inline bool operator>(const LayoutUnit& a, int b)
{
return a > LayoutUnit(b);
}
inline bool operator>(const int a, const LayoutUnit& b)
{
return LayoutUnit(a) > b;
}
inline bool operator>(const float a, const LayoutUnit& b)
{
return a > b.toFloat();
}
inline bool operator>(const double a, const LayoutUnit& b)
{
return a > b.toDouble();
}
inline bool operator!=(const LayoutUnit& a, const LayoutUnit& b)
{
return a.rawValue() != b.rawValue();
}
inline bool operator!=(const LayoutUnit& a, float b)
{
return a != LayoutUnit(b);
}
inline bool operator!=(const int a, const LayoutUnit& b)
{
return LayoutUnit(a) != b;
}
inline bool operator!=(const LayoutUnit& a, int b)
{
return a != LayoutUnit(b);
}
inline bool operator==(const LayoutUnit& a, const LayoutUnit& b)
{
return a.rawValue() == b.rawValue();
}
inline bool operator==(const LayoutUnit& a, int b)
{
return a == LayoutUnit(b);
}
inline bool operator==(const int a, const LayoutUnit& b)
{
return LayoutUnit(a) == b;
}
inline bool operator==(const LayoutUnit& a, float b)
{
return a.toFloat() == b;
}
inline bool operator==(const float a, const LayoutUnit& b)
{
return a == b.toFloat();
}
// For multiplication that's prone to overflow, this bounds it to LayoutUnit::max() and ::min()
inline LayoutUnit boundedMultiply(const LayoutUnit& a, const LayoutUnit& b)
{
int64_t result = static_cast<int64_t>(a.rawValue()) * static_cast<int64_t>(b.rawValue()) / kFixedPointDenominator;
int32_t high = static_cast<int32_t>(result >> 32);
int32_t low = static_cast<int32_t>(result);
uint32_t saturated = (static_cast<uint32_t>(a.rawValue() ^ b.rawValue()) >> 31) + std::numeric_limits<int>::max();
// If the higher 32 bits does not match the lower 32 with sign extension the operation overflowed.
if (high != low >> 31)
result = saturated;
LayoutUnit returnVal;
returnVal.setRawValue(static_cast<int>(result));
return returnVal;
}
inline LayoutUnit operator*(const LayoutUnit& a, const LayoutUnit& b)
{
return boundedMultiply(a, b);
}
inline double operator*(const LayoutUnit& a, double b)
{
return a.toDouble() * b;
}
inline float operator*(const LayoutUnit& a, float b)
{
return a.toFloat() * b;
}
inline LayoutUnit operator*(const LayoutUnit& a, int b)
{
return a * LayoutUnit(b);
}
inline LayoutUnit operator*(const LayoutUnit& a, unsigned short b)
{
return a * LayoutUnit(b);
}
inline LayoutUnit operator*(const LayoutUnit& a, unsigned b)
{
return a * LayoutUnit(b);
}
inline LayoutUnit operator*(const LayoutUnit& a, unsigned long b)
{
return a * LayoutUnit(b);
}
inline LayoutUnit operator*(const LayoutUnit& a, unsigned long long b)
{
return a * LayoutUnit(b);
}
inline LayoutUnit operator*(unsigned short a, const LayoutUnit& b)
{
return LayoutUnit(a) * b;
}
inline LayoutUnit operator*(unsigned a, const LayoutUnit& b)
{
return LayoutUnit(a) * b;
}
inline LayoutUnit operator*(unsigned long a, const LayoutUnit& b)
{
return LayoutUnit(a) * b;
}
inline LayoutUnit operator*(unsigned long long a, const LayoutUnit& b)
{
return LayoutUnit(a) * b;
}
inline LayoutUnit operator*(const int a, const LayoutUnit& b)
{
return LayoutUnit(a) * b;
}
inline float operator*(const float a, const LayoutUnit& b)
{
return a * b.toFloat();
}
inline double operator*(const double a, const LayoutUnit& b)
{
return a * b.toDouble();
}
inline LayoutUnit operator/(const LayoutUnit& a, const LayoutUnit& b)
{
LayoutUnit returnVal;
long long rawVal = static_cast<long long>(kFixedPointDenominator) * a.rawValue() / b.rawValue();
returnVal.setRawValue(clampTo<int>(rawVal));
return returnVal;
}
inline float operator/(const LayoutUnit& a, float b)
{
return a.toFloat() / b;
}
inline double operator/(const LayoutUnit& a, double b)
{
return a.toDouble() / b;
}
inline LayoutUnit operator/(const LayoutUnit& a, int b)
{
return a / LayoutUnit(b);
}
inline LayoutUnit operator/(const LayoutUnit& a, unsigned short b)
{
return a / LayoutUnit(b);
}
inline LayoutUnit operator/(const LayoutUnit& a, unsigned b)
{
return a / LayoutUnit(b);
}
inline LayoutUnit operator/(const LayoutUnit& a, unsigned long b)
{
return a / LayoutUnit(b);
}
inline LayoutUnit operator/(const LayoutUnit& a, unsigned long long b)
{
return a / LayoutUnit(b);
}
inline float operator/(const float a, const LayoutUnit& b)
{
return a / b.toFloat();
}
inline double operator/(const double a, const LayoutUnit& b)
{
return a / b.toDouble();
}
inline LayoutUnit operator/(const int a, const LayoutUnit& b)
{
return LayoutUnit(a) / b;
}
inline LayoutUnit operator/(unsigned short a, const LayoutUnit& b)
{
return LayoutUnit(a) / b;
}
inline LayoutUnit operator/(unsigned a, const LayoutUnit& b)
{
return LayoutUnit(a) / b;
}
inline LayoutUnit operator/(unsigned long a, const LayoutUnit& b)
{
return LayoutUnit(a) / b;
}
inline LayoutUnit operator/(unsigned long long a, const LayoutUnit& b)
{
return LayoutUnit(a) / b;
}
inline LayoutUnit operator+(const LayoutUnit& a, const LayoutUnit& b)
{
LayoutUnit returnVal;
returnVal.setRawValue(saturatedSum<int>(a.rawValue(), b.rawValue()));
return returnVal;
}
inline LayoutUnit operator+(const LayoutUnit& a, int b)
{
return a + LayoutUnit(b);
}
inline float operator+(const LayoutUnit& a, float b)
{
return a.toFloat() + b;
}
inline double operator+(const LayoutUnit& a, double b)
{
return a.toDouble() + b;
}
inline LayoutUnit operator+(const int a, const LayoutUnit& b)
{
return LayoutUnit(a) + b;
}
inline float operator+(const float a, const LayoutUnit& b)
{
return a + b.toFloat();
}
inline double operator+(const double a, const LayoutUnit& b)
{
return a + b.toDouble();
}
inline LayoutUnit operator-(const LayoutUnit& a, const LayoutUnit& b)
{
LayoutUnit returnVal;
returnVal.setRawValue(saturatedDifference<int>(a.rawValue(), b.rawValue()));
return returnVal;
}
inline LayoutUnit operator-(const LayoutUnit& a, int b)
{
return a - LayoutUnit(b);
}
inline LayoutUnit operator-(const LayoutUnit& a, unsigned b)
{
return a - LayoutUnit(b);
}
inline float operator-(const LayoutUnit& a, float b)
{
return a.toFloat() - b;
}
inline LayoutUnit operator-(const int a, const LayoutUnit& b)
{
return LayoutUnit(a) - b;
}
inline float operator-(const float a, const LayoutUnit& b)
{
return a - b.toFloat();
}
inline LayoutUnit operator-(const LayoutUnit& a)
{
LayoutUnit returnVal;
returnVal.setRawValue(-a.rawValue());
return returnVal;
}
// For returning the remainder after a division with integer results.
inline LayoutUnit intMod(const LayoutUnit& a, const LayoutUnit& b)
{
// This calculates the modulo so that: a = static_cast<int>(a / b) * b + intMod(a, b).
LayoutUnit returnVal;
returnVal.setRawValue(a.rawValue() % b.rawValue());
return returnVal;
}
inline LayoutUnit operator%(const LayoutUnit& a, const LayoutUnit& b)
{
// This calculates the modulo so that: a = (a / b) * b + a % b.
LayoutUnit returnVal;
long long rawVal = (static_cast<long long>(kFixedPointDenominator) * a.rawValue()) % b.rawValue();
returnVal.setRawValue(rawVal / kFixedPointDenominator);
return returnVal;
}
inline LayoutUnit operator%(const LayoutUnit& a, int b)
{
return a % LayoutUnit(b);
}
inline LayoutUnit operator%(int a, const LayoutUnit& b)
{
return LayoutUnit(a) % b;
}
inline LayoutUnit& operator+=(LayoutUnit& a, const LayoutUnit& b)
{
a.setRawValue(saturatedSum<int>(a.rawValue(), b.rawValue()));
return a;
}
inline LayoutUnit& operator+=(LayoutUnit& a, int b)
{
a = a + b;
return a;
}
inline LayoutUnit& operator+=(LayoutUnit& a, float b)
{
a = a + b;
return a;
}
inline float& operator+=(float& a, const LayoutUnit& b)
{
a = a + b;
return a;
}
inline LayoutUnit& operator-=(LayoutUnit& a, int b)
{
a = a - b;
return a;
}
inline LayoutUnit& operator-=(LayoutUnit& a, const LayoutUnit& b)
{
a.setRawValue(saturatedDifference<int>(a.rawValue(), b.rawValue()));
return a;
}
inline LayoutUnit& operator-=(LayoutUnit& a, float b)
{
a = a - b;
return a;
}
inline float& operator-=(float& a, const LayoutUnit& b)
{
a = a - b;
return a;
}
inline LayoutUnit& operator*=(LayoutUnit& a, const LayoutUnit& b)
{
a = a * b;
return a;
}
// operator*=(LayoutUnit& a, int b) is supported by the operator above plus LayoutUnit(int).
inline LayoutUnit& operator*=(LayoutUnit& a, float b)
{
a = a * b;
return a;
}
inline float& operator*=(float& a, const LayoutUnit& b)
{
a = a * b;
return a;
}
inline LayoutUnit& operator/=(LayoutUnit& a, const LayoutUnit& b)
{
a = a / b;
return a;
}
// operator/=(LayoutUnit& a, int b) is supported by the operator above plus LayoutUnit(int).
inline LayoutUnit& operator/=(LayoutUnit& a, float b)
{
a = a / b;
return a;
}
inline float& operator/=(float& a, const LayoutUnit& b)
{
a = a / b;
return a;
}
WEBCORE_EXPORT WTF::TextStream& operator<<(WTF::TextStream&, const LayoutUnit&);
inline int roundToInt(LayoutUnit value)
{
return value.round();
}
inline int floorToInt(LayoutUnit value)
{
return value.floor();
}
inline float roundToDevicePixel(LayoutUnit value, float pixelSnappingFactor, bool needsDirectionalRounding = false)
{
double valueToRound = value.toDouble();
if (needsDirectionalRounding)
valueToRound -= LayoutUnit::epsilon() / (2 * kFixedPointDenominator);
if (valueToRound >= 0)
return round(valueToRound * pixelSnappingFactor) / pixelSnappingFactor;
// This adjusts directional rounding on negative halfway values. It produces the same direction for both negative and positive values.
// Instead of rounding negative halfway cases away from zero, we translate them to positive values before rounding.
// It helps snapping relative negative coordinates to the same position as if they were positive absolute coordinates.
unsigned translateOrigin = -value.rawValue();
return (round((valueToRound + translateOrigin) * pixelSnappingFactor) / pixelSnappingFactor) - translateOrigin;
}
inline float floorToDevicePixel(LayoutUnit value, float pixelSnappingFactor)
{
return floorf((value.rawValue() * pixelSnappingFactor) / kFixedPointDenominator) / pixelSnappingFactor;
}
inline float ceilToDevicePixel(LayoutUnit value, float pixelSnappingFactor)
{
return ceilf((value.rawValue() * pixelSnappingFactor) / kFixedPointDenominator) / pixelSnappingFactor;
}
inline int roundToInt(float value) { return roundToInt(LayoutUnit(value)); }
inline float roundToDevicePixel(float value, float pixelSnappingFactor, bool needsDirectionalRounding = false) { return roundToDevicePixel(LayoutUnit(value), pixelSnappingFactor, needsDirectionalRounding); }
inline float floorToDevicePixel(float value, float pixelSnappingFactor) { return floorToDevicePixel(LayoutUnit(value), pixelSnappingFactor); }
inline float ceilToDevicePixel(float value, float pixelSnappingFactor) { return ceilToDevicePixel(LayoutUnit(value), pixelSnappingFactor); }
inline LayoutUnit absoluteValue(const LayoutUnit& value)
{
return value.abs();
}
inline bool isIntegerValue(const LayoutUnit value)
{
return value.toInt() == value;
}
inline namespace StringLiterals {
inline LayoutUnit operator"" _lu(unsigned long long value)
{
return LayoutUnit(value);
}
}
} // namespace WebCore
namespace WTF {
template<> struct DefaultHash<WebCore::LayoutUnit> {
static unsigned hash(const WebCore::LayoutUnit& p) { return DefaultHash<int>::hash(p.rawValue()); }
static bool equal(const WebCore::LayoutUnit& a, const WebCore::LayoutUnit& b) { return a == b; }
static const bool safeToCompareToEmptyOrDeleted = true;
};
// The empty value is INT_MIN, the deleted value is INT_MAX. During the course of layout
// these values are typically only used to represent uninitialized values, so they are
// good candidates to represent the deleted and empty values in HashMaps as well.
template<> struct HashTraits<WebCore::LayoutUnit> : GenericHashTraits<WebCore::LayoutUnit> {
static constexpr bool emptyValueIsZero = false;
static WebCore::LayoutUnit emptyValue()
{
WebCore::LayoutUnit value;
value.setRawValue(std::numeric_limits<int>::min());
return value;
}
static void constructDeletedValue(WebCore::LayoutUnit& slot) { slot.setRawValue(std::numeric_limits<int>::max()); }
static bool isDeletedValue(WebCore::LayoutUnit value) { return value.rawValue() == std::numeric_limits<int>::max(); }
};
} // namespace WTF