Improved text layout handling

src/style.cpp

@@ -278,8 +278,7 @@ bool Style::Layer::Paint::antialias(Layer::Type type, int zoom) const
 }
 
 Style::Layer::Layout::Layout(const QJsonObject &json)
-  : _lineCap(Qt::FlatCap), _lineJoin(Qt::MiterJoin), _font("Open Sans"),
-  _viewportAlignment(false)
+  : _lineCap(Qt::FlatCap), _lineJoin(Qt::MiterJoin), _font("Open Sans")
 {
 	// line
 	_lineCap = FunctionS(json["line-cap"], "butt");
@@ -292,18 +291,17 @@ Style::Layer::Layout::Layout(const QJsonObject &json)
 	_textMaxWidth = FunctionF(json["text-max-width"], 10);
 	_textMaxAngle = FunctionF(json["text-max-angle"], 45);
 	_textTransform = FunctionS(json["text-transform"], "none");
+	_textRotationAlignment = FunctionS(json["text-rotation-alignment"]);
+	_textAnchor = FunctionS(json["text-anchor"]);
 
 	if (json.contains("text-font") && json["text-font"].isArray())
 		_font = Font::fromJsonArray(json["text-font"].toArray());
-	if (json.contains("text-rotation-alignment")
-	  && json["text-rotation-alignment"].isString())
-		if (json["text-rotation-alignment"].toString() == "viewport")
-			_viewportAlignment = true;
-
-	_textAnchor = FunctionS(json["text-anchor"]);
 
 	// icon
 	_icon = Template(FunctionS(json["icon-image"]));
+
+	// symbol
+	_symbolPlacement = FunctionS(json["symbol-placement"]);
 }
 
 QFont Style::Layer::Layout::font(int zoom) const
@@ -367,6 +365,31 @@ Qt::PenJoinStyle Style::Layer::Layout::lineJoin(int zoom) const
 		return Qt::MiterJoin;
 }
 
+Text::SymbolPlacement Style::Layer::Layout::symbolPlacement(int zoom) const
+{
+	QString placement(_symbolPlacement.value(zoom));
+
+	if (placement == "line")
+		return Text::Line;
+	else if (placement == "line-center")
+		return Text::LineCenter;
+	else
+		return Text::Point;
+}
+
+Text::RotationAlignment Style::Layer::Layout::textRotationAlignment(int zoom)
+  const
+{
+	QString alignment(_textRotationAlignment.value(zoom));
+
+	if (alignment == "map")
+		return Text::Map;
+	else if (alignment == "viewport")
+		return Text::Viewport;
+	else
+		return Text::Auto;
+}
+
 Style::Layer::Layer(const QJsonObject &json)
   : _type(Unknown), _minZoom(-1), _maxZoom(-1)
 {
@@ -437,6 +460,8 @@ void Style::Layer::setTextProperties(Tile &tile) const
 	tile.text().setAnchor(_layout.textAnchor(tile.zoom()));
 	tile.text().setPen(_paint.pen(_type, tile.zoom()));
 	tile.text().setFont(_layout.font(tile.zoom()));
+	tile.text().setSymbolPlacement(_layout.symbolPlacement(tile.zoom()));
+	tile.text().setRotationAlignment(_layout.textRotationAlignment(tile.zoom()));
 }
 
 void Style::Layer::addSymbol(Tile &tile, const QPainterPath &path,
@@ -447,13 +472,7 @@ void Style::Layer::addSymbol(Tile &tile, const QPainterPath &path,
 		return;
 
 	QString icon = _layout.icon(tile.zoom(), tags);
-
-	if (_layout.viewportAlignment())
-		tile.text().addLabel(text, path.elementAt(0), false, sprites.icon(icon));
-	else if (path.elementCount() == 1 && path.elementAt(0).isMoveTo())
-		tile.text().addLabel(text, path.elementAt(0), true, sprites.icon(icon));
-	else
-		tile.text().addLabel(text, path);
+	tile.text().addLabel(text, sprites.icon(icon), path);
 }
 
 bool Style::load(const QString &fileName)

src/style.h

@@ -94,7 +94,7 @@ private:
 		class Layout {
 		public:
 			Layout() : _textSize(16), _textMaxWidth(10), _textMaxAngle(45),
-			  _font("Open Sans"), _viewportAlignment(false) {}
+			  _font("Open Sans") {}
 			Layout(const QJsonObject &json);
 
 			qreal maxTextWidth(int zoom) const
@@ -109,7 +109,8 @@ private:
 			Qt::PenCapStyle lineCap(int zoom) const;
 			Qt::PenJoinStyle lineJoin(int zoom) const;
 			Text::Anchor textAnchor(int zoom) const;
-			bool viewportAlignment() const {return _viewportAlignment;}
+			Text::SymbolPlacement symbolPlacement(int zoom) const;
+			Text::RotationAlignment textRotationAlignment(int zoom) const;
 
 		private:
 			QFont::Capitalization textTransform(int zoom) const;
@@ -123,8 +124,9 @@ private:
 			FunctionS _lineJoin;
 			FunctionS _textAnchor;
 			FunctionS _textTransform;
+			FunctionS _symbolPlacement;
+			FunctionS _textRotationAlignment;
 			QFont _font;
-			bool _viewportAlignment;
 		};
 
 		class Paint {

src/text.cpp

@@ -1,4 +1,4 @@
-#include <QFontMetrics>
+#include <QFontMetrics>
 #include <QPainter>
 #include "text.h"
 #include "textpointitem.h"
@@ -20,15 +20,36 @@ void Text::render(QPainter *painter) const
 	}
 }
 
-void Text::addLabel(const QString &text, const QPointF &pos, bool overlap,
-  const QImage &icon)
+void Text::addLabel(const QString &text, const QImage &icon,
+  const QPainterPath &path)
 {
-	TextPointItem *ti = new TextPointItem(text, pos, _font, _maxWidth, _anchor,
-	  icon);
-	if (!overlap && !_sceneRect.contains(ti->boundingRect())) {
-		delete ti;
-		return;
+	TextItem *ti;
+
+	switch (_placement) {
+		case Line:
+			if (_alignment == Viewport)
+				ti = new TextPointItem(text, path.elementAt(0), _font,
+				  _maxWidth, _anchor, icon);
+			else
+				ti = new TextPathItem(text, path, _font, _maxAngle, _sceneRect);
+			if (!_sceneRect.contains(ti->boundingRect()))
+				ti->setVisible(false);
+			break;
+		case LineCenter:
+			ti = new TextPointItem(text, path.pointAtPercent(0.5), _font,
+			  _maxWidth, _anchor, icon);
+			if (!_sceneRect.contains(ti->boundingRect()))
+				ti->setVisible(false);
+			break;
+		default:
+			ti = new TextPointItem(text, path.elementAt(0), _font, _maxWidth,
+			  _anchor, icon);
+			if (_alignment == Viewport
+			  && !_sceneRect.contains(ti->boundingRect()))
+				ti->setVisible(false);
+			break;
 	}
+
 	ti->setPen(_pen);
 	addItem(ti);
 
@@ -37,23 +58,6 @@ void Text::addLabel(const QString &text, const QPointF &pos, bool overlap,
 		ci[i]->setVisible(false);
 }
 
-void Text::addLabel(const QString &text, const QPainterPath &path)
-{
-	TextPathItem *ti = new TextPathItem(text, path, _font, _maxAngle,
-	  _sceneRect);
-	if (!_sceneRect.contains(ti->boundingRect())) {
-		delete ti;
-		return;
-	}
-	ti->setPen(_pen);
-
-	addItem(ti);
-
-	QList<TextItem*> ci = collidingItems(ti);
-	for (int i = 0; i < ci.size(); i++)
-		ci[i]->setVisible(false);
-}
-
 QList<TextItem*> Text::collidingItems(const TextItem *item) const
 {
 	QList<TextItem*> list;
@@ -69,3 +73,16 @@ QList<TextItem*> Text::collidingItems(const TextItem *item) const
 
 	return list;
 }
+
+void Text::setSymbolPlacement(SymbolPlacement placement)
+{
+	_placement = placement;
+
+	if (_placement != Text::Point) {
+		for (int i = 0; i < _items.size(); i++) {
+			TextItem *ti = _items[i];
+			if (!_sceneRect.contains(ti->boundingRect()))
+				ti->setVisible(false);
+		}
+	}
+}

src/text.h

@@ -22,6 +22,18 @@ public:
 		Bottom
 	};
 
+	enum SymbolPlacement {
+		Point,
+		Line,
+		LineCenter
+	};
+
+	enum RotationAlignment {
+		Map,
+		Viewport,
+		Auto
+	};
+
 	Text(const QSize &size)
 	  : _sceneRect(QRectF(QPointF(0, 0), size)) {}
 	~Text();
@@ -31,10 +43,12 @@ public:
 	void setAnchor(Anchor anchor) {_anchor = anchor;}
 	void setMaxWidth(int width) {_maxWidth = width;}
 	void setMaxAngle(int angle) {_maxAngle = angle;}
+	void setSymbolPlacement(SymbolPlacement placement);
+	void setRotationAlignment(RotationAlignment alignment)
+	  {_alignment = alignment;}
 
-	void addLabel(const QString &text, const QPointF &pos, bool overlap,
-	  const QImage &icon);
-	void addLabel(const QString &text, const QPainterPath &path);
+	void addLabel(const QString &text, const QImage &icon,
+	  const QPainterPath &path);
 
 	void render(QPainter *painter) const;
 
@@ -48,6 +62,8 @@ private:
 	int _maxWidth;
 	int _maxAngle;
 	Anchor _anchor;
+	SymbolPlacement _placement;
+	RotationAlignment _alignment;
 	QFont _font;
 	QPen _pen;
 };

src/textitem.h

@@ -11,6 +11,10 @@ public:
 	virtual ~TextItem() {}
 
 	const QString &text() const {return _text;}
+	const QFont &font() const {return _font;}
+	void setFont(const QFont &font) {_font = font;}
+	const QPen &pen() const {return _pen;}
+	void setPen(const QPen &pen) {_pen = pen;}
 
 	virtual QPainterPath shape() const = 0;
 	virtual QRectF boundingRect() const = 0;
@@ -49,6 +53,8 @@ protected:
 
 private:
 	QString _text;
+	QFont _font;
+	QPen _pen;
 	bool _visible;
 };
 

src/textpathitem.cpp

@@ -134,7 +134,7 @@ static bool reverse(const QPainterPath &path)
 
 TextPathItem::TextPathItem(const QString &text, const QPainterPath &path,
   const QFont &font, int maxAngle, const QRectF &tileRect)
-  : TextItem(text), _font(font)
+  : TextItem(text)
 {
 	int cw = avgCharWidth(text, font);
 	int textWidth = text.size() * cw;
@@ -146,6 +146,7 @@ TextPathItem::TextPathItem(const QString &text, const QPainterPath &path,
 		return;
 
 	_path = reverse(tp) ? tp.toReversed() : tp;
+	setFont(font);
 
 	QPainterPathStroker s;
 	s.setWidth(font.pixelSize());
@@ -159,14 +160,14 @@ void TextPathItem::paint(QPainter *painter) const
 	//painter->setPen(Qt::red);
 	//painter->drawPath(_shape);
 
-	QFontMetrics fm(_font);
+	QFontMetrics fm(font());
 	int textWidth = fm.width(text());
 
 	qreal factor = (textWidth) / qMax(_path.length(), (qreal)textWidth);
 	qreal percent = (1.0 - factor) / 2.0;
 
-	painter->setFont(_font);
-	painter->setPen(_pen);
+	painter->setFont(font());
+	painter->setPen(pen());
 
 	QTransform t = painter->transform();
 

src/textpathitem.h

@@ -16,14 +16,10 @@ public:
 	QRectF boundingRect() const {return _boundingRect;}
 	void paint(QPainter *painter) const;
 
-	void setPen(const QPen &pen) {_pen = pen;}
-
 private:
 	QPainterPath _path;
 	QPainterPath _shape;
 	QRectF _boundingRect;
-	QFont _font;
-	QPen _pen;
 };
 
 #endif // TEXTPATHITEM_H

src/textpointitem.cpp

@@ -72,7 +72,7 @@ QRectF TextPointItem::fuzzyBoundingRect(const QString &str,
 QRectF TextPointItem::computeTextRect(BoundingRectFunction brf) const
 {
 	QRectF iconRect = _icon.isNull() ? QRectF() : _icon.rect();
-	QRectF textRect = brf(text(), _font, _maxWidth);
+	QRectF textRect = brf(text(), font(), _maxWidth);
 
 	switch (_anchor) {
 		case Text::Center:
@@ -101,9 +101,10 @@ QRectF TextPointItem::computeTextRect(BoundingRectFunction brf) const
 
 TextPointItem::TextPointItem(const QString &text, const QPointF &pos,
   const QFont &font, int maxWidth, Text::Anchor anchor, const QImage &icon)
-  : TextItem(text), _pos(pos), _font(font), _icon(icon), _maxWidth(maxWidth),
+  : TextItem(text), _pos(pos), _icon(icon), _maxWidth(maxWidth),
   _anchor(anchor)
 {
+	setFont(font);
 	_boundingRect = computeTextRect(fuzzyBoundingRect);
 
 	if (!_icon.isNull()) {
@@ -129,7 +130,7 @@ void TextPointItem::paint(QPainter *painter) const
 	} else
 		textRect = computeTextRect(fuzzyBoundingRect);
 
-	painter->setFont(_font);
-	painter->setPen(_pen);
+	painter->setFont(font());
+	painter->setPen(pen());
 	painter->drawText(textRect, FLAGS, text());
 }

src/textpointitem.h

@@ -17,8 +17,6 @@ public:
 	QPainterPath shape() const {return _shape;}
 	void paint(QPainter *painter) const;
 
-	void setPen(const QPen &pen) {_pen = pen;}
-
 private:
 	typedef QRectF (*BoundingRectFunction)(const QString &, const QFont &, int);
 
@@ -32,8 +30,6 @@ private:
 	QPointF _pos;
 	QPainterPath _shape;
 	QRectF _boundingRect;
-	QFont _font;
-	QPen _pen;
 	QImage _icon;
 	int _maxWidth;
 	Text::Anchor _anchor;