feat(ui): ContourPlotItem 网格填充栅格热力图 + 矢量等值线/标注/异常叠加

QwtPlotItem(非 Q_OBJECT)。填充用预渲染 ARGB32 QImage(每格细分 K=4,
双线性插值, 离散色带取色 → 平滑填充带边界; 含 NaN 格的像素透明 → 不规则白边),
draw 时按数据 bbox 映射目标矩形 blit + SmoothPixmapTransform(拖动/缩放快)。
等值线复用 buildContourBands 的 lines(矢量), 黑 cosmetic 细线;
level 由线上代表点采网格值吸附最近色阶级回填(管线恒 0), 沿线方向旋转标注(字号10)。
异常按 markType 画 点(方块)/线(折线)/面(闭合多边形), lineColor + dashed->虚线。
x 轴绑 xBottom, y 轴绑 yLeft。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/CMakeLists.txt

@@ -32,6 +32,7 @@ add_executable(geopro_desktop WIN32
   panels/chart/ColorMapService.cpp
   panels/chart/ColorBarWidget.cpp
   panels/chart/ScatterPlotItem.cpp
+  panels/chart/ContourPlotItem.cpp
   panels/chart/LivePanner.cpp
   panels/AnomalyTablePanel.cpp
   panels/DatasetDetailPage.cpp

src/app/panels/chart/ContourPlotItem.cpp

@@ -0,0 +1,260 @@
+#include "panels/chart/ContourPlotItem.hpp"
+
+#include <algorithm>
+#include <cmath>
+
+#include <QFont>
+#include <QPainter>
+#include <QPen>
+#include <QPolygonF>
+#include <qwt_plot.h>
+#include <qwt_scale_map.h>
+
+#include "panels/chart/ColorMapService.hpp"
+
+namespace geopro::app {
+
+namespace {
+constexpr int kFillUpsample = 4;        // 填充图像每网格格细分 K（双线性插值平滑带边界）
+constexpr int kMaxFillDim = 2400;       // 填充图像单边像素上限（防极端网格爆内存）
+constexpr int kLabelFontPx = 10;        // 等值线标注字号
+constexpr int kLabelMinSegPx = 60;      // 太短的等值线不标注（像素长度阈值，draw 期判定）
+constexpr double kRad2Deg = 57.29577951308232;  // 180/π（避免依赖 M_PI）
+}  // namespace
+
+ContourPlotItem::ContourPlotItem() : QwtPlotItem() {
+    setRenderHint(QwtPlotItem::RenderAntialiased, false);
+    // 网格数据 x 轴在底部（与 RawDataChartView 的顶部 x 轴不同）；y 轴在左。
+    setXAxis(QwtPlot::xBottom);
+    setYAxis(QwtPlot::yLeft);
+}
+
+void ContourPlotItem::setData(const core::Grid& g, ColorMapService* svc,
+                              const std::vector<core::Anomaly>& anoms, bool showLines,
+                              bool showLabels) {
+    showLines_ = showLines;
+    showLabels_ = showLabels;
+    anoms_ = anoms;
+
+    const int nx = g.nx(), ny = g.ny();
+    if (nx < 2 || ny < 2 || static_cast<int>(g.x.size()) < nx ||
+        static_cast<int>(g.y.size()) < ny) {
+        fillImage_ = QImage();
+        dataBBox_ = QRectF();
+        lines_.clear();
+        return;
+    }
+
+    const double xmin = g.x.front(), xmax = g.x.back();
+    const double ymin = g.y.front(), ymax = g.y.back();
+    dataBBox_ = QRectF(xmin, ymin, xmax - xmin, ymax - ymin);
+
+    buildFillImage(g, svc);
+
+    // 等值线（矢量）：复用 render 管线，仅取 lines（填充走栅格）。
+    if (showLines_) {
+        render::ContourOptions opt;
+        opt.upsample = 2;
+        opt.makeLines = true;
+        auto res = render::buildContourBands(g, svc->scale(), opt);
+        lines_ = std::move(res.lines);
+        // buildContourBands 当前未回填 level（恒 0）；在此按线上代表点采网格值并吸附到最近色阶级，
+        // 使标注显示真实等值线值。
+        resolveLineLevels(g, svc->scale());
+    } else {
+        lines_.clear();
+    }
+}
+
+void ContourPlotItem::resolveLineLevels(const core::Grid& g, const core::ColorScale& cs) {
+    const auto stops = cs.stopValues();
+    if (stops.empty() || lines_.empty()) return;
+
+    const int nx = g.nx(), ny = g.ny();
+    const double xmin = g.x.front(), xmax = g.x.back();
+    const double ymin = g.y.front(), ymax = g.y.back();
+    const double xspan = (xmax - xmin), yspan = (ymax - ymin);
+
+    // 在数据坐标点做双线性采样（NaN 安全）。
+    auto sampleAt = [&](const core::Vec2& p) -> double {
+        if (xspan <= 0 || yspan <= 0) return std::nan("");
+        double fi = (p.x - xmin) / xspan * (nx - 1);
+        double fj = (p.y - ymin) / yspan * (ny - 1);
+        fi = std::clamp(fi, 0.0, static_cast<double>(nx - 1));
+        fj = std::clamp(fj, 0.0, static_cast<double>(ny - 1));
+        int i0 = std::min(static_cast<int>(fi), nx - 2);
+        int j0 = std::min(static_cast<int>(fj), ny - 2);
+        double ti = fi - i0, tj = fj - j0;
+        double v00 = g.valueAt(i0, j0), v10 = g.valueAt(i0 + 1, j0);
+        double v01 = g.valueAt(i0, j0 + 1), v11 = g.valueAt(i0 + 1, j0 + 1);
+        if (std::isnan(v00) || std::isnan(v10) || std::isnan(v01) || std::isnan(v11))
+            return std::nan("");
+        return (v00 * (1 - ti) + v10 * ti) * (1 - tj) + (v01 * (1 - ti) + v11 * ti) * tj;
+    };
+
+    for (auto& ln : lines_) {
+        double sampled = std::nan("");
+        for (const auto& p : ln.pts) {  // 取首个非 NaN 采样点
+            sampled = sampleAt(p);
+            if (!std::isnan(sampled)) break;
+        }
+        if (std::isnan(sampled)) {
+            ln.level = std::nan("");
+            continue;
+        }
+        // 吸附到最近色阶级（等值线恰落在某级上）。
+        double best = stops.front();
+        double bestD = std::fabs(sampled - best);
+        for (double s : stops) {
+            double d = std::fabs(sampled - s);
+            if (d < bestD) { bestD = d; best = s; }
+        }
+        ln.level = best;
+    }
+}
+
+void ContourPlotItem::buildFillImage(const core::Grid& g, ColorMapService* svc) {
+    const int nx = g.nx(), ny = g.ny();
+    int W = (nx - 1) * kFillUpsample + 1;
+    int H = (ny - 1) * kFillUpsample + 1;
+    // 限幅：极端网格下按比例降采样，保证内存/性能可控。
+    if (W > kMaxFillDim) W = kMaxFillDim;
+    if (H > kMaxFillDim) H = kMaxFillDim;
+
+    QImage img(W, H, QImage::Format_ARGB32);
+    img.fill(Qt::transparent);
+
+    // 每像素 → 归一化网格坐标 (fi,fj) → 四邻格双线性插值；任一邻格 NaN 则该像素透明。
+    for (int py = 0; py < H; ++py) {
+        // 图像顶行 py=0 对应 y 最大（ymax，地表）；底行对应 y 最小（最深）。
+        double fj = static_cast<double>(H - 1 - py) / (H - 1) * (ny - 1);
+        int j0 = std::min(static_cast<int>(fj), ny - 2);
+        double tj = fj - j0;
+        auto* scan = reinterpret_cast<QRgb*>(img.scanLine(py));
+        for (int px = 0; px < W; ++px) {
+            double fi = static_cast<double>(px) / (W - 1) * (nx - 1);
+            int i0 = std::min(static_cast<int>(fi), nx - 2);
+            double ti = fi - i0;
+
+            double v00 = g.valueAt(i0, j0), v10 = g.valueAt(i0 + 1, j0);
+            double v01 = g.valueAt(i0, j0 + 1), v11 = g.valueAt(i0 + 1, j0 + 1);
+            if (std::isnan(v00) || std::isnan(v10) || std::isnan(v01) || std::isnan(v11))
+                continue;  // 含无数据格 → 像素透明（不规则白边）
+
+            double v = (v00 * (1 - ti) + v10 * ti) * (1 - tj) +
+                       (v01 * (1 - ti) + v11 * ti) * tj;
+            auto c = svc->colorAtDiscrete(v);  // 离散色带 → 平滑填充带边界
+            scan[px] = qRgba(c.r, c.g, c.b, c.a ? c.a : 255);
+        }
+    }
+    fillImage_ = std::move(img);
+}
+
+QRectF ContourPlotItem::boundingRect() const {
+    return dataBBox_;
+}
+
+void ContourPlotItem::draw(QPainter* painter, const QwtScaleMap& xMap, const QwtScaleMap& yMap,
+                           const QRectF& /*canvasRect*/) const {
+    if (dataBBox_.isNull()) return;
+
+    const double xmin = dataBBox_.left(), xmax = dataBBox_.right();
+    const double ymin = dataBBox_.top(), ymax = dataBBox_.bottom();
+
+    // 1) 填充：数据 bbox → 像素矩形（注意 y 翻转：ymax→画布上沿、ymin→下沿），blit + 平滑缩放。
+    if (!fillImage_.isNull()) {
+        const double pxL = xMap.transform(xmin);
+        const double pxR = xMap.transform(xmax);
+        const double pyTop = yMap.transform(ymax);
+        const double pyBot = yMap.transform(ymin);
+        QRectF target(pxL, pyTop, pxR - pxL, pyBot - pyTop);
+        painter->save();
+        painter->setRenderHint(QPainter::SmoothPixmapTransform, true);
+        painter->drawImage(target, fillImage_);
+        painter->restore();
+    }
+
+    auto mapPt = [&](const core::Vec2& p) {
+        return QPointF(xMap.transform(p.x), yMap.transform(p.y));
+    };
+
+    // 2) 等值线：黑色 0 宽（cosmetic）细线。
+    if (showLines_ && !lines_.empty()) {
+        painter->save();
+        painter->setRenderHint(QPainter::Antialiasing, true);
+        QPen pen(QColor(0, 0, 0));
+        pen.setWidthF(0.0);  // cosmetic：恒 1px，不随缩放变粗
+        painter->setPen(pen);
+        for (const auto& ln : lines_) {
+            if (ln.pts.size() < 2) continue;
+            QPolygonF poly;
+            poly.reserve(static_cast<int>(ln.pts.size()));
+            for (const auto& p : ln.pts) poly << mapPt(p);
+            painter->drawPolyline(poly);
+        }
+        painter->restore();
+
+        // 3) 标注：沿线中段画 level 数值（小字黑，随相邻两点方向旋转）。
+        if (showLabels_) {
+            painter->save();
+            painter->setRenderHint(QPainter::Antialiasing, true);
+            QFont f = painter->font();
+            f.setPixelSize(kLabelFontPx);
+            painter->setFont(f);
+            painter->setPen(QColor(0, 0, 0));
+            for (const auto& ln : lines_) {
+                if (ln.pts.size() < 2 || std::isnan(ln.level)) continue;
+                // 取折线中段两点定位置/朝向。
+                const std::size_t mid = ln.pts.size() / 2;
+                const QPointF a = mapPt(ln.pts[mid - 1]);
+                const QPointF b = mapPt(ln.pts[mid]);
+                // 整条线像素长度太短不标注（避免密集杂乱）。
+                const QPointF s = mapPt(ln.pts.front());
+                const QPointF e = mapPt(ln.pts.back());
+                if (std::hypot(e.x() - s.x(), e.y() - s.y()) < kLabelMinSegPx) continue;
+                double ang = std::atan2(b.y() - a.y(), b.x() - a.x()) * kRad2Deg;
+                if (ang > 90.0) ang -= 180.0;  // 保持文字大体正向（不上下颠倒）
+                if (ang < -90.0) ang += 180.0;
+                const QString txt = QString::number(ln.level, 'g', 4);
+                painter->save();
+                painter->translate((a.x() + b.x()) * 0.5, (a.y() + b.y()) * 0.5);
+                painter->rotate(ang);
+                painter->drawText(QPointF(-12, -2), txt);
+                painter->restore();
+            }
+            painter->restore();
+        }
+    }
+
+    // 4) 异常叠加：点=小方块、线=折线、面=闭合多边形；颜色用 lineColor，dashed→虚线。
+    if (showAnomalies_ && !anoms_.empty()) {
+        painter->save();
+        painter->setRenderHint(QPainter::Antialiasing, true);
+        painter->setBrush(Qt::NoBrush);
+        for (const auto& a : anoms_) {
+            if (a.localPts.empty()) continue;
+            QColor col(QString::fromStdString(a.lineColor));
+            if (!col.isValid()) col = QColor(0, 0, 0);
+            QPen pen(col);
+            pen.setWidthF(a.lineWidth > 0 ? a.lineWidth : 1.0);
+            pen.setStyle(a.dashed ? Qt::DashLine : Qt::SolidLine);
+            painter->setPen(pen);
+
+            if (a.markType == core::AnomalyMarkType::Point) {
+                const QPointF c = mapPt(a.localPts.front());
+                painter->drawRect(QRectF(c.x() - 3, c.y() - 3, 6, 6));
+            } else {
+                QPolygonF poly;
+                poly.reserve(static_cast<int>(a.localPts.size()));
+                for (const auto& p : a.localPts) poly << mapPt(p);
+                if (a.markType == core::AnomalyMarkType::Polygon)
+                    painter->drawPolygon(poly);  // 闭合
+                else
+                    painter->drawPolyline(poly);
+            }
+        }
+        painter->restore();
+    }
+}
+
+}  // namespace geopro::app

src/app/panels/chart/ContourPlotItem.hpp

@@ -0,0 +1,58 @@
+#pragma once
+#include <vector>
+
+#include <QImage>
+#include <QRectF>
+#include <qwt_plot_item.h>
+
+#include "model/Anomaly.hpp"
+#include "model/Field.hpp"
+#include "ContourBands.hpp"
+
+class QPainter;
+class QwtScaleMap;
+
+namespace geopro::app {
+
+class ColorMapService;
+
+// 网格等值线图项（QwtPlotItem，非 Q_OBJECT）：
+//  - 填充：预渲染 QImage 热力图（双线性插值 + 离散色带取色），draw 时 blit+平滑缩放
+//    （避免 banded 多边形数万顶点导致拖动卡顿）；含 NaN 的像素透明 → 不规则白边。
+//  - 等值线：buildContourBands 返回的矢量折线（黑细线），随轴变换映射后 drawPolyline。
+//  - 标注：沿线方向旋转的 level 数值（小字黑）。
+//  - 异常叠加：按 markType 画 点(方块)/线(折线)/面(闭合多边形)，dashed→虚线。
+class ContourPlotItem : public QwtPlotItem {
+public:
+    ContourPlotItem();
+
+    // 构建填充图像 + 缓存等值线/异常。svc 不被拥有（由 GridDataChartView 持有）。
+    void setData(const core::Grid& g, ColorMapService* svc,
+                 const std::vector<core::Anomaly>& anoms, bool showLines, bool showLabels);
+
+    void setShowLines(bool on) { showLines_ = on; }
+    void setShowLabels(bool on) { showLabels_ = on; }
+    void setShowAnomalies(bool on) { showAnomalies_ = on; }
+
+    int rtti() const override { return QwtPlotItem::Rtti_PlotUserItem; }
+
+    QRectF boundingRect() const override;
+
+    void draw(QPainter* painter, const QwtScaleMap& xMap, const QwtScaleMap& yMap,
+              const QRectF& canvasRect) const override;
+
+private:
+    void buildFillImage(const core::Grid& g, ColorMapService* svc);
+    void resolveLineLevels(const core::Grid& g, const core::ColorScale& cs);
+
+    QImage fillImage_;                          // 预渲染填充热力图（ARGB32，含透明无数据区）
+    QRectF dataBBox_;                           // 数据包围盒（x[xmin,xmax] y[ymin,ymax]）
+    std::vector<render::ContourLine> lines_;    // 矢量等值线（含 level）
+    std::vector<core::Anomaly> anoms_;          // 异常叠加
+
+    bool showLines_ = true;
+    bool showLabels_ = true;
+    bool showAnomalies_ = true;
+};
+
+}  // namespace geopro::app