Fixed/improved path label layout algorithm

This commit is contained in:
Martin Tůma 2023-10-09 21:59:05 +02:00
parent 37c6c36204
commit aaff1c0bdb
2 changed files with 122 additions and 91 deletions

View File

@ -21,14 +21,14 @@ qreal TextItem::avgCharWidth() const
ratio = 1.0;
// Greek & Cyrilic
else if (cp >= 0x03FF && cp <= 0x04FF) {
ratio = (_font.capitalization() == QFont::AllUppercase) ? 0.80 : 0.73;
ratio = (_font.capitalization() == QFont::AllUppercase) ? 0.80 : 0.70;
if (_font.bold())
ratio *= 1.1;
if (_font.italic())
ratio *= 0.9;
// The rest (Latin scripts, Arabic, ...)
} else {
ratio = (_font.capitalization() == QFont::AllUppercase) ? 0.75 : 0.63;
ratio = (_font.capitalization() == QFont::AllUppercase) ? 0.75 : 0.60;
if (_font.bold())
ratio *= 1.1;
if (_font.italic())

View File

@ -9,23 +9,20 @@
#define INTERSECTS intersects
#endif // QT 5.15
static bool intersection(const QLineF &line, const QRectF &rect,
QPointF *p)
static void swap(const QLineF &line, QPointF *p1, QPointF *p2)
{
if (line.INTERSECTS(QLineF(rect.topLeft(), rect.topRight()), p)
== QLineF::BoundedIntersection)
return true;
if (line.INTERSECTS(QLineF(rect.topLeft(), rect.bottomLeft()), p)
== QLineF::BoundedIntersection)
return true;
if (line.INTERSECTS(QLineF(rect.bottomRight(), rect.bottomLeft()), p)
== QLineF::BoundedIntersection)
return true;
if (line.INTERSECTS(QLineF(rect.bottomRight(), rect.topRight()), p)
== QLineF::BoundedIntersection)
return true;
return false;
QPointF lp1(line.p1());
QPointF lp2(line.p2());
if ((lp1.rx() < lp2.rx() && p1->rx() > p2->rx())
|| (lp1.ry() < lp2.ry() && p1->ry() > p2->ry())
|| (lp1.rx() > lp2.rx() && p1->rx() < p2->rx())
|| (lp1.ry() > lp2.ry() && p1->ry() < p2->ry())) {
QPointF tmp(*p2);
*p2 = *p1;
*p1 = tmp;
}
}
static bool intersection(const QLineF &line, const QRectF &rect, QPointF *p1,
@ -38,43 +35,69 @@ static bool intersection(const QLineF &line, const QRectF &rect, QPointF *p1,
p = p2;
if (line.INTERSECTS(QLineF(rect.topLeft(), rect.bottomLeft()), p)
== QLineF::BoundedIntersection) {
if (p == p2)
if (p == p2) {
swap(line, p1, p2);
return true;
}
p = p2;
}
if (line.INTERSECTS(QLineF(rect.bottomRight(), rect.bottomLeft()), p)
== QLineF::BoundedIntersection) {
if (p == p2)
if (p == p2) {
swap(line, p1, p2);
return true;
}
p = p2;
}
if (line.INTERSECTS(QLineF(rect.bottomRight(), rect.topRight()), p)
== QLineF::BoundedIntersection) {
if (p == p2)
if (p == p2) {
swap(line, p1, p2);
return true;
}
}
Q_ASSERT(p != p2);
return false;
}
static QPainterPath subpath(const QList<QLineF> &lines, int start, int end,
static bool intersection(const QLineF &line, const QRectF &rect, QPointF *p)
{
if (line.INTERSECTS(QLineF(rect.topLeft(), rect.topRight()), p)
== QLineF::BoundedIntersection)
return true;
if (line.INTERSECTS(QLineF(rect.topLeft(), rect.bottomLeft()), p)
== QLineF::BoundedIntersection)
return true;
if (line.INTERSECTS(QLineF(rect.bottomRight(), rect.bottomLeft()), p)
== QLineF::BoundedIntersection)
return true;
if (line.INTERSECTS(QLineF(rect.bottomRight(), rect.topRight()), p)
== QLineF::BoundedIntersection)
return true;
return false;
}
static QPainterPath subpath(const QPolygonF &path, 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();
for (int i = start; i < end; i++) {
QLineF l(path.at(i), path.at(i+1));
qreal len = l.length();
if (ss + len < cut / 2) {
ss += len;
si++;
} else
break;
}
for (int i = end; i >= start; i--) {
qreal len = lines.at(i).length();
for (int i = end; i > start; i--) {
QLineF l(path.at(i), path.at(i-1));
qreal len = l.length();
if (es + len < cut / 2) {
es += len;
ei--;
@ -82,88 +105,92 @@ static QPainterPath subpath(const QList<QLineF> &lines, int start, int end,
break;
}
QLineF sl(lines.at(si).p2(), lines.at(si).p1());
QLineF sl(path.at(si+1), path.at(si));
sl.setLength(sl.length() - (cut / 2 - ss));
QLineF el(lines.at(ei));
QLineF el(path.at(ei-1), path.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());
for (int i = si + 1; i < ei; i++)
p.lineTo(path.at(i));
p.lineTo(el.p2());
return p;
}
static QList<QLineF> lineString(const QPainterPath &path,
const QRectF &boundingRect)
static QList<QPolygonF> polyLines(const QPainterPath &path, const QRectF &rect)
{
QList<QLineF> lines;
int start = -1, end = -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) {
QPointF p1, p2;
QList<QPolygonF> lines;
QPolygonF line;
bool lastIn = rect.contains(path.elementAt(0));
for (int i = 1; i < path.elementCount(); i++) {
QLineF l(path.elementAt(i-1), path.elementAt(i));
if (intersection(l, boundingRect, &p1, &p2)) {
lines.append(QLineF(p1, p2));
break;
}
}
if (rect.contains(path.elementAt(i))) {
if (lastIn) {
if (line.isEmpty())
line.append(path.elementAt(i-1));
line.append(path.elementAt(i));
} else {
QPointF p;
QLineF l(path.elementAt(i-1), path.elementAt(i));
if (start > 0) {
QLineF l(path.elementAt(start-1), path.elementAt(start));
if (intersection(l, boundingRect, &p))
lines.append(QLineF(p, path.elementAt(start)));
if (intersection(l, rect, &p))
line.append(p);
line.append(path.elementAt(i));
}
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));
if (intersection(l, boundingRect, &p))
lines.append(QLineF(path.elementAt(end), p));
lastIn = true;
} else {
QLineF l(path.elementAt(i-1), path.elementAt(i));
if (lastIn) {
QPointF p;
if (intersection(l, rect, &p))
line.append(p);
lines.append(line);
line.clear();
} else {
QPointF p1, p2;
if (intersection(l, rect, &p1, &p2)) {
line.append(p1);
line.append(p2);
lines.append(line);
line.clear();
}
}
lastIn = false;
}
}
if (!line.isEmpty())
lines.append(line);
return lines;
}
static QPainterPath textPath(const QPainterPath &path, qreal textWidth,
qreal maxAngle, qreal charWidth, const QRectF &tileRect)
{
QList<QLineF> lines(lineString(path, tileRect));
if (lines.isEmpty())
if (path.isEmpty())
return QPainterPath();
qreal length = 0;
qreal angle = lines.first().angle();
int last = 0;
QList<QPolygonF> lines(polyLines(path, tileRect));
for (int i = 0; i < lines.size(); i++) {
qreal sl = lines.at(i).length();
qreal a = lines.at(i).angle();
const QPolygonF &pl = lines.at(i);
qreal angle, length = 0;
int last = 0;
if (!tileRect.contains(lines.at(i).p2()) || sl < charWidth
|| qAbs(angle - a) > maxAngle) {
for (int j = 1; j < pl.size(); j ++) {
QLineF l(pl.at(j-1), pl.at(j));
qreal sl = l.length();
qreal a = l.angle();
if ((sl < charWidth) || (j > 1 && qAbs(angle - a) > maxAngle)) {
if (length > textWidth)
return subpath(lines, last, i - 1, length - textWidth);
last = i;
return subpath(pl, last, j - 1, length - textWidth);
last = j;
length = 0;
} else
length += sl;
@ -171,9 +198,11 @@ static QPainterPath textPath(const QPainterPath &path, qreal textWidth,
angle = a;
}
return (length > textWidth)
? subpath(lines, last, lines.size() - 1, length - textWidth)
: QPainterPath();
if (length > textWidth)
return subpath(pl, last, pl.size() - 1, length - textWidth);
}
return QPainterPath();
}
static bool reverse(const QPainterPath &path)
@ -208,9 +237,6 @@ TextPathItem::TextPathItem(const QString &text, const QPainterPath &path,
void TextPathItem::paint(QPainter *painter) const
{
//painter->setPen(Qt::red);
//painter->drawPath(_shape);
QFontMetrics fm(font());
int textWidth = fm.boundingRect(text()).width();
@ -259,4 +285,9 @@ void TextPathItem::paint(QPainter *painter) const
int width = fm.horizontalAdvance(text().at(i));
percent += ((qreal)width / (qreal)textWidth) * factor;
}
//painter->setBrush(Qt::NoBrush);
//painter->setPen(Qt::red);
//painter->setRenderHint(QPainter::Antialiasing, false);
//painter->drawPath(_shape);
}