ladybird/Userland/Libraries/LibWeb/PixelUnits.h

/*
 * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

#pragma once

#include <AK/Concepts.h>
#include <AK/DistinctNumeric.h>
#include <AK/Traits.h>
#include <LibGfx/Forward.h>
#include <math.h>

namespace Web {

/// DevicePixels: A position or length on the physical display.
AK_TYPEDEF_DISTINCT_NUMERIC_GENERAL(int, DevicePixels, Arithmetic, CastToUnderlying, Comparison, Increment);

template<Integral T>
constexpr bool operator==(DevicePixels left, T right) { return left.value() == right; }

template<Integral T>
constexpr bool operator!=(DevicePixels left, T right) { return left.value() != right; }

template<Integral T>
constexpr bool operator>(DevicePixels left, T right) { return left.value() > right; }

template<Integral T>
constexpr bool operator<(DevicePixels left, T right) { return left.value() < right; }

template<Integral T>
constexpr bool operator>=(DevicePixels left, T right) { return left.value() >= right; }

template<Integral T>
constexpr bool operator<=(DevicePixels left, T right) { return left.value() <= right; }

template<Integral T>
constexpr DevicePixels operator*(DevicePixels left, T right) { return left.value() * right; }
template<Integral T>
constexpr DevicePixels operator*(T left, DevicePixels right) { return right * left; }

template<Integral T>
constexpr DevicePixels operator/(DevicePixels left, T right) { return left.value() / right; }

template<Integral T>
constexpr DevicePixels operator%(DevicePixels left, T right) { return left.value() % right; }

/// CSSPixels: A position or length in CSS "reference pixels", independent of zoom or screen DPI.
/// See https://www.w3.org/TR/css-values-3/#reference-pixel
class CSSPixels {
public:
    constexpr CSSPixels() = default;

    constexpr CSSPixels(double value)
        : m_value { value }
    {
    }

    constexpr float to_float() const
    {
        return static_cast<float>(m_value);
    }

    constexpr double to_double() const
    {
        return static_cast<double>(m_value);
    }

    constexpr int to_int() const
    {
        return static_cast<int>(m_value);
    }

    constexpr bool operator==(CSSPixels const& other) const
    {
        return this->m_value == other.m_value;
    }

    constexpr explicit operator double() const
    {
        return to_double();
    }

    constexpr CSSPixels& operator++()
    {
        this->m_value += 1;
        return *this;
    }
    constexpr CSSPixels operator++(int)
    {
        CSSPixels ret = this->m_value;
        this->m_value += 1;
        return ret;
    }
    constexpr CSSPixels& operator--()
    {
        this->m_value -= 1;
        return *this;
    }
    constexpr CSSPixels operator--(int)
    {
        CSSPixels ret = this->m_value;
        this->m_value -= 1;
        return ret;
    }

    constexpr int operator<=>(CSSPixels const& other) const
    {
        return this->m_value > other.m_value ? 1 : this->m_value < other.m_value ? -1
                                                                                 : 0;
    }

    constexpr CSSPixels operator+(CSSPixels const& other) const
    {
        return this->m_value + other.m_value;
    }

    constexpr CSSPixels operator-(CSSPixels const& other) const
    {
        return this->m_value - other.m_value;
    }

    constexpr CSSPixels operator+() const
    {
        return +this->m_value;
    }

    constexpr CSSPixels operator-() const
    {
        return -this->m_value;
    }

    constexpr CSSPixels operator*(CSSPixels const& other) const
    {
        return this->m_value * other.m_value;
    }

    constexpr CSSPixels operator/(CSSPixels const& other) const
    {
        return this->m_value / other.m_value;
    }

    constexpr CSSPixels& operator+=(CSSPixels const& other)
    {
        this->m_value += other.m_value;
        return *this;
    }

    constexpr CSSPixels& operator-=(CSSPixels const& other)
    {
        this->m_value -= other.m_value;
        return *this;
    }

    constexpr CSSPixels& operator*=(CSSPixels const& other)
    {
        this->m_value *= other.m_value;
        return *this;
    }

    constexpr CSSPixels& operator/=(CSSPixels const& other)
    {
        this->m_value /= other.m_value;
        return *this;
    }

private:
    double m_value {};
};

template<Arithmetic T>
constexpr bool operator==(CSSPixels left, T right) { return left.to_double() == right; }

template<Arithmetic T>
constexpr bool operator!=(CSSPixels left, T right) { return left.to_double() != right; }

template<Arithmetic T>
constexpr bool operator>(CSSPixels left, T right) { return left.to_double() > right; }

template<Arithmetic T>
constexpr bool operator<(CSSPixels left, T right) { return left.to_double() < right; }

template<Arithmetic T>
constexpr bool operator>=(CSSPixels left, T right) { return left.to_double() >= right; }

template<Arithmetic T>
constexpr bool operator<=(CSSPixels left, T right) { return left.to_double() <= right; }

template<Arithmetic T>
constexpr CSSPixels operator*(CSSPixels left, T right) { return left.to_double() * right; }

template<Arithmetic T>
constexpr CSSPixels operator*(T left, CSSPixels right) { return right * left; }

template<Arithmetic T>
constexpr CSSPixels operator/(CSSPixels left, T right) { return left.to_double() / right; }

template<Arithmetic T>
constexpr CSSPixels operator%(CSSPixels left, T right) { return left.to_double() % right; }

using CSSPixelLine = Gfx::Line<CSSPixels>;
using CSSPixelPoint = Gfx::Point<CSSPixels>;
using CSSPixelRect = Gfx::Rect<CSSPixels>;
using CSSPixelSize = Gfx::Size<CSSPixels>;

using DevicePixelLine = Gfx::Line<DevicePixels>;
using DevicePixelPoint = Gfx::Point<DevicePixels>;
using DevicePixelRect = Gfx::Rect<DevicePixels>;
using DevicePixelSize = Gfx::Size<DevicePixels>;

}

constexpr Web::CSSPixels floor(Web::CSSPixels const& value)
{
    return ::floorf(value.to_float());
}

constexpr Web::CSSPixels ceil(Web::CSSPixels const& value)
{
    return ::ceilf(value.to_float());
}

constexpr Web::CSSPixels round(Web::CSSPixels const& value)
{
    return ::roundf(value.to_float());
}

constexpr Web::CSSPixels fmod(Web::CSSPixels const& x, Web::CSSPixels const& y)
{
    return ::fmodf(x.to_float(), y.to_float());
}

constexpr Web::CSSPixels abs(Web::CSSPixels const& value)
{
    return AK::abs(value.to_float());
}

constexpr Web::DevicePixels abs(Web::DevicePixels const& value)
{
    return AK::abs(value.value());
}

namespace AK {

template<>
struct Traits<Web::CSSPixels> : public GenericTraits<Web::CSSPixels> {
    static unsigned hash(Web::CSSPixels const& key)
    {
        VERIFY(isfinite(key.to_double()));
        return Traits<double>::hash(key.to_double());
    }

    static bool equals(Web::CSSPixels const& a, Web::CSSPixels const& b)
    {
        return a == b;
    }
};

template<>
struct Traits<Web::DevicePixels> : public GenericTraits<Web::DevicePixels> {
    static unsigned hash(Web::DevicePixels const& key)
    {
        return Traits<Web::DevicePixels::Type>::hash(key.value());
    }

    static bool equals(Web::DevicePixels const& a, Web::DevicePixels const& b)
    {
        return a == b;
    }
};

template<>
struct Formatter<Web::CSSPixels> : Formatter<double> {
    ErrorOr<void> format(FormatBuilder& builder, Web::CSSPixels const& value)
    {
        return Formatter<double>::format(builder, value.to_double());
    }
};

template<>
struct Formatter<Web::DevicePixels> : Formatter<Web::DevicePixels::Type> {
    ErrorOr<void> format(FormatBuilder& builder, Web::DevicePixels const& value)
    {
        return Formatter<Web::DevicePixels::Type>::format(builder, value.value());
    }
};

}