Add radar range circle. Web mercator projection meters are inaccurate. (~350km instead of 460km).

scwx-qt/source/scwx/qt/map/map_widget.cpp

@@ -1,6 +1,7 @@
 #include "map_widget.hpp"
 
 #include <scwx/qt/map/radar_layer.hpp>
+#include <scwx/qt/map/radar_range_layer.hpp>
 
 #include <QApplication>
 #include <QColor>
@@ -66,7 +67,8 @@ void MapWidget::changeStyle()
 void MapWidget::AddLayers()
 {
    // QMapboxGL::addCustomLayer will take ownership of the QScopedPointer
-   QScopedPointer<QMapbox::CustomLayerHostInterface> pHost(new RadarLayer(map_));
+   QScopedPointer<QMapbox::CustomLayerHostInterface> pHost(
+      new RadarLayer(map_));
 
    QString before = "ferry";
 
@@ -82,6 +84,7 @@ void MapWidget::AddLayers()
    }
 
    map_->addCustomLayer("radar", pHost, before);
+   RadarRangeLayer::Add(map_, before);
 }
 
 void MapWidget::keyPressEvent(QKeyEvent* ev)

scwx-qt/source/scwx/qt/map/radar_range_layer.cpp

@@ -0,0 +1,61 @@
+#include <scwx/qt/map/radar_range_layer.hpp>
+
+#include <boost/log/trivial.hpp>
+
+#include <glm/glm.hpp>
+
+namespace scwx
+{
+namespace qt
+{
+
+static const std::string logPrefix_ = "[scwx::qt::map::radar_range_layer] ";
+
+void RadarRangeLayer::Add(std::shared_ptr<QMapboxGL> map, const QString& before)
+{
+   BOOST_LOG_TRIVIAL(debug) << logPrefix_ << "Add()";
+
+   constexpr float range = 460.0f * 1000.0f;
+
+   constexpr float angleDelta  = glm::radians<float>(0.5f);
+   constexpr float angleDeltaH = angleDelta / 2.0f;
+
+   const QMapbox::Coordinate      radar {38.6986, -90.6828};
+   const QMapbox::ProjectedMeters radarMeters {
+      QMapbox::projectedMetersForCoordinate(radar)};
+
+   float angle = -angleDeltaH;
+
+   QMapbox::Coordinates geometry;
+
+   for (uint16_t azimuth = 0; azimuth <= 720; ++azimuth)
+   {
+      const float sinTheta = std::sinf(angle);
+      const float cosTheta = std::cosf(angle);
+
+      const float x = range * sinTheta + radarMeters.second;
+      const float y = range * cosTheta + radarMeters.first;
+
+      QMapbox::Coordinate point {QMapbox::coordinateForProjectedMeters({y, x})};
+
+      geometry.append(point);
+
+      angle += angleDelta;
+   }
+
+   QMapbox::Feature rangeCircle {QMapbox::Feature::LineStringType,
+                                 {{geometry}}};
+
+   map->addSource(
+      "rangeCircleSource",
+      {{"type", "geojson"}, {"data", QVariant::fromValue(rangeCircle)}});
+   map->addLayer({{"id", "rangeCircleLayer"},
+                  {"type", "line"},
+                  {"source", "rangeCircleSource"}},
+                 before);
+   map->setPaintProperty(
+      "rangeCircleLayer", "line-color", "rgba(128, 128, 128, 128)");
+}
+
+} // namespace qt
+} // namespace scwx

scwx-qt/source/scwx/qt/map/radar_range_layer.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <QMapboxGL>
+
+namespace scwx
+{
+namespace qt
+{
+
+namespace RadarRangeLayer
+{
+void Add(std::shared_ptr<QMapboxGL> map, const QString& before = QString());
+};
+
+} // namespace qt
+} // namespace scwx