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/*
* Copyright (c) 2009 Albert Kurucz.
*
* This file, ShapeUtilities.java is part of JTStand.
*
* JTStand 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 3 of the License, or
* (at your option) any later version.
*
* JTStand 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 GTStand. If not, see null. At the
* current time, this method supports cloning for instances of
* Line2D, RectangularShape, Area
* and GeneralPath.
*
* RectangularShape includes Arc2D,
* Ellipse2D, Rectangle2D,
* RoundRectangle2D.
*
* @param shape the shape to clone (null permitted,
* returns null).
*
* @return A clone or null.
*/
public static Shape clone(final Shape shape) {
if (shape instanceof Cloneable) {
try {
return (Shape) ObjectUtilities.clone(shape);
}
catch (CloneNotSupportedException cnse) {
}
}
final Shape result = null;
return result;
}
/**
* Tests two shapes for equality. If both shapes are null,
* this method will return true.
*
* In the current implementation, the following shapes are supported:
* Ellipse2D, Line2D and Rectangle2D
* (implicit).
*
* @param s1 the first shape (null permitted).
* @param s2 the second shape (null permitted).
*
* @return A boolean.
*/
public static boolean equal(final Shape s1, final 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 true if they are equal or
* both null.
*
* @param l1 the first line (null permitted).
* @param l2 the second line (null permitted).
*
* @return A boolean.
*/
public static boolean equal(final Line2D l1, final 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 true if they are equal or
* both null.
*
* @param e1 the first ellipse (null permitted).
* @param e2 the second ellipse (null permitted).
*
* @return A boolean.
*/
public static boolean equal(final Ellipse2D e1, final 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 true if they are equal or
* both null.
*
* @param a1 the first arc (null permitted).
* @param a2 the second arc (null permitted).
*
* @return A boolean.
*/
public static boolean equal(final Arc2D a1, final 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 null this
* method returns true.
*
* @param p1 polygon 1 (null permitted).
* @param p2 polygon 2 (null permitted).
*
* @return A boolean.
*/
public static boolean equal(final Polygon p1, final 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 null this
* method returns true.
*
* @param p1 path 1 (null permitted).
* @param p2 path 2 (null permitted).
*
* @return A boolean.
*/
public static boolean equal(final GeneralPath p1, final 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 (null 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(final Shape shape,
final double transX,
final double transY) {
if (shape == null) {
throw new IllegalArgumentException("Null 'shape' argument.");
}
final 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 (null not permitted).
* @param anchor the anchor (null 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(final Shape shape,
final RectangleAnchor anchor,
final double locationX,
final 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);
final 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 (null permitted, returns
* null).
* @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(final Shape base, final double angle,
final float x, final float y) {
if (base == null) {
return null;
}
final AffineTransform rotate = AffineTransform.getRotateInstance(
angle, x, y);
final Shape result = rotate.createTransformedShape(base);
return result;
}
/**
* Draws a shape with the specified rotation about (x, y).
*
* @param g2 the graphics device (null not permitted).
* @param shape the shape (null 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(final Graphics2D g2, final Shape shape,
final double angle,
final float x, final float y) {
final AffineTransform saved = g2.getTransform();
final 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(final float l, final float t) {
final 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(final float l, final float t) {
final 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(final float s) {
final 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(final float s) {
final 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(final float s) {
final 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 (null not permitted).
* @param width the width of the region.
*
* @return A region that surrounds the line.
*/
public static Shape createLineRegion(final Line2D line, final float width) {
final GeneralPath result = new GeneralPath();
final float x1 = (float) line.getX1();
final float x2 = (float) line.getX2();
final float y1 = (float) line.getY1();
final float y2 = (float) line.getY2();
if ((x2 - x1) != 0.0) {
final double theta = Math.atan((y2 - y1) / (x2 - x1));
final float dx = (float) Math.sin(theta) * width;
final 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 (null not
* permitted).
*
* @return A point within the rectangle.
*
* @throws NullPointerException if area is null.
*/
public static Point2D getPointInRectangle(double x, double y,
final 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(final Rectangle2D rect1,
final Rectangle2D rect2) {
final double x0 = rect1.getX();
final double y0 = rect1.getY();
final double x = rect2.getX();
final double y = rect2.getY();
final double w = rect2.getWidth();
final 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 (final Rectangle2D rect1,
final Rectangle2D rect2) {
final double x0 = rect1.getX();
final double y0 = rect1.getY();
final double x = rect2.getX();
final double width = rect2.getWidth();
final double y = rect2.getY();
final double height = rect2.getHeight();
return (x + width >= x0 && y + height >= y0 && x <= x0 + rect1.getWidth()
&& y <= y0 + rect1.getHeight());
}
}