ShapeUtilities.java
/* ===========================================================
* JFreeChart : a free chart library for the Java(tm) platform
* ===========================================================
*
* (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library 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 Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* -------------------
* ShapeUtilities.java
* -------------------
* (C)opyright 2003-2008, by Object Refinery Limited and Contributors.
*
* Original Author: David Gilbert (for Object Refinery Limited);
* Contributor(s): -;
*
* Changes
* -------
* 13-Aug-2003 : Version 1 (DG);
* 16-Mar-2004 : Moved rotateShape() from RefineryUtilities.java to here (DG);
* 13-May-2004 : Added new shape creation methods (DG);
* 30-Sep-2004 : Added createLineRegion() method (DG);
* Moved drawRotatedShape() method from RefineryUtilities class
* to this class (DG);
* 04-Oct-2004 : Renamed ShapeUtils --> ShapeUtilities (DG);
* 26-Oct-2004 : Added a method to test the equality of two Line2D
* instances (DG);
* 10-Nov-2004 : Added new translateShape() and equal(Ellipse2D, Ellipse2D)
* methods (DG);
* 11-Nov-2004 : Renamed translateShape() --> createTranslatedShape() (DG);
* 07-Jan-2005 : Minor Javadoc fix (DG);
* 11-Jan-2005 : Removed deprecated code in preparation for 1.0.0 release (DG);
* 21-Jan-2005 : Modified return type of RectangleAnchor.coordinates()
* method (DG);
* 22-Feb-2005 : Added equality tests for Arc2D and GeneralPath (DG);
* 16-Mar-2005 : Fixed bug where equal(Shape, Shape) fails for two Polygon
* instances (DG);
* 20-Jun-2007 : Copied from JCommon (DG);
* 02-Jun-2008 : Fixed bug in equal(GeneralPath, GeneralPath) (DG);
* 05-Nov-2008 : Added clipLine() method (DG);
*
*/
package org.jfree.chart.util;
import java.awt.Graphics2D;
import java.awt.Polygon;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.Arc2D;
import java.awt.geom.Ellipse2D;
import java.awt.geom.GeneralPath;
import java.awt.geom.Line2D;
import java.awt.geom.PathIterator;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.util.Arrays;
/**
* Utility methods for {@link Shape} objects.
*/
public class ShapeUtilities {
/**
* Prevents instantiation.
*/
private ShapeUtilities() {
}
/**
* Returns a clone of the specified shape, or <code>null</code>. At the
* current time, this method supports cloning for instances of
* <code>Line2D</code>, <code>RectangularShape</code>, <code>Area</code>
* and <code>GeneralPath</code>.
* <p>
* <code>RectangularShape</code> includes <code>Arc2D</code>,
* <code>Ellipse2D</code>, <code>Rectangle2D</code>,
* <code>RoundRectangle2D</code>.
*
* @param shape the shape to clone (<code>null</code> permitted,
* returns <code>null</code>).
*
* @return A clone or <code>null</code>.
*/
public static Shape clone(Shape shape) {
if (shape instanceof Cloneable) {
try {
return (Shape) ObjectUtilities.clone(shape);
}
catch (CloneNotSupportedException cnse) {
}
}
Shape result = null;
return result;
}
/**
* Tests two shapes for equality. If both shapes are <code>null</code>,
* this method will return <code>true</code>.
* <p>
* In the current implementation, the following shapes are supported:
* <code>Ellipse2D</code>, <code>Line2D</code> and <code>Rectangle2D</code>
* (implicit).
*
* @param s1 the first shape (<code>null</code> permitted).
* @param s2 the second shape (<code>null</code> permitted).
*
* @return A boolean.
*/
public static boolean equal(Shape s1, Shape s2) {
if (s1 instanceof Line2D && s2 instanceof Line2D) {
return equal((Line2D) s1, (Line2D) s2);
}
else if (s1 instanceof Ellipse2D && s2 instanceof Ellipse2D) {
return equal((Ellipse2D) s1, (Ellipse2D) s2);
}
else if (s1 instanceof Arc2D && s2 instanceof Arc2D) {
return equal((Arc2D) s1, (Arc2D) s2);
}
else if (s1 instanceof Polygon && s2 instanceof Polygon) {
return equal((Polygon) s1, (Polygon) s2);
}
else if (s1 instanceof GeneralPath && s2 instanceof GeneralPath) {
return equal((GeneralPath) s1, (GeneralPath) s2);
}
else {
// this will handle Rectangle2D...
return ObjectUtilities.equal(s1, s2);
}
}
/**
* Compares two lines are returns <code>true</code> if they are equal or
* both <code>null</code>.
*
* @param l1 the first line (<code>null</code> permitted).
* @param l2 the second line (<code>null</code> permitted).
*
* @return A boolean.
*/
public static boolean equal(Line2D l1, Line2D l2) {
if (l1 == null) {
return (l2 == null);
}
if (l2 == null) {
return false;
}
if (!l1.getP1().equals(l2.getP1())) {
return false;
}
if (!l1.getP2().equals(l2.getP2())) {
return false;
}
return true;
}
/**
* Compares two ellipses and returns <code>true</code> if they are equal or
* both <code>null</code>.
*
* @param e1 the first ellipse (<code>null</code> permitted).
* @param e2 the second ellipse (<code>null</code> permitted).
*
* @return A boolean.
*/
public static boolean equal(Ellipse2D e1, Ellipse2D e2) {
if (e1 == null) {
return (e2 == null);
}
if (e2 == null) {
return false;
}
if (!e1.getFrame().equals(e2.getFrame())) {
return false;
}
return true;
}
/**
* Compares two arcs and returns <code>true</code> if they are equal or
* both <code>null</code>.
*
* @param a1 the first arc (<code>null</code> permitted).
* @param a2 the second arc (<code>null</code> permitted).
*
* @return A boolean.
*/
public static boolean equal(Arc2D a1, Arc2D a2) {
if (a1 == null) {
return (a2 == null);
}
if (a2 == null) {
return false;
}
if (!a1.getFrame().equals(a2.getFrame())) {
return false;
}
if (a1.getAngleStart() != a2.getAngleStart()) {
return false;
}
if (a1.getAngleExtent() != a2.getAngleExtent()) {
return false;
}
if (a1.getArcType() != a2.getArcType()) {
return false;
}
return true;
}
/**
* Tests two polygons for equality. If both are <code>null</code> this
* method returns <code>true</code>.
*
* @param p1 polygon 1 (<code>null</code> permitted).
* @param p2 polygon 2 (<code>null</code> permitted).
*
* @return A boolean.
*/
public static boolean equal(Polygon p1, Polygon p2) {
if (p1 == null) {
return (p2 == null);
}
if (p2 == null) {
return false;
}
if (p1.npoints != p2.npoints) {
return false;
}
if (!Arrays.equals(p1.xpoints, p2.xpoints)) {
return false;
}
if (!Arrays.equals(p1.ypoints, p2.ypoints)) {
return false;
}
return true;
}
/**
* Tests two polygons for equality. If both are <code>null</code> this
* method returns <code>true</code>.
*
* @param p1 path 1 (<code>null</code> permitted).
* @param p2 path 2 (<code>null</code> permitted).
*
* @return A boolean.
*/
public static boolean equal(GeneralPath p1, GeneralPath p2) {
if (p1 == null) {
return (p2 == null);
}
if (p2 == null) {
return false;
}
if (p1.getWindingRule() != p2.getWindingRule()) {
return false;
}
PathIterator iterator1 = p1.getPathIterator(null);
PathIterator iterator2 = p2.getPathIterator(null);
double[] d1 = new double[6];
double[] d2 = new double[6];
boolean done = iterator1.isDone() && iterator2.isDone();
while (!done) {
if (iterator1.isDone() != iterator2.isDone()) {
return false;
}
int seg1 = iterator1.currentSegment(d1);
int seg2 = iterator2.currentSegment(d2);
if (seg1 != seg2) {
return false;
}
if (!Arrays.equals(d1, d2)) {
return false;
}
iterator1.next();
iterator2.next();
done = iterator1.isDone() && iterator2.isDone();
}
return true;
}
/**
* Creates and returns a translated shape.
*
* @param shape the shape (<code>null</code> not permitted).
* @param transX the x translation (in Java2D space).
* @param transY the y translation (in Java2D space).
*
* @return The translated shape.
*/
public static Shape createTranslatedShape(Shape shape,
double transX,
double transY) {
if (shape == null) {
throw new IllegalArgumentException("Null 'shape' argument.");
}
AffineTransform transform = AffineTransform.getTranslateInstance(
transX, transY);
return transform.createTransformedShape(shape);
}
/**
* Translates a shape to a new location such that the anchor point
* (relative to the rectangular bounds of the shape) aligns with the
* specified (x, y) coordinate in Java2D space.
*
* @param shape the shape (<code>null</code> not permitted).
* @param anchor the anchor (<code>null</code> not permitted).
* @param locationX the x-coordinate (in Java2D space).
* @param locationY the y-coordinate (in Java2D space).
*
* @return A new and translated shape.
*/
public static Shape createTranslatedShape(Shape shape,
RectangleAnchor anchor,
double locationX,
double locationY) {
if (shape == null) {
throw new IllegalArgumentException("Null 'shape' argument.");
}
if (anchor == null) {
throw new IllegalArgumentException("Null 'anchor' argument.");
}
Point2D anchorPoint = RectangleAnchor.coordinates(shape.getBounds2D(),
anchor);
AffineTransform transform = AffineTransform.getTranslateInstance(
locationX - anchorPoint.getX(), locationY - anchorPoint.getY());
return transform.createTransformedShape(shape);
}
/**
* Rotates a shape about the specified coordinates.
*
* @param base the shape (<code>null</code> permitted, returns
* <code>null</code>).
* @param angle the angle (in radians).
* @param x the x coordinate for the rotation point (in Java2D space).
* @param y the y coordinate for the rotation point (in Java2D space).
*
* @return the rotated shape.
*/
public static Shape rotateShape(Shape base, double angle,
float x, float y) {
if (base == null) {
return null;
}
AffineTransform rotate = AffineTransform.getRotateInstance(angle, x, y);
Shape result = rotate.createTransformedShape(base);
return result;
}
/**
* Draws a shape with the specified rotation about <code>(x, y)</code>.
*
* @param g2 the graphics device (<code>null</code> not permitted).
* @param shape the shape (<code>null</code> not permitted).
* @param angle the angle (in radians).
* @param x the x coordinate for the rotation point.
* @param y the y coordinate for the rotation point.
*/
public static void drawRotatedShape(Graphics2D g2, Shape shape,
double angle, float x, float y) {
AffineTransform saved = g2.getTransform();
AffineTransform rotate = AffineTransform.getRotateInstance(angle, x, y);
g2.transform(rotate);
g2.draw(shape);
g2.setTransform(saved);
}
/** A useful constant used internally. */
private static final float SQRT2 = (float) Math.pow(2.0, 0.5);
/**
* Creates a diagonal cross shape.
*
* @param l the length of each 'arm'.
* @param t the thickness.
*
* @return A diagonal cross shape.
*/
public static Shape createDiagonalCross(float l, float t) {
GeneralPath p0 = new GeneralPath();
p0.moveTo(-l - t, -l + t);
p0.lineTo(-l + t, -l - t);
p0.lineTo(0.0f, -t * SQRT2);
p0.lineTo(l - t, -l - t);
p0.lineTo(l + t, -l + t);
p0.lineTo(t * SQRT2, 0.0f);
p0.lineTo(l + t, l - t);
p0.lineTo(l - t, l + t);
p0.lineTo(0.0f, t * SQRT2);
p0.lineTo(-l + t, l + t);
p0.lineTo(-l - t, l - t);
p0.lineTo(-t * SQRT2, 0.0f);
p0.closePath();
return p0;
}
/**
* Creates a diagonal cross shape.
*
* @param l the length of each 'arm'.
* @param t the thickness.
*
* @return A diagonal cross shape.
*/
public static Shape createRegularCross(float l, float t) {
GeneralPath p0 = new GeneralPath();
p0.moveTo(-l, t);
p0.lineTo(-t, t);
p0.lineTo(-t, l);
p0.lineTo(t, l);
p0.lineTo(t, t);
p0.lineTo(l, t);
p0.lineTo(l, -t);
p0.lineTo(t, -t);
p0.lineTo(t, -l);
p0.lineTo(-t, -l);
p0.lineTo(-t, -t);
p0.lineTo(-l, -t);
p0.closePath();
return p0;
}
/**
* Creates a diamond shape.
*
* @param s the size factor (equal to half the height of the diamond).
*
* @return A diamond shape.
*/
public static Shape createDiamond(float s) {
GeneralPath p0 = new GeneralPath();
p0.moveTo(0.0f, -s);
p0.lineTo(s, 0.0f);
p0.lineTo(0.0f, s);
p0.lineTo(-s, 0.0f);
p0.closePath();
return p0;
}
/**
* Creates a triangle shape that points upwards.
*
* @param s the size factor (equal to half the height of the triangle).
*
* @return A triangle shape.
*/
public static Shape createUpTriangle(float s) {
GeneralPath p0 = new GeneralPath();
p0.moveTo(0.0f, -s);
p0.lineTo(s, s);
p0.lineTo(-s, s);
p0.closePath();
return p0;
}
/**
* Creates a triangle shape that points downwards.
*
* @param s the size factor (equal to half the height of the triangle).
*
* @return A triangle shape.
*/
public static Shape createDownTriangle(float s) {
GeneralPath p0 = new GeneralPath();
p0.moveTo(0.0f, s);
p0.lineTo(s, -s);
p0.lineTo(-s, -s);
p0.closePath();
return p0;
}
/**
* Creates a region surrounding a line segment by 'widening' the line
* segment. A typical use for this method is the creation of a
* 'clickable' region for a line that is displayed on-screen.
*
* @param line the line (<code>null</code> not permitted).
* @param width the width of the region.
*
* @return A region that surrounds the line.
*/
public static Shape createLineRegion(Line2D line, float width) {
GeneralPath result = new GeneralPath();
float x1 = (float) line.getX1();
float x2 = (float) line.getX2();
float y1 = (float) line.getY1();
float y2 = (float) line.getY2();
if ((x2 - x1) != 0.0) {
double theta = Math.atan((y2 - y1) / (x2 - x1));
float dx = (float) Math.sin(theta) * width;
float dy = (float) Math.cos(theta) * width;
result.moveTo(x1 - dx, y1 + dy);
result.lineTo(x1 + dx, y1 - dy);
result.lineTo(x2 + dx, y2 - dy);
result.lineTo(x2 - dx, y2 + dy);
result.closePath();
}
else {
// special case, vertical line
result.moveTo(x1 - width / 2.0f, y1);
result.lineTo(x1 + width / 2.0f, y1);
result.lineTo(x2 + width / 2.0f, y2);
result.lineTo(x2 - width / 2.0f, y2);
result.closePath();
}
return result;
}
/**
* Returns a point based on (x, y) but constrained to be within the bounds
* of a given rectangle.
*
* @param x the x-coordinate.
* @param y the y-coordinate.
* @param area the constraining rectangle (<code>null</code> not
* permitted).
*
* @return A point within the rectangle.
*
* @throws NullPointerException if <code>area</code> is <code>null</code>.
*/
public static Point2D getPointInRectangle(double x, double y,
Rectangle2D area) {
x = Math.max(area.getMinX(), Math.min(x, area.getMaxX()));
y = Math.max(area.getMinY(), Math.min(y, area.getMaxY()));
return new Point2D.Double(x, y);
}
/**
* Checks, whether the given rectangle1 fully contains rectangle 2
* (even if rectangle 2 has a height or width of zero!).
*
* @param rect1 the first rectangle.
* @param rect2 the second rectangle.
*
* @return A boolean.
*/
public static boolean contains(Rectangle2D rect1, Rectangle2D rect2) {
double x0 = rect1.getX();
double y0 = rect1.getY();
double x = rect2.getX();
double y = rect2.getY();
double w = rect2.getWidth();
double h = rect2.getHeight();
return ((x >= x0) && (y >= y0)
&& ((x + w) <= (x0 + rect1.getWidth()))
&& ((y + h) <= (y0 + rect1.getHeight())));
}
/**
* Checks, whether the given rectangle1 fully contains rectangle 2
* (even if rectangle 2 has a height or width of zero!).
*
* @param rect1 the first rectangle.
* @param rect2 the second rectangle.
*
* @return A boolean.
*/
public static boolean intersects(Rectangle2D rect1, Rectangle2D rect2) {
double x0 = rect1.getX();
double y0 = rect1.getY();
double x = rect2.getX();
double width = rect2.getWidth();
double y = rect2.getY();
double height = rect2.getHeight();
return (x + width >= x0 && y + height >= y0 && x <= x0 + rect1.getWidth()
&& y <= y0 + rect1.getHeight());
}
/**
* Returns <code>true</code> if the specified point (x, y) falls within or
* on the boundary of the specified rectangle.
*
* @param x the x-coordinate.
* @param y the y-coordinate.
* @param rect the rectangle (<code>null</code> not permitted).
*
* @return A boolean.
*
* @since 1.2.0
*/
public static boolean isPointInRect(double x, double y, Rectangle2D rect) {
return (x >= rect.getMinX() && x <= rect.getMaxX()
&& y >= rect.getMinY() && y <= rect.getMaxY());
}
/**
* Clips the specified line to the given rectangle.
*
* @param line the line (<code>null</code> not permitted).
* @param rect the clipping rectangle (<code>null</code> not permitted).
*
* @return <code>true</code> if the clipped line is visible, and
* <code>false</code> otherwise.
*
* @since 1.2.0
*/
public static boolean clipLine(Line2D line, Rectangle2D rect) {
double x1 = line.getX1();
double y1 = line.getY1();
double x2 = line.getX2();
double y2 = line.getY2();
double minX = rect.getMinX();
double maxX = rect.getMaxX();
double minY = rect.getMinY();
double maxY = rect.getMaxY();
int f1 = rect.outcode(x1, y1);
int f2 = rect.outcode(x2, y2);
while ((f1 | f2) != 0) {
if ((f1 & f2) != 0) {
return false;
}
double dx = (x2 - x1);
double dy = (y2 - y1);
// update (x1, y1), (x2, y2) and f1 and f2 using intersections
// then recheck
if (f1 != 0) {
// first point is outside, so we update it against one of the
// four sides then continue
if ((f1 & Rectangle2D.OUT_LEFT) == Rectangle2D.OUT_LEFT
&& dx != 0.0) {
y1 = y1 + (minX - x1) * dy / dx;
x1 = minX;
}
else if ((f1 & Rectangle2D.OUT_RIGHT) == Rectangle2D.OUT_RIGHT
&& dx != 0.0) {
y1 = y1 + (maxX - x1) * dy / dx;
x1 = maxX;
}
else if ((f1 & Rectangle2D.OUT_BOTTOM) == Rectangle2D.OUT_BOTTOM
&& dy != 0.0) {
x1 = x1 + (maxY - y1) * dx / dy;
y1 = maxY;
}
else if ((f1 & Rectangle2D.OUT_TOP) == Rectangle2D.OUT_TOP
&& dy != 0.0) {
x1 = x1 + (minY - y1) * dx / dy;
y1 = minY;
}
f1 = rect.outcode(x1, y1);
}
else if (f2 != 0) {
// second point is outside, so we update it against one of the
// four sides then continue
if ((f2 & Rectangle2D.OUT_LEFT) == Rectangle2D.OUT_LEFT
&& dx != 0.0) {
y2 = y2 + (minX - x2) * dy / dx;
x2 = minX;
}
else if ((f2 & Rectangle2D.OUT_RIGHT) == Rectangle2D.OUT_RIGHT
&& dx != 0.0) {
y2 = y2 + (maxX - x2) * dy / dx;
x2 = maxX;
}
else if ((f2 & Rectangle2D.OUT_BOTTOM) == Rectangle2D.OUT_BOTTOM
&& dy != 0.0) {
x2 = x2 + (maxY - y2) * dx / dy;
y2 = maxY;
}
else if ((f2 & Rectangle2D.OUT_TOP) == Rectangle2D.OUT_TOP
&& dy != 0.0) {
x2 = x2 + (minY - y2) * dx / dy;
y2 = minY;
}
f2 = rect.outcode(x2, y2);
}
}
line.setLine(x1, y1, x2, y2);
return true; // the line is visible - if it wasn't, we'd have
// returned false from within the while loop above
}
}