OmaPhoto/tests/CameraRawTablesTests.cpp

#include "CameraRawFixtures.h"
#include "Document/CameraRawTables.h"
#include <QtTest>

// The measured tables as Swift reads them, checked against Python.
using namespace CameraRawFixtures;

class CameraRawTablesTests : public QObject {
    Q_OBJECT
private slots:
    void theTablesDecodeAsWritten();
    void aStageBlendsTheTablesAroundItsValue();
    void eachSliderPicksItsOwnTables();
    void neutralizeFindsTheGridsGrayest();
    void identitySlidersComposeNothing();
};

namespace {
const uint8_t *entry(int table, int cell)
{
    constexpr size_t entries = size_t(CameraRawTables::size) * CameraRawTables::size * CameraRawTables::size * 3;
    return CameraRawTables::tables().data() + table * entries + size_t(cell) * 3;
}

int indexOf(const uint8_t *table)
{
    constexpr size_t entries = size_t(CameraRawTables::size) * CameraRawTables::size * CameraRawTables::size * 3;
    return table ? int((table - CameraRawTables::tables().data()) / qsizetype(entries)) : -1;
}
}

void CameraRawTablesTests::theTablesDecodeAsWritten()
{
    const std::vector<uint8_t> &tables = CameraRawTables::tables();
    QCOMPARE(tables.size(), size_t(147) * 17 * 17 * 17 * 3);
    quint64 hash = 0xcbf29ce484222325ULL;
    for (const uint8_t byte : tables)
        hash = (hash ^ byte) * 0x100000001b3ULL;
    QCOMPARE(hash, quint64(0x6a9f829e703f2df6ULL));
    QCOMPARE(std::vector<int>(entry(40, 2456), entry(40, 2456) + 3), (std::vector<int>{128, 128, 128}));
    QCOMPARE(std::vector<int>(entry(81, 100), entry(81, 100) + 3), (std::vector<int>{0, 4, 32}));
    QCOMPARE(std::vector<int>(entry(146, 4912), entry(146, 4912) + 3), (std::vector<int>{255, 255, 255}));
}

void CameraRawTablesTests::aStageBlendsTheTablesAroundItsValue()
{
    const CameraRawStage balance = CameraRawTables::whiteBalance(30, -60);
    QCOMPARE((std::vector<int>{indexOf(balance.table[0]), indexOf(balance.table[1]), indexOf(balance.table[2]), indexOf(balance.table[3])}),
             (std::vector<int>{46, 47, 55, 56}));
    QCOMPARE((std::vector<float>{balance.weight[0], balance.weight[1], balance.weight[2], balance.weight[3]}),
             (std::vector<float>{0.32f, 0.48f, 0.08f, 0.12f}));
    // At the far corner the last pair takes it all.
    const CameraRawStage corner = CameraRawTables::whiteBalance(100, 100);
    QVERIFY(indexOf(corner.table[0]) == 70 && indexOf(corner.table[3]) == 80 && corner.weight[3] == 1 && corner.weight[0] == 0);
    // Past the range it holds at the end, never beyond.
    const CameraRawStage past = CameraRawTables::whiteBalance(150, 175);
    QVERIFY(indexOf(past.table[3]) == 80 && past.weight[3] == 1 && past.weight[0] == 0);
    const CameraRawStage low = CameraRawTables::whiteBalance(-100, -100);
    QVERIFY(indexOf(low.table[0]) == 0 && low.weight[0] == 1 && low.weight[1] == 0);
}

void CameraRawTablesTests::eachSliderPicksItsOwnTables()
{
    CameraRawSettings settings;
    settings.exposure = 1.25;
    settings.temperature = 30;
    settings.contrast = -100;
    settings.whites = 100;
    settings.blacks = 12.5;
    settings.saturation = -62.5;
    settings.vibrance = 80;
    const CameraRawTables::Stages stages = CameraRawTables::stages(settings);
    QCOMPARE(stages.before.size(), size_t(3));
    QCOMPARE(stages.after.size(), size_t(4));
    const auto pair = [](const CameraRawStage &stage) {
        return std::vector<double>{double(indexOf(stage.table[0])), double(indexOf(stage.table[1])), stage.weight[0], stage.weight[1]};
    };
    QCOMPARE(pair(stages.before[0]), (std::vector<double>{93, 94, 0.5, 0.5}));
    QCOMPARE(indexOf(stages.before[1].table[0]), 5 * 9 + 4);
    QCOMPARE(pair(stages.before[2]), (std::vector<double>{102, 103, 1, 0}));
    QCOMPARE(pair(stages.after[0]), (std::vector<double>{118, 119, 0, 1}));
    QCOMPARE(pair(stages.after[1]), (std::vector<double>{124, 125, 0.5, 0.5}));
    QCOMPARE(pair(stages.after[2]), (std::vector<double>{130, 131, 0.5, 0.5}));
    QVERIFY(indexOf(stages.after[3].table[0]) == 145 && std::abs(stages.after[3].weight[1] - 0.2f) < 1e-6);
    // Tint alone still makes the white balance stage.
    CameraRawSettings tint;
    tint.tint = -25;
    const CameraRawTables::Stages tinted = CameraRawTables::stages(tint);
    QVERIFY(tinted.before.size() == 1 && tinted.after.empty() && indexOf(tinted.before[0].table[0]) == 4 * 9 + 3);
}

void CameraRawTablesTests::neutralizeFindsTheGridsGrayest()
{
    // Python's own search over the same tables found these.
    const CameraRawSettings::Balance warm = CameraRawTables::neutralize(160 / 255.0, 140 / 255.0, 120 / 255.0).value();
    QVERIFY(warm.temperature == -19 && warm.tint == -7);
    const CameraRawSettings::Balance blue = CameraRawTables::neutralize(0.2, 0.45, 0.8).value();
    QVERIFY(blue.temperature == 100 && blue.tint == 25.5);
    const CameraRawSettings::Balance green = CameraRawTables::neutralize(0.3, 0.5, 0.25).value();
    QVERIFY(green.temperature == 5 && green.tint == 90.5);
    // White stays white anywhere: the first of the ties wins.
    const CameraRawSettings::Balance white = CameraRawTables::neutralize(1, 1, 1).value();
    QVERIFY(white.temperature == 0 && white.tint == 0);
    QVERIFY(!CameraRawTables::neutralize(0.5, 0.0001, 0.5));
    QVERIFY(CameraRawTables::neutralize(0.5, 0.00011, 0.5));
}

void CameraRawTablesTests::identitySlidersComposeNothing()
{
    const CameraRawTables::Stages none = CameraRawTables::stages(CameraRawSettings());
    QVERIFY(none.before.empty() && none.after.empty() && CameraRawTables::compose(none.before).empty());
    CameraRawSettings exposure;
    exposure.exposure = 0.5;
    const std::vector<float> composed = CameraRawTables::compose(CameraRawTables::stages(exposure).before);
    QCOMPARE(composed.size(), size_t(33) * 33 * 33 * 3);
    // The corners are its table's own black and white.
    QVERIFY(composed[0] == entry(92, 0)[0] / 255.0f && composed.back() == entry(92, 4912)[2] / 255.0f);
}

QTEST_GUILESS_MAIN(CameraRawTablesTests)
#include "CameraRawTablesTests.moc"