Improved fuzzy bounding rect computation

Code cleanup

src/text.cpp

@@ -5,135 +5,6 @@
 #include "textpathitem.h"
 
 
-static QPointF intersection(const QLineF &line, const QRectF &rect)
-{
-	QPointF p;
-	if (line.intersect(QLineF(rect.topLeft(), rect.topRight()), &p)
-	  == QLineF::BoundedIntersection)
-		return p;
-	if (line.intersect(QLineF(rect.topLeft(), rect.bottomLeft()), &p)
-	  == QLineF::BoundedIntersection)
-		return p;
-	if (line.intersect(QLineF(rect.bottomRight(), rect.bottomLeft()), &p)
-	  == QLineF::BoundedIntersection)
-		return p;
-	if (line.intersect(QLineF(rect.bottomRight(), rect.topRight()), &p)
-	  == QLineF::BoundedIntersection)
-		return p;
-
-	return rect.center();
-}
-
-static QPainterPath subpath(const QList<QLineF> &lines, int start, int end,
-  qreal cut)
-{
-	qreal ss = 0, es = 0;
-	int si = start, ei = end;
-
-	for (int i = start; i <= end; i++) {
-		qreal len = lines.at(i).length();
-		if (ss + len < cut / 2) {
-			ss += len;
-			si++;
-		} else
-			break;
-	}
-	for (int i = end; i >= start; i--) {
-		qreal len = lines.at(i).length();
-		if (es + len < cut / 2) {
-			es += len;
-			ei--;
-		} else
-			break;
-	}
-
-	QLineF sl(lines.at(si).p2(), lines.at(si).p1());
-	sl.setLength(sl.length() - (cut / 2 - ss));
-	QLineF el(lines.at(ei));
-	el.setLength(el.length() - (cut / 2 - es));
-
-	QPainterPath p(sl.p2());
-	for (int i = si; i <= ei; i++)
-		p.lineTo(lines.at(i).p2());
-	p.setElementPositionAt(p.elementCount() - 1, el.p2().x(), el.p2().y());
-
-	return p;
-}
-
-static QList<QLineF> lineString(const QPainterPath &path,
-  const QRectF &boundingRect)
-{
-	QList<QLineF> lines;
-	int start = 0, end = path.elementCount() - 1;
-
-	for (int i = 0; i < path.elementCount(); i++) {
-		if (boundingRect.contains(path.elementAt(i))) {
-			start = i;
-			break;
-		}
-	}
-	for (int i = path.elementCount() - 1; i >= 0; i--) {
-		if (boundingRect.contains(path.elementAt(i))) {
-			end = i;
-			break;
-		}
-	}
-
-	if (start > 0) {
-		QLineF l(path.elementAt(start-1), path.elementAt(start));
-		QPointF p(intersection(l, boundingRect));
-		if (p != boundingRect.center())
-			lines.append(QLineF(p, path.elementAt(start)));
-	}
-	for (int i = start + 1; i <= end; i++)
-		lines.append(QLineF(path.elementAt(i-1), path.elementAt(i)));
-	if (end < path.elementCount() - 1) {
-		QLineF l(path.elementAt(end), path.elementAt(end+1));
-		QPointF p(intersection(l, boundingRect));
-		if (p != boundingRect.center())
-			lines.append(QLineF(path.elementAt(end), p));
-	}
-
-	return lines;
-}
-
-static QPainterPath textPath(const QPainterPath &path, qreal textWidth,
-  qreal maxAngle, qreal charWidth, const QRectF &tileRect)
-{
-	QList<QLineF> lines(lineString(path, tileRect));
-	qreal length = 0;
-	qreal angle = lines.first().angle();
-	int last = 0;
-
-	for (int i = 0; i < lines.size(); i++) {
-		qreal sl = lines.at(i).length();
-		qreal a = lines.at(i).angle();
-
-		if (!tileRect.contains(lines.at(i).p2()) || sl < charWidth
-		  || qAbs(angle - a) > maxAngle) {
-			if (length > textWidth)
-				return subpath(lines, last, i - 1, length - textWidth);
-			last = i;
-			length = 0;
-		} else
-			length += sl;
-
-		angle = a;
-	}
-
-	return (length > textWidth)
-	  ? subpath(lines, last, lines.size() - 1, length - textWidth)
-	  : QPainterPath();
-}
-
-static bool reverse(const QPainterPath &path)
-{
-	QLineF l(path.elementAt(0), path.elementAt(1));
-	qreal angle = l.angle();
-	return (angle > 90 && angle < 270) ? true : false;
-}
-
-
 Text::~Text()
 {
 	for (int i = 0; i < _items.size(); i++)
@@ -168,17 +39,8 @@ void Text::addLabel(const QString &text, const QPointF &pos, bool overlap,
 
 void Text::addLabel(const QString &text, const QPainterPath &path)
 {
-	int textWidth = text.size() * _font.pixelSize() * 0.6;
+	TextPathItem *ti = new TextPathItem(text, path, _font, _maxAngle,
-	if (textWidth > path.length())
+	  _sceneRect);
-		return;
-
-	QPainterPath tp(textPath(path, textWidth, _maxAngle, _font.pixelSize() / 2,
-	  _sceneRect));
-	if (tp.isEmpty())
-		return;
-
-	TextPathItem *ti = new TextPathItem(text, reverse(tp) ? tp.toReversed()
-	  : tp, _font);
 	if (!_sceneRect.contains(ti->boundingRect())) {
 		delete ti;
 		return;
@@ -207,3 +69,18 @@ QList<TextItem*> Text::collidingItems(const TextItem *item) const
 
 	return list;
 }
+
+qreal Text::avgCharRatio(const QString &str, const QFont &font)
+{
+	qreal ratio;
+
+	if (str.at(0).unicode() > 0x2E80)
+		ratio = 1.0;
+	else {
+		ratio = (font.capitalization() == QFont::AllUppercase) ? 0.66 : 0.55;
+		if (font.bold())
+			ratio *= 1.1;
+	}
+
+	return ratio;
+}

src/text.h

@@ -38,6 +38,8 @@ public:
 
 	void render(QPainter *painter) const;
 
+	static qreal avgCharRatio(const QString &str, const QFont &font);
+
 private:
 	void addItem(TextItem *item) {_items.append(item);}
 	QList<TextItem *> collidingItems(const TextItem *item) const;

src/textpathitem.cpp

@@ -3,13 +3,155 @@
 #include "textpathitem.h"
 
 
-TextPathItem::TextPathItem(const QString &text, const QPainterPath &path,
+static QPointF intersection(const QLineF &line, const QRectF &rect)
-  const QFont &font) : TextItem(text), _path(path), _font(font)
 {
+	QPointF p;
+	if (line.intersect(QLineF(rect.topLeft(), rect.topRight()), &p)
+	  == QLineF::BoundedIntersection)
+		return p;
+	if (line.intersect(QLineF(rect.topLeft(), rect.bottomLeft()), &p)
+	  == QLineF::BoundedIntersection)
+		return p;
+	if (line.intersect(QLineF(rect.bottomRight(), rect.bottomLeft()), &p)
+	  == QLineF::BoundedIntersection)
+		return p;
+	if (line.intersect(QLineF(rect.bottomRight(), rect.topRight()), &p)
+	  == QLineF::BoundedIntersection)
+		return p;
+
+	return rect.center();
+}
+
+static QPainterPath subpath(const QList<QLineF> &lines, int start, int end,
+  qreal cut)
+{
+	qreal ss = 0, es = 0;
+	int si = start, ei = end;
+
+	for (int i = start; i <= end; i++) {
+		qreal len = lines.at(i).length();
+		if (ss + len < cut / 2) {
+			ss += len;
+			si++;
+		} else
+			break;
+	}
+	for (int i = end; i >= start; i--) {
+		qreal len = lines.at(i).length();
+		if (es + len < cut / 2) {
+			es += len;
+			ei--;
+		} else
+			break;
+	}
+
+	QLineF sl(lines.at(si).p2(), lines.at(si).p1());
+	sl.setLength(sl.length() - (cut / 2 - ss));
+	QLineF el(lines.at(ei));
+	el.setLength(el.length() - (cut / 2 - es));
+
+	QPainterPath p(sl.p2());
+	for (int i = si; i <= ei; i++)
+		p.lineTo(lines.at(i).p2());
+	p.setElementPositionAt(p.elementCount() - 1, el.p2().x(), el.p2().y());
+
+	return p;
+}
+
+static QList<QLineF> lineString(const QPainterPath &path,
+  const QRectF &boundingRect)
+{
+	QList<QLineF> lines;
+	int start = 0, end = path.elementCount() - 1;
+
+	for (int i = 0; i < path.elementCount(); i++) {
+		if (boundingRect.contains(path.elementAt(i))) {
+			start = i;
+			break;
+		}
+	}
+	for (int i = path.elementCount() - 1; i >= 0; i--) {
+		if (boundingRect.contains(path.elementAt(i))) {
+			end = i;
+			break;
+		}
+	}
+
+	if (start > 0) {
+		QLineF l(path.elementAt(start-1), path.elementAt(start));
+		QPointF p(intersection(l, boundingRect));
+		if (p != boundingRect.center())
+			lines.append(QLineF(p, path.elementAt(start)));
+	}
+	for (int i = start + 1; i <= end; i++)
+		lines.append(QLineF(path.elementAt(i-1), path.elementAt(i)));
+	if (end < path.elementCount() - 1) {
+		QLineF l(path.elementAt(end), path.elementAt(end+1));
+		QPointF p(intersection(l, boundingRect));
+		if (p != boundingRect.center())
+			lines.append(QLineF(path.elementAt(end), p));
+	}
+
+	return lines;
+}
+
+static QPainterPath textPath(const QPainterPath &path, qreal textWidth,
+  qreal maxAngle, qreal charWidth, const QRectF &tileRect)
+{
+	QList<QLineF> lines(lineString(path, tileRect));
+	qreal length = 0;
+	qreal angle = lines.first().angle();
+	int last = 0;
+
+	for (int i = 0; i < lines.size(); i++) {
+		qreal sl = lines.at(i).length();
+		qreal a = lines.at(i).angle();
+
+		if (!tileRect.contains(lines.at(i).p2()) || sl < charWidth
+		  || qAbs(angle - a) > maxAngle) {
+			if (length > textWidth)
+				return subpath(lines, last, i - 1, length - textWidth);
+			last = i;
+			length = 0;
+		} else
+			length += sl;
+
+		angle = a;
+	}
+
+	return (length > textWidth)
+	  ? subpath(lines, last, lines.size() - 1, length - textWidth)
+	  : QPainterPath();
+}
+
+static bool reverse(const QPainterPath &path)
+{
+	QLineF l(path.elementAt(0), path.elementAt(1));
+	qreal angle = l.angle();
+	return (angle > 90 && angle < 270) ? true : false;
+}
+
+
+TextPathItem::TextPathItem(const QString &text, const QPainterPath &path,
+  const QFont &font, int maxAngle, const QRectF &tileRect)
+  : TextItem(text), _font(font)
+{
+	qreal acr = Text::avgCharRatio(text, _font);
+	int textWidth = text.size() * _font.pixelSize() * acr;
+	if (textWidth > path.length())
+		return;
+
+	QPainterPath tp(textPath(path, textWidth, maxAngle, _font.pixelSize() * acr,
+	  tileRect));
+	if (tp.isEmpty())
+		return;
+
+	_path = reverse(tp) ? tp.toReversed() : tp;
+
 	QPainterPathStroker s;
 	s.setWidth(font.pixelSize());
 	s.setCapStyle(Qt::FlatCap);
-	_shape = s.createStroke(path).simplified();
+	_shape = s.createStroke(_path).simplified();
 	_boundingRect = _shape.boundingRect();
 }
 

src/textpathitem.h

@@ -10,7 +10,7 @@ class TextPathItem : public TextItem
 {
 public:
 	TextPathItem(const QString &text, const QPainterPath &path,
-	  const QFont &font);
+	  const QFont &font, int maxAngle, const QRectF &tileRect);
 
 	QPainterPath shape() const {return _shape;}
 	QRectF boundingRect() const {return _boundingRect;}

src/textpointitem.cpp

@@ -28,13 +28,13 @@ static QRectF fuzzyBoundingRect(const QString &str, const QFont &font,
   int maxWidth)
 {
 	int limit = font.pixelSize() * maxWidth;
-	qreal acw = (font.capitalization() == QFont::AllUppercase) ? 0.66 : 0.55;
+	qreal cw = font.pixelSize() * Text::avgCharRatio(str, font);
-	qreal cw = font.pixelSize() * acw;
-	if (font.bold())
-		acw *= 1.1;
 	qreal lh = font.pixelSize() * 1.25;
 	int width = 0, lines = 0;
 
+	if (font.italic())
+		limit -= font.pixelSize() / 2.0;
+
 	QStringList l(str.split('\n'));
 	for (int i = 0; i < l.size(); i++) {
 		int lw = (int)(l.at(i).length() * cw);