java.lang.Object
- com.itextpdf.svg.renderers.path.impl.AbstractPathShape
- - com.itextpdf.svg.renderers.path.impl.CurveTo

All Implemented Interfaces:

IControlPointCurve, IPathShape

Direct Known Subclasses:

SmoothSCurveTo
```
public class CurveTo
extends AbstractPathShape
implements IControlPointCurve
```
Implements curveTo(C) attribute of SVG's path element.

Field Summary

Fields
Modifier and Type Field Description

(package private) static int ARGUMENT_SIZE

private static double ZERO_EPSILON
- Fields inherited from class com.itextpdf.svg.renderers.path.impl.AbstractPathShape
  context, coordinates, copier, properties, relative

Constructor Summary

Constructors
Constructor	Description
`CurveTo()`	Creates new `CurveTo` instance.
`CurveTo(boolean relative)`	Creates new `CurveTo` instance.
`CurveTo(boolean relative, IOperatorConverter copier)`	Creates new `CurveTo` instance.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`private static void`	`addTValueToList(double t, java.util.List<java.lang.Double> tValuesList)`	Check that t is in the range [0, 1] and add it to list
`private static double`	`calculateExtremeCoordinate(double t, double p0, double p1, double p2, double p3)`
`private static java.util.List<java.lang.Double>`	`calculateTValues(double p0, double p1, double p2, double p3)`	Calculate the quadratic function 3at^2 + 2bt + c = 0 to obtain the values of t
`void`	`draw()`	Draws this instruction to a canvas object.
`private static double[]`	`getBezierMinMaxPoints(double x0, double y0, double x1, double y1, double x2, double y2, double x3, double y3)`	Initial function of cubic bezier is f(t) = (t-1)^3P0 + 3(1-t)^2tP1 + 3(1-t)t^2P2 + t^3P3, where 0 <= t <= 1 After opening brackets it can be reduced to f(t) = at^3 + bt^2 + ct + d, where a = P3-3P2+3P1-P0 b = 3P2-6P1+3P0 c = 3P1-3P0 d = P0 First we must find the values of t at which the function reaches its extreme points.
`private Point`	`getFirstControlPoint()`
`Point`	`getLastControlPoint()`	Returns coordinates of the last control point (the one closest to the ending point) in the Bezier curve, in SVG space coordinates
`Rectangle`	`getPathShapeRectangle(Point lastPoint)`	Get bounding rectangle of the current path shape.
`private static double[]`	`getTValuesInExtremePoints(double x0, double y0, double x1, double y1, double x2, double y2, double x3, double y3)`	Calculate values of t at which the function reaches its extreme points.
`void`	`setCoordinates(java.lang.String[] inputCoordinates, Point startPoint)`	This method sets the coordinates for the path painting operator and does internal preprocessing, if necessary

Methods inherited from class com.itextpdf.svg.renderers.path.impl.AbstractPathShape
applyTransform, createPoint, draw, getEndingPoint, isRelative, parseHorizontalLength, parseVerticalLength, setContext, setParent, setTransform

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - ARGUMENT_SIZE
```
static final int ARGUMENT_SIZE
```
    See Also:
    
    Constant Field Values
  - ZERO_EPSILON
```
private static final double ZERO_EPSILON
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - CurveTo
```
public CurveTo()
```
    Creates new CurveTo instance.
  - CurveTo
```
public CurveTo(boolean relative)
```
    Creates new CurveTo instance.
    
    Parameters:
    
    relative - true in case it is a relative operator, false if it is an absolute operator
  - CurveTo
```
public CurveTo(boolean relative,
               IOperatorConverter copier)
```
    Creates new CurveTo 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 Detail
  - draw
```
public void draw()
```
    Description copied from class: AbstractPathShape
    
    Draws this instruction to a canvas object.
    
    Specified by:
    
    draw in class AbstractPathShape
  - setCoordinates
```
public void setCoordinates(java.lang.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
  - getFirstControlPoint
```
private Point getFirstControlPoint()
```
  - getBezierMinMaxPoints
```
private static double[] getBezierMinMaxPoints(double x0,
                                              double y0,
                                              double x1,
                                              double y1,
                                              double x2,
                                              double y2,
                                              double x3,
                                              double y3)
```
    Initial function of cubic bezier is f(t) = (t-1)^3*P0 + 3*(1-t)^2*t*P1 + 3*(1-t)*t^2*P2 + t^3*P3, where 0 <= t <= 1 After opening brackets it can be reduced to f(t) = a*t^3 + b*t^2 + c*t + d, where a = P3-3*P2+3*P1-P0 b = 3*P2-6*P1+3*P0 c = 3*P1-3*P0 d = P0 First we must find the values of t at which the function reaches its extreme points. This happens in the method getTValuesInExtremePoints(double, double, double, double, double, double, double, double). Next we get x and y values in extremes and compare it with the start and ending points coordinates to get the borders of the bounding box.
    
    Parameters:
    
    x0 - x coordinate of the starting point
    
    y0 - y coordinate of the starting point
    
    x1 - x coordinate of the first control point
    
    y1 - y coordinate of the first control point
    
    x2 - x coordinate of the second control point
    
    y2 - y coordinate of the second control point
    
    x3 - x coordinate of the ending point
    
    y3 - y coordinate of the ending point
    
    Returns:
    
    array of {xMin, yMin, xMax, yMax} values
  - getTValuesInExtremePoints
```
private static double[] getTValuesInExtremePoints(double x0,
                                                  double y0,
                                                  double x1,
                                                  double y1,
                                                  double x2,
                                                  double y2,
                                                  double x3,
                                                  double y3)
```
    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) = 3a*t^2 + 2b*t + c. This is parabola and for finding we calculate the discriminant. 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 first control point
    
    y1 - y coordinate of the first control point
    
    x2 - x coordinate of the second control point
    
    y2 - y coordinate of the second control point
    
    x3 - x coordinate of the ending point
    
    y3 - y coordinate of the ending point
    
    Returns:
    
    array of theta values corresponding to extreme points
  - calculateTValues
```
private static java.util.List<java.lang.Double> calculateTValues(double p0,
                                                                 double p1,
                                                                 double p2,
                                                                 double p3)
```
    Calculate the quadratic function 3a*t^2 + 2b*t + c = 0 to obtain the values of t
    
    Parameters:
    
    p0 - coordinate of the starting point
    
    p1 - coordinate of the first control point
    
    p2 - coordinate of the second control point
    
    p3 - coordinate of the ending point
    
    Returns:
    
    list of t values. t should be in range [0, 1]
  - addTValueToList
```
private static void addTValueToList(double t,
                                    java.util.List<java.lang.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
  - calculateExtremeCoordinate
```
private static double calculateExtremeCoordinate(double t,
                                                 double p0,
                                                 double p1,
                                                 double p2,
                                                 double p3)
```

Modifier and Type	Field	Description
`(package private) static int`	`ARGUMENT_SIZE`
`private static double`	`ZERO_EPSILON`

Class CurveTo

Field Summary

Fields inherited from class com.itextpdf.svg.renderers.path.impl.AbstractPathShape

Constructor Summary

Method Summary

Methods inherited from class com.itextpdf.svg.renderers.path.impl.AbstractPathShape

Methods inherited from class java.lang.Object

Field Detail

ARGUMENT_SIZE

ZERO_EPSILON

Constructor Detail

CurveTo

CurveTo

CurveTo

Method Detail

draw

setCoordinates

getLastControlPoint

getPathShapeRectangle

getFirstControlPoint

getBezierMinMaxPoints

getTValuesInExtremePoints

calculateTValues

addTValueToList

calculateExtremeCoordinate