ladybird/Libraries/LibWeb/CSS/StyleValues/CSSHWB.cpp
2025-07-16 13:05:33 +01:00

74 lines
2.7 KiB
C++

/*
* Copyright (c) 2024, Sam Atkins <sam@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include "CSSHWB.h"
#include <AK/TypeCasts.h>
#include <LibWeb/CSS/Serialize.h>
#include <LibWeb/CSS/StyleValues/CalculatedStyleValue.h>
#include <LibWeb/CSS/StyleValues/PercentageStyleValue.h>
namespace Web::CSS {
Optional<Color> CSSHWB::to_color(Optional<Layout::NodeWithStyle const&>, CalculationResolutionContext const& resolution_context) const
{
auto h_val = resolve_hue(m_properties.h, resolution_context);
auto raw_w_value = resolve_with_reference_value(m_properties.w, 100.0, resolution_context);
auto raw_b_value = resolve_with_reference_value(m_properties.b, 100.0, resolution_context);
auto alpha_val = resolve_alpha(m_properties.alpha, resolution_context);
if (!h_val.has_value() || !raw_w_value.has_value() || !raw_b_value.has_value() || !alpha_val.has_value())
return {};
auto w_val = clamp(raw_w_value.value(), 0, 100) / 100.0f;
auto b_val = clamp(raw_b_value.value(), 0, 100) / 100.0f;
if (w_val + b_val >= 1.0f) {
auto to_byte = [](float value) {
return round_to<u8>(clamp(value * 255.0f, 0.0f, 255.0f));
};
u8 gray = to_byte(w_val / (w_val + b_val));
return Color(gray, gray, gray, to_byte(alpha_val.value()));
}
auto value = 1 - b_val;
auto saturation = 1 - (w_val / value);
return Color::from_hsv(h_val.value(), saturation, value).with_opacity(alpha_val.value());
}
bool CSSHWB::equals(CSSStyleValue const& other) const
{
if (type() != other.type())
return false;
auto const& other_color = other.as_color();
if (color_type() != other_color.color_type())
return false;
auto const& other_hwb = as<CSSHWB>(other_color);
return m_properties == other_hwb.m_properties;
}
// https://www.w3.org/TR/css-color-4/#serializing-sRGB-values
String CSSHWB::to_string(SerializationMode mode) const
{
if (auto color = to_color({}, {}); color.has_value())
return serialize_a_srgb_value(color.value());
StringBuilder builder;
builder.append("hwb("sv);
serialize_hue_component(builder, mode, m_properties.h);
builder.append(" "sv);
serialize_color_component(builder, mode, m_properties.w, 100, 0);
builder.append(" "sv);
serialize_color_component(builder, mode, m_properties.b, 100, 0);
if ((!m_properties.alpha->is_number() || m_properties.alpha->as_number().number() < 1) && (!m_properties.alpha->is_percentage() || m_properties.alpha->as_percentage().percentage().as_fraction() < 1)) {
builder.append(" / "sv);
serialize_alpha_component(builder, mode, m_properties.alpha);
}
builder.append(")"sv);
return builder.to_string_without_validation();
}
}