Added polygon labels rendering

src/map/mapsforge/mapdata.cpp

@@ -544,7 +544,7 @@ bool MapData::readPaths(const VectorTile *tile, int zoom, QList<Path> *list)
 	QVector<unsigned> paths(rows);
 	quint32 blocks, unused, val, cnt = 0;
 	quint16 bitmap;
-	quint8 flags;
+	quint8 sb, flags;
 	QByteArray label, houseNumber, reference;
 
 
@@ -565,13 +565,14 @@ bool MapData::readPaths(const VectorTile *tile, int zoom, QList<Path> *list)
 
 	for (unsigned i = 0; i < paths[zoom - info.min]; i++) {
 		Path p;
+		qint32 lon = 0, lat = 0;
 
 		if (!(subfile.readVUInt32(unused) && subfile.readUInt16(bitmap)
-		  && subfile.readByte(flags)))
+		  && subfile.readByte(sb)))
 			return false;
 
-		p.layer = flags >> 4;
-		int tags = flags & 0x0F;
+		p.layer = sb >> 4;
+		int tags = sb & 0x0F;
 		if (!readTags(subfile, tags, _pathTags, p.tags))
 			return false;
 
@@ -592,8 +593,7 @@ bool MapData::readPaths(const VectorTile *tile, int zoom, QList<Path> *list)
 			p.reference = reference;
 		}
 		if (flags & 0x10) {
-			qint32 unused;
-			if (!(subfile.readVInt32(unused) && subfile.readVInt32(unused)))
+			if (!(subfile.readVInt32(lat) && subfile.readVInt32(lon)))
 				return false;
 		}
 		if (flags & 0x08) {
@@ -607,6 +607,9 @@ bool MapData::readPaths(const VectorTile *tile, int zoom, QList<Path> *list)
 			if (!readPolygon(subfile, tile->pos, flags & 0x04, p.poly))
 				return false;
 			p.closed = isClosed(p.poly);
+			if (flags & 0x10)
+				p.labelPos = Coordinates(p.poly.first().first().lon() + MD(lon),
+				  p.poly.first().first().lat() + MD(lat));
 
 			list->append(p);
 		}
@@ -622,7 +625,7 @@ bool MapData::readPoints(const VectorTile *tile, int zoom, QList<Point> *list)
 	int rows = info.max - info.min + 1;
 	QVector<unsigned> points(rows);
 	quint32 val, unused, cnt = 0;
-	quint8 flags;
+	quint8 sb, flags;
 	QByteArray label, houseNumber;
 
 
@@ -647,10 +650,10 @@ bool MapData::readPoints(const VectorTile *tile, int zoom, QList<Point> *list)
 		Point p(Coordinates(tile->pos.lon() + MD(lon),
 		  tile->pos.lat() + MD(lat)));
 
-		if (!subfile.readByte(flags))
+		if (!subfile.readByte(sb))
 			return false;
-		p.layer = flags >> 4;
-		int tags = flags & 0x0F;
+		p.layer = sb >> 4;
+		int tags = sb & 0x0F;
 		if (!readTags(subfile, tags, _pointTags, p.tags))
 			return false;
 

src/map/mapsforge/mapdata.h

@@ -57,6 +57,7 @@ public:
 		QString label;
 		QString reference;
 		QVector<Tag> tags;
+		Coordinates labelPos;
 		int layer;
 		bool closed;
 

src/map/mapsforge/rastertile.cpp

@@ -14,6 +14,36 @@ static const Style& style()
 	return s;
 }
 
+static qreal area(const QPainterPath &polygon)
+{
+	qreal area = 0;
+
+	for (int i = 0; i < polygon.elementCount(); i++) {
+		int j = (i + 1) % polygon.elementCount();
+		area += polygon.elementAt(i).x * polygon.elementAt(j).y;
+		area -= polygon.elementAt(i).y * polygon.elementAt(j).x;
+	}
+	area /= 2.0;
+
+	return area;
+}
+
+static QPointF centroid(const QPainterPath &polygon)
+{
+	qreal cx = 0, cy = 0;
+	qreal factor = 1.0 / (6.0 * area(polygon));
+
+	for (int i = 0; i < polygon.elementCount(); i++) {
+		int j = (i + 1) % polygon.elementCount();
+		qreal f = (polygon.elementAt(i).x * polygon.elementAt(j).y
+		  - polygon.elementAt(j).x * polygon.elementAt(i).y);
+		cx += (polygon.elementAt(i).x + polygon.elementAt(j).x) * f;
+		cy += (polygon.elementAt(i).y + polygon.elementAt(j).y) * f;
+	}
+
+	return QPointF(cx * factor, cy * factor);
+}
+
 void RasterTile::processPoints(QList<TextItem*> &textItems)
 {
 	const Style &s = style();
@@ -59,6 +89,42 @@ void RasterTile::processPoints(QList<TextItem*> &textItems)
 	}
 }
 
+void RasterTile::processPolygonNames(const QRect &tileRect,
+  QList<TextItem*> &textItems)
+{
+	const Style &s = style();
+	QSet<QString> set;
+
+	for (int i = 0; i < s.pointLabels().size(); i++) {
+		const Style::TextRender &ri = s.pointLabels().at(i);
+
+		for (int j = 0; j < _paths.size(); j++) {
+			const MapData::Path &path = _paths.at(j);
+
+			if (path.label.isEmpty())
+				continue;
+			if (!path.path.elementCount())
+				continue;
+			if (set.contains(path.label))
+				continue;
+			if (!ri.rule().match(_zoom, path.closed, path.tags))
+				continue;
+
+			QPointF pos = path.labelPos.isNull()
+			  ? centroid(path.path) : ll2xy(path.labelPos);
+
+			TextPointItem *item = new TextPointItem(pos.toPoint(), &path.label,
+			  &ri.font(), 0, &ri.fillColor(), 0, false);
+			if (item->isValid() && tileRect.contains(item->boundingRect().toRect())
+			  && !item->collides(textItems)) {
+				textItems.append(item);
+				set.insert(path.label);
+			} else
+				delete item;
+		}
+	}
+}
+
 void RasterTile::processStreetNames(const QRect &tileRect,
   QList<TextItem*> &textItems)
 {
@@ -173,6 +239,7 @@ void RasterTile::render()
 	drawPaths(&painter);
 
 	processPoints(textItems);
+	processPolygonNames(tileRect, textItems);
 	processStreetNames(tileRect, textItems);
 	drawTextItems(&painter, textItems);
 

src/map/mapsforge/rastertile.h

@@ -72,6 +72,7 @@ private:
 	QPointF ll2xy(const Coordinates &c) const
 	  {return _transform.proj2img(_proj.ll2xy(c));}
 	void processPoints(QList<TextItem*> &textItems);
+	void processPolygonNames(const QRect &tileRect, QList<TextItem*> &textItems);
 	void processStreetNames(const QRect &tileRect, QList<TextItem*> &textItems);
 	QPainterPath painterPath(const Polygon &polygon) const;
 	void drawTextItems(QPainter *painter, const QList<TextItem*> &textItems);