Quit settles a pending gradient, a pixel move and open dialogs; Dither › Scanlines (CRT) on all cores (13.17)

tests/DitherSheetTests.cpp

@@ -179,13 +179,13 @@ void DitherSheetTests::theControlsFollowTheStyle()
         dither.colors = DitherColors::twoColors;
     });
     QCOMPARE(shown.shown(), sorted(QStringList{"Style", "Pixel Size", "Density", "Contrast", "Colors", "Light on Dark", "Swatches"}));
-    // Style's menu: ten looks in four groups.
+    // Style's menu: eleven looks in four groups.
     QComboBox &style = shown.child<QComboBox>("ditherStyle");
     QStringList items;
     for (int index = 0; index < style.count(); ++index)
         items << (style.itemText(index).isEmpty() ? QStringLiteral("—") : style.itemText(index));
     QCOMPARE(items, (QStringList{"Atkinson (Classic Mac)", "Floyd–Steinberg", "—", "Bayer 2 × 2", "Bayer 4 × 4", "Bayer 8 × 8", "—", "Halftone Dots",
-                                 "Halftone Lines", "Halftone Diamonds", "—", "Mac Patterns", "ASCII"}));
+                                 "Halftone Lines", "Halftone Diamonds", "—", "Mac Patterns", "ASCII", "Scanlines (CRT)"}));
     QCOMPARE(style.currentText(), QString("Mac Patterns"));
     // Its quick preview never shows the busy line.
     QVERIFY(!shown.child<QProgressBar>("filterSpinner").isVisibleTo(shown.sheet.get()));

tests/DitherTests.cpp

@@ -67,11 +67,11 @@ void DitherTests::stylesKeepSwiftsNamesOrderAndGroups()
     for (const DitherStyle each : allDitherStyles)
         names << rawValue(each);
     QCOMPARE(names, (QStringList{"Atkinson (Classic Mac)", "Floyd–Steinberg", "Bayer 2 × 2", "Bayer 4 × 4", "Bayer 8 × 8", "Halftone Dots",
-                                 "Halftone Lines", "Halftone Diamonds", "Mac Patterns", "ASCII"}));
+                                 "Halftone Lines", "Halftone Diamonds", "Mac Patterns", "ASCII", "Scanlines (CRT)"}));
     QString groups;
     for (const DitherStyle each : allDitherStyles)
         groups += QString::number(ditherGroup(each));
-    QCOMPARE(groups, QString("0011122233"));
+    QCOMPARE(groups, QString("00111222333"));
     QVERIFY(diffuses(DitherStyle::floydSteinberg) && !diffuses(DitherStyle::bayer2));
     QVERIFY(hasTones(DitherStyle::bayer8) && !hasTones(DitherStyle::dots));
     QVERIFY(isHalftone(DitherStyle::diamonds) && !isHalftone(DitherStyle::patterns));

tests/QuitPendingEditsTests.cpp

@@ -0,0 +1,246 @@
+#include "DialogDesk.h"
+#include "Document/ProjectWorkspace.h"
+#include "SelectionFixtures.h"
+#include "UI/ProjectWorkspaceView.h"
+#include <QtTest>
+
+// Swift 1.4.4: quit applies canvas edits and cancels dialogs.
+namespace {
+ImportedImage filled(const QColor &colour)
+{
+    QImage pixels(100, 20, QImage::Format_RGBA8888_Premultiplied);
+    pixels.fill(colour);
+    return ImportedImage(pixels, pixels, QStringLiteral("Fixture"));
+}
+
+// Swift's await: true once the call's callback has run.
+bool awaited(const std::function<void(std::function<void()>)> &call)
+{
+    bool done = false;
+    call([&done] { done = true; });
+    return QTest::qWaitFor([&done] { return done; }, 10'000);
+}
+
+std::optional<bool> answer(ProjectWorkspace &workspace)
+{
+    std::optional<bool> result;
+    workspace.confirmQuit([&](bool value) { result = value; });
+    return QTest::qWaitFor([&] { return result.has_value(); }, 10'000) ? result : std::nullopt;
+}
+
+// Swift's test: a gradient waiting for Apply.
+void pendGradient(EditorSession &session)
+{
+    session.createDocument(100, 20);
+    session.addBlankLayer();
+    session.selectTool(NavigationTool::gradient);
+    session.beginGradient(QPointF(0, 10));
+    session.moveGradient(std::nullopt, QPointF(100, 10));
+    session.endGradientDrag();
+}
+
+ImageIdentity identity(const EditorSession &session)
+{
+    return session.activeLayer().value().asset.value().identity();
+}
+}
+
+class QuitPendingEditsTests : public QObject {
+    Q_OBJECT
+private slots:
+    void quittingAppliesAPendingGradient();
+    void quittingAppliesAPixelMove();
+    void quittingCancelsAnOpenDialog();
+    void quittingCancelsTheOtherDialogs();
+    void quittingCancelsAnAdjustmentsEditor();
+    void aWorkspaceGoneMidSettleCallsNothing();
+    void closingTheWindowAppliesTheGradientThenAsks();
+    void aBusyProjectHoldsTheQuit();
+    void aQuitWhileManagingIsRefusedAtOnce();
+};
+
+void QuitPendingEditsTests::quittingAppliesAPendingGradient()
+{
+    ProjectWorkspace workspace;
+    EditorSession &session = workspace.current().session;
+    pendGradient(session);
+    QVERIFY(!workspace.canSwitch());
+    const int count = session.history.undoCount();
+    QVERIFY(awaited([&](std::function<void()> done) { workspace.settlePendingEdits(std::move(done)); }));
+    QVERIFY(!session.gradientEdit());
+    QCOMPARE(session.history.undoCount(), count + 1);
+    QCOMPARE(session.history.undoName(), QString("Gradient"));
+    QVERIFY(workspace.canSwitch());
+}
+
+void QuitPendingEditsTests::quittingAppliesAPixelMove()
+{
+    ProjectWorkspace workspace;
+    EditorSession &session = workspace.current().session;
+    session.createDocument(100, 20);
+    session.insert(filled(QColor(200, 100, 50)));
+    session.applySelection(rectPath(QRectF(10, 5, 10, 10)), SelectionMode::replace, "Select");
+    QVERIFY(session.beginPixelMove());
+    session.movePixels(QSizeF(30, 0));
+    QVERIFY(!workspace.canSwitch());
+    const int count = session.history.undoCount();
+    QVERIFY(awaited([&](std::function<void()> done) { workspace.settlePendingEdits(std::move(done)); }));
+    QVERIFY(!session.pixelMove());
+    QCOMPARE(session.history.undoCount(), count + 1);
+    QCOMPARE(session.history.undoName(), QString("Move Pixels"));
+    QCOMPARE(session.selection().value().path.boundingRect(), QRectF(40, 5, 10, 10));
+    QVERIFY(workspace.canSwitch());
+}
+
+void QuitPendingEditsTests::quittingCancelsAnOpenDialog()
+{
+    ProjectWorkspace workspace;
+    EditorSession &session = workspace.current().session;
+    session.createDocument(100, 20);
+    session.insert(filled(QColor(200, 100, 50)));
+    const ImageIdentity original = identity(session);
+    const int count = session.history.undoCount();
+    const std::vector<std::function<void()>> opens{[&] { session.beginFilter(FilterKind::gaussianBlur); },
+                                                   [&] { session.beginHueSaturation(); }, [&] { session.beginLevels(); }};
+    for (const std::function<void()> &open : opens) {
+        open();
+        QVERIFY(!workspace.canSwitch());
+        QVERIFY(awaited([&](std::function<void()> done) { workspace.settlePendingEdits(std::move(done)); }));
+        QVERIFY(workspace.canSwitch());
+        QVERIFY(identity(session) == original);
+    }
+    QVERIFY(!session.filterEdit() && !session.hueSaturation() && !session.levels());
+    QCOMPARE(session.history.undoCount(), count);
+}
+
+void QuitPendingEditsTests::quittingCancelsTheOtherDialogs()
+{
+    ProjectWorkspace workspace;
+    EditorSession &session = workspace.current().session;
+    session.createDocument(100, 20);
+    session.insert(filled(QColor(200, 100, 50)));
+    const QPainterPath before = rectPath(QRectF(10, 5, 10, 10));
+    session.applySelection(before, SelectionMode::replace, "Select");
+    const PaletteColor foreground = session.foregroundColor();
+    const auto settle = [&] { return awaited([&](std::function<void()> done) { workspace.settlePendingEdits(std::move(done)); }); };
+    // Color Range: the selection goes back as it was.
+    session.beginColorRange();
+    QVERIFY(session.colorRange() && !workspace.canSwitch());
+    QVERIFY(settle());
+    QVERIFY(!session.colorRange());
+    QCOMPARE(session.selection().value().path.boundingRect(), before.boundingRect());
+    // Expand, Contract or Feather: its panel goes.
+    session.setSelectionAmountOperation(SelectionAmountOperation::feather);
+    QVERIFY(!workspace.canSwitch());
+    QVERIFY(settle());
+    QVERIFY(!session.selectionAmountOperation());
+    // The colour picker: closed, its colour not taken.
+    session.openColorPicker(false);
+    session.setColorPickerHSB(PickerHSB(120, 1, 1));
+    QVERIFY(!workspace.canSwitch());
+    QVERIFY(settle());
+    QVERIFY(!session.colorPicker());
+    QVERIFY(session.foregroundColor() == foreground);
+    QVERIFY(workspace.canSwitch());
+}
+
+void QuitPendingEditsTests::quittingCancelsAnAdjustmentsEditor()
+{
+    ProjectWorkspace workspace;
+    EditorSession &session = workspace.current().session;
+    session.createDocument(100, 20);
+    session.insert(filled(Qt::white));
+    session.addAdjustment(AdjustmentKind::exposure);
+    const QUuid id = session.adjustmentEditingID().value();
+    const LayerAdjustment made = session.activeLayer().value().adjustment.value();
+    QVERIFY(awaited([&](std::function<void()> done) { session.beginAdjustmentEditing(id, std::move(done)); }));
+    FilterSettings settings = session.filterEdit().value().settings;
+    settings.exposure.exposure = 2;
+    session.updateFilter(settings, true);
+    QVERIFY(!(session.activeLayer().value().adjustment.value() == made));
+    QVERIFY(!workspace.canSwitch());
+    QVERIFY(awaited([&](std::function<void()> done) { workspace.settlePendingEdits(std::move(done)); }));
+    QVERIFY(!session.adjustmentEditingID() && !session.adjustmentOriginal() && !session.filterEdit());
+    QVERIFY(session.activeLayer().value().adjustment.value() == made);
+    QVERIFY(workspace.canSwitch());
+}
+
+void QuitPendingEditsTests::aWorkspaceGoneMidSettleCallsNothing()
+{
+    auto workspace = std::make_unique<ProjectWorkspace>();
+    const std::shared_ptr<ProjectTab> tab = workspace->tabs().front();
+    pendGradient(tab->session);
+    bool called = false;
+    workspace->settlePendingEdits([&called] { called = true; });
+    workspace.reset();
+    // The tab lives on and its gradient lands; no answer.
+    QTRY_VERIFY(!tab->session.gradientEdit());
+    QTest::qWait(100);
+    QVERIFY(!called);
+    QCOMPARE(tab->session.history.undoName(), QString("Gradient"));
+}
+
+void QuitPendingEditsTests::closingTheWindowAppliesTheGradientThenAsks()
+{
+    ProjectWorkspace workspace;
+    ProjectWorkspaceView view(workspace);
+    view.show();
+    EditorSession &session = workspace.current().session;
+    pendGradient(session);
+    session.history.markSaved();
+    DialogDesk desk;
+    desk.replies = {"Cancel"};
+    // The gradient is a step by the time it asks.
+    desk.note = [&] { return QStringLiteral("pending=%1 step=%2").arg(session.gradientEdit().has_value()).arg(session.history.undoName()); };
+    view.close();
+    QTRY_COMPARE(desk.seen.size(), 1);
+    QVERIFY2(desk.seen[0].startsWith("alert|2|Save changes to Untitled?") && desk.seen[0].endsWith("|pending=0 step=Gradient"),
+             qPrintable(desk.seen[0]));
+    QTRY_VERIFY(!workspace.isManaging());
+    QVERIFY(view.isVisible());
+}
+
+void QuitPendingEditsTests::aBusyProjectHoldsTheQuit()
+{
+    ProjectWorkspace workspace;
+    EditorSession &session = workspace.current().session;
+    pendGradient(session);
+    session.setIsProjectBusy(true);
+    DialogDesk desk;
+    QTest::ignoreMessage(QtWarningMsg, "Quit refused: the project is still busy");
+    QCOMPARE(answer(workspace), std::optional(false));
+    // Nothing asked, nothing applied: the gradient waits.
+    QVERIFY(desk.seen.isEmpty());
+    QVERIFY(session.gradientEdit());
+    QVERIFY(!workspace.isManaging());
+    session.setIsProjectBusy(false);
+}
+
+void QuitPendingEditsTests::aQuitWhileManagingIsRefusedAtOnce()
+{
+    ProjectWorkspace workspace;
+    EditorSession &session = workspace.current().session;
+    session.createDocument(100, 20);
+    DialogDesk desk;
+    desk.replies = {"Cancel"};
+    std::optional<bool> second;
+    bool settled = false;
+    bool answered = false;
+    // While the first quit asks, a second is refused unasked.
+    desk.note = [&] {
+        session.setSelectionAmountOperation(SelectionAmountOperation::feather);
+        workspace.confirmQuit([&](bool value) { second = value; });
+        answered = QTest::qWaitFor([&] { return second.has_value(); }, 5000);
+        settled = !session.selectionAmountOperation();
+        session.setSelectionAmountOperation(std::nullopt);
+        return QString();
+    };
+    QCOMPARE(answer(workspace), std::optional(false));
+    QCOMPARE(desk.seen.size(), 1);
+    QVERIFY(answered);
+    QCOMPARE(second, std::optional(false));
+    QVERIFY(!settled);
+}
+
+QTEST_MAIN(QuitPendingEditsTests)
+#include "QuitPendingEditsTests.moc"

tests/ScanlinesTests.cpp

@@ -0,0 +1,377 @@
+#include "Document/BrushStroke.h"
+#include "Document/Dither.h"
+#include "Document/EditorSession.h"
+#include "Document/PixelAdjust.h"
+#include "UI/FilterSheet.h"
+#include <QCheckBox>
+#include <QLabel>
+#include <QLayout>
+#include <QLineEdit>
+#include <QPainter>
+#include <QSlider>
+#include <QtTest>
+#include <numeric>
+
+// Swift 1.4.4's Dither › Scanlines (CRT), on every core.
+namespace {
+QImage filled(int width, int height, QColor colour)
+{
+    QImage image = BrushRaster::context(width, height, false);
+    image.fill(colour);
+    return image;
+}
+
+DitherSettings scanlines(double spacing, double glow = 0)
+{
+    DitherSettings settings;
+    settings.style = DitherStyle::scanlines;
+    settings.lineSpacing = spacing;
+    settings.glow = glow;
+    return settings;
+}
+
+// One channel of one column, top to bottom.
+std::vector<int> column(const QImage &image, int x, int channel = 0)
+{
+    std::vector<int> values;
+    for (int y = 0; y < image.height(); ++y)
+        values.push_back(image.constScanLine(y)[x * 4 + channel]);
+    return values;
+}
+
+std::vector<int> row(const QImage &image, int y, int channel = 0)
+{
+    std::vector<int> values;
+    for (int x = 0; x < image.width(); ++x)
+        values.push_back(image.constScanLine(y)[x * 4 + channel]);
+    return values;
+}
+
+// Swift's test: one column of a flat gray's render.
+std::vector<int> gray(int level, double spacing, double glow = 0)
+{
+    return column(scanlines(spacing, glow).apply(filled(16, 32, QColor(level, level, level))), 5);
+}
+
+std::vector<int> repeated(const std::vector<int> &band, int times)
+{
+    std::vector<int> all;
+    for (int each = 0; each < times; ++each)
+        all.insert(all.end(), band.begin(), band.end());
+    return all;
+}
+
+struct Shown {
+    EditorSession session;
+    std::unique_ptr<FilterSheet> sheet;
+    Shown()
+    {
+        session.createDocument(40, 30);
+        const QImage image = filled(40, 30, QColor(200, 120, 40));
+        session.insert(ImportedImage(image, image, QStringLiteral("Colour")));
+        session.beginFilter(FilterKind::dither);
+        FilterSettings settings = session.filterEdit().value().settings;
+        settings.dither.style = DitherStyle::scanlines;
+        session.updateFilter(settings, true);
+        sheet = std::make_unique<FilterSheet>(session);
+        sheet->show();
+    }
+    const DitherSettings &dither() const { return session.filterEdit().value().settings.dither; }
+    // The shown rows in the column's order, with their help.
+    QStringList rows() const
+    {
+        QStringList titles;
+        QLayout *column = sheet->layout();
+        for (int index = 0; index < column->count(); ++index) {
+            QWidget *each = column->itemAt(index)->widget();
+            if (!each || each->isHidden())
+                continue;
+            if (auto *box = qobject_cast<QCheckBox *>(each); box && box->text() != QLatin1String("Preview"))
+                titles << box->text();
+            for (QLabel *label : each->findChildren<QLabel *>(QString(), Qt::FindDirectChildrenOnly)) {
+                if (label->buddy())
+                    titles << label->text() + u'|' + each->toolTip();
+            }
+        }
+        return titles;
+    }
+};
+}
+
+class ScanlinesTests : public QObject {
+    Q_OBJECT
+private slots:
+    void scanlinesAreLinesOfLightThatBloomWithBrightness();
+    void glowLightsBetweenTheLines();
+    void dotsBreakTheLinesIntoBeads();
+    void wobbleMovesLinesSideways();
+    void theStyleDrawsAtFullResolutionWithoutMarks();
+    void normalizingClampsTheFourSettings();
+    void eachLineIsTheAverageOfItsRows();
+    void theScreenIsTheDarkColourOrBlack();
+    void clearPixelsStayClear();
+    void everyBandOfATallImageIsDrawn();
+    void theGlowIsTheBlurredLightAtItsAmount();
+    void theGlowNeverPassesAlpha();
+    void theSheetShowsScanlinesRows();
+    void theRowsWriteTheirSettings();
+};
+
+void ScanlinesTests::scanlinesAreLinesOfLightThatBloomWithBrightness()
+{
+    const std::vector<int> white = gray(255, 8), dim = gray(89, 8), black = gray(0, 8);
+    for (int band = 0; band < 4; ++band) {
+        const std::vector<int> rows(white.begin() + band * 8, white.begin() + band * 8 + 8);
+        QVERIFY(rows[3] == 255 && rows[4] == 255);
+        QVERIFY(std::any_of(rows.begin(), rows.end(), [](int value) { return value < 40; }));
+    }
+    QVERIFY(std::accumulate(dim.begin(), dim.end(), 0) * 2 < std::accumulate(white.begin(), white.end(), 0));
+    QVERIFY(std::all_of(black.begin(), black.end(), [](int value) { return value == 0; }));
+    // The beam's half height, 2.8 white, about 1.98 at 0.35.
+    QCOMPARE(white, repeated({0, 255, 255, 255, 255, 255, 255, 0}, 4));
+    QCOMPARE(dim, repeated({0, 0, 118, 120, 120, 118, 0, 0}, 4));
+}
+
+void ScanlinesTests::glowLightsBetweenTheLines()
+{
+    const std::vector<int> plain = gray(255, 8), glowing = gray(255, 8, 100);
+    QVERIFY2(glowing[0] > plain[0] + 40, qPrintable(QString::number(glowing[0])));
+}
+
+void ScanlinesTests::dotsBreakTheLinesIntoBeads()
+{
+    const QImage white = filled(64, 16, Qt::white);
+    DitherSettings settings = scanlines(8);
+    QCOMPARE(row(settings.apply(white), 4), std::vector<int>(64, 255));
+    settings.dots = 100;
+    // Each bead lit at its middle, dark at its ends.
+    const std::vector<int> lit = row(settings.apply(white), 4);
+    QCOMPARE(std::vector<int>(lit.begin(), lit.begin() + 8), (std::vector<int>{0, 255, 255, 255, 255, 255, 255, 0}));
+    QCOMPARE(std::vector<int>(lit.begin() + 8, lit.begin() + 16), (std::vector<int>{0, 255, 255, 255, 255, 255, 255, 0}));
+    // Half dots: the bead ends dim off the middle.
+    settings.dots = 50;
+    QCOMPARE(row(settings.apply(white), 1)[0], 85);
+}
+
+void ScanlinesTests::wobbleMovesLinesSideways()
+{
+    QImage edge = filled(64, 64, Qt::black);
+    QPainter(&edge).fillRect(QRect(32, 0, 32, 64), Qt::white);
+    const auto edges = [&edge](double wobble) {
+        DitherSettings settings = scanlines(8);
+        settings.wobble = wobble;
+        const QImage result = settings.apply(edge);
+        std::vector<int> found;
+        for (int line = 0; line < 8; ++line) {
+            const std::vector<int> middle = row(result, line * 8 + 4);
+            found.push_back(int(std::find_if(middle.begin(), middle.end(), [](int value) { return value > 128; }) - middle.begin()));
+        }
+        return found;
+    };
+    QCOMPARE(edges(0), std::vector<int>(8, 32));
+    // Each line's shift: 12 times the two waves, rounded.
+    QCOMPARE(edges(12), (std::vector<int>{35, 36, 35, 41, 44, 37, 32, 34}));
+}
+
+void ScanlinesTests::theStyleDrawsAtFullResolutionWithoutMarks()
+{
+    QVERIFY(!usesPixelSize(DitherStyle::scanlines) && !usesPixelSize(DitherStyle::ascii) && usesPixelSize(DitherStyle::patterns));
+    QVERIFY(!drawsMarks(DitherStyle::scanlines) && drawsMarks(DitherStyle::ascii));
+    QVERIFY(!hasTones(DitherStyle::scanlines) && !isHalftone(DitherStyle::scanlines) && ditherGroup(DitherStyle::scanlines) == 3);
+    // A pixel size changes nothing: no chunks, no dots.
+    const QImage image = filled(20, 24, QColor(180, 90, 30));
+    DitherSettings settings = scanlines(4);
+    const QImage plain = settings.apply(image);
+    settings.pixelSize = 5;
+    settings.pixelShape = DitherPixelShape::dot;
+    QCOMPARE(settings.apply(image), plain);
+    // The cell is the line spacing, not the cell size.
+    settings.cellSize = 32;
+    QCOMPARE(settings.apply(image), plain);
+}
+
+void ScanlinesTests::normalizingClampsTheFourSettings()
+{
+    DitherSettings settings;
+    QCOMPARE(settings.lineSpacing, 4.0);
+    QCOMPARE(settings.glow, 35.0);
+    QCOMPARE(settings.dots, 0.0);
+    QCOMPARE(settings.wobble, 0.0);
+    settings.lineSpacing = 1.4;
+    settings.glow = 150;
+    settings.dots = -5;
+    settings.wobble = 3.5;
+    DitherSettings result = settings.normalized();
+    QCOMPARE(result.lineSpacing, 2.0);
+    QCOMPARE(result.glow, 100.0);
+    QCOMPARE(result.dots, 0.0);
+    QCOMPARE(result.wobble, 3.5);
+    settings.lineSpacing = 40;
+    settings.glow = -1;
+    settings.dots = 120;
+    settings.wobble = 70;
+    result = settings.normalized();
+    QCOMPARE(result.lineSpacing, 32.0);
+    QCOMPARE(result.glow, 0.0);
+    QCOMPARE(result.dots, 100.0);
+    QCOMPARE(result.wobble, 64.0);
+    // Rounded within; not a number takes the default.
+    settings.lineSpacing = 5.5;
+    settings.glow = std::nan("");
+    settings.dots = std::nan("");
+    settings.wobble = std::nan("");
+    result = settings.normalized();
+    QCOMPARE(result.lineSpacing, 6.0);
+    QCOMPARE(result.glow, 35.0);
+    QCOMPARE(result.dots, 0.0);
+    QCOMPARE(result.wobble, 0.0);
+    settings.lineSpacing = std::nan("");
+    QCOMPARE(settings.normalized().lineSpacing, 4.0);
+    // Glow and dots keep their fractions.
+    settings.glow = 12.5;
+    settings.dots = 33.3;
+    QCOMPARE(settings.normalized().glow, 12.5);
+    QCOMPARE(settings.normalized().dots, 33.3);
+}
+
+void ScanlinesTests::eachLineIsTheAverageOfItsRows()
+{
+    // Rows of white and black: each line lights at half.
+    QImage stripes = filled(8, 16, Qt::black);
+    for (int y = 0; y < 16; y += 2)
+        QPainter(&stripes).fillRect(QRect(0, y, 8, 1), Qt::white);
+    QCOMPARE(column(scanlines(8).apply(stripes), 3), repeated({0, 37, 172, 172, 172, 172, 37, 0}, 2));
+}
+
+void ScanlinesTests::theScreenIsTheDarkColourOrBlack()
+{
+    const QImage image = filled(8, 8, QColor(255, 128, 0));
+    DitherSettings settings = scanlines(8);
+    settings.colors = DitherColors::twoColors;
+    settings.dark = AdjustmentColor(0, 0, 1);
+    settings.light = AdjustmentColor(1, 1, 0);
+    const QImage two = settings.apply(image);
+    // Off the line the dark colour; on it, the mix.
+    QCOMPARE(two.pixelColor(2, 0), QColor(0, 0, 255));
+    QCOMPARE(two.pixelColor(2, 4), QColor(197, 197, 147));
+    settings.colors = DitherColors::original;
+    const QImage original = settings.apply(image);
+    QCOMPARE(original.pixelColor(2, 0), QColor(0, 0, 0));
+    QCOMPARE(original.pixelColor(2, 4), QColor(255, 173, 0));
+}
+
+void ScanlinesTests::clearPixelsStayClear()
+{
+    QImage image = filled(8, 16, Qt::white);
+    QPainter painter(&image);
+    painter.setCompositionMode(QPainter::CompositionMode_Source);
+    painter.fillRect(QRect(0, 0, 8, 8), Qt::transparent);
+    painter.end();
+    const QImage result = scanlines(8, 100).apply(image);
+    QCOMPARE(column(result, 2, 3), (std::vector<int>{0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 255, 255, 255, 255, 255, 255}));
+    QCOMPARE(column(result, 2, 0)[4], 0);
+}
+
+void ScanlinesTests::everyBandOfATallImageIsDrawn()
+{
+    // 150 two-row lines: 32 bands of 5, two empty.
+    const QImage image = filled(3, 300, Qt::white);
+    QCOMPARE(column(scanlines(2).apply(image), 1), repeated({241, 241}, 150));
+    // 70 lines of 8: bands of 3, the last one.
+    const std::vector<int> tall = column(scanlines(8).apply(filled(3, 560, Qt::white)), 1);
+    QCOMPARE(tall, repeated({0, 255, 255, 255, 255, 255, 255, 0}, 70));
+}
+
+void ScanlinesTests::theGlowIsTheBlurredLightAtItsAmount()
+{
+    QImage image = filled(64, 160, Qt::black);
+    QPainter(&image).fillRect(QRect(0, 0, 32, 40), Qt::white);
+    const QImage lines = scanlines(8).apply(image);
+    // Swift's first glow: the lines blurred whole, sigma 27.
+    const QImage blurred = PixelAdjust::gaussianBlur(lines, 8 * 3 + 3, true);
+    for (const double glow : {20.0, 100.0}) {
+        const QImage result = scanlines(8, glow).apply(image);
+        const float amount = float(glow / 100 * 2.5);
+        int worst = 0;
+        for (int y = 0; y < 160; ++y) {
+            for (int x = 0; x < 64; ++x) {
+                const int plain = lines.constScanLine(y)[x * 4], light = blurred.constScanLine(y)[x * 4];
+                const int expected = int(std::lround(std::min(255.0f, float(plain) + float(light) * amount)));
+                worst = std::max(worst, std::abs(result.constScanLine(y)[x * 4] - expected));
+            }
+        }
+        // Three levels of the shrink's blur, times 2.5.
+        QVERIFY2(worst <= 8, qPrintable(QString::number(worst)));
+    }
+    // Below the light, at amount 0.5, it fades.
+    const std::vector<int> fading = column(scanlines(8, 20).apply(image), 16);
+    QVERIFY(fading[48] > 20 && fading[48] < fading[40] && fading[120] < 3);
+}
+
+void ScanlinesTests::theGlowNeverPassesAlpha()
+{
+    QImage image = BrushRaster::context(16, 32, false);
+    image.fill(QColor(255, 255, 255, 128));
+    const QImage result = scanlines(4, 100).apply(image);
+    for (int y = 0; y < 32; ++y) {
+        for (int x = 0; x < 16; ++x) {
+            const uchar *at = result.constScanLine(y) + x * 4;
+            QCOMPARE(int(at[3]), 128);
+            QVERIFY(at[0] <= 128 && at[1] <= 128 && at[2] <= 128);
+        }
+    }
+    QCOMPARE(int(result.constScanLine(0)[0]), 128);
+}
+
+void ScanlinesTests::theSheetShowsScanlinesRows()
+{
+    Shown shown;
+    QCOMPARE(shown.rows(), (QStringList{"Style|", "Line Spacing|How far apart the screen's lines are",
+                                        "Glow|Light blooming around the lines, like a CRT's phosphors", "Dots|Break the lines into glowing beads",
+                                        "Wobble|Make the lines waver sideways down the screen, like a CRT losing sync",
+                                        "Density|More ink (darker) or less before dithering", "Contrast|", "Colors|"}));
+    // Each slider's travel reaches its range's ends.
+    const std::tuple<const char *, double DitherSettings::*, double, double> sliders[] = {
+        {"lineSpacingSlider", &DitherSettings::lineSpacing, 2, 32}, {"glowSlider", &DitherSettings::glow, 0, 100},
+        {"dotsSlider", &DitherSettings::dots, 0, 100},               {"wobbleSlider", &DitherSettings::wobble, 0, 64}};
+    for (const auto &[name, setting, low, high] : sliders) {
+        QSlider *slider = shown.sheet->findChild<QSlider *>(QString::fromLatin1(name));
+        QVERIFY2(slider, name);
+        slider->setValue(slider->maximum());
+        QCOMPARE(shown.dither().*setting, high);
+        slider->setValue(slider->minimum());
+        QCOMPARE(shown.dither().*setting, low);
+    }
+    // Pixel Size and Pixel Shape stay away under Scanlines.
+    FilterSettings settings = shown.session.filterEdit().value().settings;
+    settings.dither.pixelSize = 4;
+    shown.session.updateFilter(settings, true);
+    QVERIFY(!shown.rows().join(',').contains("Pixel"));
+    settings.dither.style = DitherStyle::bayer4;
+    shown.session.updateFilter(settings, true);
+    QVERIFY(shown.rows().contains("Pixel Shape|Draw each chunky pixel as a solid square, or as a round dot like a dot-matrix screen"));
+    QVERIFY(!shown.rows().join(',').contains("Glow"));
+}
+
+void ScanlinesTests::theRowsWriteTheirSettings()
+{
+    Shown shown;
+    const std::tuple<const char *, double DitherSettings::*, const char *, double> rows[] = {
+        {"lineSpacingField", &DitherSettings::lineSpacing, "12", 12}, {"glowField", &DitherSettings::glow, "60", 60},
+        {"dotsField", &DitherSettings::dots, "25", 25},               {"wobbleField", &DitherSettings::wobble, "9", 9}};
+    for (const auto &[name, setting, typed, expected] : rows) {
+        const DitherSettings before = shown.dither();
+        QLineEdit *field = shown.sheet->findChild<QLineEdit *>(QString::fromLatin1(name));
+        QVERIFY2(field, name);
+        field->setFocus();
+        field->selectAll();
+        QTest::keyClicks(field, QString::fromLatin1(typed));
+        QTest::keyClick(field, Qt::Key_Return);
+        DitherSettings wanted = before;
+        wanted.*setting = expected;
+        QVERIFY2(shown.dither() == wanted, name);
+    }
+}
+
+QTEST_MAIN(ScanlinesTests)
+#include "ScanlinesTests.moc"

tests/Tests.cmake

@@ -166,6 +166,8 @@ compositor_test(ProjectReceiveTests)
 compositor_test(ProjectReplaceTests)
 compositor_test(ProjectWorkspaceFlowTests)
 compositor_test(QuitWhileEditingTextTests)
+compositor_test(QuitPendingEditsTests)
+compositor_test(ScanlinesTests)
 compositor_test(OpenRecentTests)
 compositor_test(ColoredSliderTests)
 compositor_test(SheetTeardownTests)