| /* |
| * Copyright (c) 1998, 2006, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package sun.awt.geom; |
| |
| import java.awt.geom.Rectangle2D; |
| import java.awt.geom.PathIterator; |
| import java.util.Vector; |
| |
| final class Order1 extends Curve { |
| private double x0; |
| private double y0; |
| private double x1; |
| private double y1; |
| private double xmin; |
| private double xmax; |
| |
| public Order1(double x0, double y0, |
| double x1, double y1, |
| int direction) |
| { |
| super(direction); |
| this.x0 = x0; |
| this.y0 = y0; |
| this.x1 = x1; |
| this.y1 = y1; |
| if (x0 < x1) { |
| this.xmin = x0; |
| this.xmax = x1; |
| } else { |
| this.xmin = x1; |
| this.xmax = x0; |
| } |
| } |
| |
| public int getOrder() { |
| return 1; |
| } |
| |
| public double getXTop() { |
| return x0; |
| } |
| |
| public double getYTop() { |
| return y0; |
| } |
| |
| public double getXBot() { |
| return x1; |
| } |
| |
| public double getYBot() { |
| return y1; |
| } |
| |
| public double getXMin() { |
| return xmin; |
| } |
| |
| public double getXMax() { |
| return xmax; |
| } |
| |
| public double getX0() { |
| return (direction == INCREASING) ? x0 : x1; |
| } |
| |
| public double getY0() { |
| return (direction == INCREASING) ? y0 : y1; |
| } |
| |
| public double getX1() { |
| return (direction == DECREASING) ? x0 : x1; |
| } |
| |
| public double getY1() { |
| return (direction == DECREASING) ? y0 : y1; |
| } |
| |
| public double XforY(double y) { |
| if (x0 == x1 || y <= y0) { |
| return x0; |
| } |
| if (y >= y1) { |
| return x1; |
| } |
| // assert(y0 != y1); /* No horizontal lines... */ |
| return (x0 + (y - y0) * (x1 - x0) / (y1 - y0)); |
| } |
| |
| public double TforY(double y) { |
| if (y <= y0) { |
| return 0; |
| } |
| if (y >= y1) { |
| return 1; |
| } |
| return (y - y0) / (y1 - y0); |
| } |
| |
| public double XforT(double t) { |
| return x0 + t * (x1 - x0); |
| } |
| |
| public double YforT(double t) { |
| return y0 + t * (y1 - y0); |
| } |
| |
| public double dXforT(double t, int deriv) { |
| switch (deriv) { |
| case 0: |
| return x0 + t * (x1 - x0); |
| case 1: |
| return (x1 - x0); |
| default: |
| return 0; |
| } |
| } |
| |
| public double dYforT(double t, int deriv) { |
| switch (deriv) { |
| case 0: |
| return y0 + t * (y1 - y0); |
| case 1: |
| return (y1 - y0); |
| default: |
| return 0; |
| } |
| } |
| |
| public double nextVertical(double t0, double t1) { |
| return t1; |
| } |
| |
| public boolean accumulateCrossings(Crossings c) { |
| double xlo = c.getXLo(); |
| double ylo = c.getYLo(); |
| double xhi = c.getXHi(); |
| double yhi = c.getYHi(); |
| if (xmin >= xhi) { |
| return false; |
| } |
| double xstart, ystart, xend, yend; |
| if (y0 < ylo) { |
| if (y1 <= ylo) { |
| return false; |
| } |
| ystart = ylo; |
| xstart = XforY(ylo); |
| } else { |
| if (y0 >= yhi) { |
| return false; |
| } |
| ystart = y0; |
| xstart = x0; |
| } |
| if (y1 > yhi) { |
| yend = yhi; |
| xend = XforY(yhi); |
| } else { |
| yend = y1; |
| xend = x1; |
| } |
| if (xstart >= xhi && xend >= xhi) { |
| return false; |
| } |
| if (xstart > xlo || xend > xlo) { |
| return true; |
| } |
| c.record(ystart, yend, direction); |
| return false; |
| } |
| |
| public void enlarge(Rectangle2D r) { |
| r.add(x0, y0); |
| r.add(x1, y1); |
| } |
| |
| public Curve getSubCurve(double ystart, double yend, int dir) { |
| if (ystart == y0 && yend == y1) { |
| return getWithDirection(dir); |
| } |
| if (x0 == x1) { |
| return new Order1(x0, ystart, x1, yend, dir); |
| } |
| double num = x0 - x1; |
| double denom = y0 - y1; |
| double xstart = (x0 + (ystart - y0) * num / denom); |
| double xend = (x0 + (yend - y0) * num / denom); |
| return new Order1(xstart, ystart, xend, yend, dir); |
| } |
| |
| public Curve getReversedCurve() { |
| return new Order1(x0, y0, x1, y1, -direction); |
| } |
| |
| public int compareTo(Curve other, double yrange[]) { |
| if (!(other instanceof Order1)) { |
| return super.compareTo(other, yrange); |
| } |
| Order1 c1 = (Order1) other; |
| if (yrange[1] <= yrange[0]) { |
| throw new InternalError("yrange already screwed up..."); |
| } |
| yrange[1] = Math.min(Math.min(yrange[1], y1), c1.y1); |
| if (yrange[1] <= yrange[0]) { |
| throw new InternalError("backstepping from "+yrange[0]+" to "+yrange[1]); |
| } |
| if (xmax <= c1.xmin) { |
| return (xmin == c1.xmax) ? 0 : -1; |
| } |
| if (xmin >= c1.xmax) { |
| return 1; |
| } |
| /* |
| * If "this" is curve A and "other" is curve B, then... |
| * xA(y) = x0A + (y - y0A) (x1A - x0A) / (y1A - y0A) |
| * xB(y) = x0B + (y - y0B) (x1B - x0B) / (y1B - y0B) |
| * xA(y) == xB(y) |
| * x0A + (y - y0A) (x1A - x0A) / (y1A - y0A) |
| * == x0B + (y - y0B) (x1B - x0B) / (y1B - y0B) |
| * 0 == x0A (y1A - y0A) (y1B - y0B) + (y - y0A) (x1A - x0A) (y1B - y0B) |
| * - x0B (y1A - y0A) (y1B - y0B) - (y - y0B) (x1B - x0B) (y1A - y0A) |
| * 0 == (x0A - x0B) (y1A - y0A) (y1B - y0B) |
| * + (y - y0A) (x1A - x0A) (y1B - y0B) |
| * - (y - y0B) (x1B - x0B) (y1A - y0A) |
| * If (dxA == x1A - x0A), etc... |
| * 0 == (x0A - x0B) * dyA * dyB |
| * + (y - y0A) * dxA * dyB |
| * - (y - y0B) * dxB * dyA |
| * 0 == (x0A - x0B) * dyA * dyB |
| * + y * dxA * dyB - y0A * dxA * dyB |
| * - y * dxB * dyA + y0B * dxB * dyA |
| * 0 == (x0A - x0B) * dyA * dyB |
| * + y * dxA * dyB - y * dxB * dyA |
| * - y0A * dxA * dyB + y0B * dxB * dyA |
| * 0 == (x0A - x0B) * dyA * dyB |
| * + y * (dxA * dyB - dxB * dyA) |
| * - y0A * dxA * dyB + y0B * dxB * dyA |
| * y == ((x0A - x0B) * dyA * dyB |
| * - y0A * dxA * dyB + y0B * dxB * dyA) |
| * / (-(dxA * dyB - dxB * dyA)) |
| * y == ((x0A - x0B) * dyA * dyB |
| * - y0A * dxA * dyB + y0B * dxB * dyA) |
| * / (dxB * dyA - dxA * dyB) |
| */ |
| double dxa = x1 - x0; |
| double dya = y1 - y0; |
| double dxb = c1.x1 - c1.x0; |
| double dyb = c1.y1 - c1.y0; |
| double denom = dxb * dya - dxa * dyb; |
| double y; |
| if (denom != 0) { |
| double num = ((x0 - c1.x0) * dya * dyb |
| - y0 * dxa * dyb |
| + c1.y0 * dxb * dya); |
| y = num / denom; |
| if (y <= yrange[0]) { |
| // intersection is above us |
| // Use bottom-most common y for comparison |
| y = Math.min(y1, c1.y1); |
| } else { |
| // intersection is below the top of our range |
| if (y < yrange[1]) { |
| // If intersection is in our range, adjust valid range |
| yrange[1] = y; |
| } |
| // Use top-most common y for comparison |
| y = Math.max(y0, c1.y0); |
| } |
| } else { |
| // lines are parallel, choose any common y for comparison |
| // Note - prefer an endpoint for speed of calculating the X |
| // (see shortcuts in Order1.XforY()) |
| y = Math.max(y0, c1.y0); |
| } |
| return orderof(XforY(y), c1.XforY(y)); |
| } |
| |
| public int getSegment(double coords[]) { |
| if (direction == INCREASING) { |
| coords[0] = x1; |
| coords[1] = y1; |
| } else { |
| coords[0] = x0; |
| coords[1] = y0; |
| } |
| return PathIterator.SEG_LINETO; |
| } |
| } |
