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Runtime

org.eclipse.gmf.runtime.draw2d.ui.geometry
Class PointListUtilities

java.lang.Object
  extended by 
org.eclipse.gmf.runtime.draw2d.ui.geometry.PointListUtilities

public class PointListUtilities
extends java.lang.Object

A set of utility methods around manipulating PointList objects


Field Summary
static int DEFAULT_BEZIERLINES
          Constant that is the default number of lines that a bezier is approximated by as a polyline point list.
static int DEFAULT_CORNER_APPROXIMATION_PTS
           
 
Constructor Summary
PointListUtilities ()
           
 
Method Summary
static  PointList calcRoundedCornersPolyline ( PointList points, int r, java.util.Hashtable<java.lang.Integer,java.lang.Integer> rForBendpoint, boolean calculateAppoxPoints)
          Replaces bendpoints (all points except the first and last) in points list by points defining corresponding arcs.
static  PointList calcSmoothPolyline ( PointList points, int nSmoothFactor, int nBezierSteps)
          Method calcSmoothPolyline.
static  PointList calcSmoothPolyline ( PointList points, int nSmoothFactor, int nBezierSteps, int nStartIndex, int nEndIndex)
          Calculates the smooth polyline equivalent of the given points list.
static  Point calculatePointRelativeToLine ( PointList pointList, int fromLine, int fromEnd, boolean isPercentage)
          Finds a point relative to the pointList passed in based on the parameters passed in.
static boolean containsPoint ( PointList points, Point point)
          Utility method used to check if a point is contained inside a polygon
static  PointList copyPoints ( PointList pointsFrom)
          copyPoints This method is necessary because of an apparrent defect in the getCopy() routine of PointList class.
static  PointList createPointsFromRect ( Rectangle rBox)
          createPointsFromRect
protected static double distanceAlong (java.util.List mySegments, Point aPoint)
          Method distanceAlong.
static boolean findIntersections ( PointList points, PointList poly, PointList intersections, PointList distances)
          Method findIntersections.
static int findNearestLineSegIndexOfPoint ( PointList points, Point ptCoord)
          Method findNearestLineSegIndexOfPoint.
static java.util.List getLineSegments ( PointList points)
          Method getLineSegments.
static  LineSeg getNearestSegment (java.util.List mySegments, int xCoord, int yCoord)
          Static utility method to get the nearest segment in the polyline from the given coordinates.
static  Point getPointsInfimum ( PointList points)
          Method getPointsSupremum.
static long getPointsLength ( PointList points)
          Method getPointsLength.
static  Point getPointsSupremum ( PointList points)
          Method getPointsSupremum.
protected static long length (java.util.List mySegments)
          Method length.
static boolean normalizeSegments ( PointList points)
          Normalizes the line segments in the polyline.
static boolean normalizeSegments ( PointList points, int straightLineTolerance)
          Normalizes the line segments in the polyline.
static  Point pickClosestPoint ( PointList points, Point p)
          Assumption: Points in the PointList and Point p lie on the same line.
static  Point pickFarestPoint ( PointList points, Point p)
          Assumption: Points in the PointList and Point p lie on the same line.
protected static  Point pointOn (java.util.List mySegments, long theDistance, LineSeg.KeyPoint fromKeyPoint, Point ptResult)
          Method pointOn.
static  Point pointOn ( PointList points, long theDistance, LineSeg.KeyPoint fromKeyPoint, Point ptResult)
          Calculate the point on the polyline given a distance from a key point.
static  PointList routeAroundPoint ( PointList points, Point ptCenter, int nHeight, int nWidth, int nSmoothFactor, int nInclineOffset, boolean bTop)
          Method routeAroundPoint.
static  PointList routeAroundPoly ( PointList points, PointList poly, int nSmoothFactor, boolean bShortestDistance, boolean bIncludeIntersectionPoints, int nBuffer)
          Routes this polyline around another polyline that is presumably intersecting with it.
static  PointList routeAroundRect ( PointList points, Rectangle rBox, int nSmoothFactor, boolean bIncludeIntersectionPoints, int nBuffer)
          Method routeAroundRect.
protected static double segmentDistance (java.util.List mySegments, LineSeg theSegment, LineSeg.KeyPoint uptoKeyPoint)
          Method segmentDistance.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

DEFAULT_BEZIERLINES

public static final int DEFAULT_BEZIERLINES
Constant that is the default number of lines that a bezier is approximated by as a polyline point list.

See Also:
Constant Field Values

DEFAULT_CORNER_APPROXIMATION_PTS

public static final int DEFAULT_CORNER_APPROXIMATION_PTS
Since:
1.2
See Also:
Constant Field Values
Constructor Detail

PointListUtilities

public PointListUtilities()
Method Detail

normalizeSegments

public static boolean normalizeSegments(
PointList points)
Normalizes the line segments in the polyline. Checks for lines that are with-in a threshold for length and removes them. Additionally, it will remove points that that adjacent segments that are both horizontal, or both vertical.

Parameters:
points - PointList to be normalized
Returns:
boolean true if segments were changed, false otherwise

normalizeSegments

public static boolean normalizeSegments(
PointList points,
                                        int straightLineTolerance)
Normalizes the line segments in the polyline. Checks for lines that are with-in a threshold for length and removes them. Additionally, it will remove points that that adjacent segments that are both horizontal, or both vertical. Will utilize a tolerance value to determine if segments needs to flattened or not.

Parameters:
points - PointList to normalize
straightLineTolerance - the tolerance value within which indicates the line is straight in relative coordinates.
Returns:
boolean true if segments were changed, false otherwise

getPointsSupremum

public static 
Point getPointsSupremum(
PointList points)
Method getPointsSupremum. Get points representing the extrema for this poly line.

Parameters:
points - PointList to calculate the highest point from.
Returns:
Point value of the highest point in the bounding box of the polyline.

getPointsInfimum

public static 
Point getPointsInfimum(
PointList points)
Method getPointsSupremum. Get points representing the minimum for this poly line.

Parameters:
points - PointList to calculate the minimum point from.
Returns:
Point value of the lowest point in the bounding box of the polyline.

createPointsFromRect

public static 
PointList createPointsFromRect(
Rectangle rBox)
createPointsFromRect

Parameters:
rBox - Rectangle to base the PointList from
Returns:
PointList that is equivalent to the Rectangle

routeAroundRect

public static 
PointList routeAroundRect(
PointList points,
                                        
Rectangle rBox,
                                        int nSmoothFactor,
                                        boolean bIncludeIntersectionPoints,
                                        int nBuffer)
Method routeAroundRect. Route this polyline around a rectangle that is presumably intersecting with it.

Parameters:
points - PointList that will be modified to route around the given rectangle
rBox - the Rectangle around which the routing will occur.
nSmoothFactor - the int smooth factor to route the line with 0 - None, 15 - some, 30 - lots
bIncludeIntersectionPoints - the boolean determining whether to include the points that intersect with the rectangle in the newly routed polyline.
nBuffer - the int buffer around the rectangle.
Returns:
PointList that is the newly routed version of points of null if operation was not successful or if the calculation is not possible.

getLineSegments

public static java.util.List getLineSegments(
PointList points)
Method getLineSegments. Converts the points of this polyline into a list of LineSeg objects

Parameters:
points - PointList to get LineSeg equivalents of.
Returns:
List of LineSeg objects.

routeAroundPoly

public static 
PointList routeAroundPoly(
PointList points,
                                        
PointList poly,
                                        int nSmoothFactor,
                                        boolean bShortestDistance,
                                        boolean bIncludeIntersectionPoints,
                                        int nBuffer)
Routes this polyline around another polyline that is presumably intersecting with it.

Parameters:
points - the PointList that is to be modified based on the routing calculations made around the poly parameter.
poly - the PolylinePointList around which the routing will occur.
nSmoothFactor - the int smooth factor to route the line with 0 - None, 15 - some, 30 - lots
bShortestDistance - the boolean determining whether to use the shortest distance possible to achieve this or else minimally modify the existing polyline.
bIncludeIntersectionPoints - the boolean determining whether to include the points that intersect with the rectangle in the newly routed polyline.
nBuffer - the int buffer around the rectangle.
Returns:
PointList that is the newly routed version of points of null if operation was not successful or if the calculation is not possible.

copyPoints

public static 
PointList copyPoints(
PointList pointsFrom)
copyPoints This method is necessary because of an apparrent defect in the getCopy() routine of PointList class. It is initializing the copy based on size but then making the copy based on the array allocation which may be different causing an ArrayIndexOutOfBounds exception.

Parameters:
pointsFrom -
Returns:
PointList

calcSmoothPolyline

public static final 
PointList calcSmoothPolyline(
PointList points,
                                                 int nSmoothFactor,
                                                 int nBezierSteps)
Method calcSmoothPolyline. Calculate the smooth polyline approximation of this polyline based on a smooth factor.

Parameters:
points - the PointList that is used to calculate the smooth point list from.
nSmoothFactor - the int smooth factor to smooth the line with 0 - None, 15 - some, 30 - lots
nBezierSteps - the int number of line steps used to approximate the smooth curve
Returns:
PolylinePointList List of PolylinePoint representing the smooth polyline.

calcSmoothPolyline

public static 
PointList calcSmoothPolyline(
PointList points,
                                           int nSmoothFactor,
                                           int nBezierSteps,
                                           int nStartIndex,
                                           int nEndIndex)
Calculates the smooth polyline equivalent of the given points list. It will extrapolate a bezier approximation in polylines that resembles a curved line.

Parameters:
points - the PointList that is used to calculate the smooth bezier approximation.
nSmoothFactor - the int smooth factor to smooth the line with 0 - None, 15 - some, 30 - lots
nBezierSteps - the int number of line steps used to approximate the smooth curve
nStartIndex - the int index in the line to start from to create the smooth approximation
nEndIndex - the int index in the line to end at to create the smooth approximation
Returns:
PolylinePointList List of PolylinePoint representing the smooth polyline.

pointOn

public static 
Point pointOn(
PointList points,
                            long theDistance,
                            
LineSeg.KeyPoint fromKeyPoint,
                            
Point ptResult)
Calculate the point on the polyline given a distance from a key point.

Parameters:
points - the PointList to calculate the point on the polyline.
theDistance - the long x coordinate of the point
fromKeyPoint - the int constant value indicating the key point Origin, Terminus, Midpoint
ptResult - the Point where the resulting point value is set.
Returns:
Point the calculated point residing on the polyline.

getPointsLength

public static long getPointsLength(
PointList points)
Method getPointsLength. Static utility function to calculate the length of a series of points if interpreted as line segments.

Parameters:
points - PointList to calculate the length of.
Returns:
length of the line segments

length

protected static long length(java.util.List mySegments)
Method length. Static utility function to calculate the length of a series of line segments.

Parameters:
mySegments - List of line segments to calculate the length of.
Returns:
long length of the line segments

getNearestSegment

public static 
LineSeg getNearestSegment(java.util.List mySegments,
                                        int xCoord,
                                        int yCoord)
Static utility method to get the nearest segment in the polyline from the given coordinates.

Parameters:
mySegments - the List of LineSeg objects
xCoord - the int x coordinate of the point
yCoord - the int y coordinate of the point
Returns:
the LineSeg by reference which is closest to the given coordinates.

pointOn

protected static 
Point pointOn(java.util.List mySegments,
                               long theDistance,
                               
LineSeg.KeyPoint fromKeyPoint,
                               
Point ptResult)
Method pointOn. Static utility function used by pointOn.

Parameters:
mySegments -
theDistance - the long x coordinate of the point
fromKeyPoint - the int constant value indicating the key point Origin, Terminus, Midpoint
ptResult - the Point where the resulting point value is set.
Returns:
Point the calculated point residing on the polyline.

distanceAlong

protected static double distanceAlong(java.util.List mySegments,
                                      
Point aPoint)
Method distanceAlong. Static utility function to calculate the distanceAlong a series of line segments a given point is on the line.

Parameters:
mySegments -
aPoint - Point to calculate the distance along the polyline of.
Returns:
double value of the distance along the polyline of the given point.

segmentDistance

protected static double segmentDistance(java.util.List mySegments,
                                        
LineSeg theSegment,
                                        
LineSeg.KeyPoint uptoKeyPoint)
Method segmentDistance. Compute the percentage of the distance along this polyline that the given segment occurs. If the keypoint specified is Origin, then the given segment will not be included in the percentage; if the keypoint is Midpoint, then half of the length will be included; if the keypoint is Terminus, the the whole length will be included. The segment must be a segment of this polyline.

Parameters:
mySegments -
theSegment -
uptoKeyPoint -
Returns:
double

routeAroundPoint

public static 
PointList routeAroundPoint(
PointList points,
                                         
Point ptCenter,
                                         int nHeight,
                                         int nWidth,
                                         int nSmoothFactor,
                                         int nInclineOffset,
                                         boolean bTop)
Method routeAroundPoint. Calculate a new routed version of this polyline that will route itself around a given point.

Parameters:
points - PointList to modify
ptCenter - the Point around which the routing will occur.
nHeight - the int height to route around the point.
nWidth - the int width to route around the point.
nSmoothFactor - the int smooth factor to route the line with 0 - None, 15 - some, 30 - lots
nInclineOffset - the int amount to incline the routed points.
bTop - the boolean route above or below the point on the line.
Returns:
PointList that is the newly routed version of points of null if operation was not successful or if the calculation is not possible.

findNearestLineSegIndexOfPoint

public static int findNearestLineSegIndexOfPoint(
PointList points,
                                                 
Point ptCoord)
Method findNearestLineSegIndexOfPoint. Calculate the nearest line segment index distance wise to the given point.

Parameters:
points - PointList to calculate the nearest line segment of.
ptCoord - the Point to test containment of.
Returns:
int Index of line segment that is nearest in the polyline to the given point. The index is 1 based where 1 represents the first segment.

findIntersections

public static boolean findIntersections(
PointList points,
                                        
PointList poly,
                                        
PointList intersections,
                                        
PointList distances)
Method findIntersections. Find all intersection points between this polyline and another polyline passed into the method.

Parameters:
points - PointList to calculate interesections with.
poly - the PointList to calculate intersections with.
intersections - the PointList containing the resulting calculated intersection points.
distances - the PointList containing point values representing the distance along the polyline the intersections occur.
Returns:
boolean true if intersections could be calculated, false otherwise.

calculatePointRelativeToLine

public static 
Point calculatePointRelativeToLine(
PointList pointList,
                                                 int fromLine,
                                                 int fromEnd,
                                                 boolean isPercentage)
Finds a point relative to the pointList passed in based on the parameters passed in.

Parameters:
pointList - the PointList
fromLine - distance off the line
fromEnd - distance from the starting point of the line (i.e. distance from source end along the line)
isPercentage - is the fromEnd given as a percentage?
Returns:
Point

pickClosestPoint

public static 
Point pickClosestPoint(
PointList points,
                                     
Point p)
Assumption: Points in the PointList and Point p lie on the same line. Returns the Point from the PointList closest to @param p

Parameters:
points - - the list of points to select the result from
p - - the point to which the closest point must be found
Returns:
the Point from the PointList closest to @param p

pickFarestPoint

public static 
Point pickFarestPoint(
PointList points,
                                    
Point p)
Assumption: Points in the PointList and Point p lie on the same line. Returns the Point from the PointList closest to @param p

Parameters:
points - - the list of points to select the result from
p - - the point to which the closest point must be found
Returns:
the Point from the PointList closest to @param p

containsPoint

public static boolean containsPoint(
PointList points,
                                    
Point point)
Utility method used to check if a point is contained inside a polygon

Parameters:
points - the polygon
point - point to check
Returns:
true is the pointis inside the polygon, otherwise false

calcRoundedCornersPolyline

public static 
PointList calcRoundedCornersPolyline(
PointList points,
                                                   int r,
                                                   java.util.Hashtable<java.lang.Integer,java.lang.Integer> rForBendpoint,
                                                   boolean calculateAppoxPoints)
Replaces bendpoints (all points except the first and last) in points list by points defining corresponding arcs. That is, each bendpoint is replaced with the start and end point of the arc, and if calculateApproxPoints is true, there will also be points in between that approximate the arc. Arc size is r. Sometimes, segment between two bendpoints is shorter than r. In that case, arc size for both bendpoints has to be reduced to be half of the segment length, so that both arcs can fit. These reduced arc sizes (if any) are kept in rForBendpoint hashtable.

Parameters:
points - Initial list of connection points
r - Size (radius) of the arc that should replace bendpoint
rForBendpoint - Hashtable keeping track of bendpoints whose arcs have to be smaller than r
calculateAppoxPoints - Indicates if arcs replacing bendpoints should be approximated
Returns:
Since:
1.2

Runtime

Guidelines for using Eclipse APIs.

Copyright (c) IBM Corp., Borland Software Corp., and others 2005,2006. All rights reserved.


 
 
  Published under the terms of the Eclipse Public License Version 1.0 ("EPL") Design by Interspire