| /******************************************************************************* |
| * Copyright (c) 2000, 2010 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| * Alexander Shatalin (Borland) - Contribution for Bug 238874 |
| *******************************************************************************/ |
| package org.eclipse.draw2d.geometry; |
| |
| /** |
| * Represents a List of Points. This class is used for building an |
| * <code>int[]</code>. The array is internal, and is constructed and queried by |
| * the client using {@link Point Points}. SWT uses integer arrays when painting |
| * polylines and polygons. |
| */ |
| public class PointList implements java.io.Serializable, Translatable { |
| |
| private int[] points = new int[0]; |
| private Rectangle bounds; |
| private int size = 0; |
| |
| static final long serialVersionUID = 1; |
| |
| /** |
| * Constructs an empty PointList. |
| * |
| * @since 2.0 |
| */ |
| public PointList() { |
| } |
| |
| /** |
| * Constructs a PointList with the given points. |
| * |
| * @param points |
| * int array where two consecutive ints form the coordinates of a |
| * point |
| * @since 3.1 |
| */ |
| public PointList(int points[]) { |
| this.points = points; |
| this.size = points.length / 2; |
| } |
| |
| /** |
| * Constructs a PointList with initial capacity <i>size</i>, but no points. |
| * |
| * @param size |
| * Number of points to hold. |
| * @since 2.0 |
| */ |
| public PointList(int size) { |
| points = new int[size * 2]; |
| } |
| |
| /** |
| * Appends all of the given points to this PointList. |
| * |
| * @param source |
| * the source pointlist |
| */ |
| public void addAll(PointList source) { |
| ensureCapacity(size + source.size); |
| System.arraycopy(source.points, 0, points, size * 2, source.size * 2); |
| size += source.size; |
| } |
| |
| /** |
| * Adds Point <i>p</i> to this PointList. |
| * |
| * @param p |
| * the point to be added |
| * @see #removePoint(int) |
| * @since 2.0 |
| */ |
| public void addPoint(Point p) { |
| addPoint(p.x, p.y); |
| } |
| |
| /** |
| * Adds the input point values to this PointList. |
| * |
| * @param x |
| * X value of a point to add |
| * @param y |
| * Y value of a point to add |
| * @since 2.0 |
| */ |
| public void addPoint(int x, int y) { |
| bounds = null; |
| int index = size * 2; |
| ensureCapacity(size + 1); |
| points[index] = x; |
| points[index + 1] = y; |
| size++; |
| } |
| |
| private void ensureCapacity(int newSize) { |
| newSize *= 2; |
| if (points.length < newSize) { |
| int old[] = points; |
| points = new int[Math.max(newSize, size * 4)]; |
| System.arraycopy(old, 0, points, 0, size * 2); |
| } |
| } |
| |
| /** |
| * Returns the smallest Rectangle which contains all Points. |
| * |
| * @return The smallest Rectangle which contains all Points. |
| * @since 2.0 |
| */ |
| public Rectangle getBounds() { |
| if (bounds != null) |
| return bounds; |
| bounds = new Rectangle(); |
| if (size > 0) { |
| bounds.setLocation(getPoint(0)); |
| for (int i = 0; i < size; i++) |
| bounds.union(getPoint(i)); |
| } |
| return bounds; |
| } |
| |
| /** |
| * Creates a copy |
| * |
| * @return PointList A copy of this PointList |
| */ |
| public PointList getCopy() { |
| PointList result = new PointList(size); |
| System.arraycopy(points, 0, result.points, 0, size * 2); |
| result.size = size; |
| result.bounds = null; |
| return result; |
| } |
| |
| /** |
| * Returns the first Point in the list. |
| * |
| * @return The first point in the list. |
| * @throws IndexOutOfBoundsException |
| * if the list is empty |
| * @since 2.0 |
| */ |
| public Point getFirstPoint() { |
| return getPoint(0); |
| } |
| |
| /** |
| * Returns the last point in the list. |
| * |
| * @throws IndexOutOfBoundsException |
| * if the list is empty |
| * @return The last Point in the list |
| * @since 2.0 |
| */ |
| public Point getLastPoint() { |
| return getPoint(size - 1); |
| } |
| |
| /** |
| * Returns the midpoint of the list of Points. The midpoint is the median of |
| * the List, unless there are 2 medians (size is even), then the middle of |
| * the medians is returned. |
| * |
| * @return The midpoint |
| * @throws IndexOutOfBoundsException |
| * if the list is empty |
| */ |
| public Point getMidpoint() { |
| if (size() % 2 == 0) |
| return getPoint(size() / 2 - 1).getTranslated(getPoint(size() / 2)) |
| .scale(0.5f); |
| return getPoint(size() / 2); |
| } |
| |
| /** |
| * Returns the Point in the list at the specified index. |
| * |
| * @param index |
| * Index of the desired Point |
| * @return The requested Point |
| * @throws IndexOutOfBoundsException |
| * If the specified index is out of range |
| * @since 2.0 |
| */ |
| public Point getPoint(int index) { |
| if (index < 0 || index >= size) |
| throw new IndexOutOfBoundsException("Index: " + index + //$NON-NLS-1$ |
| ", Size: " + size); //$NON-NLS-1$ |
| index *= 2; |
| return new Point(points[index], points[index + 1]); |
| } |
| |
| /** |
| * Copies the x and y values at given index into a specified Point. This |
| * method exists to avoid the creation of a new <code>Point</code>. |
| * |
| * @see #getPoint(int) |
| * @param p |
| * The Point which will be set with the <x, y> values |
| * @param index |
| * The index being requested |
| * @return The parameter <code>p</code> is returned for convenience |
| * @since 2.0 |
| */ |
| public Point getPoint(Point p, int index) { |
| if (index < 0 || index >= size) |
| throw new IndexOutOfBoundsException("Index: " + index + //$NON-NLS-1$ |
| ", Size: " + size); //$NON-NLS-1$ |
| index *= 2; |
| p.x = points[index]; |
| p.y = points[index + 1]; |
| return p; |
| } |
| |
| /** |
| * Inserts a given point at a specified index. |
| * |
| * @param p |
| * Point to be inserted. |
| * @param index |
| * Position where the point is to be inserted. |
| * @exception IndexOutOfBoundsException |
| * if the index is invalid |
| * @see #setPoint(Point, int) |
| * @since 2.0 |
| */ |
| public void insertPoint(Point p, int index) { |
| if (bounds != null && !bounds.contains(p)) |
| bounds = null; |
| if (index > size || index < 0) |
| throw new IndexOutOfBoundsException("Index: " + index + //$NON-NLS-1$ |
| ", Size: " + size); //$NON-NLS-1$ |
| index *= 2; |
| |
| int length = points.length; |
| int old[] = points; |
| points = new int[length + 2]; |
| System.arraycopy(old, 0, points, 0, index); |
| System.arraycopy(old, index, points, index + 2, length - index); |
| |
| points[index] = p.x; |
| points[index + 1] = p.y; |
| size++; |
| } |
| |
| /** |
| * Determines whether any of the line segments represented by this PointList |
| * intersect the given Rectangle. If a segment touches the given rectangle, |
| * that's considered intersection. |
| * |
| * @param r |
| * the rectangle |
| * @return <code>true</code> if the given rectangle intersects any of the |
| * line segments represented by this PointList |
| * @since 3.1 |
| */ |
| public boolean intersects(Rectangle r) { |
| if (r.isEmpty()) |
| return false; |
| for (int i = 0; i < size * 2; i += 2) { |
| if (r.contains(points[i], points[i + 1])) |
| return true; |
| } |
| int diagonal1x1 = r.x, diagonal1y1 = r.y, diagonal1x2 = r.x + r.width |
| - 1, diagonal1y2 = r.y + r.height - 1, diagonal2x1 = r.x |
| + r.width - 1, diagonal2y1 = r.y, diagonal2x2 = r.x, diagonal2y2 = r.y |
| + r.height - 1; |
| for (int i = 0; i < (size - 1) * 2; i += 2) { |
| if (Geometry.linesIntersect(diagonal1x1, diagonal1y1, diagonal1x2, |
| diagonal1y2, points[i], points[i + 1], points[i + 2], |
| points[i + 3]) |
| || Geometry.linesIntersect(diagonal2x1, diagonal2y1, |
| diagonal2x2, diagonal2y2, points[i], points[i + 1], |
| points[i + 2], points[i + 3])) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * @see org.eclipse.draw2d.geometry.Translatable#performScale(double) |
| */ |
| public void performScale(double factor) { |
| for (int i = 0; i < points.length; i++) |
| points[i] = (int) Math.floor(points[i] * factor); |
| bounds = null; |
| } |
| |
| /** |
| * @see org.eclipse.draw2d.geometry.Translatable#performTranslate(int, int) |
| */ |
| public void performTranslate(int dx, int dy) { |
| for (int i = 0; i < size * 2; i += 2) { |
| points[i] += dx; |
| points[i + 1] += dy; |
| } |
| if (bounds != null) |
| bounds.translate(dx, dy); |
| } |
| |
| /** |
| * Removes all the points stored by this list. Resets all the properties |
| * based on the point information. |
| * |
| * @since 2.0 |
| */ |
| public void removeAllPoints() { |
| bounds = null; |
| size = 0; |
| } |
| |
| /** |
| * Removes the point at the specified index from the PointList, and returns |
| * it. |
| * |
| * @since 2.0 |
| * @see #addPoint(Point) |
| * @param index |
| * Index of the point to be removed. |
| * @return The point which has been removed |
| * @throws IndexOutOfBoundsException |
| * if the removal index is beyond the list capacity |
| */ |
| public Point removePoint(int index) { |
| bounds = null; |
| if (index < 0 || index >= size) |
| throw new IndexOutOfBoundsException("Index: " + index + //$NON-NLS-1$ |
| ", Size: " + size); //$NON-NLS-1$ |
| |
| index *= 2; |
| Point pt = new Point(points[index], points[index + 1]); |
| if (index != size * 2 - 2) |
| System.arraycopy(points, index + 2, points, index, size * 2 - index |
| - 2); |
| size--; |
| return pt; |
| } |
| |
| /** |
| * Reverses the order of the points in the list. |
| * |
| * @since 3.2 |
| */ |
| public void reverse() { |
| int temp; |
| for (int i = 0, j = size * 2 - 2; i < size; i += 2, j -= 2) { |
| temp = points[i]; |
| points[i] = points[j]; |
| points[j] = temp; |
| temp = points[i + 1]; |
| points[i + 1] = points[j + 1]; |
| points[j + 1] = temp; |
| } |
| } |
| |
| /** |
| * Overwrites a point at a given index in the list with the specified Point. |
| * |
| * @param pt |
| * Point which is to be stored at the index. |
| * @param index |
| * Index where the given point is to be stored. |
| * @since 2.0 |
| */ |
| public void setPoint(Point pt, int index) { |
| if (index < 0 || index >= size) |
| throw new IndexOutOfBoundsException("Index: " + index + //$NON-NLS-1$ |
| ", Size: " + size); //$NON-NLS-1$ |
| if (bounds != null && !bounds.contains(pt)) |
| bounds = null; |
| points[index * 2] = pt.x; |
| points[index * 2 + 1] = pt.y; |
| } |
| |
| /** |
| * Sets the size of this PointList. |
| * |
| * @param newSize |
| * the new size |
| */ |
| public void setSize(int newSize) { |
| if (points.length > newSize * 2) { |
| size = newSize; |
| return; |
| } |
| int[] newArray = new int[newSize * 2]; |
| System.arraycopy(points, 0, newArray, 0, points.length); |
| points = newArray; |
| size = newSize; |
| } |
| |
| /** |
| * Returns the number of points in this PointList. |
| * |
| * @return The number of points |
| * @since 2.0 |
| */ |
| public int size() { |
| return size; |
| } |
| |
| /** |
| * Returns the contents of this PointList as an integer array. The returned |
| * array is by reference. Any changes made to the array will also be |
| * changing the original PointList. |
| * |
| * @return the integer array of points by reference |
| * @since 2.0 |
| */ |
| public int[] toIntArray() { |
| if (points.length != size * 2) { |
| int[] old = points; |
| points = new int[size * 2]; |
| System.arraycopy(old, 0, points, 0, size * 2); |
| } |
| return points; |
| } |
| |
| /** |
| * Moves the origin (0,0) of the coordinate system of all the points to the |
| * Point <i>pt</i>. This updates the position of all the points in this |
| * PointList. |
| * |
| * @param pt |
| * Position by which all the points will be shifted. |
| * @see #translate(int,int) |
| * @since 2.0 |
| */ |
| public final void translate(Point pt) { |
| translate(pt.x, pt.y); |
| } |
| |
| /** |
| * Moves the origin (0,0) of the coordinate system of all the points to the |
| * Point (x,y). This updates the position of all the points in this |
| * PointList. |
| * |
| * @param x |
| * Amount by which all the points will be shifted on the X axis. |
| * @param y |
| * Amount by which all the points will be shifted on the Y axis. |
| * @see #translate(Point) |
| * @since 2.0 |
| */ |
| public void translate(int x, int y) { |
| if (x == 0 && y == 0) |
| return; |
| if (bounds != null) |
| bounds.translate(x, y); |
| for (int i = 0; i < size * 2; i += 2) { |
| points[i] += x; |
| points[i + 1] += y; |
| } |
| } |
| |
| /** |
| * Transposes all x and y values. Useful for orientation changes. |
| * |
| * @since 3.2 |
| */ |
| public void transpose() { |
| int temp; |
| if (bounds != null) |
| bounds.transpose(); |
| for (int i = 0; i < size * 2; i += 2) { |
| temp = points[i]; |
| points[i] = points[i + 1]; |
| points[i + 1] = temp; |
| } |
| } |
| |
| /** |
| * @param x |
| * - X coordinate of the point |
| * @param y |
| * - Y coordinate of the point |
| * |
| * @return true if specified point belongs to the polygon drawn using this |
| * PointList |
| * @see Geometry#polygonContainsPoint(PointList, int, int) |
| * @since 3.5 |
| */ |
| public boolean polygonContainsPoint(int x, int y) { |
| return Geometry.polygonContainsPoint(this, x, y); |
| } |
| |
| /** |
| * @param x |
| * - X coordinate of the point |
| * @param y |
| * - Y coordinate of the point |
| * @param tolerance |
| * - allowed distance between point and polyline segment |
| * |
| * @return true if the least distance between specified point and polyline |
| * drawn using this PointList is less then specified tolerance |
| * @see Geometry#polylineContainsPoint(PointList, int, int, int) |
| * @since 3.5 |
| */ |
| public boolean polylineContainsPoint(int x, int y, int tolerance) { |
| return Geometry.polylineContainsPoint(this, x, y, tolerance); |
| } |
| |
| } |