replace pre-baked bitmap fonts with a runtime glyph atlas

src/CMakeLists.txt

@@ -2,6 +2,8 @@ set(mmapper_SRCS
     main.cpp
     adventure/AdventureLogModel.cpp
     adventure/AdventureLogModel.h
+    font/GlyphAtlas.cpp
+    font/GlyphAtlas.h
     adventure/adventuresession.cpp
     adventure/adventuresession.h
     adventure/adventuretracker.cpp

src/configuration/NamedConfig.h

@@ -15,7 +15,7 @@ class NODISCARD NamedConfig final
 private:
     std::string m_name;
     ChangeMonitor m_changeMonitor;
-    T m_value = 0;
+    T m_value{};
     bool m_notifying = false;
 
 public:

src/configuration/configuration.cpp

@@ -304,6 +304,8 @@ ConstString KEY_USE_INTERNAL_EDITOR = "Use internal editor";
 ConstString KEY_USE_TRILINEAR_FILTERING = "Use trilinear filtering";
 ConstString KEY_WEATHER_ATMOSPHERE_INTENSITY = "weather.atmosphereIntensity";
 ConstString KEY_WEATHER_PRECIPITATION_INTENSITY = "weather.precipitationIntensity";
+ConstString KEY_MAP_FONT_FAMILY = "Map font family";
+ConstString KEY_MAP_FONT_SIZE = "Map font point size";
 ConstString KEY_WEATHER_TIME_OF_DAY_INTENSITY = "weather.todIntensity";
 ConstString KEY_WINDOW_GEOMETRY = "Window Geometry";
 ConstString KEY_WINDOW_STATE = "Window State";
@@ -686,6 +688,9 @@ void Configuration::CanvasSettings::read(const QSettings &conf)
                                         .append(DEFAULT_MMAPPER_SUBDIR)
                                         .append(DEFAULT_RESOURCES_SUBDIR))
                              .toString();
+    mapFontFamily.set(conf.value(KEY_MAP_FONT_FAMILY, mapFontFamily.get()).toString());
+    mapFontPointSize.set(conf.value(KEY_MAP_FONT_SIZE, mapFontPointSize.get()).toInt());
+    mapFontPointSize.clamp(6, 72);
     showMissingMapId.set(conf.value(KEY_SHOW_MISSING_MAP_ID, true).toBool());
     showUnsavedChanges.set(conf.value(KEY_SHOW_UNSAVED_CHANGES, true).toBool());
     showUnmappedExits.set(conf.value(KEY_DRAW_NOT_MAPPED_EXITS, true).toBool());
@@ -897,6 +902,8 @@ NODISCARD static auto getQColorName(const XNamedColor &color)
 void Configuration::CanvasSettings::write(QSettings &conf) const
 {
     conf.setValue(KEY_RESOURCES_DIRECTORY, resourcesDirectory);
+    conf.setValue(KEY_MAP_FONT_FAMILY, mapFontFamily.get());
+    conf.setValue(KEY_MAP_FONT_SIZE, mapFontPointSize.get());
     conf.setValue(KEY_SHOW_MISSING_MAP_ID, showMissingMapId.get());
     conf.setValue(KEY_SHOW_UNSAVED_CHANGES, showUnsavedChanges.get());
     conf.setValue(KEY_DRAW_NOT_MAPPED_EXITS, showUnmappedExits.get());

src/configuration/configuration.h

@@ -182,6 +182,8 @@ class NODISCARD Configuration final
         NamedConfig<bool> showMissingMapId{"SHOW_MISSING_MAPID", false};
         NamedConfig<bool> showUnsavedChanges{"SHOW_UNSAVED_CHANGES", false};
         NamedConfig<bool> showUnmappedExits{"SHOW_UNMAPPED_EXITS", false};
+        NamedConfig<QString> mapFontFamily{"MAP_FONT_FAMILY", QStringLiteral("Cantarell")};
+        NamedConfig<int> mapFontPointSize{"MAP_FONT_POINT_SIZE", platformPointSize(11)};
         bool drawUpperLayersTextured = false;
         bool drawDoorNames = false;
         bool softwareOpenGL = false;

src/display/Characters.cpp

@@ -544,7 +544,7 @@ void MapCanvas::drawGroupCharacters(CharacterBatch &batch, ServerRoomId yourServ
             QString name = character.getLabel().isEmpty() ? character.getName().toQString()
                                                           : character.getLabel().toQString();
             if (!name.isEmpty()) {
-                batch.drawName(pos, mmqt::toStdStringLatin1(name), color);
+                batch.drawName(pos, mmqt::toStdStringUtf8(name), color);
             }
         }
 

src/display/Connections.cpp

@@ -223,7 +223,7 @@ void ConnectionDrawer::drawRoomDoorName(const RoomHandle &sourceRoom,
     static const auto bg = Colors::black.withAlpha(0.4f);
     const glm::vec3 pos{xy, static_cast<float>(m_currentLayer)};
     m_roomNameBatch.emplace_back(GLText{pos,
-                                        mmqt::toStdStringLatin1(name), // GL font is latin1
+                                        mmqt::toStdStringUtf8(name),
                                         Colors::white,
                                         bg,
                                         FontFormatFlags{FontFormatFlagEnum::HALIGN_CENTER}});

src/display/Infomarks.cpp

@@ -263,9 +263,8 @@ void MapCanvas::drawInfomark(InfomarksBatch &batch,
     switch (infoMarkType) {
     case InfomarkTypeEnum::TEXT: {
         const auto utf8 = marker.getText().getStdStringViewUtf8();
-        const auto latin1_to_render = charset::conversion::utf8ToLatin1(utf8); // GL font is latin1
         batch.renderText(pos,
-                         latin1_to_render,
+                         std::string{utf8},
                          textColor(bgColor),
                          bgColor,
                          fontFormatFlag,

src/display/MapCanvasWindow.h

@@ -24,6 +24,7 @@
 
 #include <QOpenGLDebugMessage>
 #include <QOpenGLWindow>
+#include <QScreen>
 #include <QtCore>
 
 class ConnectionSelection;
@@ -63,6 +64,11 @@ class NODISCARD_QOBJECT MapCanvasWindow final : public QOpenGLWindow, private Ma
     // MapCanvasHost
     void virt_requestCanvasUpdate() final { update(); }
     NODISCARD qreal virt_hostDevicePixelRatio() const final { return devicePixelRatioF(); }
+    NODISCARD qreal virt_hostLogicalDpi() const final
+    {
+        const QScreen *const s = screen();
+        return (s != nullptr) ? s->logicalDotsPerInchY() : 96.0;
+    }
     NODISCARD QSize virt_hostSize() const final
     {
         return QSize(QOpenGLWindow::width(), QOpenGLWindow::height());

src/display/mapcanvas.cpp

@@ -1420,6 +1420,13 @@ void MapCanvas::screenChanged()
     const auto newDpi = static_cast<float>(currentDpr());
     const auto oldDpi = gl.getHostDevicePixelRatio();
 
+    // same DPR but different logical DPI (e.g. per-monitor font scaling)
+    if (utils::isSameFloat(newDpi, oldDpi)
+        && !utils::isSameFloat(currentLogicalDpi(), getGLFont().getLogicalDpi())) {
+        m_pendingFontReload = true;
+        m_frameManager.requestUpdate();
+    }
+
     if (!utils::isSameFloat(newDpi, oldDpi)) {
         log(QString("Display: %1 DPI").arg(static_cast<double>(newDpi)));
 

src/display/mapcanvas.h

@@ -73,6 +73,9 @@ class NODISCARD MapCanvasHost
     // The host's current device pixel ratio.
     NODISCARD qreal hostDevicePixelRatio() const { return virt_hostDevicePixelRatio(); }
 
+    // The logical DPI of the host's current screen.
+    NODISCARD qreal hostLogicalDpi() const { return virt_hostLogicalDpi(); }
+
     // The host's current size in logical pixels.
     NODISCARD QSize hostSize() const { return virt_hostSize(); }
 
@@ -92,6 +95,7 @@ class NODISCARD MapCanvasHost
 private:
     virtual void virt_requestCanvasUpdate() = 0;
     NODISCARD virtual qreal virt_hostDevicePixelRatio() const = 0;
+    NODISCARD virtual qreal virt_hostLogicalDpi() const = 0;
     NODISCARD virtual QSize virt_hostSize() const = 0;
     virtual void virt_setHostCursor(Qt::CursorShape shape) = 0;
     virtual void virt_applyPresentViewport() {}
@@ -204,6 +208,8 @@ class NODISCARD_QOBJECT MapCanvas final : public QObject,
     bool m_pendingUpdateTextures = false;
     std::optional<float> m_pendingDpr;
     std::optional<float> m_pendingRenderScale;
+    // font preference or logical DPI changed; applied like m_pendingRenderScale
+    bool m_pendingFontReload = false;
 
     // Touch long-press -> context menu. A left press synthesized from touch
     // arms the timer; moving past the drag threshold or releasing disarms it
@@ -236,6 +242,10 @@ class NODISCARD_QOBJECT MapCanvas final : public QObject,
 
 private:
     NODISCARD qreal currentDpr() const { return m_host.hostDevicePixelRatio(); }
+    NODISCARD float currentLogicalDpi() const
+    {
+        return static_cast<float>(m_host.hostLogicalDpi());
+    }
     // Configuration::canvas.renderScale (a percentage) as the factor the
     // offscreen FBO is rendered at; see Legacy::Functions::setRenderScale().
     NODISCARD static float configuredRenderScale();

src/display/mapcanvas_gl.cpp

@@ -341,7 +341,7 @@ bool MapCanvas::hostInitializeGL()
     initTextures();
     auto &font = getGLFont();
     font.setTextureId(allocateTextureId());
-    font.init();
+    font.init(currentLogicalDpi());
     updateTextures();
 
     // compile all shaders
@@ -386,6 +386,14 @@ bool MapCanvas::hostInitializeGL()
         this->requestUpdateTextures();
     });
 
+    const auto requestFontReload = [this]() {
+        // Deferred like m_pendingRenderScale: needs the GL context.
+        m_pendingFontReload = true;
+        m_frameManager.requestUpdate();
+    };
+    setConfig().canvas.mapFontFamily.registerChangeCallback(m_lifetime, requestFontReload);
+    setConfig().canvas.mapFontPointSize.registerChangeCallback(m_lifetime, requestFontReload);
+
     // NOTE: The host facade is responsible for connecting to
     // QOpenGLContext::aboutToBeDestroyed (see MapCanvas::initializeGL()); the
     // core has no notion of a QOpenGLContext or its lifetime.
@@ -610,7 +618,7 @@ void MapCanvas::applyPendingGLWork()
         getOpenGL().setDevicePixelRatio(newDpi);
         auto &font = getGLFont();
         font.cleanup();
-        font.init();
+        font.init(currentLogicalDpi());
     }
     if (m_pendingRenderScale.has_value()) {
         const float newScale = *m_pendingRenderScale;
@@ -622,14 +630,21 @@ void MapCanvas::applyPendingGLWork()
             // and the FBO is sized from it.
             auto &font = getGLFont();
             font.cleanup();
-            font.init();
+            font.init(currentLogicalDpi());
             m_batches.resetExistingMeshesButKeepPendingRemesh();
             markMultisamplingDirty();
         }
     }
     if (std::exchange(m_pendingUpdateTextures, false)) {
         updateTextures();
     }
+    if (std::exchange(m_pendingFontReload, false)) {
+        auto &font = getGLFont();
+        font.cleanup();
+        font.init(currentLogicalDpi());
+        // existing text meshes reference the old atlas
+        m_pendingForceUpdateMeshes = true;
+    }
     if (std::exchange(m_pendingForceUpdateMeshes, false)) {
         forceUpdateMeshes();
     }
@@ -948,7 +963,7 @@ void MapCanvas::hostPaintGL()
     auto y = lineHeight;
     const auto print = [lineHeight, rightMargin, &text, &y](const QString &msg) {
         text.emplace_back(glm::vec3(rightMargin, y, 0),
-                          mmqt::toStdStringLatin1(msg), // GL font is latin1
+                          mmqt::toStdStringUtf8(msg),
                           Colors::white,
                           Colors::black.withAlpha(0.4f),
                           FontFormatFlags{FontFormatFlagEnum::HALIGN_RIGHT});