com.itextpdf.kernel.pdf.canvas.parser.clipper

Class ClipperBridge

java.lang.Object

com.itextpdf.kernel.pdf.canvas.parser.clipper.ClipperBridge

public final class ClipperBridge
extends Object

This class contains a variety of methods allowing the conversion of iText abstractions into abstractions of the Clipper library, and vice versa.

For example:

• PolyTree to Path
• Point to Point.LongPoint
• Point.LongPoint to Point

Field Summary

Fields

Modifier and Type	Field and Description
static Double	floatMultiplier Since the clipper library uses integer coordinates, we should convert our floating point numbers into fixed point numbers by multiplying by this coefficient.

Constructor Summary

Constructors

Constructor and Description
ClipperBridge() Creates new ClipperBridge instance with default float multiplier value which is 10^14.
ClipperBridge(Path... paths) Creates new ClipperBridge instance with adjusted float multiplier value.
ClipperBridge(Point[]... points) Creates new ClipperBridge instance with adjusted float multiplier value.

Method Summary

Modifier and Type	Method and Description
List<Subpath>	addPath(ClipperOffset offset, Path path, IClipper.JoinType joinType, IClipper.EndType endType) Adds all iText Subpaths of the iText Path to the ClipperOffset object with one note: it doesn't add degenerate subpaths.
void	addPath(IClipper clipper, Path path, IClipper.PolyType polyType) Adds iText Path to the given IClipper object.
boolean	addPolygonToClipper(IClipper clipper, Point[] polyVertices, IClipper.PolyType polyType) Adds polygon path based on array of Point (internally converting them by convertToLongPoints(java.util.List<com.itextpdf.kernel.geom.Point>)) and adds this path to IClipper instance, treating the path as a closed polygon.
boolean	addPolylineSubjectToClipper(IClipper clipper, Point[] lineVertices) Adds polyline path based on array of Point (internally converting them by convertToLongPoints(java.util.List<com.itextpdf.kernel.geom.Point>)) and adds this path to IClipper instance, treating the path as a polyline (an open path in terms of clipper library).
List<Point>	convertToFloatPoints(List<Point.LongPoint> points) Converts list of Point.LongPoint objects into list of Point objects.
List<Point.LongPoint>	convertToLongPoints(List<Point> points) Converts list of Point objects into list of Point.LongPoint objects.
Path	convertToPath(PolyTree result) Converts Clipper library PolyTree abstraction into iText Path object.
static IClipper.EndType	getEndType(int lineCapStyle) Converts iText line cap style constant into the corresponding constant of the Clipper library.
static IClipper.PolyFillType	getFillType(int fillingRule) Converts iText filling rule constant into the corresponding constant of the Clipper library.
double	getFloatMultiplier() Gets multiplier coefficient for converting our floating point numbers into fixed point numbers.
static IClipper.JoinType	getJoinType(int lineJoinStyle) Converts iText line join style constant into the corresponding constant of the Clipper library.
float	longRectCalculateHeight(LongRect rect) Calculates the height of the rectangle represented by the LongRect object.
float	longRectCalculateWidth(LongRect rect) Calculates the width of the rectangle represented by the LongRect object.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

floatMultiplier

public static Double floatMultiplier

Since the clipper library uses integer coordinates, we should convert our floating point numbers into fixed point numbers by multiplying by this coefficient. Vary it to adjust the preciseness of the calculations.

Note that if this value is specified, it will be used for all ClipperBridge instances and dynamic float multiplier calculation will be disabled.

Constructor Detail

ClipperBridge

public ClipperBridge()

Creates new ClipperBridge instance with default float multiplier value which is 10^14.

Since the clipper library uses integer coordinates, we should convert our floating point numbers into fixed point numbers by multiplying by float multiplier coefficient. It is possible to vary it to adjust the preciseness of the calculations: if static floatMultiplier is specified, it will be used for all ClipperBridge instances and default value will be ignored.

ClipperBridge

public ClipperBridge(Path... paths)

Creates new ClipperBridge instance with adjusted float multiplier value. This instance will work correctly with the provided paths only.

Since the clipper library uses integer coordinates, we should convert our floating point numbers into fixed point numbers by multiplying by float multiplier coefficient. It is calculated automatically, however it is possible to vary it to adjust the preciseness of the calculations: if static floatMultiplier is specified, it will be used for all ClipperBridge instances and automatic calculation won't work.

Parameters:

paths - paths to calculate multiplier coefficient to convert floating point numbers into fixed point numbers

ClipperBridge

public ClipperBridge(Point[]... points)

Creates new ClipperBridge instance with adjusted float multiplier value. This instance will work correctly with the provided point only.

Since the clipper library uses integer coordinates, we should convert our floating point numbers into fixed point numbers by multiplying by float multiplier coefficient. It is calculated automatically, however it is possible to vary it to adjust the preciseness of the calculations: if static floatMultiplier is specified, it will be used for all ClipperBridge instances and automatic calculation won't work.

Parameters:

points - points to calculate multiplier coefficient to convert floating point numbers into fixed point numbers

Method Detail

convertToPath

public Path convertToPath(PolyTree result)

Converts Clipper library PolyTree abstraction into iText Path object.

Parameters:

result - PolyTree object to convert

Returns:

resultant Path object

addPath

public void addPath(IClipper clipper,
                    Path path,
                    IClipper.PolyType polyType)

Adds iText Path to the given IClipper object.

Parameters:

clipper - The IClipper object.

path - The Path object to be added to the IClipper.

polyType - See IClipper.PolyType.

addPath

public List<Subpath> addPath(ClipperOffset offset,
                             Path path,
                             IClipper.JoinType joinType,
                             IClipper.EndType endType)

Adds all iText Subpaths of the iText Path to the ClipperOffset object with one note: it doesn't add degenerate subpaths.

Parameters:

offset - the ClipperOffset object to add all iText Subpaths that are not degenerated.

path - Path object, containing the required Subpaths

joinType - IClipper join type. The value could be IClipper.JoinType.BEVEL, IClipper.JoinType.ROUND, IClipper.JoinType.MITER

endType - IClipper end type. The value could be IClipper.EndType.CLOSED_POLYGON, IClipper.EndType.CLOSED_LINE, IClipper.EndType.OPEN_BUTT, IClipper.EndType.OPEN_SQUARE, IClipper.EndType.OPEN_ROUND

Returns:

List consisting of all degenerate iText Subpaths of the path.

convertToFloatPoints

public List<Point> convertToFloatPoints(List<Point.LongPoint> points)

Converts list of Point.LongPoint objects into list of Point objects.

Parameters:

points - the list of Point.LongPoint objects to convert

Returns:

the resultant list of Point objects.

convertToLongPoints

public List<Point.LongPoint> convertToLongPoints(List<Point> points)

Converts list of Point objects into list of Point.LongPoint objects.

Parameters:

points - the list of Point objects to convert

Returns:

the resultant list of Point.LongPoint objects.

getJoinType

public static IClipper.JoinType getJoinType(int lineJoinStyle)

Converts iText line join style constant into the corresponding constant of the Clipper library.

Parameters:

lineJoinStyle - iText line join style constant. See PdfCanvasConstants

Returns:

Clipper line join style constant.

getEndType

public static IClipper.EndType getEndType(int lineCapStyle)

Converts iText line cap style constant into the corresponding constant of the Clipper library.

Parameters:

lineCapStyle - iText line cap style constant. See PdfCanvasConstants

Returns:

Clipper line cap (end type) style constant.

getFillType

public static IClipper.PolyFillType getFillType(int fillingRule)

Converts iText filling rule constant into the corresponding constant of the Clipper library.

Parameters:

fillingRule - Either PdfCanvasConstants.FillingRule.NONZERO_WINDING or PdfCanvasConstants.FillingRule.EVEN_ODD.

Returns:

Clipper fill type constant.

addPolygonToClipper

public boolean addPolygonToClipper(IClipper clipper,
                                   Point[] polyVertices,
                                   IClipper.PolyType polyType)

Adds polygon path based on array of Point (internally converting them by convertToLongPoints(java.util.List<com.itextpdf.kernel.geom.Point>)) and adds this path to IClipper instance, treating the path as a closed polygon.

The return value will be false if the path is invalid for clipping. A path is invalid for clipping when:

• it has less than 3 vertices;
• the vertices are all co-linear.

Parameters:

clipper - IClipper instance to which the created polygon path will be added.

polyVertices - an array of Point which will be internally converted to clipper path and added to the clipper instance.

polyType - either IClipper.PolyType.SUBJECT or IClipper.PolyType.CLIP denoting whether added path is a subject of clipping or a part of the clipping polygon.

Returns:

true if polygon path was successfully added, false otherwise.

addPolylineSubjectToClipper

public boolean addPolylineSubjectToClipper(IClipper clipper,
                                           Point[] lineVertices)

Adds polyline path based on array of Point (internally converting them by convertToLongPoints(java.util.List<com.itextpdf.kernel.geom.Point>)) and adds this path to IClipper instance, treating the path as a polyline (an open path in terms of clipper library). This path is added to the subject of future clipping. Polylines cannot be part of clipping polygon.

The return value will be false if the path is invalid for clipping. A path is invalid for clipping when:

• it has less than 2 vertices;

Parameters:

clipper - IClipper instance to which the created polyline path will be added.

lineVertices - an array of Point which will be internally converted to clipper path and added to the clipper instance.

Returns:

true if polyline path was successfully added, false otherwise.

longRectCalculateWidth

public float longRectCalculateWidth(LongRect rect)

Calculates the width of the rectangle represented by the LongRect object.

Parameters:

rect - the LongRect object representing the rectangle.

Returns:

the width of the rectangle.

longRectCalculateHeight

public float longRectCalculateHeight(LongRect rect)

Calculates the height of the rectangle represented by the LongRect object.

Parameters:

rect - the LongRect object representing the rectangle.

Returns:

the height of the rectangle.

getFloatMultiplier

public double getFloatMultiplier()

Gets multiplier coefficient for converting our floating point numbers into fixed point numbers.

Returns:

multiplier coefficient for converting our floating point numbers into fixed point numbers