| /* PolyEdge.java -- An edge in a polygon, used for polygon filling |
| Copyright (C) 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 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 gnu.java.awt.java2d; |
| |
| /** |
| * An edge in a polygon. This is used by the scanline conversion algorithm |
| * implemented in {@link AbstractGraphics2D#rawFillShape}. |
| * |
| * @author Roman Kennke (kennke@aicas.com) |
| */ |
| public class PolyEdge |
| implements Comparable |
| { |
| |
| /** |
| * The start and end coordinates of the edge. y0 is always smaller or equal |
| * than y1. |
| */ |
| public double x0, y0, x1, y1; |
| |
| /** |
| * The slope of the edge. This is dx / dy. |
| */ |
| double slope; |
| |
| /** |
| * The intersection of this edge with the current scanline. |
| */ |
| double xIntersection; |
| |
| /** |
| * Indicates whether this edge is from the clip or from the target shape. |
| */ |
| boolean isClip; |
| |
| /** |
| * Creates a new PolyEdge with the specified coordinates. |
| * |
| * @param x0 the starting point, x coordinate |
| * @param y0 the starting point, y coordinate |
| * @param x1 the end point, x coordinate |
| * @param y1 the end point, y coordinate |
| */ |
| PolyEdge(double x0, double y0, double x1, double y1, boolean clip) |
| { |
| isClip = clip; |
| if (y0 < y1) |
| { |
| this.x0 = x0; |
| this.y0 = y0; |
| this.x1 = x1; |
| this.y1 = y1; |
| } |
| else |
| { |
| this.x0 = x1; |
| this.y0 = y1; |
| this.x1 = x0; |
| this.y1 = y0; |
| } |
| slope = (this.x1 - this.x0) / (this.y1 - this.y0); |
| if (this.y0 == this.y1) // Horizontal edge. |
| xIntersection = Math.min(this.x0, this.x1); |
| else |
| xIntersection = this.x0 + slope * (Math.ceil(this.y0) - this.y0); |
| } |
| |
| /** |
| * Sorts PolyEdges by the x coordinate from the minimum x value. |
| */ |
| public int compareTo(Object o) |
| { |
| PolyEdge other = (PolyEdge) o; |
| int comp = 0; |
| if (x0 < other.x0) |
| comp = -1; |
| else if (x0 > other.x0) |
| comp = 1; |
| return comp; |
| } |
| |
| public String toString() |
| { |
| return "Edge: " + x0 + ", " + y0 + ", " + x1 + ", " + y1 + ", slope: " |
| + slope + ", xIntersection: " + xIntersection |
| + ", isClip: " + isClip; |
| } |
| } |