double QgsGeometryUtils::circleTangentDirection( const QgsPointV2& tangentPoint, const QgsPointV2& cp1,
const QgsPointV2& cp2, const QgsPointV2& cp3 )
{
//calculate circle midpoint
double mX, mY, radius;
circleCenterRadius( cp1, cp2, cp3, radius, mX, mY );
double p1Angle = QgsGeometryUtils::ccwAngle( cp1.y() - mY, cp1.x() - mX );
double p2Angle = QgsGeometryUtils::ccwAngle( cp2.y() - mY, cp2.x() - mX );
double p3Angle = QgsGeometryUtils::ccwAngle( cp3.y() - mY, cp3.x() - mX );
if ( circleClockwise( p1Angle, p2Angle, p3Angle ) )
{
return lineAngle( tangentPoint.x(), tangentPoint.y(), mX, mY );
}
else
{
return lineAngle( mX, mY, tangentPoint.x(), tangentPoint.y() );
}
}
void CircleLayout::layout()
{
int total = vertexdraws.count();
QPointF center = centerOf(vertexdraws);
float radius = qMax(25.0, vertexdraws[0]->radius()*total/1.0);
QMultiMap<double, VertexDraw*> sorteddraws;
foreach(VertexDraw* draw, vertexdraws)
{
sorteddraws.insert(lineAngle(center, draw->pos()), draw);
}