QGIS API Documentation
3.14.0-Pi (9f7028fd23)
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52 double yDelta_a = pt2.
y() - pt1.
y();
53 double xDelta_a = pt2.
x() - pt1.
x();
54 double yDelta_b = pt3.
y() - pt2.
y();
55 double xDelta_b = pt3.
x() - pt2.
x();
57 if ( ( std::fabs( xDelta_a ) <= epsilon ) && ( std::fabs( yDelta_b ) <= epsilon ) )
62 if ( std::fabs( yDelta_a ) <= epsilon )
66 else if ( std::fabs( yDelta_b ) <= epsilon )
70 else if ( std::fabs( xDelta_a ) <= epsilon )
74 else if ( std::fabs( xDelta_b ) <= epsilon )
87 if ( !isPerpendicular( pt1, pt2, pt3, epsilon ) )
93 else if ( !isPerpendicular( pt1, pt3, pt2, epsilon ) )
99 else if ( !isPerpendicular( pt2, pt1, pt3, epsilon ) )
105 else if ( !isPerpendicular( pt2, pt3, pt1, epsilon ) )
111 else if ( !isPerpendicular( pt3, pt2, pt1, epsilon ) )
117 else if ( !isPerpendicular( pt3, pt1, pt2, epsilon ) )
130 double yDelta_a = p2.
y() - p1.
y();
131 double xDelta_a = p2.
x() - p1.
x();
132 double yDelta_b = p3.
y() - p2.
y();
133 double xDelta_b = p3.
x() - p2.
x();
140 double aSlope = yDelta_a / xDelta_a;
141 double bSlope = yDelta_b / xDelta_b;
146 if ( ( std::fabs( xDelta_a ) <= epsilon ) && ( std::fabs( yDelta_b ) <= epsilon ) )
155 if ( std::fabs( aSlope - bSlope ) <= epsilon )
161 ( aSlope * bSlope * ( p1.
y() - p3.
y() ) +
162 bSlope * ( p1.
x() + p2.
x() ) -
163 aSlope * ( p2.
x() + p3.
x() ) ) /
164 ( 2.0 * ( bSlope - aSlope ) )
167 -1.0 * (
center.
x() - ( p1.
x() + p2.
x() ) / 2.0 ) /
168 aSlope + ( p1.
y() + p2.
y() ) / 2.0
194 bool isIntersect =
false;
229 if ( ( l1 * l1 ) - ( l2 * l2 + l3 * l3 ) >= epsilon )
230 return QgsCircle().from2Points( pt2, pt3 );
231 else if ( ( l2 * l2 ) - ( l1 * l1 + l3 * l3 ) >= epsilon )
232 return QgsCircle().from2Points( pt3, pt1 );
233 else if ( ( l3 * l3 ) - ( l1 * l1 + l2 * l2 ) >= epsilon )
234 return QgsCircle().from2Points( pt1, pt2 );
236 return QgsCircle().from3Points( pt1, pt2, pt3, epsilon );
281 double delta_x = std::fabs( pt1.
x() - pt2.
x() );
282 double delta_y = std::fabs( pt1.
x() - pt2.
y() );
318 QVector<QgsPoint> quad;
331 QVector<QgsPoint> quad;
340 quad.append( quad.at( 0 ) );
341 for ( QVector<QgsPoint>::const_iterator it = quad.constBegin(); it != quad.constEnd(); ++it )
345 circString->setPoints(
points );
347 return circString.release();
364 rep = QStringLiteral(
"Empty" );
366 rep = QStringLiteral(
"Circle (Center: %1, Radius: %2, Azimuth: %3)" )
QgsPoint center() const
Returns the center point.
bool contains(const QgsPoint &point, double epsilon=1E-8) const
Returns true if the circle contains the point.
void setY(double y)
Sets the point's y-coordinate.
int outerTangents(const QgsCircle &other, QgsPointXY &line1P1, QgsPointXY &line1P2, QgsPointXY &line2P1, QgsPointXY &line2P2) const
Calculates the outer tangent points between this circle and an other circle.
QString toString(int pointPrecision=17, int radiusPrecision=17, int azimuthPrecision=2) const override
returns a string representation of the ellipse.
double distance(double x, double y) const
Returns the Cartesian 2D distance between this point and a specified x, y coordinate.
QgsWkbTypes::Type wkbType() const
Returns the WKB type of the geometry.
static QgsPoint midpoint(const QgsPoint &pt1, const QgsPoint &pt2)
Returns a middle point between points pt1 and pt2.
double semiMajorAxis() const
Returns the semi-major axis.
Point geometry type, with support for z-dimension and m-values.
static QgsCircle fromCenterPoint(const QgsPoint ¢er, const QgsPoint &pt1)
Constructs a circle by a center point and another point.
double area() const override
The area of the ellipse.
int innerTangents(const QgsCircle &other, QgsPointXY &line1P1, QgsPointXY &line1P2, QgsPointXY &line2P1, QgsPointXY &line2P2) const
Calculates the inner tangent points between this circle and an other circle.
QString asWkt(int precision=17) const override
Returns a WKT representation of the geometry.
bool addZValue(double zValue=0) override
Adds a z-dimension to the geometry, initialized to a preset value.
QgsRectangle boundingBox() const override
Returns the minimal bounding box for the ellipse.
static QgsCircle fromCenterDiameter(const QgsPoint ¢er, double diameter, double azimuth=0)
Constructs a circle by a center point and a diameter.
virtual QVector< QgsPoint > quadrant() const
The four quadrants of the ellipse.
virtual QgsPointSequence points(unsigned int segments=36) const
Returns a list of points with segmentation from segments.
QString qgsDoubleToString(double a, int precision=17)
Returns a string representation of a double.
double radius() const
Returns the radius of the circle.
QVector< QgsPoint > northQuadrant() const
The four quadrants of the ellipse.
int intersections(const QgsCircle &other, QgsPoint &intersection1, QgsPoint &intersection2, bool useZ=false) const
Calculates the intersections points between this circle and an other circle.
Circular string geometry type.
bool qgsDoubleNear(double a, double b, double epsilon=4 *std::numeric_limits< double >::epsilon())
Compare two doubles (but allow some difference)
void setX(double x)
Sets the point's x-coordinate.
static QgsCircle from3Tangents(const QgsPoint &pt1_tg1, const QgsPoint &pt2_tg1, const QgsPoint &pt1_tg2, const QgsPoint &pt2_tg2, const QgsPoint &pt1_tg3, const QgsPoint &pt2_tg3, double epsilon=1E-8)
Constructs a circle by 3 tangents on the circle (aka inscribed circle of a triangle).
QgsCircularString * toCircularString(bool oriented=false) const
Returns a circular string from the circle.
static int circleCircleIntersections(QgsPointXY center1, double radius1, QgsPointXY center2, double radius2, QgsPointXY &intersection1, QgsPointXY &intersection2)
Calculates the intersections points between the circle with center center1 and radius radius1 and the...
bool is3D() const
Returns true if the geometry is 3D and contains a z-value.
static int circleCircleInnerTangents(const QgsPointXY ¢er1, double radius1, const QgsPointXY ¢er2, double radius2, QgsPointXY &line1P1, QgsPointXY &line1P2, QgsPointXY &line2P1, QgsPointXY &line2P2)
Calculates the inner tangent points for two circles, centered at center1 and center2 and with radii o...
bool tangentToPoint(const QgsPointXY &p, QgsPointXY &pt1, QgsPointXY &pt2) const
Calculates the tangent points between this circle and the point p.
void setSemiMajorAxis(double semiMajorAxis) override
Inherited method.
QVector< QgsPoint > QgsPointSequence
static int circleCircleOuterTangents(const QgsPointXY ¢er1, double radius1, const QgsPointXY ¢er2, double radius2, QgsPointXY &line1P1, QgsPointXY &line1P2, QgsPointXY &line2P1, QgsPointXY &line2P2)
Calculates the outer tangent points for two circles, centered at center1 and center2 and with radii o...
double azimuth() const
Returns the azimuth.
static QgsCircle from2Points(const QgsPoint &pt1, const QgsPoint &pt2)
Constructs a circle by 2 points on the circle.
double perimeter() const override
The circumference of the ellipse using first approximation of Ramanujan.
void setSemiMinorAxis(double semiMinorAxis) override
Inherited method.
bool convertTo(QgsWkbTypes::Type type) override
Converts the geometry to a specified type.
double semiMinorAxis() const
Returns the semi-minor axis.
static QgsCircle fromExtent(const QgsPoint &pt1, const QgsPoint &pt2)
Constructs a circle by an extent (aka bounding box / QgsRectangle).
static QgsCircle from3Points(const QgsPoint &pt1, const QgsPoint &pt2, const QgsPoint &pt3, double epsilon=1E-8)
Constructs a circle by 3 points on the circle.
static bool segmentIntersection(const QgsPoint &p1, const QgsPoint &p2, const QgsPoint &q1, const QgsPoint &q2, QgsPoint &intersectionPoint, bool &isIntersection, double tolerance=1e-8, bool acceptImproperIntersection=false)
Compute the intersection between two segments.
static Type dropZ(Type type)
Drops the z dimension (if present) for a WKB type and returns the new type.
static QgsCircle minimalCircleFrom3Points(const QgsPoint &pt1, const QgsPoint &pt2, const QgsPoint &pt3, double epsilon=1E-8)
Constructs the smallest circle from 3 points.
static bool setZValueFromPoints(const QgsPointSequence &points, QgsPoint &point)
A Z dimension is added to point if one of the point in the list points is in 3D.
static bool tangentPointAndCircle(const QgsPointXY ¢er, double radius, const QgsPointXY &p, QgsPointXY &pt1, QgsPointXY &pt2)
Calculates the tangent points between the circle with the specified center and radius and the point p...
static double lineAngle(double x1, double y1, double x2, double y2)
Calculates the direction of line joining two points in radians, clockwise from the north direction.
QgsCircle inscribedCircle() const
Inscribed circle of the triangle.
virtual bool isEmpty() const
An ellipse is empty if axes are equal to 0.