Import simple Photoshop text as editable text (12.11b2)

src/IO/PSD/PSDDocumentBuilder.cpp

@@ -8,11 +8,30 @@ ImportedImage imported(const QImage &image, const QString &name)
     return ImportedImage(image, PixelAdjust::thumbnail(image), name);
 }
 
-std::vector<QString> notes(const PSDRecord &record)
+// Swift's `try?`: text that cannot be drawn stays pixels.
+std::optional<PSDText::Rendered> rendered(const PSDRecord &record)
+{
+    if (!record.text)
+        return std::nullopt;
+    try {
+        return PSDText::render(*record.text);
+    } catch (const std::runtime_error &) {
+        return std::nullopt;
+    }
+}
+
+std::vector<QString> notes(const PSDRecord &record, bool typed)
 {
     std::vector<QString> result;
-    if (record.kind == PSDLayerKind::text)
-        result.push_back(QStringLiteral("Editable Photoshop text becomes pixels and can’t be retyped."));
+    if (record.kind == PSDLayerKind::text) {
+        if (typed) {
+            result.insert(result.end(), record.text->notes.begin(), record.text->notes.end());
+            if (const std::optional<QString> missing = PSDText::missingFontNote(record.text->style.fontName))
+                result.push_back(*missing);
+        } else {
+            result.push_back(PSDText::rasterizedNote);
+        }
+    }
     if (record.kind == PSDLayerKind::smartObject)
         result.push_back(QStringLiteral("The smart object was rasterized. Linked contents can’t be edited."));
     if (record.kind == PSDLayerKind::effects)
@@ -41,10 +60,14 @@ std::vector<QString> notes(const PSDRecord &record)
     return result;
 }
 
-ImageLayer layerFor(const PSDRecord &record, QSizeF canvas, const std::map<QUuid, ImportedImage> &assets)
+ImageLayer layerFor(const PSDRecord &record, QSizeF canvas, const std::map<QUuid, ImportedImage> &assets, const std::optional<PSDText::Rendered> &typed)
 {
     ImageLayer layer(record.name, canvas);
-    if (record.image && !record.isGroup && !record.adjustment) {
+    if (typed && !record.adjustment) {
+        layer = ImageLayer(imported(typed->image, record.name), QPointF());
+        layer.transform = typed->transform;
+        layer.text = LayerText{record.text->style, layer.asset->identity()};
+    } else if (record.image && !record.isGroup && !record.adjustment) {
         const ImportedImage asset = assets.contains(record.id) ? assets.at(record.id) : imported(*record.image, record.name);
         const QSizeF size = record.bounds.width() > 0 && record.bounds.height() > 0 ? record.bounds.size() : QSizeF(record.image->size());
         layer = ImageLayer(asset, record.bounds.topLeft());
@@ -83,11 +106,12 @@ PSDImport PSDDocumentBuilder::makeImport(const PSDDocument &document, const std:
         if (record.croppedToCanvas)
             conversions.push_back(PSDConversion{.layerName = record.name,
                                                 .message = QStringLiteral("Cropped to the canvas so the file fits in memory. Pixels outside the canvas weren't imported.")});
-        for (const QString &note : notes(record))
+        const std::optional<PSDText::Rendered> typed = rendered(record);
+        for (const QString &note : notes(record, typed.has_value()))
             conversions.push_back(PSDConversion{.layerName = record.name, .message = note});
         if (record.kind == PSDLayerKind::adjustment && !record.adjustment)
             continue;
-        ImageLayer layer = layerFor(record, canvas, assets);
+        ImageLayer layer = layerFor(record, canvas, assets, typed);
         if (record.mask) {
             try {
                 layer.mask = LayerMask(LayerMask::assetFrom(*record.mask), record.maskEnabled, std::nullopt, record.maskLinked);

src/IO/PSD/PSDReader.cpp

@@ -61,7 +61,9 @@ std::vector<PSDRecord> assemble(const std::vector<RawLayer> &raw, QSizeF canvas,
         record.opacity = hasEffects && layer.fill != 255 ? layer.opacity / 255.0 : (layer.opacity / 255.0) * (layer.fill / 255.0);
         record.bounds = isGroup ? QRectF(QPointF(0, 0), canvas) : QRectF(layer.left, layer.top, std::max<qint64>(0, layer.right - layer.left), std::max<qint64>(0, layer.bottom - layer.top));
         record.image = isGroup ? std::nullopt : layer.image;
-        std::optional<PSDVector::Live> live = isGroup ? std::nullopt : PSDVector::live(layer.extra, canvas, remaining);
+        if (record.kind == PSDLayerKind::text)
+            record.text = PSDText::parse(layer.extra);
+        std::optional<PSDVector::Live> live = isGroup || record.text ? std::nullopt : PSDVector::live(layer.extra, canvas, remaining);
         if (live) {
             record.image = live->image;
             record.bounds = live->bounds;
@@ -69,7 +71,7 @@ std::vector<PSDRecord> assemble(const std::vector<RawLayer> &raw, QSizeF canvas,
             record.shapeNotes = live->notes;
             record.kind = PSDLayerKind::vector;
             remaining = std::max<qint64>(0, remaining - qint64(live->image.width()) * live->image.height());
-        } else if (!record.image && !isGroup) {
+        } else if (!record.text && !record.image && !isGroup) {
             if (const std::optional<PSDVector::Raster> raster = PSDVector::raster(layer.extra, canvas, remaining)) {
                 record.image = raster->image;
                 record.bounds = raster->bounds;

src/IO/PSD/PSDText+Descriptor.cpp

@@ -0,0 +1,264 @@
+#include "IO/PSD/PSDText+Descriptor.h"
+#include <QStringDecoder>
+#include <QtEndian>
+#include <bit>
+#include <cmath>
+
+namespace PSDDescriptor {
+namespace {
+// Nesting past this reads as broken, where Swift's stack overflows.
+constexpr int maxDepth = 512;
+
+// Swift's ASCII decoding: a high byte fails.
+std::optional<QString> ascii(const QByteArray &raw)
+{
+    for (const char byte : raw)
+        if (uchar(byte) >= 0x80)
+            return std::nullopt;
+    return QString::fromLatin1(raw);
+}
+
+template <typename T>
+const T *find(const Items &items, const QString &key)
+{
+    return items.contains(key) ? std::get_if<T>(&items.at(key).value) : nullptr;
+}
+
+// Swift's `??`: the key present decides, then its type.
+std::optional<double> side(const Items &items, const QString &name)
+{
+    const double *found = find<double>(items, items.contains(name) ? name : name.trimmed());
+    return found ? std::optional(*found) : std::nullopt;
+}
+}
+
+std::optional<QString> string(const Items &items, const QString &key)
+{
+    const QString *found = find<QString>(items, key);
+    return found ? std::optional(*found) : std::nullopt;
+}
+
+std::optional<QString> enumeration(const Items &items, const QString &key)
+{
+    const Enumeration *found = find<Enumeration>(items, key);
+    return found ? std::optional(found->name) : std::nullopt;
+}
+
+std::optional<QByteArray> data(const Items &items, const QString &key)
+{
+    const QByteArray *found = find<QByteArray>(items, key);
+    return found ? std::optional(*found) : std::nullopt;
+}
+
+QString utf16(const QByteArray &raw)
+{
+    QString text = QStringDecoder(QStringConverter::Utf16BE, QStringConverter::Flag::ConvertInitialBom).decode(raw);
+    for (qsizetype index = 0; index < text.size(); ++index) {
+        if (text[index].isHighSurrogate() && index + 1 < text.size() && text[index + 1].isLowSurrogate())
+            ++index;
+        else if (text[index].isSurrogate())
+            text[index] = QChar::ReplacementCharacter;
+    }
+    return text;
+}
+
+std::optional<QRectF> rect(const Items &items, const QString &key)
+{
+    const Items *box = find<Items>(items, key);
+    if (!box)
+        return std::nullopt;
+    const std::optional<double> left = side(*box, QStringLiteral("Left")), top = side(*box, QStringLiteral("Top ")),
+                                right = side(*box, QStringLiteral("Rght")), bottom = side(*box, QStringLiteral("Btom"));
+    if (!left || !top || !right || !bottom)
+        return std::nullopt;
+    if (!std::isfinite(*left) || !std::isfinite(*top) || !std::isfinite(*right) || !std::isfinite(*bottom))
+        return std::nullopt;
+    return QRectF(QPointF(*left, *top), QPointF(*right, *bottom)).normalized();
+}
+
+std::optional<Items> Reader::descriptor(bool versioned)
+{
+    if (versioned && u32() != 16u)
+        return std::nullopt;
+    if (!unicode() || !identifier())
+        return std::nullopt;
+    const std::optional<quint32> count = u32();
+    if (!count || *count > 10'000)
+        return std::nullopt;
+    Items result;
+    for (quint32 index = 0; index < *count; ++index) {
+        const std::optional<QString> key = identifier();
+        const std::optional<QString> type = key ? fourCC() : std::nullopt;
+        std::optional<Value> item = type ? value(*type) : std::nullopt;
+        if (!item)
+            return std::nullopt;
+        result.insert_or_assign(*key, std::move(*item));
+    }
+    return result;
+}
+
+std::optional<Value> Reader::value(const QString &type)
+{
+    if (depth >= maxDepth)
+        return std::nullopt;
+    ++depth;
+    std::optional<Value> result = read(type);
+    --depth;
+    return result;
+}
+
+std::optional<Value> Reader::read(const QString &type)
+{
+    if (type == QLatin1String("doub")) {
+        const std::optional<double> number = f64();
+        return number ? std::optional(Value{*number}) : std::nullopt;
+    }
+    if (type == QLatin1String("UntF")) {
+        const std::optional<double> number = fourCC() ? f64() : std::nullopt;
+        return number ? std::optional(Value{*number}) : std::nullopt;
+    }
+    if (type == QLatin1String("long")) {
+        const std::optional<qint32> number = i32();
+        return number ? std::optional(Value{double(*number)}) : std::nullopt;
+    }
+    if (type == QLatin1String("comp")) {
+        const std::optional<QByteArray> raw = bytes(8);
+        return raw ? std::optional(Value{double(qFromBigEndian<qint64>(raw->constData()))}) : std::nullopt;
+    }
+    if (type == QLatin1String("bool"))
+        return u8() ? std::optional(Value{0.0}) : std::nullopt;
+    if (type == QLatin1String("TEXT")) {
+        const std::optional<QString> text = unicode();
+        return text ? std::optional(Value{*text}) : std::nullopt;
+    }
+    if (type == QLatin1String("enum")) {
+        const std::optional<QString> name = identifier() ? identifier() : std::nullopt;
+        return name ? std::optional(Value{Enumeration{*name}}) : std::nullopt;
+    }
+    if (type == QLatin1String("tdta")) {
+        const std::optional<quint32> length = u32();
+        const std::optional<QByteArray> raw = length && *length <= 8'000'000 ? bytes(*length) : std::nullopt;
+        return raw ? std::optional(Value{*raw}) : std::nullopt;
+    }
+    if (type == QLatin1String("Objc") || type == QLatin1String("GlbO")) {
+        std::optional<Items> nested = descriptor(false);
+        return nested ? std::optional(Value{std::move(*nested)}) : std::nullopt;
+    }
+    if (type == QLatin1String("VlLs")) {
+        const std::optional<quint32> count = u32();
+        if (!count || *count > 10'000)
+            return std::nullopt;
+        std::vector<Value> list;
+        for (quint32 index = 0; index < *count; ++index) {
+            const std::optional<QString> itemType = fourCC();
+            std::optional<Value> item = itemType ? value(*itemType) : std::nullopt;
+            if (!item)
+                return std::nullopt;
+            list.push_back(std::move(*item));
+        }
+        return Value{std::move(list)};
+    }
+    if (type == QLatin1String("alis")) {
+        const std::optional<quint32> length = u32();
+        return length && *length <= 8'000'000 && bytes(*length) ? std::optional(Value{0.0}) : std::nullopt;
+    }
+    if (type == QLatin1String("obj "))
+        return reference() ? std::optional(Value{0.0}) : std::nullopt;
+    if (type == QLatin1String("type") || type == QLatin1String("GlbC"))
+        return unicode() && identifier() ? std::optional(Value{0.0}) : std::nullopt;
+    return std::nullopt;
+}
+
+bool Reader::reference()
+{
+    const std::optional<quint32> count = u32();
+    if (!count || *count > 10'000)
+        return false;
+    for (quint32 index = 0; index < *count; ++index) {
+        const std::optional<QString> form = fourCC();
+        if (!form)
+            return false;
+        bool read = false;
+        if (*form == QLatin1String("prop"))
+            read = unicode() && identifier() && identifier();
+        else if (*form == QLatin1String("Clss"))
+            read = unicode() && identifier();
+        else if (*form == QLatin1String("Enmr"))
+            read = unicode() && identifier() && identifier() && identifier();
+        else if (*form == QLatin1String("rele"))
+            read = unicode() && identifier() && i32();
+        else if (*form == QLatin1String("Idnt") || *form == QLatin1String("indx"))
+            read = bool(i32());
+        else if (*form == QLatin1String("name"))
+            read = bool(unicode());
+        if (!read)
+            return false;
+    }
+    return true;
+}
+
+std::optional<QString> Reader::unicode()
+{
+    const std::optional<quint32> count = u32();
+    const std::optional<QByteArray> raw = count && *count <= 1'000'000 ? bytes(qint64(*count) * 2) : std::nullopt;
+    if (!raw)
+        return std::nullopt;
+    return utf16(*raw);
+}
+
+std::optional<QString> Reader::identifier()
+{
+    const std::optional<quint32> length = u32();
+    if (!length)
+        return std::nullopt;
+    if (*length == 0)
+        return fourCC();
+    const std::optional<QByteArray> raw = *length <= 10'000 ? bytes(*length) : std::nullopt;
+    return raw ? ascii(*raw) : std::nullopt;
+}
+
+std::optional<QString> Reader::fourCC()
+{
+    const std::optional<QByteArray> raw = bytes(4);
+    return raw ? ascii(*raw) : std::nullopt;
+}
+
+std::optional<QByteArray> Reader::bytes(qint64 count)
+{
+    if (count < 0 || count > remaining())
+        return std::nullopt;
+    const QByteArray slice = data.mid(offset, count);
+    offset += count;
+    return slice;
+}
+
+std::optional<uchar> Reader::u8()
+{
+    const std::optional<QByteArray> raw = bytes(1);
+    return raw ? std::optional(uchar(raw->at(0))) : std::nullopt;
+}
+
+std::optional<quint16> Reader::u16()
+{
+    const std::optional<QByteArray> raw = bytes(2);
+    return raw ? std::optional(qFromBigEndian<quint16>(raw->constData())) : std::nullopt;
+}
+
+std::optional<quint32> Reader::u32()
+{
+    const std::optional<QByteArray> raw = bytes(4);
+    return raw ? std::optional(qFromBigEndian<quint32>(raw->constData())) : std::nullopt;
+}
+
+std::optional<qint32> Reader::i32()
+{
+    const std::optional<quint32> value = u32();
+    return value ? std::optional(qint32(*value)) : std::nullopt;
+}
+
+std::optional<double> Reader::f64()
+{
+    const std::optional<QByteArray> raw = bytes(8);
+    return raw ? std::optional(std::bit_cast<double>(qFromBigEndian<quint64>(raw->constData()))) : std::nullopt;
+}
+}

src/IO/PSD/PSDText+Descriptor.h

@@ -0,0 +1,53 @@
+#pragma once
+#include <QByteArray>
+#include <QRectF>
+#include <QString>
+#include <map>
+#include <optional>
+#include <variant>
+#include <vector>
+
+// Adobe's action descriptors, as far as a type layer needs.
+namespace PSDDescriptor {
+struct Value;
+using Items = std::map<QString, Value>;
+
+struct Enumeration {
+    QString name;
+};
+
+struct Value {
+    std::variant<QString, double, Enumeration, QByteArray, Items, std::vector<Value>> value;
+};
+
+std::optional<QString> string(const Items &items, const QString &key);
+std::optional<QString> enumeration(const Items &items, const QString &key);
+std::optional<QByteArray> data(const Items &items, const QString &key);
+// Standardised, as CGRect's reads are.
+std::optional<QRectF> rect(const Items &items, const QString &key);
+// Big-endian UTF-16, a lone surrogate read as U+FFFD.
+QString utf16(const QByteArray &raw);
+
+// Big-endian reads over a block; each fails past its end.
+struct Reader {
+    const QByteArray &data;
+    qsizetype offset = 0;
+    int depth = 0;
+    qsizetype remaining() const { return data.size() - offset; }
+    std::optional<Items> descriptor(bool versioned);
+    std::optional<QByteArray> bytes(qint64 count);
+    std::optional<uchar> u8();
+    std::optional<quint16> u16();
+    std::optional<quint32> u32();
+    std::optional<qint32> i32();
+    std::optional<double> f64();
+
+private:
+    std::optional<Value> value(const QString &type);
+    std::optional<Value> read(const QString &type);
+    bool reference();
+    std::optional<QString> unicode();
+    std::optional<QString> identifier();
+    std::optional<QString> fourCC();
+};
+}

src/IO/PSD/PSDText+Engine.cpp

@@ -0,0 +1,323 @@
+#include "IO/PSD/PSDText+Engine.h"
+#include "IO/PSD/PSDText+Descriptor.h"
+#include <clocale>
+#include <cstdlib>
+#include <locale.h>
+
+namespace PSDTextEngine {
+namespace {
+// Nesting past this reads as broken, where Swift's stack overflows.
+constexpr int maxDepth = 512;
+
+bool isDelimiter(uchar byte)
+{
+    return byte <= 0x20 || byte == '/' || byte == '<' || byte == '>' || byte == '[' || byte == ']' || byte == '(' || byte == ')';
+}
+
+bool isDigit(uchar byte)
+{
+    return byte >= '0' && byte <= '9';
+}
+
+std::optional<uchar> hex(uchar byte)
+{
+    if (isDigit(byte))
+        return uchar(byte - '0');
+    if (byte >= 'a' && byte <= 'f')
+        return uchar(byte - 'a' + 10);
+    if (byte >= 'A' && byte <= 'F')
+        return uchar(byte - 'A' + 10);
+    return std::nullopt;
+}
+
+// Swift's `Double(text)`: whole text, C numbers, overflow infinite.
+std::optional<double> toDouble(const QByteArray &text)
+{
+    static const locale_t c = newlocale(LC_ALL_MASK, "C", locale_t(nullptr));
+    char *end = nullptr;
+    const double value = strtod_l(text.constData(), &end, c);
+    if (end != text.constData() + text.size())
+        return std::nullopt;
+    return value;
+}
+
+QString decoded(const QByteArray &raw)
+{
+    if (raw.size() >= 2 && uchar(raw[0]) == 0xFE && uchar(raw[1]) == 0xFF) {
+        // Foundation reads no odd count of UTF-16 bytes.
+        if (raw.size() % 2 == 1)
+            return QString();
+        return PSDDescriptor::utf16(raw.mid(2));
+    }
+    return QString::fromLatin1(raw);
+}
+
+struct Cursor {
+    const QByteArray &bytes;
+    qsizetype index = 0;
+    int depth = 0;
+
+    std::optional<uchar> peek(qsizetype ahead = 0) const
+    {
+        const qsizetype at = index + ahead;
+        return at < bytes.size() ? std::optional(uchar(bytes[at])) : std::nullopt;
+    }
+
+    bool take(const char *token)
+    {
+        const QByteArray encoded(token);
+        if (bytes.mid(index, encoded.size()) != encoded)
+            return false;
+        index += encoded.size();
+        return true;
+    }
+
+    bool takeWord(const char *word)
+    {
+        const QByteArray encoded(word);
+        if (bytes.mid(index, encoded.size()) != encoded)
+            return false;
+        const qsizetype after = index + encoded.size();
+        if (after < bytes.size() && !isDelimiter(uchar(bytes[after])))
+            return false;
+        index = after;
+        return true;
+    }
+
+    void skipWhitespace()
+    {
+        while (peek() && (*peek() <= 0x20 || *peek() == '%')) {
+            if (*peek() == '%') {
+                while (peek() && *peek() != '\n' && *peek() != '\r')
+                    ++index;
+            } else {
+                ++index;
+            }
+        }
+    }
+
+    // Swift's ASCII decoding: a high byte leaves the name empty.
+    QString readToken()
+    {
+        const qsizetype start = index;
+        while (peek() && !isDelimiter(*peek()))
+            ++index;
+        const QByteArray token = bytes.mid(start, index - start);
+        for (const char byte : token)
+            if (uchar(byte) >= 0x80)
+                return QString();
+        return QString::fromLatin1(token);
+    }
+
+    std::optional<Engine> value()
+    {
+        if (depth >= maxDepth)
+            return std::nullopt;
+        ++depth;
+        std::optional<Engine> result = parseValue();
+        --depth;
+        return result;
+    }
+
+    std::optional<Engine> parseValue()
+    {
+        skipWhitespace();
+        const std::optional<uchar> byte = peek();
+        if (!byte)
+            return std::nullopt;
+        if (*byte == '<')
+            return peek(1) == uchar('<') ? parseDictionary() : parseHex();
+        if (*byte == '[')
+            return parseArray();
+        if (*byte == '(')
+            return parseString();
+        if (*byte == '/') {
+            ++index;
+            return Engine{readToken()};
+        }
+        if (*byte == '-' || *byte == '+' || *byte == '.' || isDigit(*byte)) {
+            const std::optional<double> parsed = parseNumber();
+            return parsed ? std::optional(Engine{*parsed}) : std::nullopt;
+        }
+        if (takeWord("true"))
+            return Engine{true};
+        if (takeWord("false"))
+            return Engine{false};
+        if (takeWord("null"))
+            return Engine{QString()};
+        return std::nullopt;
+    }
+
+    std::optional<Engine> parseDictionary()
+    {
+        take("<<");
+        Dictionary items;
+        while (true) {
+            skipWhitespace();
+            if (!peek() || *peek() == '>')
+                break;
+            if (*peek() != '/')
+                return std::nullopt;
+            ++index;
+            const QString key = readToken();
+            std::optional<Engine> item = value();
+            if (!item)
+                return std::nullopt;
+            items.insert_or_assign(key, std::move(*item));
+        }
+        if (!take(">>"))
+            return std::nullopt;
+        return Engine{std::move(items)};
+    }
+
+    std::optional<Engine> parseArray()
+    {
+        take("[");
+        Array items;
+        while (true) {
+            skipWhitespace();
+            if (!peek() || *peek() == ']')
+                break;
+            std::optional<Engine> item = value();
+            if (!item)
+                return std::nullopt;
+            items.push_back(std::move(*item));
+        }
+        if (!take("]"))
+            return std::nullopt;
+        return Engine{std::move(items)};
+    }
+
+    void digits()
+    {
+        while (peek() && isDigit(*peek()))
+            ++index;
+    }
+
+    std::optional<double> parseNumber()
+    {
+        const qsizetype start = index;
+        if (peek() == uchar('+') || peek() == uchar('-'))
+            ++index;
+        digits();
+        if (peek() == uchar('.')) {
+            ++index;
+            digits();
+        }
+        if (peek() == uchar('e') || peek() == uchar('E')) {
+            ++index;
+            if (peek() == uchar('+') || peek() == uchar('-'))
+                ++index;
+            digits();
+        }
+        return toDouble(bytes.mid(start, index - start));
+    }
+
+    std::optional<Engine> parseString()
+    {
+        take("(");
+        QByteArray raw;
+        while (peek()) {
+            const uchar byte = *peek();
+            ++index;
+            if (byte == ')')
+                break;
+            if (byte != '\\') {
+                raw.append(char(byte));
+                continue;
+            }
+            const std::optional<uchar> escaped = peek();
+            if (!escaped)
+                return std::nullopt;
+            ++index;
+            if (*escaped == 'n') {
+                raw.append('\n');
+            } else if (*escaped == 'r') {
+                raw.append('\r');
+            } else if (*escaped == 't') {
+                raw.append('\t');
+            } else if (*escaped >= '0' && *escaped <= '7') {
+                int octal = *escaped - '0';
+                for (int count = 0; count < 2 && peek() && *peek() >= '0' && *peek() <= '7'; ++count)
+                    octal = octal * 8 + (bytes[index++] - '0');
+                raw.append(char(octal & 0xFF));
+            } else if (*escaped != '\n' && *escaped != '\r') {
+                raw.append(char(*escaped));
+            }
+        }
+        return Engine{decoded(raw)};
+    }
+
+    std::optional<Engine> parseHex()
+    {
+        take("<");
+        std::vector<uchar> nibbles;
+        while (peek() && *peek() != '>') {
+            if (const std::optional<uchar> nibble = hex(*peek()))
+                nibbles.push_back(*nibble);
+            ++index;
+        }
+        if (!take(">"))
+            return std::nullopt;
+        QByteArray raw;
+        for (size_t at = 0; at + 1 < nibbles.size(); at += 2)
+            raw.append(char(nibbles[at] << 4 | nibbles[at + 1]));
+        return Engine{decoded(raw)};
+    }
+};
+
+std::optional<Engine> dictionary(const QByteArray &data, qsizetype start)
+{
+    Cursor cursor{data, start};
+    std::optional<Engine> value = cursor.value();
+    if (!value || !std::holds_alternative<Dictionary>(value->value))
+        return std::nullopt;
+    return value;
+}
+}
+
+std::optional<Engine> parse(const QByteArray &data)
+{
+    if (std::optional<Engine> found = dictionary(data, 0))
+        return found;
+    const qsizetype start = data.indexOf("<<");
+    if (start <= 0)
+        return std::nullopt;
+    return dictionary(data, start);
+}
+
+const Engine *walk(const Engine *value, std::initializer_list<const char *> keys)
+{
+    for (const char *key : keys) {
+        const Dictionary *items = value ? std::get_if<Dictionary>(&value->value) : nullptr;
+        if (!items || !items->contains(QString::fromLatin1(key)))
+            return nullptr;
+        value = &items->at(QString::fromLatin1(key));
+    }
+    return value;
+}
+
+std::optional<double> number(const Engine *value)
+{
+    const double *found = value ? std::get_if<double>(&value->value) : nullptr;
+    return found ? std::optional(*found) : std::nullopt;
+}
+
+std::optional<bool> boolean(const Engine *value)
+{
+    const bool *found = value ? std::get_if<bool>(&value->value) : nullptr;
+    return found ? std::optional(*found) : std::nullopt;
+}
+
+std::optional<QString> string(const Engine *value)
+{
+    const QString *found = value ? std::get_if<QString>(&value->value) : nullptr;
+    return found ? std::optional(*found) : std::nullopt;
+}
+
+Array array(const Engine *value)
+{
+    const Array *found = value ? std::get_if<Array>(&value->value) : nullptr;
+    return found ? *found : Array();
+}
+}

src/IO/PSD/PSDText+Engine.h

@@ -0,0 +1,27 @@
+#pragma once
+#include <QByteArray>
+#include <QString>
+#include <map>
+#include <optional>
+#include <variant>
+#include <vector>
+
+// Photoshop's text-engine dictionary, a small PostScript subset.
+namespace PSDTextEngine {
+struct Engine;
+using Dictionary = std::map<QString, Engine>;
+using Array = std::vector<Engine>;
+
+struct Engine {
+    std::variant<double, bool, QString, Dictionary, Array> value;
+};
+
+std::optional<Engine> parse(const QByteArray &data);
+// Swift's `walk`: nested dictionary keys, else none.
+const Engine *walk(const Engine *value, std::initializer_list<const char *> keys);
+std::optional<double> number(const Engine *value);
+std::optional<bool> boolean(const Engine *value);
+std::optional<QString> string(const Engine *value);
+// An array's items; anything else reads empty.
+Array array(const Engine *value);
+}

src/IO/PSD/PSDText.cpp

@@ -0,0 +1,287 @@
+#include "IO/PSD/PSDText.h"
+#include "Document/EditorSession.h"
+#include "IO/PSD/PSDText+Descriptor.h"
+#include "IO/PSD/PSDText+Engine.h"
+#include "IO/ProjectStore.h"
+#include "Rendering/TextLayout.h"
+#include <cmath>
+#include <numbers>
+
+namespace PSDText {
+namespace {
+using namespace PSDTextEngine;
+
+// Uniform scale, a turn and a vertical flip; no shear.
+struct Placement {
+    double pixelScale;
+    double rotation;
+    bool flipY;
+    QTransform map;
+};
+
+// The matrix alone maps engine sizes to pixels.
+std::optional<Placement> placement(double xx, double xy, double yx, double yy, double tx, double ty)
+{
+    const double scaleX = std::hypot(xx, yx);
+    if (!(scaleX > 1e-6))
+        return std::nullopt;
+    const double cosR = xx / scaleX, sinR = yx / scaleX;
+    const double localX = cosR * xy + sinR * yy;
+    const double localY = -sinR * xy + cosR * yy;
+    const double scaleY = std::abs(localY);
+    if (!(scaleY > 1e-6))
+        return std::nullopt;
+    const double largest = std::max(scaleX, scaleY);
+    if (!(std::abs(localX) <= 0.02 * largest && std::abs(scaleX - scaleY) <= 0.02 * largest))
+        return std::nullopt;
+    const double ySign = localY < 0 ? -1.0 : 1.0;
+    // Swift's exx, eyx, exy and eyy, then the offset.
+    const QTransform map(cosR * scaleX, sinR * scaleX, -sinR * scaleX * ySign, cosR * scaleX * ySign, tx, ty);
+    return Placement{scaleX, std::atan2(sinR, cosR) * 180 / std::numbers::pi, localY < 0, map};
+}
+
+// Swift's `Int(x.rounded())`, with no trap on a wild value.
+std::optional<qint64> rounded(double value)
+{
+    const double whole = std::round(value);
+    if (!(std::abs(whole) < 9e18))
+        return std::nullopt;
+    return qint64(whole);
+}
+
+double unit(double value)
+{
+    return value > 1 ? std::min(255.0, std::max(0.0, value)) / 255 : std::min(1.0, std::max(0.0, value));
+}
+
+std::array<double, 3> color(const std::vector<double> &values)
+{
+    if (values.size() >= 4)
+        return {unit(values[1]), unit(values[2]), unit(values[3])};
+    if (values.size() == 3)
+        return {unit(values[0]), unit(values[1]), unit(values[2])};
+    if (!values.empty())
+        return {unit(values[0]), unit(values[0]), unit(values[0])};
+    return {0, 0, 0};
+}
+
+std::vector<double> channels(const Engine *data)
+{
+    std::vector<double> result;
+    for (const Engine &value : array(walk(data, {"FillColor", "Values"})))
+        if (const std::optional<double> channel = number(&value))
+            result.push_back(*channel);
+    return result;
+}
+
+struct Signature {
+    double font = 0, size = 0, tracking = 0, leading = 0;
+    bool autoLeading = true;
+    double horizontalScale = 1, verticalScale = 1;
+    bool bold = false, italic = false;
+    std::array<double, 3> rgb{};
+    friend bool operator==(const Signature &, const Signature &) = default;
+};
+
+Signature signature(const Engine &run)
+{
+    const Engine *sheet = walk(&run, {"StyleSheet", "StyleSheetData"});
+    const Engine *data = sheet ? sheet : &run;
+    return Signature{.font = number(walk(data, {"Font"})).value_or(0),
+                     .size = number(walk(data, {"FontSize"})).value_or(0),
+                     .tracking = number(walk(data, {"Tracking"})).value_or(0),
+                     .leading = number(walk(data, {"Leading"})).value_or(0),
+                     .autoLeading = boolean(walk(data, {"AutoLeading"})).value_or(true),
+                     .horizontalScale = number(walk(data, {"HorizontalScale"})).value_or(1),
+                     .verticalScale = number(walk(data, {"VerticalScale"})).value_or(1),
+                     .bold = boolean(walk(data, {"FauxBold"})).value_or(false),
+                     .italic = boolean(walk(data, {"FauxItalic"})).value_or(false),
+                     .rgb = color(channels(data))};
+}
+
+void applyStyle(LayerTextStyle &style, const Engine &engine, double pixelScale, std::vector<QString> &notes)
+{
+    const Array runs = array(walk(&engine, {"EngineDict", "StyleRun", "RunArray"}));
+    const Engine &first = runs.empty() ? engine : runs.front();
+    // Swift falls back on the run array, where nothing reads.
+    const Engine *sheet = walk(&first, {"StyleSheet", "StyleSheetData"});
+    const Engine *data = sheet ? sheet : walk(&engine, {"EngineDict", "StyleRun", "RunArray"});
+    if (!data)
+        data = &first;
+    const double points = number(walk(data, {"FontSize"})).value_or(12);
+    if (!(std::isfinite(points) && points > 0))
+        return;
+    style.fontSize = std::min(2000.0, std::max(1.0, points * pixelScale));
+    const Array fonts = array(walk(&engine, {"ResourceDict", "FontSet"}));
+    const std::optional<qint64> index = rounded(number(walk(data, {"Font"})).value_or(0));
+    if (index && *index >= 0 && *index < qint64(fonts.size())) {
+        const QString name = string(walk(&fonts[size_t(*index)], {"Name"})).value_or(QString());
+        if (!name.isEmpty())
+            style.fontName = name;
+    }
+    if (!array(walk(data, {"FillColor", "Values"})).empty()) {
+        const std::array<double, 3> rgb = color(channels(data));
+        style.red = rgb[0];
+        style.green = rgb[1];
+        style.blue = rgb[2];
+    }
+    const double tracking = number(walk(data, {"Tracking"})).value_or(0);
+    if (std::isfinite(tracking))
+        style.tracking = std::min(1000.0, std::max(-100.0, tracking * style.fontSize / 1000));
+    const bool automatic = boolean(walk(data, {"AutoLeading"})).value_or(true);
+    const std::optional<double> leading = number(walk(data, {"Leading"}));
+    if (!automatic && leading && std::isfinite(*leading) && *leading > 0)
+        style.leading = std::min(5000.0, std::max(0.0, *leading * pixelScale));
+    if (boolean(walk(data, {"FauxBold"})) == true || boolean(walk(data, {"FauxItalic"})) == true)
+        notes.push_back(fauxNote);
+    const Signature firstSignature = signature(first);
+    if (runs.size() > 1 && std::any_of(runs.begin() + 1, runs.end(), [&](const Engine &run) { return signature(run) != firstSignature; }))
+        notes.push_back(firstStyleNote);
+    const Array paragraphs = array(walk(&engine, {"EngineDict", "ParagraphRun", "RunArray"}));
+    const Engine &paragraph = paragraphs.empty() ? engine : paragraphs.front();
+    const std::optional<qint64> justification = rounded(number(walk(&paragraph, {"ParagraphSheet", "Properties", "Justification"})).value_or(0));
+    if (justification == 1) {
+        style.alignment = TextAlignment::right;
+    } else if (justification == 2) {
+        style.alignment = TextAlignment::center;
+    } else {
+        style.alignment = TextAlignment::left;
+        if (justification != 0)
+            notes.push_back(justifyNote);
+    }
+}
+
+std::optional<QString> cleaned(std::optional<QString> text)
+{
+    if (!text)
+        return std::nullopt;
+    while (!text->isEmpty() && (text->front() == QChar(0xFEFF) || text->front() == QChar(0)))
+        text->remove(0, 1);
+    while (!text->isEmpty() && text->back() == QChar(0))
+        text->chop(1);
+    text->replace(QStringLiteral("\r\n"), QStringLiteral("\n"));
+    text->replace(QChar('\r'), QChar('\n'));
+    return text;
+}
+
+double horizontalAnchor(const LayerTextStyle &style, double width)
+{
+    switch (style.alignment) {
+    case TextAlignment::left:
+        return LayerTextStyle::padding;
+    case TextAlignment::center:
+        return width / 2;
+    case TextAlignment::right:
+        return width - LayerTextStyle::padding;
+    }
+    Q_UNREACHABLE();
+}
+
+// The first line's baseline, laid as `textImage` lays it.
+double baseline(const LayerTextStyle &style, QSizeF image)
+{
+    const double padding = LayerTextStyle::padding;
+    const TextLines lines(style, QSizeF(std::max(1.0, image.width() - 2 * padding), std::max(1.0, image.height() - 2 * padding)));
+    return padding + lines.baseline(0);
+}
+
+// As `pixelToDocument`: flip, then a clockwise turn about the centre.
+LayerTransform layerTransform(QSizeF image, QPointF imageAnchor, QPointF documentAnchor, double rotation, bool flipY)
+{
+    QPointF local(imageAnchor.x() - image.width() / 2, imageAnchor.y() - image.height() / 2);
+    if (flipY)
+        local.setY(-local.y());
+    const double radians = rotation * std::numbers::pi / 180;
+    const QPointF turned(local.x() * std::cos(radians) - local.y() * std::sin(radians), local.x() * std::sin(radians) + local.y() * std::cos(radians));
+    const QPointF centre = documentAnchor - turned;
+    LayerTransform transform{QPointF(centre.x() - image.width() / 2, centre.y() - image.height() / 2), image};
+    transform.rotation = rotation;
+    transform.flipY = flipY;
+    return transform;
+}
+}
+
+std::optional<QString> missingFontNote(const QString &name)
+{
+    if (TextLayout::availableFonts().contains(name))
+        return std::nullopt;
+    return QStringLiteral("The font “%1” isn’t installed, so the text was drawn with a substitute font.").arg(name);
+}
+
+std::optional<Source> parse(const std::map<QString, QByteArray> &extra)
+{
+    const QString key = extra.contains(QStringLiteral("TySh")) ? QStringLiteral("TySh") : QStringLiteral("tySh");
+    if (!extra.contains(key) || extra.at(key).size() > 8'000'000)
+        return std::nullopt;
+    PSDDescriptor::Reader reader{extra.at(key)};
+    if (reader.u16() != 1u)
+        return std::nullopt;
+    std::array<double, 6> matrix{};
+    for (double &value : matrix) {
+        const std::optional<double> read = reader.f64();
+        if (!read || !std::isfinite(*read))
+            return std::nullopt;
+        value = *read;
+    }
+    if (reader.u16() != 50u)
+        return std::nullopt;
+    const std::optional<PSDDescriptor::Items> text = reader.descriptor(true);
+    if (!text || PSDDescriptor::enumeration(*text, QStringLiteral("Ornt")) == QStringLiteral("Vrtc"))
+        return std::nullopt;
+    const std::optional<Placement> placed = placement(matrix[0], matrix[1], matrix[2], matrix[3], matrix[4], matrix[5]);
+    if (!placed)
+        return std::nullopt;
+
+    std::vector<QString> notes;
+    if (reader.remaining() >= 2 && reader.u16() == 1u) {
+        const std::optional<PSDDescriptor::Items> warp = reader.descriptor(true);
+        const std::optional<QString> style = warp ? PSDDescriptor::enumeration(*warp, QStringLiteral("warpStyle")) : std::nullopt;
+        if (style && *style != QLatin1String("warpNone") && *style != QLatin1String("none"))
+            notes.push_back(warpNote);
+    }
+
+    const std::optional<QByteArray> engineData = PSDDescriptor::data(*text, QStringLiteral("EngineData"));
+    const std::optional<Engine> engine = engineData ? PSDTextEngine::parse(*engineData) : std::nullopt;
+    std::optional<QString> typed = PSDDescriptor::string(*text, QStringLiteral("Txt "));
+    if (!typed)
+        typed = PSDDescriptor::string(*text, QStringLiteral("Txt"));
+    std::optional<QString> content = cleaned(typed);
+    if (!content && engine)
+        content = cleaned(string(walk(&*engine, {"EngineDict", "Editor", "Text"})));
+    if (!content || content->isEmpty() || content->size() > 100'000)
+        return std::nullopt;
+
+    LayerTextStyle style;
+    style.content = *content;
+    if (engine)
+        applyStyle(style, *engine, placed->pixelScale, notes);
+    else
+        style.fontSize = std::min(2000.0, std::max(1.0, 12 * placed->pixelScale));
+
+    QPointF anchor(matrix[4], matrix[5]);
+    bool anchorIsFrame = false;
+    const std::optional<QRectF> bounds = PSDDescriptor::rect(*text, QStringLiteral("bounds"));
+    const std::optional<QRectF> glyphs = PSDDescriptor::rect(*text, QStringLiteral("boundingBox"));
+    if (bounds && glyphs && bounds->width() > glyphs->width() + 4 && bounds->height() > glyphs->height() + 4) {
+        const double pad = LayerTextStyle::padding;
+        style.boxSize = QSizeF(bounds->width() * placed->pixelScale + pad * 2, bounds->height() * placed->pixelScale + pad * 2);
+        anchor = placed->map.map(bounds->topLeft());
+        anchorIsFrame = true;
+    }
+    if (!style.isValid())
+        return std::nullopt;
+    return Source{style, notes, anchor, placed->rotation, placed->flipY, anchorIsFrame};
+}
+
+Rendered render(const Source &source)
+{
+    const QImage image = EditorSession::textImage(source.style);
+    const QSizeF size = image.size();
+    const QPointF anchor = source.anchorIsFrame ? QPointF(LayerTextStyle::padding, LayerTextStyle::padding)
+                                                : QPointF(horizontalAnchor(source.style, size.width()), baseline(source.style, size));
+    const LayerTransform transform = layerTransform(size, anchor, source.documentAnchor, source.rotation, source.flipY);
+    if (!transform.isValid())
+        throw ProjectError(ProjectError::Kind::tooLarge);
+    return Rendered{image, transform};
+}
+}

src/IO/PSD/PSDText.h

@@ -0,0 +1,36 @@
+#pragma once
+#include "Document/TypeTool.h"
+#include <QByteArray>
+#include <QImage>
+#include <map>
+#include <optional>
+#include <vector>
+
+// Photoshop 6 type (`TySh`) read into the text model.
+namespace PSDText {
+struct Source {
+    LayerTextStyle style;
+    std::vector<QString> notes;
+    // The document point the image's anchor lands on.
+    QPointF documentAnchor;
+    double rotation = 0;
+    bool flipY = false;
+    // The paragraph frame's corner, else point text's baseline.
+    bool anchorIsFrame = false;
+};
+
+struct Rendered {
+    QImage image;
+    LayerTransform transform;
+};
+
+inline const QString rasterizedNote = QStringLiteral("Editable Photoshop text becomes pixels and can’t be retyped.");
+inline const QString firstStyleNote = QStringLiteral("Only the first text style was kept.");
+inline const QString warpNote = QStringLiteral("The Photoshop text warp was omitted.");
+inline const QString fauxNote = QStringLiteral("Faux bold or faux italic was omitted.");
+inline const QString justifyNote = QStringLiteral("Full justification was imported as left alignment.");
+
+std::optional<QString> missingFontNote(const QString &name);
+std::optional<Source> parse(const std::map<QString, QByteArray> &extra);
+Rendered render(const Source &source);
+}

src/IO/PSD/PSDTypes.h

@@ -1,5 +1,6 @@
 #pragma once
 #include "Document/EditorSession+Model.h"
+#include "IO/PSD/PSDText.h"
 #include <QImage>
 #include <QRectF>
 #include <QString>
@@ -43,6 +44,8 @@ struct PSDRecord {
     PSDLayerKind kind = PSDLayerKind::raster;
     std::optional<LayerShapeStyle> shape;
     std::vector<QString> shapeNotes;
+    // Photoshop type the text model can hold.
+    std::optional<PSDText::Source> text;
     // Cut to the canvas so the file fits the budget.
     bool croppedToCanvas = false;
     std::optional<LayerBlendMode> blendMode() const;