mirror of git://gcc.gnu.org/git/gcc.git
752 lines
24 KiB
Java
752 lines
24 KiB
Java
/* Polygon.java -- class representing a polygon
|
|
Copyright (C) 1999, 2002 Free Software Foundation, Inc.
|
|
|
|
This file is part of GNU Classpath.
|
|
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2, or (at your option)
|
|
any later version.
|
|
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
|
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA.
|
|
|
|
Linking this library statically or dynamically with other modules is
|
|
making a combined work based on this library. Thus, the terms and
|
|
conditions of the GNU General Public License cover the whole
|
|
combination.
|
|
|
|
As a special exception, the copyright holders of this library give you
|
|
permission to link this library with independent modules to produce an
|
|
executable, regardless of the license terms of these independent
|
|
modules, and to copy and distribute the resulting executable under
|
|
terms of your choice, provided that you also meet, for each linked
|
|
independent module, the terms and conditions of the license of that
|
|
module. An independent module is a module which is not derived from
|
|
or based on this library. If you modify this library, you may extend
|
|
this exception to your version of the library, but you are not
|
|
obligated to do so. If you do not wish to do so, delete this
|
|
exception statement from your version. */
|
|
|
|
|
|
package java.awt;
|
|
|
|
import java.awt.geom.AffineTransform;
|
|
import java.awt.geom.PathIterator;
|
|
import java.awt.geom.Point2D;
|
|
import java.awt.geom.Rectangle2D;
|
|
import java.io.Serializable;
|
|
|
|
/**
|
|
* This class represents a polygon, a closed, two-dimensional region in a
|
|
* coordinate space. The region is bounded by an arbitrary number of line
|
|
* segments, between (x,y) coordinate vertices. The polygon has even-odd
|
|
* winding, meaning that a point is inside the shape if it crosses the
|
|
* boundary an odd number of times on the way to infinity.
|
|
*
|
|
* <p>There are some public fields; if you mess with them in an inconsistent
|
|
* manner, it is your own fault when you get NullPointerException,
|
|
* ArrayIndexOutOfBoundsException, or invalid results. Also, this class is
|
|
* not threadsafe.
|
|
*
|
|
* @author Aaron M. Renn <arenn@urbanophile.com>
|
|
* @author Eric Blake <ebb9@email.byu.edu>
|
|
* @since 1.0
|
|
* @status updated to 1.4
|
|
*/
|
|
public class Polygon implements Shape, Serializable
|
|
{
|
|
/**
|
|
* Compatible with JDK 1.0+.
|
|
*/
|
|
private static final long serialVersionUID = -6460061437900069969L;
|
|
|
|
/**
|
|
* This total number of endpoints.
|
|
*
|
|
* @serial the number of endpoints, possibly less than the array sizes
|
|
*/
|
|
public int npoints;
|
|
|
|
/**
|
|
* The array of X coordinates of endpoints. This should not be null.
|
|
*
|
|
* @see #addPoint(int, int)
|
|
* @serial the x coordinates
|
|
*/
|
|
public int[] xpoints;
|
|
|
|
/**
|
|
* The array of Y coordinates of endpoints. This should not be null.
|
|
*
|
|
* @see #addPoint(int, int)
|
|
* @serial the y coordinates
|
|
*/
|
|
public int[] ypoints;
|
|
|
|
/**
|
|
* The bounding box of this polygon. This is lazily created and cached, so
|
|
* it must be invalidated after changing points.
|
|
*
|
|
* @see #getBounds()
|
|
* @serial the bounding box, or null
|
|
*/
|
|
protected Rectangle bounds;
|
|
|
|
/**
|
|
* Cached flattened version - condense points and parallel lines, so the
|
|
* result has area if there are >= 3 condensed vertices. flat[0] is the
|
|
* number of condensed points, and (flat[odd], flat[odd+1]) form the
|
|
* condensed points.
|
|
*
|
|
* @see #condense()
|
|
* @see #contains(double, double)
|
|
* @see #contains(double, double, double, double)
|
|
*/
|
|
private transient int[] condensed;
|
|
|
|
/**
|
|
* Initializes an empty polygon.
|
|
*/
|
|
public Polygon()
|
|
{
|
|
// Leave room for growth.
|
|
xpoints = new int[4];
|
|
ypoints = new int[4];
|
|
}
|
|
|
|
/**
|
|
* Create a new polygon with the specified endpoints. The arrays are copied,
|
|
* so that future modifications to the parameters do not affect the polygon.
|
|
*
|
|
* @param xpoints the array of X coordinates for this polygon
|
|
* @param ypoints the array of Y coordinates for this polygon
|
|
* @param npoints the total number of endpoints in this polygon
|
|
* @throws NegativeArraySizeException if npoints is negative
|
|
* @throws IndexOutOfBoundsException if npoints exceeds either array
|
|
* @throws NullPointerException if xpoints or ypoints is null
|
|
*/
|
|
public Polygon(int[] xpoints, int[] ypoints, int npoints)
|
|
{
|
|
this.xpoints = new int[npoints];
|
|
this.ypoints = new int[npoints];
|
|
System.arraycopy(xpoints, 0, this.xpoints, 0, npoints);
|
|
System.arraycopy(ypoints, 0, this.ypoints, 0, npoints);
|
|
this.npoints = npoints;
|
|
}
|
|
|
|
/**
|
|
* Reset the polygon to be empty. The arrays are left alone, to avoid object
|
|
* allocation, but the number of points is set to 0, and all cached data
|
|
* is discarded. If you are discarding a huge number of points, it may be
|
|
* more efficient to just create a new Polygon.
|
|
*
|
|
* @see #invalidate()
|
|
* @since 1.4
|
|
*/
|
|
public void reset()
|
|
{
|
|
npoints = 0;
|
|
invalidate();
|
|
}
|
|
|
|
/**
|
|
* Invalidate or flush all cached data. After direct manipulation of the
|
|
* public member fields, this is necessary to avoid inconsistent results
|
|
* in methods like <code>contains</code>.
|
|
*
|
|
* @see #getBounds()
|
|
* @since 1.4
|
|
*/
|
|
public void invalidate()
|
|
{
|
|
bounds = null;
|
|
condensed = null;
|
|
}
|
|
|
|
/**
|
|
* Translates the polygon by adding the specified values to all X and Y
|
|
* coordinates. This updates the bounding box, if it has been calculated.
|
|
*
|
|
* @param dx the amount to add to all X coordinates
|
|
* @param dy the amount to add to all Y coordinates
|
|
* @since 1.1
|
|
*/
|
|
public void translate(int dx, int dy)
|
|
{
|
|
int i = npoints;
|
|
while (--i >= 0)
|
|
{
|
|
xpoints[i] += dx;
|
|
xpoints[i] += dy;
|
|
}
|
|
if (bounds != null)
|
|
{
|
|
bounds.x += dx;
|
|
bounds.y += dy;
|
|
}
|
|
condensed = null;
|
|
}
|
|
|
|
/**
|
|
* Adds the specified endpoint to the polygon. This updates the bounding
|
|
* box, if it has been created.
|
|
*
|
|
* @param x the X coordinate of the point to add
|
|
* @param y the Y coordiante of the point to add
|
|
*/
|
|
public void addPoint(int x, int y)
|
|
{
|
|
if (npoints + 1 > xpoints.length)
|
|
{
|
|
int[] newx = new int[npoints + 1];
|
|
System.arraycopy(xpoints, 0, newx, 0, npoints);
|
|
xpoints = newx;
|
|
}
|
|
if (npoints + 1 > ypoints.length)
|
|
{
|
|
int[] newy = new int[npoints + 1];
|
|
System.arraycopy(ypoints, 0, newy, 0, npoints);
|
|
ypoints = newy;
|
|
}
|
|
xpoints[npoints] = x;
|
|
ypoints[npoints] = y;
|
|
npoints++;
|
|
if (bounds != null)
|
|
{
|
|
if (npoints == 1)
|
|
{
|
|
bounds.x = x;
|
|
bounds.y = y;
|
|
}
|
|
else
|
|
{
|
|
if (x < bounds.x)
|
|
{
|
|
bounds.width += bounds.x - x;
|
|
bounds.x = x;
|
|
}
|
|
else if (x > bounds.x + bounds.width)
|
|
bounds.width = x - bounds.x;
|
|
if (y < bounds.y)
|
|
{
|
|
bounds.height += bounds.y - y;
|
|
bounds.y = y;
|
|
}
|
|
else if (y > bounds.y + bounds.height)
|
|
bounds.height = y - bounds.y;
|
|
}
|
|
}
|
|
condensed = null;
|
|
}
|
|
|
|
/**
|
|
* Returns the bounding box of this polygon. This is the smallest
|
|
* rectangle with sides parallel to the X axis that will contain this
|
|
* polygon.
|
|
*
|
|
* @return the bounding box for this polygon
|
|
* @see #getBounds2D()
|
|
* @since 1.1
|
|
*/
|
|
public Rectangle getBounds()
|
|
{
|
|
if (bounds == null)
|
|
{
|
|
if (npoints == 0)
|
|
return bounds = new Rectangle();
|
|
int i = npoints - 1;
|
|
int minx = xpoints[i];
|
|
int maxx = minx;
|
|
int miny = ypoints[i];
|
|
int maxy = miny;
|
|
while (--i >= 0)
|
|
{
|
|
int x = xpoints[i];
|
|
int y = ypoints[i];
|
|
if (x < minx)
|
|
minx = x;
|
|
else if (x > maxx)
|
|
maxx = x;
|
|
if (y < miny)
|
|
miny = y;
|
|
else if (y > maxy)
|
|
maxy = y;
|
|
}
|
|
bounds = new Rectangle(minx, maxy, maxx - minx, maxy - miny);
|
|
}
|
|
return bounds;
|
|
}
|
|
|
|
/**
|
|
* Returns the bounding box of this polygon. This is the smallest
|
|
* rectangle with sides parallel to the X axis that will contain this
|
|
* polygon.
|
|
*
|
|
* @return the bounding box for this polygon
|
|
* @see #getBounds2D()
|
|
* @deprecated use {@link #getBounds()} instead
|
|
*/
|
|
public Rectangle getBoundingBox()
|
|
{
|
|
return getBounds();
|
|
}
|
|
|
|
/**
|
|
* Tests whether or not the specified point is inside this polygon.
|
|
*
|
|
* @param p the point to test
|
|
* @return true if the point is inside this polygon
|
|
* @throws NullPointerException if p is null
|
|
* @see #contains(double, double)
|
|
*/
|
|
public boolean contains(Point p)
|
|
{
|
|
return contains(p.getX(), p.getY());
|
|
}
|
|
|
|
/**
|
|
* Tests whether or not the specified point is inside this polygon.
|
|
*
|
|
* @param x the X coordinate of the point to test
|
|
* @param y the Y coordinate of the point to test
|
|
* @return true if the point is inside this polygon
|
|
* @see #contains(double, double)
|
|
* @since 1.1
|
|
*/
|
|
public boolean contains(int x, int y)
|
|
{
|
|
return contains((double) x, (double) y);
|
|
}
|
|
|
|
/**
|
|
* Tests whether or not the specified point is inside this polygon.
|
|
*
|
|
* @param x the X coordinate of the point to test
|
|
* @param y the Y coordinate of the point to test
|
|
* @return true if the point is inside this polygon
|
|
* @see #contains(double, double)
|
|
* @deprecated use {@link #contains(int, int)} instead
|
|
*/
|
|
public boolean inside(int x, int y)
|
|
{
|
|
return contains((double) x, (double) y);
|
|
}
|
|
|
|
/**
|
|
* Returns a high-precision bounding box of this polygon. This is the
|
|
* smallest rectangle with sides parallel to the X axis that will contain
|
|
* this polygon.
|
|
*
|
|
* @return the bounding box for this polygon
|
|
* @see #getBounds()
|
|
* @since 1.2
|
|
*/
|
|
public Rectangle2D getBounds2D()
|
|
{
|
|
// For polygons, the integer version is exact!
|
|
return getBounds();
|
|
}
|
|
|
|
/**
|
|
* Tests whether or not the specified point is inside this polygon.
|
|
*
|
|
* @param x the X coordinate of the point to test
|
|
* @param y the Y coordinate of the point to test
|
|
* @return true if the point is inside this polygon
|
|
* @since 1.2
|
|
*/
|
|
public boolean contains(double x, double y)
|
|
{
|
|
// First, the obvious bounds checks.
|
|
if (! condense() || ! getBounds().contains(x, y))
|
|
return false;
|
|
// A point is contained if a ray to (-inf, y) crosses an odd number
|
|
// of segments. This must obey the semantics of Shape when the point is
|
|
// exactly on a segment or vertex: a point is inside only if the adjacent
|
|
// point in the increasing x or y direction is also inside. Note that we
|
|
// are guaranteed that the condensed polygon has area, and no consecutive
|
|
// segments with identical slope.
|
|
boolean inside = false;
|
|
int limit = condensed[0];
|
|
int curx = condensed[(limit << 1) - 1];
|
|
int cury = condensed[limit << 1];
|
|
for (int i = 1; i <= limit; i++)
|
|
{
|
|
int priorx = curx;
|
|
int priory = cury;
|
|
curx = condensed[(i << 1) - 1];
|
|
cury = condensed[i << 1];
|
|
if ((priorx > x && curx > x) // Left of segment, or NaN.
|
|
|| (priory > y && cury > y) // Below segment, or NaN.
|
|
|| (priory < y && cury < y)) // Above segment.
|
|
continue;
|
|
if (priory == cury) // Horizontal segment, y == cury == priory
|
|
{
|
|
if (priorx < x && curx < x) // Right of segment.
|
|
{
|
|
inside = ! inside;
|
|
continue;
|
|
}
|
|
// Did we approach this segment from above or below?
|
|
// This mess is necessary to obey rules of Shape.
|
|
priory = condensed[((limit + i - 2) % limit) << 1];
|
|
boolean above = priory > cury;
|
|
if ((curx == x && (curx > priorx || above))
|
|
|| (priorx == x && (curx < priorx || ! above))
|
|
|| (curx > priorx && ! above) || above)
|
|
inside = ! inside;
|
|
continue;
|
|
}
|
|
if (priorx == x && priory == y) // On prior vertex.
|
|
continue;
|
|
if (priorx == curx // Vertical segment.
|
|
|| (priorx < x && curx < x)) // Right of segment.
|
|
{
|
|
inside = ! inside;
|
|
continue;
|
|
}
|
|
// The point is inside the segment's bounding box, compare slopes.
|
|
double leftx = curx > priorx ? priorx : curx;
|
|
double lefty = curx > priorx ? priory : cury;
|
|
double slopeseg = (double) (cury - priory) / (curx - priorx);
|
|
double slopepoint = (double) (y - lefty) / (x - leftx);
|
|
if ((slopeseg > 0 && slopeseg > slopepoint)
|
|
|| slopeseg < slopepoint)
|
|
inside = ! inside;
|
|
}
|
|
return inside;
|
|
}
|
|
|
|
/**
|
|
* Tests whether or not the specified point is inside this polygon.
|
|
*
|
|
* @param p the point to test
|
|
* @return true if the point is inside this polygon
|
|
* @throws NullPointerException if p is null
|
|
* @see #contains(double, double)
|
|
* @since 1.2
|
|
*/
|
|
public boolean contains(Point2D p)
|
|
{
|
|
return contains(p.getX(), p.getY());
|
|
}
|
|
|
|
/**
|
|
* Test if a high-precision rectangle intersects the shape. This is true
|
|
* if any point in the rectangle is in the shape. This implementation is
|
|
* precise.
|
|
*
|
|
* @param x the x coordinate of the rectangle
|
|
* @param y the y coordinate of the rectangle
|
|
* @param w the width of the rectangle, treated as point if negative
|
|
* @param h the height of the rectangle, treated as point if negative
|
|
* @return true if the rectangle intersects this shape
|
|
* @since 1.2
|
|
*/
|
|
public boolean intersects(double x, double y, double w, double h)
|
|
{
|
|
// First, the obvious bounds checks.
|
|
if (w <= 0 || h <= 0 || npoints == 0 ||
|
|
! getBounds().intersects(x, y, w, h))
|
|
return false; // Disjoint bounds.
|
|
if ((x <= bounds.x && x + w >= bounds.x + bounds.width
|
|
&& y <= bounds.y && y + h >= bounds.y + bounds.height)
|
|
|| contains(x, y))
|
|
return true; // Rectangle contains the polygon, or one point matches.
|
|
// If any vertex is in the rectangle, the two might intersect.
|
|
int curx = 0;
|
|
int cury = 0;
|
|
for (int i = 0; i < npoints; i++)
|
|
{
|
|
curx = xpoints[i];
|
|
cury = ypoints[i];
|
|
if (curx >= x && curx < x + w && cury >= y && cury < y + h
|
|
&& contains(curx, cury)) // Boundary check necessary.
|
|
return true;
|
|
}
|
|
// Finally, if at least one of the four bounding lines intersect any
|
|
// segment of the polygon, return true. Be careful of the semantics of
|
|
// Shape; coinciding lines do not necessarily return true.
|
|
for (int i = 0; i < npoints; i++)
|
|
{
|
|
int priorx = curx;
|
|
int priory = cury;
|
|
curx = xpoints[i];
|
|
cury = ypoints[i];
|
|
if (priorx == curx) // Vertical segment.
|
|
{
|
|
if (curx < x || curx >= x + w) // Outside rectangle.
|
|
continue;
|
|
if ((cury >= y + h && priory <= y)
|
|
|| (cury <= y && priory >= y + h))
|
|
return true; // Bisects rectangle.
|
|
continue;
|
|
}
|
|
if (priory == cury) // Horizontal segment.
|
|
{
|
|
if (cury < y || cury >= y + h) // Outside rectangle.
|
|
continue;
|
|
if ((curx >= x + w && priorx <= x)
|
|
|| (curx <= x && priorx >= x + w))
|
|
return true; // Bisects rectangle.
|
|
continue;
|
|
}
|
|
// Slanted segment.
|
|
double slope = (double) (cury - priory) / (curx - priorx);
|
|
double intersect = slope * (x - curx) + cury;
|
|
if (intersect > y && intersect < y + h) // Intersects left edge.
|
|
return true;
|
|
intersect = slope * (x + w - curx) + cury;
|
|
if (intersect > y && intersect < y + h) // Intersects right edge.
|
|
return true;
|
|
intersect = (y - cury) / slope + curx;
|
|
if (intersect > x && intersect < x + w) // Intersects bottom edge.
|
|
return true;
|
|
intersect = (y + h - cury) / slope + cury;
|
|
if (intersect > x && intersect < x + w) // Intersects top edge.
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Test if a high-precision rectangle intersects the shape. This is true
|
|
* if any point in the rectangle is in the shape. This implementation is
|
|
* precise.
|
|
*
|
|
* @param r the rectangle
|
|
* @return true if the rectangle intersects this shape
|
|
* @throws NullPointerException if r is null
|
|
* @see #intersects(double, double, double, double)
|
|
* @since 1.2
|
|
*/
|
|
public boolean intersects(Rectangle2D r)
|
|
{
|
|
return intersects(r.getX(), r.getY(), r.getWidth(), r.getHeight());
|
|
}
|
|
|
|
/**
|
|
* Test if a high-precision rectangle lies completely in the shape. This is
|
|
* true if all points in the rectangle are in the shape. This implementation
|
|
* is precise.
|
|
*
|
|
* @param x the x coordinate of the rectangle
|
|
* @param y the y coordinate of the rectangle
|
|
* @param w the width of the rectangle, treated as point if negative
|
|
* @param h the height of the rectangle, treated as point if negative
|
|
* @return true if the rectangle is contained in this shape
|
|
* @since 1.2
|
|
*/
|
|
public boolean contains(double x, double y, double w, double h)
|
|
{
|
|
// First, the obvious bounds checks.
|
|
if (w <= 0 || h <= 0 || ! contains(x, y)
|
|
|| ! bounds.contains(x, y, w, h))
|
|
return false;
|
|
// Now, if any of the four bounding lines intersects a polygon segment,
|
|
// return false. The previous check had the side effect of setting
|
|
// the condensed array, which we use. Be careful of the semantics of
|
|
// Shape; coinciding lines do not necessarily return false.
|
|
int limit = condensed[0];
|
|
int curx = condensed[(limit << 1) - 1];
|
|
int cury = condensed[limit << 1];
|
|
for (int i = 1; i <= limit; i++)
|
|
{
|
|
int priorx = curx;
|
|
int priory = cury;
|
|
curx = condensed[(i << 1) - 1];
|
|
cury = condensed[i << 1];
|
|
if (curx > x && curx < x + w && cury > y && cury < y + h)
|
|
return false; // Vertex is in rectangle.
|
|
if (priorx == curx) // Vertical segment.
|
|
{
|
|
if (curx < x || curx > x + w) // Outside rectangle.
|
|
continue;
|
|
if ((cury >= y + h && priory <= y)
|
|
|| (cury <= y && priory >= y + h))
|
|
return false; // Bisects rectangle.
|
|
continue;
|
|
}
|
|
if (priory == cury) // Horizontal segment.
|
|
{
|
|
if (cury < y || cury > y + h) // Outside rectangle.
|
|
continue;
|
|
if ((curx >= x + w && priorx <= x)
|
|
|| (curx <= x && priorx >= x + w))
|
|
return false; // Bisects rectangle.
|
|
continue;
|
|
}
|
|
// Slanted segment.
|
|
double slope = (double) (cury - priory) / (curx - priorx);
|
|
double intersect = slope * (x - curx) + cury;
|
|
if (intersect > y && intersect < y + h) // Intersects left edge.
|
|
return false;
|
|
intersect = slope * (x + w - curx) + cury;
|
|
if (intersect > y && intersect < y + h) // Intersects right edge.
|
|
return false;
|
|
intersect = (y - cury) / slope + curx;
|
|
if (intersect > x && intersect < x + w) // Intersects bottom edge.
|
|
return false;
|
|
intersect = (y + h - cury) / slope + cury;
|
|
if (intersect > x && intersect < x + w) // Intersects top edge.
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Test if a high-precision rectangle lies completely in the shape. This is
|
|
* true if all points in the rectangle are in the shape. This implementation
|
|
* is precise.
|
|
*
|
|
* @param r the rectangle
|
|
* @return true if the rectangle is contained in this shape
|
|
* @throws NullPointerException if r is null
|
|
* @see #contains(double, double, double, double)
|
|
* @since 1.2
|
|
*/
|
|
public boolean contains(Rectangle2D r)
|
|
{
|
|
return contains(r.getX(), r.getY(), r.getWidth(), r.getHeight());
|
|
}
|
|
|
|
/**
|
|
* Return an iterator along the shape boundary. If the optional transform
|
|
* is provided, the iterator is transformed accordingly. Each call returns
|
|
* a new object, independent from others in use. This class is not
|
|
* threadsafe to begin with, so the path iterator is not either.
|
|
*
|
|
* @param transform an optional transform to apply to the iterator
|
|
* @return a new iterator over the boundary
|
|
* @since 1.2
|
|
*/
|
|
public PathIterator getPathIterator(final AffineTransform transform)
|
|
{
|
|
return new PathIterator()
|
|
{
|
|
/** The current vertex of iteration. */
|
|
private int vertex;
|
|
|
|
public int getWindingRule()
|
|
{
|
|
return WIND_EVEN_ODD;
|
|
}
|
|
|
|
public boolean isDone()
|
|
{
|
|
return vertex > npoints;
|
|
}
|
|
|
|
public void next()
|
|
{
|
|
vertex++;
|
|
}
|
|
|
|
public int currentSegment(float[] coords)
|
|
{
|
|
if (vertex >= npoints)
|
|
return SEG_CLOSE;
|
|
coords[0] = xpoints[vertex];
|
|
coords[1] = ypoints[vertex];
|
|
if (transform != null)
|
|
transform.transform(coords, 0, coords, 0, 1);
|
|
return vertex == 0 ? SEG_MOVETO : SEG_LINETO;
|
|
}
|
|
|
|
public int currentSegment(double[] coords)
|
|
{
|
|
if (vertex >= npoints)
|
|
return SEG_CLOSE;
|
|
coords[0] = xpoints[vertex];
|
|
coords[1] = ypoints[vertex];
|
|
if (transform != null)
|
|
transform.transform(coords, 0, coords, 0, 1);
|
|
return vertex == 0 ? SEG_MOVETO : SEG_LINETO;
|
|
}
|
|
};
|
|
}
|
|
|
|
/**
|
|
* Return an iterator along the flattened version of the shape boundary.
|
|
* Since polygons are already flat, the flatness parameter is ignored, and
|
|
* the resulting iterator only has SEG_MOVETO, SEG_LINETO and SEG_CLOSE
|
|
* points. If the optional transform is provided, the iterator is
|
|
* transformed accordingly. Each call returns a new object, independent
|
|
* from others in use. This class is not threadsafe to begin with, so the
|
|
* path iterator is not either.
|
|
*
|
|
* @param transform an optional transform to apply to the iterator
|
|
* @param double the maximum distance for deviation from the real boundary
|
|
* @return a new iterator over the boundary
|
|
* @since 1.2
|
|
*/
|
|
public PathIterator getPathIterator(AffineTransform transform,
|
|
double flatness)
|
|
{
|
|
return getPathIterator(transform);
|
|
}
|
|
|
|
/**
|
|
* Helper for contains, which caches a condensed version of the polygon.
|
|
* This condenses all colinear points, so that consecutive segments in
|
|
* the condensed version always have different slope.
|
|
*
|
|
* @return true if the condensed polygon has area
|
|
* @see #condensed
|
|
* @see #contains(double, double)
|
|
*/
|
|
private boolean condense()
|
|
{
|
|
if (npoints <= 2)
|
|
return false;
|
|
if (condensed != null)
|
|
return condensed[0] > 2;
|
|
condensed = new int[npoints * 2 + 1];
|
|
int curx = xpoints[npoints - 1];
|
|
int cury = ypoints[npoints - 1];
|
|
double curslope = Double.NaN;
|
|
int count = 0;
|
|
outer:
|
|
for (int i = 0; i < npoints; i++)
|
|
{
|
|
int priorx = curx;
|
|
int priory = cury;
|
|
double priorslope = curslope;
|
|
curx = xpoints[i];
|
|
cury = ypoints[i];
|
|
while (curx == priorx && cury == priory)
|
|
{
|
|
if (++i == npoints)
|
|
break outer;
|
|
curx = xpoints[i];
|
|
cury = ypoints[i];
|
|
}
|
|
curslope = (curx == priorx ? Double.POSITIVE_INFINITY
|
|
: (double) (cury - priory) / (curx - priorx));
|
|
if (priorslope == curslope)
|
|
{
|
|
if (count > 1 && condensed[(count << 1) - 3] == curx
|
|
&& condensed[(count << 1) - 2] == cury)
|
|
{
|
|
count--;
|
|
continue;
|
|
}
|
|
}
|
|
else
|
|
count++;
|
|
condensed[(count << 1) - 1] = curx;
|
|
condensed[count << 1] = cury;
|
|
}
|
|
condensed[0] = count;
|
|
return count > 2;
|
|
}
|
|
} // class Polygon
|