Text rendering algorithm improvements

src/function.h

@@ -22,9 +22,9 @@ private:
 
 class FunctionC {
 public:
-	FunctionC(const QColor &deflt = QColor())
+	FunctionC(const QColor &deflt = QColor(Qt::black))
 	  : _default(deflt), _base(1.0) {}
-	FunctionC(const QJsonObject &json, const QColor &dflt = QColor());
+	FunctionC(const QJsonObject &json, const QColor &dflt = QColor(Qt::black));
 
 	QColor value(qreal x) const;
 

src/style.cpp

@@ -141,11 +141,14 @@ Style::Layer::Paint::Paint(const QJsonObject &json)
 		_fillOpacity = FunctionF(json["fill-opacity"].toDouble());
 	else if (json.contains("fill-opacity") && json["fill-opacity"].isObject())
 		_fillOpacity = FunctionF(json["fill-opacity"].toObject());
-	if (json.contains("fill-color") && json["fill-color"].isString())
+	if (json.contains("fill-color") && json["fill-color"].isString()) {
 		_fillColor = FunctionC(Color::fromJsonString(
 		  json["fill-color"].toString()));
-	if (json.contains("fill-color") && json["fill-color"].isObject())
+		_fillOutlineColor = _fillColor;
+	} else if (json.contains("fill-color") && json["fill-color"].isObject()) {
 		_fillColor = FunctionC(json["fill-color"].toObject());
+		_fillOutlineColor = _fillColor;
+	}
 	if (json.contains("fill-outline-color")
 	  && json["fill-outline-color"].isString())
 		_fillOutlineColor = FunctionC(Color::fromJsonString(
@@ -155,6 +158,11 @@ Style::Layer::Paint::Paint(const QJsonObject &json)
 		_fillOutlineColor = FunctionC(json["fill-outline-color"].toObject());
 	if (json.contains("fill-antialias") && json["fill-antialias"].isBool())
 		_fillAntialias = json["fill-antialias"].toBool();
+	if (json.contains("fill-pattern")) {
+		_fillColor = FunctionC(QColor());
+		_fillOutlineColor = FunctionC(QColor());
+	}
+
 
 	if (json.contains("line-color") && json["line-color"].isString())
 		_lineColor = FunctionC(Color::fromJsonString(json["line-color"]
@@ -208,11 +216,6 @@ QPen Style::Layer::Paint::pen(Type type, int zoom) const
 			color = _fillOutlineColor.value(zoom);
 			if (color.isValid())
 				pen = QPen(color);
-			else {
-				color = _fillColor.value(zoom);
-				if (color.isValid())
-					pen = QPen(color);
-			}
 			break;
 		case Symbol:
 			color = _textColor.value(zoom);
@@ -267,8 +270,8 @@ bool Style::Layer::Paint::antialias(Layer::Type type) const
 }
 
 Style::Layer::Layout::Layout(const QJsonObject &json)
-  : _textSize(16), _textMaxWidth(10), _textMaxAngle(45), _lineCap(Qt::FlatCap),
+  : _textSize(16), _textMaxWidth(10), _textMaxAngle(45), _symbolSpacing(250),
-  _lineJoin(Qt::MiterJoin), _capitalize(false)
+  _lineCap(Qt::FlatCap), _lineJoin(Qt::MiterJoin), _capitalize(false)
 {
 	if (!(json.contains("text-field") && json["text-field"].isString()))
 		return;
@@ -296,6 +299,11 @@ Style::Layer::Layout::Layout(const QJsonObject &json)
 	else if (json.contains("text-max-angle") && json["text-max-angle"].isDouble())
 		_textMaxWidth = json["text-max-angle"].toDouble();
 
+	if (json.contains("symbol-spacing") && json["symbol-spacing"].isObject())
+		_symbolSpacing = json["symbol-spacing"].toObject();
+	else if (json.contains("symbol-spacing") && json["symbol-spacing"].isDouble())
+		_symbolSpacing = json["symbol-spacing"].toDouble();
+
 	if (json.contains("text-transform") && json["text-transform"].isString())
 		_capitalize = json["text-transform"].toString() == "uppercase";
 
@@ -409,7 +417,7 @@ void Style::Layer::drawSymbol(int zoom, const QPainterPath &path,
 		  _layout.maxTextWidth(zoom));
 	else
 		tile.text().addLabel(text.trimmed(), path, font, pen,
-		  _layout.maxTextAngle(zoom));
+		  _layout.maxTextAngle(zoom), _layout.symbolSpacing(zoom));
 }
 
 bool Style::load(const QString &fileName)

src/style.h

@@ -79,13 +79,17 @@ private:
 		class Layout {
 		public:
 			Layout() : _textSize(16), _textMaxWidth(10), _textMaxAngle(45),
-			  _lineCap(Qt::FlatCap), _lineJoin(Qt::MiterJoin),
+			  _symbolSpacing(250), _lineCap(Qt::FlatCap),
-			  _capitalize(false) {}
+			  _lineJoin(Qt::MiterJoin), _capitalize(false) {}
 			Layout(const QJsonObject &json);
 
 			bool capitalize() const {return _capitalize;}
-			qreal maxTextWidth(int zoom) const {return _textMaxWidth.value(zoom);}
+			qreal maxTextWidth(int zoom) const
-			qreal maxTextAngle(int zoom) const {return _textMaxAngle.value(zoom);}
+			  {return _textMaxWidth.value(zoom);}
+			qreal maxTextAngle(int zoom) const
+			  {return _textMaxAngle.value(zoom);}
+			qreal symbolSpacing(int zoom) const
+			  {return _symbolSpacing.value(zoom);}
 			const QString &field() const {return _textField;}
 			const QStringList &keys() const {return _keys;}
 			QFont font(int zoom) const;
@@ -98,6 +102,7 @@ private:
 			FunctionF _textSize;
 			FunctionF _textMaxWidth;
 			FunctionF _textMaxAngle;
+			FunctionF _symbolSpacing;
 			Qt::PenCapStyle _lineCap;
 			Qt::PenJoinStyle _lineJoin;
 			bool _capitalize;

src/text.cpp

@@ -6,43 +6,60 @@
 #include "textpathitem.h"
 
 
-static QPainterPath subpath(const QPainterPath &path, int start, int end)
+static QPainterPath subpath(const QPainterPath &path, int start, int end,
+  qreal cut)
 {
 	QPainterPath p(path.elementAt(start));
-	for (int i = start + 1; i <= end; i++)
+
+	for (int i = start + 1; i < end; i++)
 		p.lineTo(path.elementAt(i));
+
+	QLineF l(path.elementAt(end - 1), path.elementAt(end));
+	l.setLength(l.length() - cut);
+	p.lineTo(l.p2());
+
 	return p;
 }
 
-static QList<QPainterPath> segments(const QPainterPath &path, qreal pathLimit,
+static QList<QPainterPath> segments(const QPainterPath &path, qreal textLength,
-  qreal maxAngle, qreal charWidth, const QRectF &tileRect)
+  qreal maxAngle, qreal charWidth, int symbolSpacing, const QRectF &tileRect)
 {
 	QList<QPainterPath> list;
 	int start = 0;
 	qreal length = 0;
 	qreal angle = -1;
+	qreal dist = symbolSpacing;
 
 	for (int i = 1; i < path.elementCount(); i++) {
 		QLineF l(path.elementAt(i-1), path.elementAt(i));
-		qreal a = l.angle();
 		qreal sl = l.length();
+
+		if (dist < symbolSpacing) {
+			dist += sl;
+			start++;
+			continue;
+		}
+
+		qreal a = l.angle();
 		if (angle < 0)
 			angle = a;
+
 		if (!tileRect.contains(path.elementAt(i))
 		  || sl < charWidth || qAbs(angle - a) > maxAngle
-		  || length > pathLimit) {
+		  || length > textLength) {
-			if (length > pathLimit)
+			if (length > textLength) {
-				list.append(subpath(path, start, i - 1));
+				list.append(subpath(path, start, i - 1, length - textLength - 1));
+				dist = 0;
+			}
 			start = i;
 			length = 0;
 		} else
 			length += sl;
+
+		dist += sl;
 		angle = a;
 	}
 
-	if (length > pathLimit)
-		list.append(subpath(path, start, path.elementCount() - 1));
-
 	return list;
 }
 
@@ -76,7 +93,7 @@ void Text::addLabel(const QString &text, const QPointF &pos, const QFont &font,
 }
 
 void Text::addLabel(const QString &text, const QPainterPath &path,
-  const QFont &font, const QPen &pen, qreal maxAngle)
+  const QFont &font, const QPen &pen, qreal maxAngle, qreal symbolSpacing)
 {
 	if (path.elementCount() < 2 || !path.elementAt(0).isMoveTo())
 		return;
@@ -90,7 +107,7 @@ void Text::addLabel(const QString &text, const QPainterPath &path,
 		return;
 
 	QList<QPainterPath> list(segments(path, textWidth, maxAngle,
-	  fm.averageCharWidth(), sceneRect()));
+	  fm.averageCharWidth(), symbolSpacing, sceneRect()));
 	for (int i = 0; i < list.size(); i++) {
 		const QPainterPath &segment = list.at(i);
 		TextPathItem *pi = new TextPathItem(text, reverse(segment)

src/text.h

@@ -12,7 +12,7 @@ public:
 	void addLabel(const QString &text, const QPointF &pos, const QFont &font,
 	  const QPen &pen, qreal maxTextWidth);
 	void addLabel(const QString &text, const QPainterPath &path,
-	  const QFont &font, const QPen &pen, qreal maxAngle);
+	  const QFont &font, const QPen &pen, qreal maxAngle, qreal symbolSpacing);
 };
 
 #endif // TEXT_H