完成主要交互、高性能组件、国际化和A型传感器数据包接收

README.md

@@ -257,3 +257,79 @@ m_dotsProg->release();
 - 想要更柔和的圆边：用 `smoothstep` 做 alpha 边缘 + 开启 blending
 - 想要真正的 3D 圆柱/球：就不能靠 discard 了，需要真正的几何或法线光照
 
+## Metrics ????
+
+Metrics ?????????? payload?`DataFrame.data`??????? `metricsChanged` ???
+
+- ??????
+- ????sqrt(mean(v^2))
+- ????mean(v)
+- ??????? - ???
+
+## Live Trend ??
+
+Live Trend ????? payload ???sum of `DataFrame.data`???????????????? `src/data_backend.cpp` ? `updateMetrics_()` ???? `metricSum`??? `qml/content/RightPanel.qml` ??? `Backend.data.metricSum` ??????
+
+## Live Trend ??????????
+
+????????? `QImage` ?????????? DPI?devicePixelRatio??????? DPI ??????????????????????? y ???????????????????????
+
+?????
+- ???????? `devicePixelRatio` ???????
+- ????????????????????
+- ???????? y ????????????????
+
+?????????
+
+```cpp
+// src/sparkline_plotitem.h
+private:
+    QSGTexture* getTextTexture(const QString& text, const QFont& font, QSize* outSize = nullptr);
+```
+
+```cpp
+// src/sparkling_plotitem.cpp
+QSGTexture* SparklinePlotItem::getTextTexture(const QString& text, const QFont& font, QSize* outSize) {
+    const qreal dpr = window() ? window()->devicePixelRatio() : 1.0;
+    const QString key = text + "|" + font.family() + "|" + QString::number(font.pixelSize()) +
+        "|" + QString::number(dpr, 'f', 2);
+    ...
+    const QSize pixelSize(qMax(1, qRound(sz.width() * dpr)), qMax(1, qRound(sz.height() * dpr)));
+    QImage img(pixelSize, QImage::Format_ARGB32_Premultiplied);
+    img.setDevicePixelRatio(dpr);
+    ...
+    m_textCache[key] = { tex, sz };
+    if (outSize)
+        *outSize = sz;
+    return tex;
+}
+
+QSGNode* SparklinePlotItem::updatePaintNode(QSGNode* oldNode, UpdatePaintNodeData*) {
+    const qreal dpr = window()->devicePixelRatio();
+    auto alignToPixel = [dpr](float v) -> float {
+        return (dpr > 0.0) ? (std::round(v * dpr) / dpr) : v;
+    };
+    ...
+    float py = alignToPixel(bottom - yn * plotH);
+    ...
+    QSize logicalSize;
+    QSGTexture* tex = getTextTexture(label, font, &logicalSize);
+    float ty = alignToPixel(py - logicalSize.height() / 2.0f);
+    tnode->setRect(QRectF(tx, ty, logicalSize.width(), logicalSize.height()));
+    ...
+}
+```
+
+## Export Logic
+
+Export is driven by the Save dialog and DataBackend::exportHandler():
+
+- QML triggers Backend.data.exportHandler(folder, filename, format, method) from qml/content/LeftPanel.qml.
+- older is a local QUrl (e.g. ile:///C:/...), converted to a local path on the C++ side.
+- Supported formats: csv, json.
+- Supported methods: overwrite (default), ppend.
+  - CSV append: appends all current frames to the file.
+  - JSON append: loads existing array (if any), appends all current frames, and rewrites the file.
+- xlsx and zip are not implemented yet and will log a warning.
+
+Relevant code: src/data_backend.cpp (exportHandler, uildCsv_, uildJson_), qml/content/SaveAsExportDialog.qml.