Small improvements to stroke simplifying

preferencesAboutTextFull
Craig Watson 7 years ago
parent 5f65292d11
commit d67046f003
  1. 24
      src/domain/UBGraphicsStroke.cpp

@ -244,8 +244,6 @@ UBGraphicsStroke* UBGraphicsStroke::simplify()
while (b_it+1 != points.end()) {
qreal angle = qFabs(180-(UBGeometryUtils::angle(it->first, b_it->first, (b_it+1)->first)));
qreal widthRatio = qMax(it->second, b_it->second)/qMin(it->second, b_it->second);
if (widthRatio > thresholdWidthDifference)
qDebug() << "Width ratio: " << widthRatio;
if (angle < thresholdAngle && widthRatio < thresholdWidthDifference)
b_it = points.erase(b_it);
@ -259,7 +257,8 @@ UBGraphicsStroke* UBGraphicsStroke::simplify()
it = b_it;
}
// Next, we iterate over the new points to build the polygons that make up the stroke
// Next, we iterate over the new points to build the polygons that make up the stroke.
// A new polygon is created every time drawCurve is true.
QList<UBGraphicsPolygonItem*> newPolygons;
QList<strokePoint> newStrokePoints;
@ -270,29 +269,26 @@ UBGraphicsStroke* UBGraphicsStroke::simplify()
newStrokePoints << points[i];
// When a polygon is transparent and it overlaps with itself, it is *sometimes* filled incorrectly.
// Limiting the size of the polygons, and creating new ones when the angle between consecutive points is above a
// certain threshold helps mitigate this issue.
// TODO: fix fill issue
// Limiting the size of the polygons, and creating new ones when there is a sharp angle between
// consecutive point helps with two issues:
// 1. When a polygon is transparent and it overlaps with itself, it is *sometimes* filled incorrectly.
// 2. This way of simplifying strokes resuls in sharp, rather than rounded, corners when there is a sharp angle
// in the stroke
if (hasAlpha()) {
if (newStrokePoints.size() > 1 && i < points.size() - 1) {
qreal angle = qFabs(UBGeometryUtils::angle(points[i-1].first, points[i].first, points[i+1].first));
if (angle > 40 && angle < 320)
if (angle < 150) // arbitrary threshold, change if necessary
drawCurve = true;
}
if (newStrokePoints.size() % 20 == 0)
if (hasAlpha() && newStrokePoints.size() % 20 == 0)
drawCurve = true;
}
if (drawCurve) {
UBGraphicsPolygonItem* poly = mScene->polygonToPolygonItem(UBGeometryUtils::curveToPolygon(newStrokePoints, true, true));
//poly->setColor(QColor(rand()%256, rand()%256, rand()%256, poly->brush().color().alpha()));
//poly->setColor(QColor(rand()%256, rand()%256, rand()%256, poly->brush().color().alpha())); // useful for debugging
// Subtract overlapping polygons if the stroke is translucent
if (!poly->brush().isOpaque()) {
foreach(UBGraphicsPolygonItem* prev, newPolygons)
poly->subtract(prev);

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