/**
* Creates an arc from 3 points.
*/
RArc RArc::createFrom3Points(const RVector& startPoint,
const RVector& point,
const RVector& endPoint) {
// intersection of two middle lines
// middle points between first two points:
RVector mp1 = RVector::getAverage(startPoint, point);
double a1 = startPoint.getAngleTo(point) + M_PI / 2.0;
// direction from middle point to center:
RVector dir1 = RVector::createPolar(1.0, a1);
// middle points between last two points:
RVector mp2 = RVector::getAverage(point, endPoint);
double a2 = point.getAngleTo(endPoint) + M_PI / 2.0;
// direction from middle point to center:
RVector dir2 = RVector::createPolar(1.0, a2);
RLine midLine1(mp1, mp1 + dir1);
RLine midLine2(mp2, mp2 + dir2);
QList<RVector> ips = midLine1.getIntersectionPoints(midLine2, false);
if (ips.length()!=1) {
//this.error = qsTr("No arc possible");
return RArc();
}
RVector center = ips[0];
double radius = center.getDistanceTo(endPoint);
double angle1 = center.getAngleTo(startPoint);
double angle2 = center.getAngleTo(endPoint);
bool reversed = RMath::isAngleBetween(center.getAngleTo(point),
angle1, angle2, true);
return RArc(center, radius, angle1, angle2, reversed);
}
void RExporter::exportArc(const RArc& arc, double offset) {
if (!arc.isValid()) {
return;
}
RLinetypePattern p = getLinetypePattern();
if (getEntity() == NULL || !p.isValid() || p.getNumDashes() == 1 || draftMode || screenBasedLinetypes) {
exportArcSegment(arc);
return;
}
RArc normalArc = arc;
if (arc.isReversed()) {
normalArc.reverse();
}
if (normalArc.radius < 1.0e-12) {
return;
}
p.scale(getPatternFactor());
double length = normalArc.getLength();
double patternLength = p.getPatternLength();
// avoid huge number of small segments due to very fine
// pattern or long lines:
if (patternLength<RS::PointTolerance || length / patternLength > 5000) {
exportArcSegment(arc);
return;
}
double* vp = NULL;
vp = new double[p.getNumDashes()];
for (int i = 0; i < p.getNumDashes(); ++i) {
vp[i] = fabs(p.getDashLengthAt(i)) / normalArc.radius;
}
if (RMath::isNaN(offset)) {
offset = getPatternOffset(length, p);
}
QList<RArc> arcSegments;
bool done = false;
int i = 0;
double cursor = normalArc.getStartAngle() + offset / normalArc.radius;
double total = offset;
bool dashFound = false;
bool gapFound = false;
double a1 = normalArc.getStartAngle();
double a2;
do {
if (dashFound && !gapFound) {
if (total + fabs(p.getDashLengthAt(i)) >= length - 1.0e-6) {
arcSegments.append(RArc(normalArc.getCenter(), normalArc.getRadius(), a1, normalArc.getEndAngle()));
break;
}
arcSegments.append(RArc(normalArc.getCenter(), normalArc.getRadius(), a1, a2));
}
if (p.getDashLengthAt(i) > 0) {
// dash, no gap
if (total + p.getDashLengthAt(i) > 0) {
a1 = cursor;
if (total < 0 || !dashFound) {
a1 = normalArc.startAngle;
}
a2 = cursor + vp[i];
if (fabs(a2 - normalArc.getStartAngle()) > 1.0e-6) {
dashFound = true;
}
}
gapFound = false;
} else {
gapFound = true;
}
cursor += vp[i];
total += fabs(p.getDashLengthAt(i));
done = total > length;
++i;
if (i >= p.getNumDashes()) {
i = 0;
}
} while (!done);
if (!gapFound || !dashFound) {
if (total + fabs(p.getDashLengthAt(i)) >= length - 1.0e-6) {
arcSegments.append(RArc(normalArc.getCenter(), normalArc.getRadius(), a1, normalArc.getEndAngle()));
} else {
arcSegments.append(RArc(normalArc.getCenter(), normalArc.getRadius(), a1, a2));
}
}
if (arc.isReversed()) {
for (int i=arcSegments.length()-1; i>=0; i--) {
arcSegments[i].reverse();
exportArcSegment(arcSegments[i]);
}
}
else {
for (int i=0; i<arcSegments.length(); i++) {
exportArcSegment(arcSegments[i]);
}
}
delete[] vp;
}
