| /* |
| * 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.awt.geom.QuadCurve2D; |
| import java.util.Vector; |
| |
| final class Order3 extends Curve { |
| private double x0; |
| private double y0; |
| private double cx0; |
| private double cy0; |
| private double cx1; |
| private double cy1; |
| private double x1; |
| private double y1; |
| |
| private double xmin; |
| private double xmax; |
| |
| private double xcoeff0; |
| private double xcoeff1; |
| private double xcoeff2; |
| private double xcoeff3; |
| |
| private double ycoeff0; |
| private double ycoeff1; |
| private double ycoeff2; |
| private double ycoeff3; |
| |
| public static void insert(Vector curves, double tmp[], |
| double x0, double y0, |
| double cx0, double cy0, |
| double cx1, double cy1, |
| double x1, double y1, |
| int direction) |
| { |
| int numparams = getHorizontalParams(y0, cy0, cy1, y1, tmp); |
| if (numparams == 0) { |
| // We are using addInstance here to avoid inserting horisontal |
| // segments |
| addInstance(curves, x0, y0, cx0, cy0, cx1, cy1, x1, y1, direction); |
| return; |
| } |
| // Store coordinates for splitting at tmp[3..10] |
| tmp[3] = x0; tmp[4] = y0; |
| tmp[5] = cx0; tmp[6] = cy0; |
| tmp[7] = cx1; tmp[8] = cy1; |
| tmp[9] = x1; tmp[10] = y1; |
| double t = tmp[0]; |
| if (numparams > 1 && t > tmp[1]) { |
| // Perform a "2 element sort"... |
| tmp[0] = tmp[1]; |
| tmp[1] = t; |
| t = tmp[0]; |
| } |
| split(tmp, 3, t); |
| if (numparams > 1) { |
| // Recalculate tmp[1] relative to the range [tmp[0]...1] |
| t = (tmp[1] - t) / (1 - t); |
| split(tmp, 9, t); |
| } |
| int index = 3; |
| if (direction == DECREASING) { |
| index += numparams * 6; |
| } |
| while (numparams >= 0) { |
| addInstance(curves, |
| tmp[index + 0], tmp[index + 1], |
| tmp[index + 2], tmp[index + 3], |
| tmp[index + 4], tmp[index + 5], |
| tmp[index + 6], tmp[index + 7], |
| direction); |
| numparams--; |
| if (direction == INCREASING) { |
| index += 6; |
| } else { |
| index -= 6; |
| } |
| } |
| } |
| |
| public static void addInstance(Vector curves, |
| double x0, double y0, |
| double cx0, double cy0, |
| double cx1, double cy1, |
| double x1, double y1, |
| int direction) { |
| if (y0 > y1) { |
| curves.add(new Order3(x1, y1, cx1, cy1, cx0, cy0, x0, y0, |
| -direction)); |
| } else if (y1 > y0) { |
| curves.add(new Order3(x0, y0, cx0, cy0, cx1, cy1, x1, y1, |
| direction)); |
| } |
| } |
| |
| /* |
| * Return the count of the number of horizontal sections of the |
| * specified cubic Bezier curve. Put the parameters for the |
| * horizontal sections into the specified <code>ret</code> array. |
| * <p> |
| * If we examine the parametric equation in t, we have: |
| * Py(t) = C0(1-t)^3 + 3CP0 t(1-t)^2 + 3CP1 t^2(1-t) + C1 t^3 |
| * = C0 - 3C0t + 3C0t^2 - C0t^3 + |
| * 3CP0t - 6CP0t^2 + 3CP0t^3 + |
| * 3CP1t^2 - 3CP1t^3 + |
| * C1t^3 |
| * Py(t) = (C1 - 3CP1 + 3CP0 - C0) t^3 + |
| * (3C0 - 6CP0 + 3CP1) t^2 + |
| * (3CP0 - 3C0) t + |
| * (C0) |
| * If we take the derivative, we get: |
| * Py(t) = Dt^3 + At^2 + Bt + C |
| * dPy(t) = 3Dt^2 + 2At + B = 0 |
| * 0 = 3*(C1 - 3*CP1 + 3*CP0 - C0)t^2 |
| * + 2*(3*CP1 - 6*CP0 + 3*C0)t |
| * + (3*CP0 - 3*C0) |
| * 0 = 3*(C1 - 3*CP1 + 3*CP0 - C0)t^2 |
| * + 3*2*(CP1 - 2*CP0 + C0)t |
| * + 3*(CP0 - C0) |
| * 0 = (C1 - CP1 - CP1 - CP1 + CP0 + CP0 + CP0 - C0)t^2 |
| * + 2*(CP1 - CP0 - CP0 + C0)t |
| * + (CP0 - C0) |
| * 0 = (C1 - CP1 + CP0 - CP1 + CP0 - CP1 + CP0 - C0)t^2 |
| * + 2*(CP1 - CP0 - CP0 + C0)t |
| * + (CP0 - C0) |
| * 0 = ((C1 - CP1) - (CP1 - CP0) - (CP1 - CP0) + (CP0 - C0))t^2 |
| * + 2*((CP1 - CP0) - (CP0 - C0))t |
| * + (CP0 - C0) |
| * Note that this method will return 0 if the equation is a line, |
| * which is either always horizontal or never horizontal. |
| * Completely horizontal curves need to be eliminated by other |
| * means outside of this method. |
| */ |
| public static int getHorizontalParams(double c0, double cp0, |
| double cp1, double c1, |
| double ret[]) { |
| if (c0 <= cp0 && cp0 <= cp1 && cp1 <= c1) { |
| return 0; |
| } |
| c1 -= cp1; |
| cp1 -= cp0; |
| cp0 -= c0; |
| ret[0] = cp0; |
| ret[1] = (cp1 - cp0) * 2; |
| ret[2] = (c1 - cp1 - cp1 + cp0); |
| int numroots = QuadCurve2D.solveQuadratic(ret, ret); |
| int j = 0; |
| for (int i = 0; i < numroots; i++) { |
| double t = ret[i]; |
| // No splits at t==0 and t==1 |
| if (t > 0 && t < 1) { |
| if (j < i) { |
| ret[j] = t; |
| } |
| j++; |
| } |
| } |
| return j; |
| } |
| |
| /* |
| * Split the cubic Bezier stored at coords[pos...pos+7] representing |
| * the parametric range [0..1] into two subcurves representing the |
| * parametric subranges [0..t] and [t..1]. Store the results back |
| * into the array at coords[pos...pos+7] and coords[pos+6...pos+13]. |
| */ |
| public static void split(double coords[], int pos, double t) { |
| double x0, y0, cx0, cy0, cx1, cy1, x1, y1; |
| coords[pos+12] = x1 = coords[pos+6]; |
| coords[pos+13] = y1 = coords[pos+7]; |
| cx1 = coords[pos+4]; |
| cy1 = coords[pos+5]; |
| x1 = cx1 + (x1 - cx1) * t; |
| y1 = cy1 + (y1 - cy1) * t; |
| x0 = coords[pos+0]; |
| y0 = coords[pos+1]; |
| cx0 = coords[pos+2]; |
| cy0 = coords[pos+3]; |
| x0 = x0 + (cx0 - x0) * t; |
| y0 = y0 + (cy0 - y0) * t; |
| cx0 = cx0 + (cx1 - cx0) * t; |
| cy0 = cy0 + (cy1 - cy0) * t; |
| cx1 = cx0 + (x1 - cx0) * t; |
| cy1 = cy0 + (y1 - cy0) * t; |
| cx0 = x0 + (cx0 - x0) * t; |
| cy0 = y0 + (cy0 - y0) * t; |
| coords[pos+2] = x0; |
| coords[pos+3] = y0; |
| coords[pos+4] = cx0; |
| coords[pos+5] = cy0; |
| coords[pos+6] = cx0 + (cx1 - cx0) * t; |
| coords[pos+7] = cy0 + (cy1 - cy0) * t; |
| coords[pos+8] = cx1; |
| coords[pos+9] = cy1; |
| coords[pos+10] = x1; |
| coords[pos+11] = y1; |
| } |
| |
| public Order3(double x0, double y0, |
| double cx0, double cy0, |
| double cx1, double cy1, |
| double x1, double y1, |
| int direction) |
| { |
| super(direction); |
| // REMIND: Better accuracy in the root finding methods would |
| // ensure that cys are in range. As it stands, they are never |
| // more than "1 mantissa bit" out of range... |
| if (cy0 < y0) cy0 = y0; |
| if (cy1 > y1) cy1 = y1; |
| this.x0 = x0; |
| this.y0 = y0; |
| this.cx0 = cx0; |
| this.cy0 = cy0; |
| this.cx1 = cx1; |
| this.cy1 = cy1; |
| this.x1 = x1; |
| this.y1 = y1; |
| xmin = Math.min(Math.min(x0, x1), Math.min(cx0, cx1)); |
| xmax = Math.max(Math.max(x0, x1), Math.max(cx0, cx1)); |
| xcoeff0 = x0; |
| xcoeff1 = (cx0 - x0) * 3.0; |
| xcoeff2 = (cx1 - cx0 - cx0 + x0) * 3.0; |
| xcoeff3 = x1 - (cx1 - cx0) * 3.0 - x0; |
| ycoeff0 = y0; |
| ycoeff1 = (cy0 - y0) * 3.0; |
| ycoeff2 = (cy1 - cy0 - cy0 + y0) * 3.0; |
| ycoeff3 = y1 - (cy1 - cy0) * 3.0 - y0; |
| YforT1 = YforT2 = YforT3 = y0; |
| } |
| |
| public int getOrder() { |
| return 3; |
| } |
| |
| 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 getCX0() { |
| return (direction == INCREASING) ? cx0 : cx1; |
| } |
| |
| public double getCY0() { |
| return (direction == INCREASING) ? cy0 : cy1; |
| } |
| |
| public double getCX1() { |
| return (direction == DECREASING) ? cx0 : cx1; |
| } |
| |
| public double getCY1() { |
| return (direction == DECREASING) ? cy0 : cy1; |
| } |
| |
| public double getX1() { |
| return (direction == DECREASING) ? x0 : x1; |
| } |
| |
| public double getY1() { |
| return (direction == DECREASING) ? y0 : y1; |
| } |
| |
| private double TforY1; |
| private double YforT1; |
| private double TforY2; |
| private double YforT2; |
| private double TforY3; |
| private double YforT3; |
| |
| /* |
| * Solve the cubic whose coefficients are in the a,b,c,d fields and |
| * return the first root in the range [0, 1]. |
| * The cubic solved is represented by the equation: |
| * x^3 + (ycoeff2)x^2 + (ycoeff1)x + (ycoeff0) = y |
| * @return the first valid root (in the range [0, 1]) |
| */ |
| public double TforY(double y) { |
| if (y <= y0) return 0; |
| if (y >= y1) return 1; |
| if (y == YforT1) return TforY1; |
| if (y == YforT2) return TforY2; |
| if (y == YforT3) return TforY3; |
| // From Numerical Recipes, 5.6, Quadratic and Cubic Equations |
| if (ycoeff3 == 0.0) { |
| // The cubic degenerated to quadratic (or line or ...). |
| return Order2.TforY(y, ycoeff0, ycoeff1, ycoeff2); |
| } |
| double a = ycoeff2 / ycoeff3; |
| double b = ycoeff1 / ycoeff3; |
| double c = (ycoeff0 - y) / ycoeff3; |
| int roots = 0; |
| double Q = (a * a - 3.0 * b) / 9.0; |
| double R = (2.0 * a * a * a - 9.0 * a * b + 27.0 * c) / 54.0; |
| double R2 = R * R; |
| double Q3 = Q * Q * Q; |
| double a_3 = a / 3.0; |
| double t; |
| if (R2 < Q3) { |
| double theta = Math.acos(R / Math.sqrt(Q3)); |
| Q = -2.0 * Math.sqrt(Q); |
| t = refine(a, b, c, y, Q * Math.cos(theta / 3.0) - a_3); |
| if (t < 0) { |
| t = refine(a, b, c, y, |
| Q * Math.cos((theta + Math.PI * 2.0)/ 3.0) - a_3); |
| } |
| if (t < 0) { |
| t = refine(a, b, c, y, |
| Q * Math.cos((theta - Math.PI * 2.0)/ 3.0) - a_3); |
| } |
| } else { |
| boolean neg = (R < 0.0); |
| double S = Math.sqrt(R2 - Q3); |
| if (neg) { |
| R = -R; |
| } |
| double A = Math.pow(R + S, 1.0 / 3.0); |
| if (!neg) { |
| A = -A; |
| } |
| double B = (A == 0.0) ? 0.0 : (Q / A); |
| t = refine(a, b, c, y, (A + B) - a_3); |
| } |
| if (t < 0) { |
| //throw new InternalError("bad t"); |
| double t0 = 0; |
| double t1 = 1; |
| while (true) { |
| t = (t0 + t1) / 2; |
| if (t == t0 || t == t1) { |
| break; |
| } |
| double yt = YforT(t); |
| if (yt < y) { |
| t0 = t; |
| } else if (yt > y) { |
| t1 = t; |
| } else { |
| break; |
| } |
| } |
| } |
| if (t >= 0) { |
| TforY3 = TforY2; |
| YforT3 = YforT2; |
| TforY2 = TforY1; |
| YforT2 = YforT1; |
| TforY1 = t; |
| YforT1 = y; |
| } |
| return t; |
| } |
| |
| public double refine(double a, double b, double c, |
| double target, double t) |
| { |
| if (t < -0.1 || t > 1.1) { |
| return -1; |
| } |
| double y = YforT(t); |
| double t0, t1; |
| if (y < target) { |
| t0 = t; |
| t1 = 1; |
| } else { |
| t0 = 0; |
| t1 = t; |
| } |
| double origt = t; |
| double origy = y; |
| boolean useslope = true; |
| while (y != target) { |
| if (!useslope) { |
| double t2 = (t0 + t1) / 2; |
| if (t2 == t0 || t2 == t1) { |
| break; |
| } |
| t = t2; |
| } else { |
| double slope = dYforT(t, 1); |
| if (slope == 0) { |
| useslope = false; |
| continue; |
| } |
| double t2 = t + ((target - y) / slope); |
| if (t2 == t || t2 <= t0 || t2 >= t1) { |
| useslope = false; |
| continue; |
| } |
| t = t2; |
| } |
| y = YforT(t); |
| if (y < target) { |
| t0 = t; |
| } else if (y > target) { |
| t1 = t; |
| } else { |
| break; |
| } |
| } |
| boolean verbose = false; |
| if (false && t >= 0 && t <= 1) { |
| y = YforT(t); |
| long tdiff = diffbits(t, origt); |
| long ydiff = diffbits(y, origy); |
| long yerr = diffbits(y, target); |
| if (yerr > 0 || (verbose && tdiff > 0)) { |
| System.out.println("target was y = "+target); |
| System.out.println("original was y = "+origy+", t = "+origt); |
| System.out.println("final was y = "+y+", t = "+t); |
| System.out.println("t diff is "+tdiff); |
| System.out.println("y diff is "+ydiff); |
| System.out.println("y error is "+yerr); |
| double tlow = prev(t); |
| double ylow = YforT(tlow); |
| double thi = next(t); |
| double yhi = YforT(thi); |
| if (Math.abs(target - ylow) < Math.abs(target - y) || |
| Math.abs(target - yhi) < Math.abs(target - y)) |
| { |
| System.out.println("adjacent y's = ["+ylow+", "+yhi+"]"); |
| } |
| } |
| } |
| return (t > 1) ? -1 : t; |
| } |
| |
| public double XforY(double y) { |
| if (y <= y0) { |
| return x0; |
| } |
| if (y >= y1) { |
| return x1; |
| } |
| return XforT(TforY(y)); |
| } |
| |
| public double XforT(double t) { |
| return (((xcoeff3 * t) + xcoeff2) * t + xcoeff1) * t + xcoeff0; |
| } |
| |
| public double YforT(double t) { |
| return (((ycoeff3 * t) + ycoeff2) * t + ycoeff1) * t + ycoeff0; |
| } |
| |
| public double dXforT(double t, int deriv) { |
| switch (deriv) { |
| case 0: |
| return (((xcoeff3 * t) + xcoeff2) * t + xcoeff1) * t + xcoeff0; |
| case 1: |
| return ((3 * xcoeff3 * t) + 2 * xcoeff2) * t + xcoeff1; |
| case 2: |
| return (6 * xcoeff3 * t) + 2 * xcoeff2; |
| case 3: |
| return 6 * xcoeff3; |
| default: |
| return 0; |
| } |
| } |
| |
| public double dYforT(double t, int deriv) { |
| switch (deriv) { |
| case 0: |
| return (((ycoeff3 * t) + ycoeff2) * t + ycoeff1) * t + ycoeff0; |
| case 1: |
| return ((3 * ycoeff3 * t) + 2 * ycoeff2) * t + ycoeff1; |
| case 2: |
| return (6 * ycoeff3 * t) + 2 * ycoeff2; |
| case 3: |
| return 6 * ycoeff3; |
| default: |
| return 0; |
| } |
| } |
| |
| public double nextVertical(double t0, double t1) { |
| double eqn[] = {xcoeff1, 2 * xcoeff2, 3 * xcoeff3}; |
| int numroots = QuadCurve2D.solveQuadratic(eqn, eqn); |
| for (int i = 0; i < numroots; i++) { |
| if (eqn[i] > t0 && eqn[i] < t1) { |
| t1 = eqn[i]; |
| } |
| } |
| return t1; |
| } |
| |
| public void enlarge(Rectangle2D r) { |
| r.add(x0, y0); |
| double eqn[] = {xcoeff1, 2 * xcoeff2, 3 * xcoeff3}; |
| int numroots = QuadCurve2D.solveQuadratic(eqn, eqn); |
| for (int i = 0; i < numroots; i++) { |
| double t = eqn[i]; |
| if (t > 0 && t < 1) { |
| r.add(XforT(t), YforT(t)); |
| } |
| } |
| r.add(x1, y1); |
| } |
| |
| public Curve getSubCurve(double ystart, double yend, int dir) { |
| if (ystart <= y0 && yend >= y1) { |
| return getWithDirection(dir); |
| } |
| double eqn[] = new double[14]; |
| double t0, t1; |
| t0 = TforY(ystart); |
| t1 = TforY(yend); |
| eqn[0] = x0; |
| eqn[1] = y0; |
| eqn[2] = cx0; |
| eqn[3] = cy0; |
| eqn[4] = cx1; |
| eqn[5] = cy1; |
| eqn[6] = x1; |
| eqn[7] = y1; |
| if (t0 > t1) { |
| /* This happens in only rare cases where ystart is |
| * very near yend and solving for the yend root ends |
| * up stepping slightly lower in t than solving for |
| * the ystart root. |
| * Ideally we might want to skip this tiny little |
| * segment and just fudge the surrounding coordinates |
| * to bridge the gap left behind, but there is no way |
| * to do that from here. Higher levels could |
| * potentially eliminate these tiny "fixup" segments, |
| * but not without a lot of extra work on the code that |
| * coalesces chains of curves into subpaths. The |
| * simplest solution for now is to just reorder the t |
| * values and chop out a miniscule curve piece. |
| */ |
| double t = t0; |
| t0 = t1; |
| t1 = t; |
| } |
| if (t1 < 1) { |
| split(eqn, 0, t1); |
| } |
| int i; |
| if (t0 <= 0) { |
| i = 0; |
| } else { |
| split(eqn, 0, t0 / t1); |
| i = 6; |
| } |
| return new Order3(eqn[i+0], ystart, |
| eqn[i+2], eqn[i+3], |
| eqn[i+4], eqn[i+5], |
| eqn[i+6], yend, |
| dir); |
| } |
| |
| public Curve getReversedCurve() { |
| return new Order3(x0, y0, cx0, cy0, cx1, cy1, x1, y1, -direction); |
| } |
| |
| public int getSegment(double coords[]) { |
| if (direction == INCREASING) { |
| coords[0] = cx0; |
| coords[1] = cy0; |
| coords[2] = cx1; |
| coords[3] = cy1; |
| coords[4] = x1; |
| coords[5] = y1; |
| } else { |
| coords[0] = cx1; |
| coords[1] = cy1; |
| coords[2] = cx0; |
| coords[3] = cy0; |
| coords[4] = x0; |
| coords[5] = y0; |
| } |
| return PathIterator.SEG_CUBICTO; |
| } |
| |
| public String controlPointString() { |
| return (("("+round(getCX0())+", "+round(getCY0())+"), ")+ |
| ("("+round(getCX1())+", "+round(getCY1())+"), ")); |
| } |
| } |
