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Compute the centroids from projected coordinates

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This commit is contained in:
Martin Tůma 2024-06-24 08:47:46 +02:00
parent df8e8d76b8
commit f8deb573b0
2 changed files with 47 additions and 54 deletions
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98
src/map/ENC/rastertile.cpp
View File

@ -12,7 +12,7 @@
using namespace ENC;
#define TEXT_EXTENT 160
#define TSSLPT_SIZE 0.005 /* ll */
#define TSSLPT_SIZE 24
typedef QSet<Coordinates> PointSet;
@ -20,40 +20,6 @@ static const float C1 = 0.866025f; /* sqrt(3)/2 */
static const QColor tsslptPen = QColor(0xeb, 0x49, 0xeb);
static const QColor tsslptBrush = QColor(0xeb, 0x49, 0xeb, 0x80);
static double area(const QVector<Coordinates> &polygon)
{
double area = 0;
for (int i = 0; i < polygon.size() - 1; i++) {
const Coordinates &pi = polygon.at(i);
const Coordinates &pj = polygon.at(i+1);
area += pi.lon() * pj.lat();
area -= pi.lat() * pj.lon();
}
area /= 2.0;
return area;
}
static Coordinates centroid(const QVector<Coordinates> &polygon)
{
Q_ASSERT(polygon.size() > 3);
Q_ASSERT(polygon.first() == polygon.last());
double cx = 0, cy = 0;
double factor = 1.0 / (6.0 * area(polygon));
for (int i = 0; i < polygon.size() - 1; i++) {
const Coordinates &pi = polygon.at(i);
const Coordinates &pj = polygon.at(i+1);
double f = (pi.lon() * pj.lat() - pj.lon() * pi.lat());
cx += (pi.lon() + pj.lon()) * f;
cy += (pi.lat() + pj.lat()) * f;
}
return Coordinates(cx * factor, cy * factor);
}
static double angle(uint type, const QVariant &param)
{
uint bt = type>>16;
@ -75,6 +41,31 @@ static bool showLabel(const QImage *img, const Range &range, int zoom, int type)
return true;
}
QPointF RasterTile::centroid(const QVector<Coordinates> &polygon) const
{
Q_ASSERT(polygon.size() > 3);
Q_ASSERT(polygon.first() == polygon.last());
double area = 0;
double cx = 0, cy = 0;
QPointF pi;
QPointF pj(ll2xy(polygon.at(0)));
for (int i = 0; i < polygon.size() - 1; i++) {
pi = pj;
pj = ll2xy(polygon.at(i + 1));
double f = pi.x() * pj.y() - pj.x() * pi.y();
area += f;
cx += (pi.x() + pj.x()) * f;
cy += (pi.y() + pj.y()) * f;
}
double factor = 1.0 / (3.0 * area);
return QPointF(cx * factor, cy * factor);
}
QPainterPath RasterTile::painterPath(const Polygon &polygon) const
{
QPainterPath path;
@ -136,27 +127,26 @@ QVector<QPolygonF> RasterTile::polylineM(const QVector<Coordinates> &path) const
return polys;
}
QPolygonF RasterTile::tsslptArrow(const Coordinates &c, qreal angle) const
QPolygonF RasterTile::tsslptArrow(const QPointF &p, qreal angle) const
{
Coordinates t[3], r[4];
QPointF t[3], r[4];
QPolygonF polygon;
t[0] = c;
t[1] = Coordinates(t[0].lon() - qCos(angle - M_PI/3) * TSSLPT_SIZE,
t[0].lat() - qSin(angle - M_PI/3) * TSSLPT_SIZE);
t[2] = Coordinates(t[0].lon() - qCos(angle - M_PI + M_PI/3) * TSSLPT_SIZE,
t[0].lat() - qSin(angle - M_PI + M_PI/3) * TSSLPT_SIZE);
t[0] = p;
t[1] = QPointF(t[0].x() - qCos(angle - M_PI/3) * TSSLPT_SIZE,
t[0].y() - qSin(angle - M_PI/3) * TSSLPT_SIZE);
t[2] = QPointF(t[0].x() - qCos(angle - M_PI + M_PI/3) * TSSLPT_SIZE,
t[0].y() - qSin(angle - M_PI + M_PI/3) * TSSLPT_SIZE);
LineC l(t[1], t[2]);
QLineF l(t[1], t[2]);
r[0] = l.pointAt(0.25);
r[1] = l.pointAt(0.75);
r[2] = Coordinates(r[0].lon() - C1 * TSSLPT_SIZE * qCos(angle - M_PI/2),
r[0].lat() - C1 * TSSLPT_SIZE * qSin(angle - M_PI/2));
r[3] = Coordinates(r[1].lon() - C1 * TSSLPT_SIZE * qCos(angle - M_PI/2),
r[1].lat() - C1 * TSSLPT_SIZE * qSin(angle - M_PI/2));
r[2] = QPointF(r[0].x() - C1 * TSSLPT_SIZE * qCos(angle - M_PI/2),
r[0].y() - C1 * TSSLPT_SIZE * qSin(angle - M_PI/2));
r[3] = QPointF(r[1].x() - C1 * TSSLPT_SIZE * qCos(angle - M_PI/2),
r[1].y() - C1 * TSSLPT_SIZE * qSin(angle - M_PI/2));
polygon << ll2xy(t[0]) << ll2xy(t[2]) << ll2xy(r[1]) << ll2xy(r[3])
<< ll2xy(r[2]) << ll2xy(r[0]) << ll2xy(t[1]);
polygon << t[0] << t[2] << r[1] << r[3] << r[2] << r[0] << t[1];
return polygon;
}
@ -169,7 +159,7 @@ void RasterTile::drawArrows(QPainter *painter,
if (poly.type()>>16 == TSSLPT) {
QPolygonF polygon(tsslptArrow(centroid(poly.path().first()),
deg2rad(180 - poly.param().toDouble())));
deg2rad(poly.param().toDouble())));
painter->setPen(QPen(tsslptPen, 1));
painter->setBrush(QBrush(tsslptBrush));
@ -245,6 +235,7 @@ void RasterTile::processPolygons(const QList<MapData::Poly> &polygons,
const QString *label = 0;
const QFont *fnt = 0;
const QColor *color = 0, *hColor = 0;
QPoint offset(0, 0);
if (!poly.label().isEmpty()) {
const Style::Point &style = _style->point(poly.type());
@ -257,14 +248,15 @@ void RasterTile::processPolygons(const QList<MapData::Poly> &polygons,
|| poly.type() == SUBTYPE(I_BERTHS, 6)) {
const Style::Point &style = _style->point(poly.type());
img = style.img().isNull() ? 0 : &style.img();
offset = style.offset();
}
if ((!label || !fnt) && !img)
continue;
TextPointItem *item = new TextPointItem(
ll2xy(centroid(poly.path().first())).toPoint(),
label, fnt, img, color, hColor, 0, 0);
TextPointItem *item = new TextPointItem(offset +
centroid(poly.path().first()).toPoint(), label, fnt, img, color,
hColor, 0, 0);
if (item->isValid() && _rect.contains(item->boundingRect().toRect())
&& !item->collides(textItems))
textItems.append(item);

3
src/map/ENC/rastertile.h
View File

@ -41,7 +41,8 @@ private:
QPainterPath painterPath(const Polygon &polygon) const;
QPolygonF polyline(const QVector<Coordinates> &path) const;
QVector<QPolygonF> polylineM(const QVector<Coordinates> &path) const;
QPolygonF tsslptArrow(const Coordinates &c, qreal angle) const;
QPolygonF tsslptArrow(const QPointF &p, qreal angle) const;
QPointF centroid(const QVector<Coordinates> &polygon) const;
void processPoints(QList<MapData::Point> &points,
QList<TextItem*> &textItems, QList<TextItem *> &lights);
void processLines(const QList<MapData::Line> &lines,