ladybird/Userland/Libraries/LibPDF/ColorSpace.cpp
Ben Wiederhake f84a7e2e22 LibPDF: Replace Value class by AK::Variant
This decreases the memory consumption by LibPDF by 4 bytes per Value,
compensating exactly for the increase in an earlier commit. :^)
2021-09-20 17:39:36 +04:30

227 lines
7.4 KiB
C++

/*
* Copyright (c) 2021, Matthew Olsson <mattco@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibPDF/ColorSpace.h>
#include <LibPDF/CommonNames.h>
#include <LibPDF/ObjectDerivatives.h>
namespace PDF {
RefPtr<DeviceGrayColorSpace> DeviceGrayColorSpace::the()
{
static auto instance = adopt_ref(*new DeviceGrayColorSpace());
return instance;
}
Color DeviceGrayColorSpace::color(Vector<Value> const& arguments) const
{
VERIFY(arguments.size() == 1);
auto gray = static_cast<u8>(arguments[0].to_float() * 255.0f);
return Color(gray, gray, gray);
}
RefPtr<DeviceRGBColorSpace> DeviceRGBColorSpace::the()
{
static auto instance = adopt_ref(*new DeviceRGBColorSpace());
return instance;
}
Color DeviceRGBColorSpace::color(Vector<Value> const& arguments) const
{
VERIFY(arguments.size() == 3);
auto r = static_cast<u8>(arguments[0].to_float() * 255.0f);
auto g = static_cast<u8>(arguments[1].to_float() * 255.0f);
auto b = static_cast<u8>(arguments[2].to_float() * 255.0f);
return Color(r, g, b);
}
RefPtr<DeviceCMYKColorSpace> DeviceCMYKColorSpace::the()
{
static auto instance = adopt_ref(*new DeviceCMYKColorSpace());
return instance;
}
Color DeviceCMYKColorSpace::color(Vector<Value> const& arguments) const
{
VERIFY(arguments.size() == 4);
auto c = arguments[0].to_float();
auto m = arguments[1].to_float();
auto y = arguments[2].to_float();
auto k = arguments[3].to_float();
return Color::from_cmyk(c, m, y, k);
}
RefPtr<CalRGBColorSpace> CalRGBColorSpace::create(RefPtr<Document> document, Vector<Value>&& parameters)
{
if (parameters.size() != 1)
return {};
auto param = parameters[0];
if (!param.has<NonnullRefPtr<Object>>() || !param.get<NonnullRefPtr<Object>>()->is_dict())
return {};
auto dict = object_cast<DictObject>(param.get<NonnullRefPtr<Object>>());
if (!dict->contains(CommonNames::WhitePoint))
return {};
auto white_point_array = dict->get_array(document, CommonNames::WhitePoint);
if (white_point_array->size() != 3)
return {};
auto color_space = adopt_ref(*new CalRGBColorSpace());
color_space->m_whitepoint[0] = white_point_array->at(0).to_float();
color_space->m_whitepoint[1] = white_point_array->at(1).to_float();
color_space->m_whitepoint[2] = white_point_array->at(2).to_float();
if (color_space->m_whitepoint[1] != 1.0f)
return {};
if (dict->contains(CommonNames::BlackPoint)) {
auto black_point_array = dict->get_array(document, CommonNames::BlackPoint);
if (black_point_array->size() == 3) {
color_space->m_blackpoint[0] = black_point_array->at(0).to_float();
color_space->m_blackpoint[1] = black_point_array->at(1).to_float();
color_space->m_blackpoint[2] = black_point_array->at(2).to_float();
}
}
if (dict->contains(CommonNames::Gamma)) {
auto gamma_array = dict->get_array(document, CommonNames::Gamma);
if (gamma_array->size() == 3) {
color_space->m_gamma[0] = gamma_array->at(0).to_float();
color_space->m_gamma[1] = gamma_array->at(1).to_float();
color_space->m_gamma[2] = gamma_array->at(2).to_float();
}
}
if (dict->contains(CommonNames::Matrix)) {
auto matrix_array = dict->get_array(document, CommonNames::Matrix);
if (matrix_array->size() == 3) {
color_space->m_matrix[0] = matrix_array->at(0).to_float();
color_space->m_matrix[1] = matrix_array->at(1).to_float();
color_space->m_matrix[2] = matrix_array->at(2).to_float();
color_space->m_matrix[3] = matrix_array->at(3).to_float();
color_space->m_matrix[4] = matrix_array->at(4).to_float();
color_space->m_matrix[5] = matrix_array->at(5).to_float();
color_space->m_matrix[6] = matrix_array->at(6).to_float();
color_space->m_matrix[7] = matrix_array->at(7).to_float();
color_space->m_matrix[8] = matrix_array->at(8).to_float();
}
}
return color_space;
}
constexpr Array<float, 3> matrix_multiply(Array<float, 9> a, Array<float, 3> b)
{
return Array<float, 3> {
a[0] * b[0] + a[1] * b[1] + a[2] * b[2],
a[3] * b[0] + a[4] * b[1] + a[5] * b[2],
a[6] * b[0] + a[7] * b[1] + a[8] * b[2]
};
}
// Converts to a flat XYZ space with white point = (1, 1, 1)
// Step 2 of https://www.adobe.com/content/dam/acom/en/devnet/photoshop/sdk/AdobeBPC.pdf
constexpr Array<float, 3> flatten_and_normalize_whitepoint(Array<float, 3> whitepoint, Array<float, 3> xyz)
{
VERIFY(whitepoint[1] == 1.0f);
return {
(1.0f / whitepoint[0]) * xyz[0],
xyz[1],
(1.0f / whitepoint[2]) * xyz[2],
};
}
constexpr float decode_l(float input)
{
constexpr float decode_l_scaling_constant = 0.00110705646f; // (((8 + 16) / 116) ^ 3) / 8
if (input < 0.0f)
return -decode_l(-input);
if (input >= 0.0f && input <= 8.0f)
return input * decode_l_scaling_constant;
return powf(((input + 16.0f) / 116.0f), 3.0f);
}
constexpr Array<float, 3> scale_black_point(Array<float, 3> blackpoint, Array<float, 3> xyz)
{
auto y_dst = decode_l(0); // DestinationBlackPoint is just [0, 0, 0]
auto y_src = decode_l(blackpoint[0]);
auto scale = (1 - y_dst) / (1 - y_src);
auto offset = 1 - scale;
return {
xyz[0] * scale + offset,
xyz[1] * scale + offset,
xyz[2] * scale + offset,
};
}
// https://en.wikipedia.org/wiki/Illuminant_D65
constexpr Array<float, 3> convert_to_d65(Array<float, 3> whitepoint, Array<float, 3> xyz)
{
constexpr float d65x = 0.95047f;
constexpr float d65y = 1.0f;
constexpr float d65z = 1.08883f;
return {
(xyz[0] * d65x) / whitepoint[0],
(xyz[1] * d65y) / whitepoint[1],
(xyz[2] * d65z) / whitepoint[2],
};
}
// https://en.wikipedia.org/wiki/SRGB
constexpr Array<float, 3> convert_to_srgb(Array<float, 3> xyz)
{
// See the sRGB D65 [M]^-1 matrix in the following page
// http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
constexpr Array<float, 9> conversion_matrix = {
3.2404542,
-1.5371385,
-0.4985314,
-0.969266,
1.8760108,
0.0415560,
0.0556434,
-0.2040259,
1.0572252,
};
return matrix_multiply(conversion_matrix, xyz);
}
Color CalRGBColorSpace::color(Vector<Value> const& arguments) const
{
VERIFY(arguments.size() == 3);
auto a = clamp(arguments[0].to_float(), 0.0f, 1.0f);
auto b = clamp(arguments[1].to_float(), 0.0f, 1.0f);
auto c = clamp(arguments[2].to_float(), 0.0f, 1.0f);
auto agr = powf(a, m_gamma[0]);
auto bgg = powf(b, m_gamma[1]);
auto cgb = powf(c, m_gamma[2]);
auto x = m_matrix[0] * agr + m_matrix[3] * bgg + m_matrix[6] * cgb;
auto y = m_matrix[1] * agr + m_matrix[4] * bgg + m_matrix[7] * cgb;
auto z = m_matrix[2] * agr + m_matrix[5] * bgg + m_matrix[8] * cgb;
auto flattened_xyz = flatten_and_normalize_whitepoint(m_whitepoint, { x, y, z });
auto scaled_black_point_xyz = scale_black_point(m_blackpoint, flattened_xyz);
auto d65_normalized = convert_to_d65(m_whitepoint, scaled_black_point_xyz);
auto srgb = convert_to_srgb(d65_normalized);
auto red = static_cast<u8>(srgb[0] * 255.0f);
auto green = static_cast<u8>(srgb[1] * 255.0f);
auto blue = static_cast<u8>(srgb[2] * 255.0f);
return Color(red, green, blue);
}
}