Add polished macOS location plotter experience

src/GlobeWidget.cpp

@@ -1,12 +1,14 @@
 #include "GlobeWidget.h"
 
 #include <QLinearGradient>
+#include <QDateTime>
 #include <QHash>
 #include <QFile>
 #include <QJsonArray>
 #include <QJsonDocument>
 #include <QJsonObject>
 #include <QMouseEvent>
+#include <QNativeGestureEvent>
 #include <QPainter>
 #include <QPainterPath>
 #include <QPolygonF>
@@ -184,6 +186,15 @@ const QImage &landMask()
     return mask;
 }
 
+const QImage &blueMarbleTexture()
+{
+    static const QImage texture = [] {
+        QImage image(QStringLiteral(":/resources/bluemarble-2048.png"));
+        return image.convertToFormat(QImage::Format_RGB32);
+    }();
+    return texture;
+}
+
 bool maskIsLand(double longitude, double latitude)
 {
     const QImage &mask = landMask();
@@ -369,11 +380,28 @@ void GlobeWidget::paintEvent(QPaintEvent *)
     QPainterPath sphereClip;
     sphereClip.addEllipse(center, radius, radius);
     painter.setClipPath(sphereClip);
-    drawContinents(painter);
+    drawBlueMarble(painter);
     drawGraticule(painter);
     painter.restore();
 
+    // A subtle limb shadow and ocean highlight add depth without hiding the
+    // geographic texture or telemetry overlays.
+    painter.save();
+    QPainterPath lightingClip;
+    lightingClip.addEllipse(center, radius, radius);
+    painter.setClipPath(lightingClip);
+    QRadialGradient limb(center - QPointF(radius * .30, radius * .34), radius * 1.30);
+    limb.setColorAt(0.0, QColor(255, 255, 255, 18));
+    limb.setColorAt(0.50, QColor(70, 175, 225, 5));
+    limb.setColorAt(0.82, QColor(0, 8, 20, 35));
+    limb.setColorAt(1.0, QColor(0, 3, 12, 155));
+    painter.setPen(Qt::NoPen);
+    painter.setBrush(limb);
+    painter.drawEllipse(center, radius, radius);
+    painter.restore();
+
     for (int i = 0; i < 3; ++i) drawOrbit(painter, 55.0 + i * 1.8, i * 61.0 + 12.0);
+    drawSatelliteCoverage(painter);
     if (m_hasReceiver) drawVisibilityCone(painter);
     if (m_hasReceiver) drawReceiver(painter);
     drawSatellites(painter);
@@ -391,6 +419,9 @@ void GlobeWidget::paintEvent(QPaintEvent *)
     painter.setFont(smallFont);
     painter.setPen(m_statusError ? QColor(255, 177, 77) : QColor(132, 177, 204));
     painter.drawText(QRect(20, 43, width() - 40, 22), Qt::AlignLeft | Qt::AlignVCenter, m_status);
+    painter.setPen(QColor(105, 143, 166, 145));
+    painter.drawText(QRect(20, 43, width() - 40, 22), Qt::AlignRight | Qt::AlignVCenter,
+                     QStringLiteral("Earth: NASA/GSFC Blue Marble"));
 
     const int legendY = height() - 25;
     const int legendX = width() / 2 - 125;
@@ -425,6 +456,100 @@ void GlobeWidget::paintEvent(QPaintEvent *)
     }
 }
 
+void GlobeWidget::drawBlueMarble(QPainter &painter) const
+{
+    const QImage &source = blueMarbleTexture();
+    if (source.isNull()) {
+        drawContinents(painter);
+        return;
+    }
+
+    const double radius = std::min(width(), height()) * 0.255 * m_zoom;
+    const double pixelRatio = std::min(devicePixelRatioF(), 2.0);
+    const int textureSize = std::clamp(
+        static_cast<int>(std::ceil(radius * 2.0 * pixelRatio)), 420, 1200);
+    const QPointF center(width() * 0.5, height() * 0.52);
+    const QRectF target(center.x() - radius, center.y() - radius,
+                        radius * 2.0, radius * 2.0);
+    const QDateTime nowUtc = QDateTime::currentDateTimeUtc();
+    const qint64 lightingMinute = nowUtc.toSecsSinceEpoch() / 60;
+    if (!m_landTexture.isNull() && m_landTexture.width() == textureSize
+        && m_landTextureYaw == m_yaw && m_landTexturePitch == m_pitch
+        && m_landTextureLightingMinute == lightingMinute) {
+        painter.setRenderHint(QPainter::SmoothPixmapTransform, true);
+        painter.drawImage(target, m_landTexture);
+        return;
+    }
+
+    QImage globe(textureSize, textureSize, QImage::Format_ARGB32_Premultiplied);
+    globe.fill(Qt::transparent);
+    const double cy = std::cos(m_yaw);
+    const double sy = std::sin(m_yaw);
+    const double cp = std::cos(m_pitch);
+    const double sp = std::sin(m_pitch);
+    const double utcHours = nowUtc.time().msecsSinceStartOfDay() / 3600000.0;
+    const double declination = 23.44 * std::sin(
+        2.0 * Pi * (284.0 + nowUtc.date().dayOfYear()) / 365.25);
+    const Vec3 sun = globeVector(declination, (12.0 - utcHours) * 15.0);
+    const Vec3 camera {sy * cp, cy * cp, -sp};
+    const double halfLength = std::sqrt(std::pow(sun.x + camera.x, 2.0)
+        + std::pow(sun.y + camera.y, 2.0) + std::pow(sun.z + camera.z, 2.0));
+    const Vec3 halfVector {(sun.x + camera.x) / halfLength,
+                           (sun.y + camera.y) / halfLength,
+                           (sun.z + camera.z) / halfLength};
+
+    for (int py = 0; py < textureSize; ++py) {
+        QRgb *destination = reinterpret_cast<QRgb *>(globe.scanLine(py));
+        const double screenZ = -((py + 0.5) / textureSize * 2.0 - 1.0);
+        for (int px = 0; px < textureSize; ++px) {
+            const double screenX = (px + 0.5) / textureSize * 2.0 - 1.0;
+            const double radiusSquared = screenX * screenX + screenZ * screenZ;
+            if (radiusSquared > 1.0) continue;
+            const double depth = std::sqrt(1.0 - radiusSquared);
+            const double yawY = cp * depth + sp * screenZ;
+            const double worldZ = -sp * depth + cp * screenZ;
+            const double worldX = cy * screenX + sy * yawY;
+            const double worldY = -sy * screenX + cy * yawY;
+            const double latitude = std::asin(std::clamp(worldZ, -1.0, 1.0));
+            const double longitude = std::atan2(worldY, worldX);
+            int sourceX = static_cast<int>((longitude / (2.0 * Pi) + 0.5) * source.width());
+            sourceX = (sourceX % source.width() + source.width()) % source.width();
+            const int sourceY = std::clamp(static_cast<int>((0.5 - latitude / Pi)
+                                               * source.height()), 0, source.height() - 1);
+            const QRgb sample = reinterpret_cast<const QRgb *>(source.constScanLine(sourceY))[sourceX];
+
+            double red = qRed(sample);
+            double green = qGreen(sample);
+            double blue = qBlue(sample);
+            const double solarDot = worldX * sun.x + worldY * sun.y + worldZ * sun.z;
+            const double daylight = smoothStep(-0.10, 0.07, solarDot);
+            const double diffuse = 0.16 + 0.84 * std::max(0.0, solarDot);
+            const bool ocean = blue > green * 1.18 && blue > red * 1.35;
+            if (ocean) {
+                const double halfDot = std::max(0.0, worldX * halfVector.x
+                    + worldY * halfVector.y + worldZ * halfVector.z);
+                const double specular = std::pow(halfDot, 80.0) * daylight * 115.0;
+                red += specular;
+                green += specular;
+                blue += specular * 0.92;
+            }
+            const double limb = smoothStep(0.02, 0.34, depth);
+            const double lighting = (0.08 + diffuse * 0.92) * (0.45 + limb * 0.55);
+            destination[px] = qRgba(
+                std::clamp(static_cast<int>(red * lighting), 0, 255),
+                std::clamp(static_cast<int>(green * lighting), 0, 255),
+                std::clamp(static_cast<int>(blue * lighting), 0, 255), 255);
+        }
+    }
+
+    m_landTexture = globe;
+    m_landTextureYaw = m_yaw;
+    m_landTexturePitch = m_pitch;
+    m_landTextureLightingMinute = lightingMinute;
+    painter.setRenderHint(QPainter::SmoothPixmapTransform, true);
+    painter.drawImage(target, m_landTexture);
+}
+
 void GlobeWidget::drawContinents(QPainter &painter) const
 {
     const double radius = std::min(width(), height()) * 0.255 * m_zoom;
@@ -434,8 +559,11 @@ void GlobeWidget::drawContinents(QPainter &painter) const
     const QPointF center(width() * 0.5, height() * 0.52);
     const QRectF target(center.x() - radius, center.y() - radius,
                         radius * 2.0, radius * 2.0);
+    const QDateTime nowUtc = QDateTime::currentDateTimeUtc();
+    const qint64 lightingMinute = nowUtc.toSecsSinceEpoch() / 60;
     if (!m_landTexture.isNull() && m_landTexture.width() == textureSize
-        && m_landTextureYaw == m_yaw && m_landTexturePitch == m_pitch) {
+        && m_landTextureYaw == m_yaw && m_landTexturePitch == m_pitch
+        && m_landTextureLightingMinute == lightingMinute) {
         painter.setRenderHint(QPainter::SmoothPixmapTransform, true);
         painter.drawImage(target, m_landTexture);
         return;
@@ -447,6 +575,18 @@ void GlobeWidget::drawContinents(QPainter &painter) const
     const double sy = std::sin(m_yaw);
     const double cp = std::cos(m_pitch);
     const double sp = std::sin(m_pitch);
+    const double utcHours = nowUtc.time().msecsSinceStartOfDay() / 3600000.0;
+    const double solarDeclination = 23.44 * std::sin(
+        2.0 * Pi * (284.0 + nowUtc.date().dayOfYear()) / 365.25);
+    const double subsolarLongitude = (12.0 - utcHours) * 15.0;
+    const Vec3 sun = globeVector(solarDeclination, subsolarLongitude);
+    const Vec3 camera {sy * cp, cy * cp, -sp};
+    const double halfLength = std::sqrt(
+        std::pow(sun.x + camera.x, 2.0) + std::pow(sun.y + camera.y, 2.0)
+        + std::pow(sun.z + camera.z, 2.0));
+    const Vec3 halfVector {(sun.x + camera.x) / halfLength,
+                           (sun.y + camera.y) / halfLength,
+                           (sun.z + camera.z) / halfLength};
     for (int py = 0; py < textureSize; ++py) {
         QRgb *scanLine = reinterpret_cast<QRgb *>(land.scanLine(py));
         const double screenZ = -((py + 0.5) / textureSize * 2.0 - 1.0);
@@ -467,16 +607,37 @@ void GlobeWidget::drawContinents(QPainter &painter) const
                 || maskIsLand(longitude - 0.55, latitude)
                 || maskIsLand(longitude, latitude + 0.55)
                 || maskIsLand(longitude, latitude - 0.55);
+            const double cloudNoise = 0.50
+                + 0.24 * std::sin(longitude * Pi / 22.0 + latitude * Pi / 19.0)
+                + 0.18 * std::sin(longitude * Pi / 7.0 - latitude * Pi / 13.0)
+                + 0.12 * std::cos(longitude * Pi / 3.7 + latitude * Pi / 8.0);
+            const double cloud = smoothStep(0.72, 0.94, cloudNoise)
+                * smoothStep(0.03, 0.25, depth);
+            const double solarDot = worldX * sun.x + worldY * sun.y + worldZ * sun.z;
+            const double daylight = smoothStep(-0.11, 0.08, solarDot);
+            const double diffuse = 0.12 + 0.88 * std::max(0.0, solarDot);
             if (!onLand) {
-                if (nearLand) {
-                    const int alpha = static_cast<int>(65.0 * std::clamp(depth * 1.5, 0.0, 1.0));
-                    scanLine[px] = qRgba(33, 151, 174, alpha);
-                }
+                const double oceanPattern = 0.5 + 0.25 * std::sin(longitude * Pi / 31.0)
+                    + 0.18 * std::cos(latitude * Pi / 17.0 + longitude * Pi / 47.0);
+                double red = nearLand ? 18.0 : 3.0 + oceanPattern * 5.0;
+                double green = nearLand ? 104.0 : 32.0 + oceanPattern * 16.0;
+                double blue = nearLand ? 132.0 : 72.0 + oceanPattern * 26.0;
+                const double halfDot = std::max(0.0, worldX * halfVector.x
+                    + worldY * halfVector.y + worldZ * halfVector.z);
+                const double specular = std::pow(halfDot, 72.0) * daylight * 150.0;
+                const double shade = 0.18 + diffuse * 0.82;
+                red = red * shade + specular;
+                green = green * shade + specular;
+                blue = blue * shade + specular * 0.92;
+                red = red * (1.0 - cloud * 0.58) + 226.0 * cloud * 0.58;
+                green = green * (1.0 - cloud * 0.58) + 237.0 * cloud * 0.58;
+                blue = blue * (1.0 - cloud * 0.58) + 243.0 * cloud * 0.58;
+                scanLine[px] = qRgba(std::clamp(static_cast<int>(red), 0, 255),
+                                     std::clamp(static_cast<int>(green), 0, 255),
+                                     std::clamp(static_cast<int>(blue), 0, 255), 248);
                 continue;
             }
 
-            const double light = std::clamp(0.30 + 0.70
-                * (0.35 - screenX * 0.38 + screenZ * 0.48 + depth * 0.38), 0.18, 1.0);
             const double lon = longitude * Pi / 180.0;
             const double lat = latitude * Pi / 180.0;
             const double broadRelief = 0.50 + 0.24 * std::sin(lon * 5.0 + lat * 2.2)
@@ -505,31 +666,110 @@ void GlobeWidget::drawContinents(QPainter &painter) const
             red = red * (1.0 - snow) + 224.0 * snow;
             green = green * (1.0 - snow) + 231.0 * snow;
             blue = blue * (1.0 - snow) + 224.0 * snow;
+            red = red * (1.0 - cloud * 0.62) + 232.0 * cloud * 0.62;
+            green = green * (1.0 - cloud * 0.62) + 241.0 * cloud * 0.62;
+            blue = blue * (1.0 - cloud * 0.62) + 244.0 * cloud * 0.62;
 
             const bool coast = !maskIsLand(longitude + 0.55, latitude)
                 || !maskIsLand(longitude - 0.55, latitude)
                 || !maskIsLand(longitude, latitude + 0.55)
                 || !maskIsLand(longitude, latitude - 0.55);
-            const double shade = light * (0.86 + relief * 0.14);
+            const double shade = (0.15 + diffuse * 0.85) * (0.86 + relief * 0.14);
             if (coast) {
                 red += 28.0;
                 green += 31.0;
                 blue += 18.0;
             }
+            const double settlementNoise = 0.5 + 0.28 * std::sin(lon * 41.0 + lat * 19.0)
+                + 0.22 * std::cos(lon * 73.0 - lat * 31.0);
+            const double cityLights = smoothStep(0.82, 0.98, settlementNoise)
+                * (1.0 - daylight) * smoothStep(68.0, 42.0, std::abs(latitude));
             scanLine[px] = qRgba(
-                std::clamp(static_cast<int>(red * shade), 0, 255),
-                std::clamp(static_cast<int>(green * shade), 0, 255),
-                std::clamp(static_cast<int>(blue * shade), 0, 255), 238);
+                std::clamp(static_cast<int>(red * shade + cityLights * 235.0), 0, 255),
+                std::clamp(static_cast<int>(green * shade + cityLights * 155.0), 0, 255),
+                std::clamp(static_cast<int>(blue * shade + cityLights * 52.0), 0, 255), 248);
         }
     }
 
     m_landTexture = land;
     m_landTextureYaw = m_yaw;
     m_landTexturePitch = m_pitch;
+    m_landTextureLightingMinute = lightingMinute;
     painter.setRenderHint(QPainter::SmoothPixmapTransform, true);
     painter.drawImage(target, m_landTexture);
 }
 
+void GlobeWidget::drawSatelliteCoverage(QPainter &painter) const
+{
+    if (m_satellites.isEmpty()) return;
+
+    constexpr double EarthRadiusMeters = 6378137.0;
+    const double earthRadiusPixels = std::min(width(), height()) * 0.255 * m_zoom;
+    const double elevation = m_elevationMaskDegrees * Pi / 180.0;
+
+    for (const SatellitePosition &satellite : m_satellites) {
+        const double orbitRadius = std::sqrt(satellite.x * satellite.x
+                                             + satellite.y * satellite.y
+                                             + satellite.z * satellite.z);
+        if (orbitRadius <= EarthRadiusMeters) continue;
+
+        const Vec3 normal {satellite.x / orbitRadius, satellite.y / orbitRadius,
+                           satellite.z / orbitRadius};
+        const double footprintAngle = std::acos(std::clamp(
+            EarthRadiusMeters / orbitRadius * std::cos(elevation), -1.0, 1.0)) - elevation;
+        Vec3 reference = std::abs(normal.z) < 0.88
+            ? Vec3{0.0, 0.0, 1.0} : Vec3{1.0, 0.0, 0.0};
+        Vec3 tangentA {
+            reference.y * normal.z - reference.z * normal.y,
+            reference.z * normal.x - reference.x * normal.z,
+            reference.x * normal.y - reference.y * normal.x
+        };
+        const double tangentLength = std::sqrt(tangentA.x * tangentA.x
+                                                + tangentA.y * tangentA.y
+                                                + tangentA.z * tangentA.z);
+        if (tangentLength <= 0.0) continue;
+        tangentA = {tangentA.x / tangentLength, tangentA.y / tangentLength,
+                    tangentA.z / tangentLength};
+        const Vec3 tangentB {
+            normal.y * tangentA.z - normal.z * tangentA.y,
+            normal.z * tangentA.x - normal.x * tangentA.z,
+            normal.x * tangentA.y - normal.y * tangentA.x
+        };
+
+        const bool tracked = m_observedPrns.contains(satellite.prn);
+        QColor coverageColor = tracked ? QColor(69, 232, 157, 78)
+                                       : QColor(83, 188, 230, 25);
+        painter.setPen(QPen(coverageColor, tracked ? 1.15 : 0.65, Qt::DashLine));
+        painter.setBrush(Qt::NoBrush);
+        QPainterPath visibleSegments;
+        bool drawing = false;
+        constexpr int Segments = 72;
+        for (int segment = 0; segment <= Segments; ++segment) {
+            const double angle = 2.0 * Pi * segment / Segments;
+            const Vec3 tangent {
+                tangentA.x * std::cos(angle) + tangentB.x * std::sin(angle),
+                tangentA.y * std::cos(angle) + tangentB.y * std::sin(angle),
+                tangentA.z * std::cos(angle) + tangentB.z * std::sin(angle)
+            };
+            const Vec3 surface {
+                normal.x * std::cos(footprintAngle) + tangent.x * std::sin(footprintAngle),
+                normal.y * std::cos(footprintAngle) + tangent.y * std::sin(footprintAngle),
+                normal.z * std::cos(footprintAngle) + tangent.z * std::sin(footprintAngle)
+            };
+            const ProjectedPoint point = project(surface.x, surface.y, surface.z,
+                                                 earthRadiusPixels * 1.006);
+            if (point.depth >= -0.015) {
+                if (!drawing) visibleSegments.moveTo(point.point);
+                else visibleSegments.lineTo(point.point);
+                drawing = true;
+            } else {
+                drawing = false;
+            }
+        }
+        painter.drawPath(visibleSegments);
+    }
+}
+
 void GlobeWidget::drawStars(QPainter &painter) const
 {
     painter.setPen(Qt::NoPen);
@@ -546,6 +786,10 @@ void GlobeWidget::drawStars(QPainter &painter) const
 void GlobeWidget::drawGraticule(QPainter &painter) const
 {
     const double radius = std::min(width(), height()) * 0.255 * m_zoom;
+    // Paths are open grid lines. Inheriting the radial Earth brush makes
+    // QPainter implicitly close and fill them, which produced the black
+    // rectangular/polygonal artifacts on the globe.
+    painter.setBrush(Qt::NoBrush);
     painter.setPen(QPen(QColor(100, 193, 221, 48), 0.8));
     for (int latitude = -60; latitude <= 60; latitude += 30) {
         QPainterPath path;
@@ -662,14 +906,10 @@ void GlobeWidget::drawVisibilityCone(QPainter &painter) const
                                earthRadiusPixels * displayOrbitRatio));
     }
 
-    painter.setPen(Qt::NoPen);
-    for (int i = 0; i < Segments; ++i) {
-        const double averageDepth = (apex.depth + ring[i].depth + ring[i + 1].depth) / 3.0;
-        const int alpha = averageDepth >= 0.0 ? 18 : 7;
-        painter.setBrush(QColor(48, 207, 218, alpha));
-        painter.drawPolygon(QPolygonF{apex.point, ring[i].point, ring[i + 1].point});
-    }
-
+    // Do not fill the projected cone with a triangle fan. When part of the
+    // ring is behind the globe that fan self-intersects and produces dark
+    // rectangular/polygonal artifacts over the Earth texture. The boundary,
+    // spokes and sight lines communicate the same mask without obscuring it.
     QPainterPath boundary;
     boundary.moveTo(ring.first().point);
     for (int i = 1; i < ring.size(); ++i) boundary.lineTo(ring[i].point);
@@ -808,7 +1048,26 @@ void GlobeWidget::mouseReleaseEvent(QMouseEvent *event)
 
 void GlobeWidget::wheelEvent(QWheelEvent *event)
 {
-    m_zoom = std::clamp(m_zoom + event->angleDelta().y() / 1200.0, 0.72, 1.28);
+    const QPoint pixelDelta = event->pixelDelta();
+    const double delta = !pixelDelta.isNull()
+        ? pixelDelta.y() / 420.0
+        : event->angleDelta().y() / 1200.0;
+    if (qFuzzyIsNull(delta)) return;
+    m_zoom = std::clamp(m_zoom + delta, 0.62, 1.42);
     update();
     event->accept();
 }
+
+bool GlobeWidget::event(QEvent *event)
+{
+    if (event->type() == QEvent::NativeGesture) {
+        auto *gesture = static_cast<QNativeGestureEvent *>(event);
+        if (gesture->gestureType() == Qt::ZoomNativeGesture) {
+            m_zoom = std::clamp(m_zoom + gesture->value() * 0.85, 0.62, 1.42);
+            update();
+            gesture->accept();
+            return true;
+        }
+    }
+    return QWidget::event(event);
+}