Class QuadraticCurveTo

java.lang.Object
com.itextpdf.svg.renderers.path.impl.AbstractPathShape
com.itextpdf.svg.renderers.path.impl.QuadraticCurveTo
All Implemented Interfaces:
IControlPointCurve, IPathShape
Direct Known Subclasses:
QuadraticSmoothCurveTo
public class QuadraticCurveTo extends AbstractPathShape implements IControlPointCurve
Implements quadratic Bezier curveTo(Q) attribute of SVG's path element.

  • Field Details

  • Constructor Details

    • QuadraticCurveTo

      public QuadraticCurveTo()
      Creates new QuadraticCurveTo instance.

    • QuadraticCurveTo

      public QuadraticCurveTo(boolean relative)
      Creates new QuadraticCurveTo instance.
      Parameters:
      relative - true in case it is a relative operator, false if it is an absolute operator

    • QuadraticCurveTo

      public QuadraticCurveTo(boolean relative, IOperatorConverter copier)
      Creates new QuadraticCurveTo instance.
      Parameters:
      relative - true in case it is a relative operator, false if it is an absolute operator
      copier - IOperatorConverter copier for converting relative coordinates to absolute coordinates

  • Method Details

    • draw

      public void draw()
      Draws a quadratic Bezier curve from the current point to (x,y) using (x1,y1) as the control point
      Specified by:
      draw in class AbstractPathShape

    • setCoordinates

      public void setCoordinates(String[] inputCoordinates, Point startPoint)
      Description copied from interface: IPathShape
      This method sets the coordinates for the path painting operator and does internal preprocessing, if necessary
      Specified by:
      setCoordinates in interface IPathShape
      Parameters:
      inputCoordinates - an array containing point values for path coordinates
      startPoint - the ending point of the previous operator, or, in broader terms, the point that the coordinates should be absolutized against, for relative operators

    • getLastControlPoint

      public Point getLastControlPoint()
      Description copied from interface: IControlPointCurve
      Returns coordinates of the last control point (the one closest to the ending point) in the Bezier curve, in SVG space coordinates
      Specified by:
      getLastControlPoint in interface IControlPointCurve
      Returns:
      coordinates of the last control point in SVG space coordinates

    • getPathShapeRectangle

      public Rectangle getPathShapeRectangle(Point lastPoint)
      Description copied from class: AbstractPathShape
      Get bounding rectangle of the current path shape.
      Specified by:
      getPathShapeRectangle in interface IPathShape
      Overrides:
      getPathShapeRectangle in class AbstractPathShape
      Parameters:
      lastPoint - start point for this shape
      Returns:
      calculated rectangle

    • getBezierMinMaxPoints

      private static double[] getBezierMinMaxPoints(double x0, double y0, double x1, double y1, double x2, double y2)
      The algorithm is similar to cubic curve in the method CurveTo#getBezierMinMaxPoints, but the initial function is f(t) = (1 - t)^2*P0 + 2*(1-t)*t*P1 + t^2*P2, 0 invalid input: '<'= t invalid input: '<'= 1
      Parameters:
      x0 - x coordinate of the starting point
      y0 - y coordinate of the starting point
      x1 - x coordinate of the control point
      y1 - y coordinate of the control point
      x2 - x coordinate of the ending point
      y2 - y coordinate of the ending point
      Returns:
      array of {xMin, yMin, xMax, yMax} values

    • getExtremeTValues

      private static double[] getExtremeTValues(double x0, double y0, double x1, double y1, double x2, double y2)
      Calculate values of t at which the function reaches its extreme points. To do this, we get the derivative of the function and equate it to 0: f'(t) = 2a*t + b. t can only be in the range [0, 1] and it discarded otherwise.
      Parameters:
      x0 - x coordinate of the starting point
      y0 - y coordinate of the starting point
      x1 - x coordinate of the control point
      y1 - y coordinate of the control point
      x2 - x coordinate of the ending point
      y2 - y coordinate of the ending point
      Returns:
      array of theta values corresponding to extreme points

    • addTValueToList

      private static void addTValueToList(double t, List<Double> tValuesList)
      Check that t is in the range [0, 1] and add it to list
      Parameters:
      t - value of t
      tValuesList - list storing t values

    • getTValue

      private static double getTValue(double p0, double p1, double p2)

    • calculateExtremeCoordinate

      private static double calculateExtremeCoordinate(double t, double p0, double p1, double p2)