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Diffstat (limited to 'libjava/java/awt/geom/QuadCurve2D.java')
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diff --git a/libjava/java/awt/geom/QuadCurve2D.java b/libjava/java/awt/geom/QuadCurve2D.java deleted file mode 100644 index 41021dbc683..00000000000 --- a/libjava/java/awt/geom/QuadCurve2D.java +++ /dev/null @@ -1,1467 +0,0 @@ -/* QuadCurve2D.java -- represents a parameterized quadratic curve in 2-D space - Copyright (C) 2002, 2003, 2004 Free Software Foundation - -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 java.awt.geom; - -import java.awt.Rectangle; -import java.awt.Shape; -import java.util.NoSuchElementException; - -/** - * A two-dimensional curve that is parameterized with a quadratic - * function. - * - * <p><img src="doc-files/QuadCurve2D-1.png" width="350" height="180" - * alt="A drawing of a QuadCurve2D" /> - * - * @author Eric Blake (ebb9@email.byu.edu) - * @author Graydon Hoare (graydon@redhat.com) - * @author Sascha Brawer (brawer@dandelis.ch) - * @author Sven de Marothy (sven@physto.se) - * - * @since 1.2 - */ -public abstract class QuadCurve2D implements Shape, Cloneable -{ - private static final double BIG_VALUE = java.lang.Double.MAX_VALUE / 10.0; - private static final double EPSILON = 1E-10; - - /** - * Constructs a new QuadCurve2D. Typical users will want to - * construct instances of a subclass, such as {@link - * QuadCurve2D.Float} or {@link QuadCurve2D.Double}. - */ - protected QuadCurve2D() - { - } - - /** - * Returns the <i>x</i> coordinate of the curve’s start - * point. - */ - public abstract double getX1(); - - /** - * Returns the <i>y</i> coordinate of the curve’s start - * point. - */ - public abstract double getY1(); - - /** - * Returns the curve’s start point. - */ - public abstract Point2D getP1(); - - /** - * Returns the <i>x</i> coordinate of the curve’s control - * point. - */ - public abstract double getCtrlX(); - - /** - * Returns the <i>y</i> coordinate of the curve’s control - * point. - */ - public abstract double getCtrlY(); - - /** - * Returns the curve’s control point. - */ - public abstract Point2D getCtrlPt(); - - /** - * Returns the <i>x</i> coordinate of the curve’s end - * point. - */ - public abstract double getX2(); - - /** - * Returns the <i>y</i> coordinate of the curve’s end - * point. - */ - public abstract double getY2(); - - /** - * Returns the curve’s end point. - */ - public abstract Point2D getP2(); - - /** - * Changes the curve geometry, separately specifying each coordinate - * value. - * - * @param x1 the <i>x</i> coordinate of the curve’s new start - * point. - * - * @param y1 the <i>y</i> coordinate of the curve’s new start - * point. - * - * @param cx the <i>x</i> coordinate of the curve’s new - * control point. - * - * @param cy the <i>y</i> coordinate of the curve’s new - * control point. - * - * @param x2 the <i>x</i> coordinate of the curve’s new end - * point. - * - * @param y2 the <i>y</i> coordinate of the curve’s new end - * point. - */ - public abstract void setCurve(double x1, double y1, double cx, double cy, - double x2, double y2); - - /** - * Changes the curve geometry, passing coordinate values in an - * array. - * - * @param coords an array containing the new coordinate values. The - * <i>x</i> coordinate of the new start point is located at - * <code>coords[offset]</code>, its <i>y</i> coordinate at - * <code>coords[offset + 1]</code>. The <i>x</i> coordinate of the - * new control point is located at <code>coords[offset + 2]</code>, - * its <i>y</i> coordinate at <code>coords[offset + 3]</code>. The - * <i>x</i> coordinate of the new end point is located at - * <code>coords[offset + 4]</code>, its <i>y</i> coordinate at - * <code>coords[offset + 5]</code>. - * - * @param offset the offset of the first coordinate value in - * <code>coords</code>. - */ - public void setCurve(double[] coords, int offset) - { - setCurve(coords[offset++], coords[offset++], coords[offset++], - coords[offset++], coords[offset++], coords[offset++]); - } - - /** - * Changes the curve geometry, specifying coordinate values in - * separate Point objects. - * - * <p><img src="doc-files/QuadCurve2D-1.png" width="350" height="180" - * alt="A drawing of a QuadCurve2D" /> - * - * <p>The curve does not keep any reference to the passed point - * objects. Therefore, a later change to <code>p1</code>, - * <code>c</code> <code>p2</code> will not affect the curve - * geometry. - * - * @param p1 the new start point. - * @param c the new control point. - * @param p2 the new end point. - */ - public void setCurve(Point2D p1, Point2D c, Point2D p2) - { - setCurve(p1.getX(), p1.getY(), c.getX(), c.getY(), p2.getX(), p2.getY()); - } - - /** - * Changes the curve geometry, specifying coordinate values in an - * array of Point objects. - * - * <p><img src="doc-files/QuadCurve2D-1.png" width="350" height="180" - * alt="A drawing of a QuadCurve2D" /> - * - * <p>The curve does not keep references to the passed point - * objects. Therefore, a later change to the <code>pts</code> array - * or any of its elements will not affect the curve geometry. - * - * @param pts an array containing the points. The new start point - * is located at <code>pts[offset]</code>, the new control - * point at <code>pts[offset + 1]</code>, and the new end point - * at <code>pts[offset + 2]</code>. - * - * @param offset the offset of the start point in <code>pts</code>. - */ - public void setCurve(Point2D[] pts, int offset) - { - setCurve(pts[offset].getX(), pts[offset].getY(), pts[offset + 1].getX(), - pts[offset + 1].getY(), pts[offset + 2].getX(), - pts[offset + 2].getY()); - } - - /** - * Changes the geometry of the curve to that of another curve. - * - * @param c the curve whose coordinates will be copied. - */ - public void setCurve(QuadCurve2D c) - { - setCurve(c.getX1(), c.getY1(), c.getCtrlX(), c.getCtrlY(), c.getX2(), - c.getY2()); - } - - /** - * Calculates the squared flatness of a quadratic curve, directly - * specifying each coordinate value. The flatness is the distance of - * the control point to the line between start and end point. - * - * <p><img src="doc-files/QuadCurve2D-4.png" width="350" height="180" - * alt="A drawing that illustrates the flatness" /> - * - * <p>In the above drawing, the straight line connecting start point - * P1 and end point P2 is depicted in gray. The result will be the - * the square of the distance between C and the gray line, i.e. - * the squared length of the red line. - * - * @param x1 the <i>x</i> coordinate of the start point P1. - * @param y1 the <i>y</i> coordinate of the start point P1. - * @param cx the <i>x</i> coordinate of the control point C. - * @param cy the <i>y</i> coordinate of the control point C. - * @param x2 the <i>x</i> coordinate of the end point P2. - * @param y2 the <i>y</i> coordinate of the end point P2. - */ - public static double getFlatnessSq(double x1, double y1, double cx, - double cy, double x2, double y2) - { - return Line2D.ptSegDistSq(x1, y1, x2, y2, cx, cy); - } - - /** - * Calculates the flatness of a quadratic curve, directly specifying - * each coordinate value. The flatness is the distance of the - * control point to the line between start and end point. - * - * <p><img src="doc-files/QuadCurve2D-4.png" width="350" height="180" - * alt="A drawing that illustrates the flatness" /> - * - * <p>In the above drawing, the straight line connecting start point - * P1 and end point P2 is depicted in gray. The result will be the - * the distance between C and the gray line, i.e. the length of - * the red line. - * - * @param x1 the <i>x</i> coordinate of the start point P1. - * @param y1 the <i>y</i> coordinate of the start point P1. - * @param cx the <i>x</i> coordinate of the control point C. - * @param cy the <i>y</i> coordinate of the control point C. - * @param x2 the <i>x</i> coordinate of the end point P2. - * @param y2 the <i>y</i> coordinate of the end point P2. - */ - public static double getFlatness(double x1, double y1, double cx, double cy, - double x2, double y2) - { - return Line2D.ptSegDist(x1, y1, x2, y2, cx, cy); - } - - /** - * Calculates the squared flatness of a quadratic curve, specifying - * the coordinate values in an array. The flatness is the distance - * of the control point to the line between start and end point. - * - * <p><img src="doc-files/QuadCurve2D-4.png" width="350" height="180" - * alt="A drawing that illustrates the flatness" /> - * - * <p>In the above drawing, the straight line connecting start point - * P1 and end point P2 is depicted in gray. The result will be the - * the square of the distance between C and the gray line, i.e. - * the squared length of the red line. - * - * @param coords an array containing the coordinate values. The - * <i>x</i> coordinate of the start point P1 is located at - * <code>coords[offset]</code>, its <i>y</i> coordinate at - * <code>coords[offset + 1]</code>. The <i>x</i> coordinate of the - * control point C is located at <code>coords[offset + 2]</code>, - * its <i>y</i> coordinate at <code>coords[offset + 3]</code>. The - * <i>x</i> coordinate of the end point P2 is located at - * <code>coords[offset + 4]</code>, its <i>y</i> coordinate at - * <code>coords[offset + 5]</code>. - * - * @param offset the offset of the first coordinate value in - * <code>coords</code>. - */ - public static double getFlatnessSq(double[] coords, int offset) - { - return Line2D.ptSegDistSq(coords[offset], coords[offset + 1], - coords[offset + 4], coords[offset + 5], - coords[offset + 2], coords[offset + 3]); - } - - /** - * Calculates the flatness of a quadratic curve, specifying the - * coordinate values in an array. The flatness is the distance of - * the control point to the line between start and end point. - * - * <p><img src="doc-files/QuadCurve2D-4.png" width="350" height="180" - * alt="A drawing that illustrates the flatness" /> - * - * <p>In the above drawing, the straight line connecting start point - * P1 and end point P2 is depicted in gray. The result will be the - * the the distance between C and the gray line, i.e. the length of - * the red line. - * - * @param coords an array containing the coordinate values. The - * <i>x</i> coordinate of the start point P1 is located at - * <code>coords[offset]</code>, its <i>y</i> coordinate at - * <code>coords[offset + 1]</code>. The <i>x</i> coordinate of the - * control point C is located at <code>coords[offset + 2]</code>, - * its <i>y</i> coordinate at <code>coords[offset + 3]</code>. The - * <i>x</i> coordinate of the end point P2 is located at - * <code>coords[offset + 4]</code>, its <i>y</i> coordinate at - * <code>coords[offset + 5]</code>. - * - * @param offset the offset of the first coordinate value in - * <code>coords</code>. - */ - public static double getFlatness(double[] coords, int offset) - { - return Line2D.ptSegDist(coords[offset], coords[offset + 1], - coords[offset + 4], coords[offset + 5], - coords[offset + 2], coords[offset + 3]); - } - - /** - * Calculates the squared flatness of this curve. The flatness is - * the distance of the control point to the line between start and - * end point. - * - * <p><img src="doc-files/QuadCurve2D-4.png" width="350" height="180" - * alt="A drawing that illustrates the flatness" /> - * - * <p>In the above drawing, the straight line connecting start point - * P1 and end point P2 is depicted in gray. The result will be the - * the square of the distance between C and the gray line, i.e. the - * squared length of the red line. - */ - public double getFlatnessSq() - { - return Line2D.ptSegDistSq(getX1(), getY1(), getX2(), getY2(), getCtrlX(), - getCtrlY()); - } - - /** - * Calculates the flatness of this curve. The flatness is the - * distance of the control point to the line between start and end - * point. - * - * <p><img src="doc-files/QuadCurve2D-4.png" width="350" height="180" - * alt="A drawing that illustrates the flatness" /> - * - * <p>In the above drawing, the straight line connecting start point - * P1 and end point P2 is depicted in gray. The result will be the - * the distance between C and the gray line, i.e. the length of the - * red line. - */ - public double getFlatness() - { - return Line2D.ptSegDist(getX1(), getY1(), getX2(), getY2(), getCtrlX(), - getCtrlY()); - } - - /** - * Subdivides this curve into two halves. - * - * <p><img src="doc-files/QuadCurve2D-3.png" width="700" - * height="180" alt="A drawing that illustrates the effects of - * subdividing a QuadCurve2D" /> - * - * @param left a curve whose geometry will be set to the left half - * of this curve, or <code>null</code> if the caller is not - * interested in the left half. - * - * @param right a curve whose geometry will be set to the right half - * of this curve, or <code>null</code> if the caller is not - * interested in the right half. - */ - public void subdivide(QuadCurve2D left, QuadCurve2D right) - { - // Use empty slots at end to share single array. - double[] d = new double[] - { - getX1(), getY1(), getCtrlX(), getCtrlY(), getX2(), getY2(), - 0, 0, 0, 0 - }; - subdivide(d, 0, d, 0, d, 4); - if (left != null) - left.setCurve(d, 0); - if (right != null) - right.setCurve(d, 4); - } - - /** - * Subdivides a quadratic curve into two halves. - * - * <p><img src="doc-files/QuadCurve2D-3.png" width="700" - * height="180" alt="A drawing that illustrates the effects of - * subdividing a QuadCurve2D" /> - * - * @param src the curve to be subdivided. - * - * @param left a curve whose geometry will be set to the left half - * of <code>src</code>, or <code>null</code> if the caller is not - * interested in the left half. - * - * @param right a curve whose geometry will be set to the right half - * of <code>src</code>, or <code>null</code> if the caller is not - * interested in the right half. - */ - public static void subdivide(QuadCurve2D src, QuadCurve2D left, - QuadCurve2D right) - { - src.subdivide(left, right); - } - - /** - * Subdivides a quadratic curve into two halves, passing all - * coordinates in an array. - * - * <p><img src="doc-files/QuadCurve2D-3.png" width="700" - * height="180" alt="A drawing that illustrates the effects of - * subdividing a QuadCurve2D" /> - * - * <p>The left end point and the right start point will always be - * identical. Memory-concious programmers thus may want to pass the - * same array for both <code>left</code> and <code>right</code>, and - * set <code>rightOff</code> to <code>leftOff + 4</code>. - * - * @param src an array containing the coordinates of the curve to be - * subdivided. The <i>x</i> coordinate of the start point is - * located at <code>src[srcOff]</code>, its <i>y</i> at - * <code>src[srcOff + 1]</code>. The <i>x</i> coordinate of the - * control point is located at <code>src[srcOff + 2]</code>, its - * <i>y</i> at <code>src[srcOff + 3]</code>. The <i>x</i> - * coordinate of the end point is located at <code>src[srcOff + - * 4]</code>, its <i>y</i> at <code>src[srcOff + 5]</code>. - * - * @param srcOff an offset into <code>src</code>, specifying - * the index of the start point’s <i>x</i> coordinate. - * - * @param left an array that will receive the coordinates of the - * left half of <code>src</code>. It is acceptable to pass - * <code>src</code>. A caller who is not interested in the left half - * can pass <code>null</code>. - * - * @param leftOff an offset into <code>left</code>, specifying the - * index where the start point’s <i>x</i> coordinate will be - * stored. - * - * @param right an array that will receive the coordinates of the - * right half of <code>src</code>. It is acceptable to pass - * <code>src</code> or <code>left</code>. A caller who is not - * interested in the right half can pass <code>null</code>. - * - * @param rightOff an offset into <code>right</code>, specifying the - * index where the start point’s <i>x</i> coordinate will be - * stored. - */ - public static void subdivide(double[] src, int srcOff, double[] left, - int leftOff, double[] right, int rightOff) - { - double x1; - double y1; - double xc; - double yc; - double x2; - double y2; - - x1 = src[srcOff]; - y1 = src[srcOff + 1]; - xc = src[srcOff + 2]; - yc = src[srcOff + 3]; - x2 = src[srcOff + 4]; - y2 = src[srcOff + 5]; - - if (left != null) - { - left[leftOff] = x1; - left[leftOff + 1] = y1; - } - - if (right != null) - { - right[rightOff + 4] = x2; - right[rightOff + 5] = y2; - } - - x1 = (x1 + xc) / 2; - x2 = (xc + x2) / 2; - xc = (x1 + x2) / 2; - y1 = (y1 + yc) / 2; - y2 = (y2 + yc) / 2; - yc = (y1 + y2) / 2; - - if (left != null) - { - left[leftOff + 2] = x1; - left[leftOff + 3] = y1; - left[leftOff + 4] = xc; - left[leftOff + 5] = yc; - } - - if (right != null) - { - right[rightOff] = xc; - right[rightOff + 1] = yc; - right[rightOff + 2] = x2; - right[rightOff + 3] = y2; - } - } - - /** - * Finds the non-complex roots of a quadratic equation, placing the - * results into the same array as the equation coefficients. The - * following equation is being solved: - * - * <blockquote><code>eqn[2]</code> · <i>x</i><sup>2</sup> - * + <code>eqn[1]</code> · <i>x</i> - * + <code>eqn[0]</code> - * = 0 - * </blockquote> - * - * <p>For some background about solving quadratic equations, see the - * article <a href= - * "http://planetmath.org/encyclopedia/QuadraticFormula.html" - * >“Quadratic Formula”</a> in <a href= - * "http://planetmath.org/">PlanetMath</a>. For an extensive library - * of numerical algorithms written in the C programming language, - * see the <a href="http://www.gnu.org/software/gsl/">GNU Scientific - * Library</a>. - * - * @see #solveQuadratic(double[], double[]) - * @see CubicCurve2D#solveCubic(double[], double[]) - * - * @param eqn an array with the coefficients of the equation. When - * this procedure has returned, <code>eqn</code> will contain the - * non-complex solutions of the equation, in no particular order. - * - * @return the number of non-complex solutions. A result of 0 - * indicates that the equation has no non-complex solutions. A - * result of -1 indicates that the equation is constant (i.e., - * always or never zero). - * - * @author Brian Gough (bjg@network-theory.com) - * (original C implementation in the <a href= - * "http://www.gnu.org/software/gsl/">GNU Scientific Library</a>) - * - * @author Sascha Brawer (brawer@dandelis.ch) - * (adaptation to Java) - */ - public static int solveQuadratic(double[] eqn) - { - return solveQuadratic(eqn, eqn); - } - - /** - * Finds the non-complex roots of a quadratic equation. The - * following equation is being solved: - * - * <blockquote><code>eqn[2]</code> · <i>x</i><sup>2</sup> - * + <code>eqn[1]</code> · <i>x</i> - * + <code>eqn[0]</code> - * = 0 - * </blockquote> - * - * <p>For some background about solving quadratic equations, see the - * article <a href= - * "http://planetmath.org/encyclopedia/QuadraticFormula.html" - * >“Quadratic Formula”</a> in <a href= - * "http://planetmath.org/">PlanetMath</a>. For an extensive library - * of numerical algorithms written in the C programming language, - * see the <a href="http://www.gnu.org/software/gsl/">GNU Scientific - * Library</a>. - * - * @see CubicCurve2D#solveCubic(double[],double[]) - * - * @param eqn an array with the coefficients of the equation. - * - * @param res an array into which the non-complex roots will be - * stored. The results may be in an arbitrary order. It is safe to - * pass the same array object reference for both <code>eqn</code> - * and <code>res</code>. - * - * @return the number of non-complex solutions. A result of 0 - * indicates that the equation has no non-complex solutions. A - * result of -1 indicates that the equation is constant (i.e., - * always or never zero). - * - * @author Brian Gough (bjg@network-theory.com) - * (original C implementation in the <a href= - * "http://www.gnu.org/software/gsl/">GNU Scientific Library</a>) - * - * @author Sascha Brawer (brawer@dandelis.ch) - * (adaptation to Java) - */ - public static int solveQuadratic(double[] eqn, double[] res) - { - // Taken from poly/solve_quadratic.c in the GNU Scientific Library - // (GSL), cvs revision 1.7 of 2003-07-26. For the original source, - // see http://www.gnu.org/software/gsl/ - // - // Brian Gough, the author of that code, has granted the - // permission to use it in GNU Classpath under the GNU Classpath - // license, and has assigned the copyright to the Free Software - // Foundation. - // - // The Java implementation is very similar to the GSL code, but - // not a strict one-to-one copy. For example, GSL would sort the - // result. - double a; - double b; - double c; - double disc; - - c = eqn[0]; - b = eqn[1]; - a = eqn[2]; - - // Check for linear or constant functions. This is not done by the - // GNU Scientific Library. Without this special check, we - // wouldn't return -1 for constant functions, and 2 instead of 1 - // for linear functions. - if (a == 0) - { - if (b == 0) - return -1; - - res[0] = -c / b; - return 1; - } - - disc = b * b - 4 * a * c; - - if (disc < 0) - return 0; - - if (disc == 0) - { - // The GNU Scientific Library returns two identical results here. - // We just return one. - res[0] = -0.5 * b / a; - return 1; - } - - // disc > 0 - if (b == 0) - { - double r; - - r = Math.abs(0.5 * Math.sqrt(disc) / a); - res[0] = -r; - res[1] = r; - } - else - { - double sgnb; - double temp; - - sgnb = (b > 0 ? 1 : -1); - temp = -0.5 * (b + sgnb * Math.sqrt(disc)); - - // The GNU Scientific Library sorts the result here. We don't. - res[0] = temp / a; - res[1] = c / temp; - } - return 2; - } - - /** - * Determines whether a point is inside the area bounded - * by the curve and the straight line connecting its end points. - * - * <p><img src="doc-files/QuadCurve2D-5.png" width="350" height="180" - * alt="A drawing of the area spanned by the curve" /> - * - * <p>The above drawing illustrates in which area points are - * considered “inside” a QuadCurve2D. - */ - public boolean contains(double x, double y) - { - if (! getBounds2D().contains(x, y)) - return false; - - return ((getAxisIntersections(x, y, true, BIG_VALUE) & 1) != 0); - } - - /** - * Determines whether a point is inside the area bounded - * by the curve and the straight line connecting its end points. - * - * <p><img src="doc-files/QuadCurve2D-5.png" width="350" height="180" - * alt="A drawing of the area spanned by the curve" /> - * - * <p>The above drawing illustrates in which area points are - * considered “inside” a QuadCurve2D. - */ - public boolean contains(Point2D p) - { - return contains(p.getX(), p.getY()); - } - - /** - * Determines whether any part of a rectangle is inside the area bounded - * by the curve and the straight line connecting its end points. - * - * <p><img src="doc-files/QuadCurve2D-5.png" width="350" height="180" - * alt="A drawing of the area spanned by the curve" /> - * - * <p>The above drawing illustrates in which area points are - * considered “inside” in a CubicCurve2D. - */ - public boolean intersects(double x, double y, double w, double h) - { - if (! getBounds2D().contains(x, y, w, h)) - return false; - - /* Does any edge intersect? */ - if (getAxisIntersections(x, y, true, w) != 0 /* top */ - || getAxisIntersections(x, y + h, true, w) != 0 /* bottom */ - || getAxisIntersections(x + w, y, false, h) != 0 /* right */ - || getAxisIntersections(x, y, false, h) != 0) /* left */ - return true; - - /* No intersections, is any point inside? */ - if ((getAxisIntersections(x, y, true, BIG_VALUE) & 1) != 0) - return true; - - return false; - } - - /** - * Determines whether any part of a Rectangle2D is inside the area bounded - * by the curve and the straight line connecting its end points. - * @see #intersects(double, double, double, double) - */ - public boolean intersects(Rectangle2D r) - { - return intersects(r.getX(), r.getY(), r.getWidth(), r.getHeight()); - } - - /** - * Determines whether a rectangle is entirely inside the area bounded - * by the curve and the straight line connecting its end points. - * - * <p><img src="doc-files/QuadCurve2D-5.png" width="350" height="180" - * alt="A drawing of the area spanned by the curve" /> - * - * <p>The above drawing illustrates in which area points are - * considered “inside” a QuadCurve2D. - * @see #contains(double, double) - */ - public boolean contains(double x, double y, double w, double h) - { - if (! getBounds2D().intersects(x, y, w, h)) - return false; - - /* Does any edge intersect? */ - if (getAxisIntersections(x, y, true, w) != 0 /* top */ - || getAxisIntersections(x, y + h, true, w) != 0 /* bottom */ - || getAxisIntersections(x + w, y, false, h) != 0 /* right */ - || getAxisIntersections(x, y, false, h) != 0) /* left */ - return false; - - /* No intersections, is any point inside? */ - if ((getAxisIntersections(x, y, true, BIG_VALUE) & 1) != 0) - return true; - - return false; - } - - /** - * Determines whether a Rectangle2D is entirely inside the area that is - * bounded by the curve and the straight line connecting its end points. - * @see #contains(double, double, double, double) - */ - public boolean contains(Rectangle2D r) - { - return contains(r.getX(), r.getY(), r.getWidth(), r.getHeight()); - } - - /** - * Determines the smallest rectangle that encloses the - * curve’s start, end and control point. As the illustration - * below shows, the invisible control point may cause the bounds to - * be much larger than the area that is actually covered by the - * curve. - * - * <p><img src="doc-files/QuadCurve2D-2.png" width="350" height="180" - * alt="An illustration of the bounds of a QuadCurve2D" /> - */ - public Rectangle getBounds() - { - return getBounds2D().getBounds(); - } - - public PathIterator getPathIterator(final AffineTransform at) - { - return new PathIterator() - { - /** Current coordinate. */ - private int current = 0; - - public int getWindingRule() - { - return WIND_NON_ZERO; - } - - public boolean isDone() - { - return current >= 2; - } - - public void next() - { - current++; - } - - public int currentSegment(float[] coords) - { - int result; - switch (current) - { - case 0: - coords[0] = (float) getX1(); - coords[1] = (float) getY1(); - result = SEG_MOVETO; - break; - case 1: - coords[0] = (float) getCtrlX(); - coords[1] = (float) getCtrlY(); - coords[2] = (float) getX2(); - coords[3] = (float) getY2(); - result = SEG_QUADTO; - break; - default: - throw new NoSuchElementException("quad iterator out of bounds"); - } - if (at != null) - at.transform(coords, 0, coords, 0, 2); - return result; - } - - public int currentSegment(double[] coords) - { - int result; - switch (current) - { - case 0: - coords[0] = getX1(); - coords[1] = getY1(); - result = SEG_MOVETO; - break; - case 1: - coords[0] = getCtrlX(); - coords[1] = getCtrlY(); - coords[2] = getX2(); - coords[3] = getY2(); - result = SEG_QUADTO; - break; - default: - throw new NoSuchElementException("quad iterator out of bounds"); - } - if (at != null) - at.transform(coords, 0, coords, 0, 2); - return result; - } - }; - } - - public PathIterator getPathIterator(AffineTransform at, double flatness) - { - return new FlatteningPathIterator(getPathIterator(at), flatness); - } - - /** - * Creates a new curve with the same contents as this one. - * - * @return the clone. - */ - public Object clone() - { - try - { - return super.clone(); - } - catch (CloneNotSupportedException e) - { - throw (Error) new InternalError().initCause(e); // Impossible - } - } - - /** - * Helper method used by contains() and intersects() methods - * Return the number of curve/line intersections on a given axis - * extending from a certain point. useYaxis is true for using the Y axis, - * @param x x coordinate of the origin point - * @param y y coordinate of the origin point - * @param useYaxis axis to follow, if true the positive Y axis is used, - * false uses the positive X axis. - * - * This is an implementation of the line-crossings algorithm, - * Detailed in an article on Eric Haines' page: - * http://www.acm.org/tog/editors/erich/ptinpoly/ - */ - private int getAxisIntersections(double x, double y, boolean useYaxis, - double distance) - { - int nCrossings = 0; - double a0; - double a1; - double a2; - double b0; - double b1; - double b2; - double[] r = new double[3]; - int nRoots; - - a0 = a2 = 0.0; - - if (useYaxis) - { - a0 = getY1() - y; - a1 = getCtrlY() - y; - a2 = getY2() - y; - b0 = getX1() - x; - b1 = getCtrlX() - x; - b2 = getX2() - x; - } - else - { - a0 = getX1() - x; - a1 = getCtrlX() - x; - a2 = getX2() - x; - b0 = getY1() - y; - b1 = getCtrlY() - y; - b2 = getY2() - y; - } - - /* If the axis intersects a start/endpoint, shift it up by some small - amount to guarantee the line is 'inside' - If this is not done,bad behaviour may result for points on that axis. */ - if (a0 == 0.0 || a2 == 0.0) - { - double small = getFlatness() * EPSILON; - if (a0 == 0.0) - a0 -= small; - - if (a2 == 0.0) - a2 -= small; - } - - r[0] = a0; - r[1] = 2 * (a1 - a0); - r[2] = (a2 - 2 * a1 + a0); - - nRoots = solveQuadratic(r); - for (int i = 0; i < nRoots; i++) - { - double t = r[i]; - if (t >= 0.0 && t <= 1.0) - { - double crossing = t * t * (b2 - 2 * b1 + b0) + 2 * t * (b1 - b0) - + b0; - /* single root is always doubly degenerate in quads */ - if (crossing > 0 && crossing < distance) - nCrossings += (nRoots == 1) ? 2 : 1; - } - } - - if (useYaxis) - { - if (Line2D.linesIntersect(b0, a0, b2, a2, EPSILON, 0.0, distance, 0.0)) - nCrossings++; - } - else - { - if (Line2D.linesIntersect(a0, b0, a2, b2, 0.0, EPSILON, 0.0, distance)) - nCrossings++; - } - - return (nCrossings); - } - - /** - * A two-dimensional curve that is parameterized with a quadratic - * function and stores coordinate values in double-precision - * floating-point format. - * - * @see QuadCurve2D.Float - * - * @author Eric Blake (ebb9@email.byu.edu) - * @author Sascha Brawer (brawer@dandelis.ch) - */ - public static class Double extends QuadCurve2D - { - /** - * The <i>x</i> coordinate of the curve’s start point. - */ - public double x1; - - /** - * The <i>y</i> coordinate of the curve’s start point. - */ - public double y1; - - /** - * The <i>x</i> coordinate of the curve’s control point. - */ - public double ctrlx; - - /** - * The <i>y</i> coordinate of the curve’s control point. - */ - public double ctrly; - - /** - * The <i>x</i> coordinate of the curve’s end point. - */ - public double x2; - - /** - * The <i>y</i> coordinate of the curve’s end point. - */ - public double y2; - - /** - * Constructs a new QuadCurve2D that stores its coordinate values - * in double-precision floating-point format. All points are - * initially at position (0, 0). - */ - public Double() - { - } - - /** - * Constructs a new QuadCurve2D that stores its coordinate values - * in double-precision floating-point format, specifying the - * initial position of each point. - * - * @param x1 the <i>x</i> coordinate of the curve’s start - * point. - * - * @param y1 the <i>y</i> coordinate of the curve’s start - * point. - * - * @param cx the <i>x</i> coordinate of the curve’s control - * point. - * - * @param cy the <i>y</i> coordinate of the curve’s control - * point. - * - * @param x2 the <i>x</i> coordinate of the curve’s end - * point. - * - * @param y2 the <i>y</i> coordinate of the curve’s end - * point. - */ - public Double(double x1, double y1, double cx, double cy, double x2, - double y2) - { - this.x1 = x1; - this.y1 = y1; - ctrlx = cx; - ctrly = cy; - this.x2 = x2; - this.y2 = y2; - } - - /** - * Returns the <i>x</i> coordinate of the curve’s start - * point. - */ - public double getX1() - { - return x1; - } - - /** - * Returns the <i>y</i> coordinate of the curve’s start - * point. - */ - public double getY1() - { - return y1; - } - - /** - * Returns the curve’s start point. - */ - public Point2D getP1() - { - return new Point2D.Double(x1, y1); - } - - /** - * Returns the <i>x</i> coordinate of the curve’s control - * point. - */ - public double getCtrlX() - { - return ctrlx; - } - - /** - * Returns the <i>y</i> coordinate of the curve’s control - * point. - */ - public double getCtrlY() - { - return ctrly; - } - - /** - * Returns the curve’s control point. - */ - public Point2D getCtrlPt() - { - return new Point2D.Double(ctrlx, ctrly); - } - - /** - * Returns the <i>x</i> coordinate of the curve’s end - * point. - */ - public double getX2() - { - return x2; - } - - /** - * Returns the <i>y</i> coordinate of the curve’s end - * point. - */ - public double getY2() - { - return y2; - } - - /** - * Returns the curve’s end point. - */ - public Point2D getP2() - { - return new Point2D.Double(x2, y2); - } - - /** - * Changes the geometry of the curve. - * - * @param x1 the <i>x</i> coordinate of the curve’s new - * start point. - * - * @param y1 the <i>y</i> coordinate of the curve’s new - * start point. - * - * @param cx the <i>x</i> coordinate of the curve’s new - * control point. - * - * @param cy the <i>y</i> coordinate of the curve’s new - * control point. - * - * @param x2 the <i>x</i> coordinate of the curve’s new - * end point. - * - * @param y2 the <i>y</i> coordinate of the curve’s new - * end point. - */ - public void setCurve(double x1, double y1, double cx, double cy, - double x2, double y2) - { - this.x1 = x1; - this.y1 = y1; - ctrlx = cx; - ctrly = cy; - this.x2 = x2; - this.y2 = y2; - } - - /** - * Determines the smallest rectangle that encloses the - * curve’s start, end and control point. As the - * illustration below shows, the invisible control point may cause - * the bounds to be much larger than the area that is actually - * covered by the curve. - * - * <p><img src="doc-files/QuadCurve2D-2.png" width="350" height="180" - * alt="An illustration of the bounds of a QuadCurve2D" /> - */ - public Rectangle2D getBounds2D() - { - double nx1 = Math.min(Math.min(x1, ctrlx), x2); - double ny1 = Math.min(Math.min(y1, ctrly), y2); - double nx2 = Math.max(Math.max(x1, ctrlx), x2); - double ny2 = Math.max(Math.max(y1, ctrly), y2); - return new Rectangle2D.Double(nx1, ny1, nx2 - nx1, ny2 - ny1); - } - } - - /** - * A two-dimensional curve that is parameterized with a quadratic - * function and stores coordinate values in single-precision - * floating-point format. - * - * @see QuadCurve2D.Double - * - * @author Eric Blake (ebb9@email.byu.edu) - * @author Sascha Brawer (brawer@dandelis.ch) - */ - public static class Float extends QuadCurve2D - { - /** - * The <i>x</i> coordinate of the curve’s start point. - */ - public float x1; - - /** - * The <i>y</i> coordinate of the curve’s start point. - */ - public float y1; - - /** - * The <i>x</i> coordinate of the curve’s control point. - */ - public float ctrlx; - - /** - * The <i>y</i> coordinate of the curve’s control point. - */ - public float ctrly; - - /** - * The <i>x</i> coordinate of the curve’s end point. - */ - public float x2; - - /** - * The <i>y</i> coordinate of the curve’s end point. - */ - public float y2; - - /** - * Constructs a new QuadCurve2D that stores its coordinate values - * in single-precision floating-point format. All points are - * initially at position (0, 0). - */ - public Float() - { - } - - /** - * Constructs a new QuadCurve2D that stores its coordinate values - * in single-precision floating-point format, specifying the - * initial position of each point. - * - * @param x1 the <i>x</i> coordinate of the curve’s start - * point. - * - * @param y1 the <i>y</i> coordinate of the curve’s start - * point. - * - * @param cx the <i>x</i> coordinate of the curve’s control - * point. - * - * @param cy the <i>y</i> coordinate of the curve’s control - * point. - * - * @param x2 the <i>x</i> coordinate of the curve’s end - * point. - * - * @param y2 the <i>y</i> coordinate of the curve’s end - * point. - */ - public Float(float x1, float y1, float cx, float cy, float x2, float y2) - { - this.x1 = x1; - this.y1 = y1; - ctrlx = cx; - ctrly = cy; - this.x2 = x2; - this.y2 = y2; - } - - /** - * Returns the <i>x</i> coordinate of the curve’s start - * point. - */ - public double getX1() - { - return x1; - } - - /** - * Returns the <i>y</i> coordinate of the curve’s start - * point. - */ - public double getY1() - { - return y1; - } - - /** - * Returns the curve’s start point. - */ - public Point2D getP1() - { - return new Point2D.Float(x1, y1); - } - - /** - * Returns the <i>x</i> coordinate of the curve’s control - * point. - */ - public double getCtrlX() - { - return ctrlx; - } - - /** - * Returns the <i>y</i> coordinate of the curve’s control - * point. - */ - public double getCtrlY() - { - return ctrly; - } - - /** - * Returns the curve’s control point. - */ - public Point2D getCtrlPt() - { - return new Point2D.Float(ctrlx, ctrly); - } - - /** - * Returns the <i>x</i> coordinate of the curve’s end - * point. - */ - public double getX2() - { - return x2; - } - - /** - * Returns the <i>y</i> coordinate of the curve’s end - * point. - */ - public double getY2() - { - return y2; - } - - /** - * Returns the curve’s end point. - */ - public Point2D getP2() - { - return new Point2D.Float(x2, y2); - } - - /** - * Changes the geometry of the curve, specifying coordinate values - * as double-precision floating-point numbers. - * - * @param x1 the <i>x</i> coordinate of the curve’s new - * start point. - * - * @param y1 the <i>y</i> coordinate of the curve’s new - * start point. - * - * @param cx the <i>x</i> coordinate of the curve’s new - * control point. - * - * @param cy the <i>y</i> coordinate of the curve’s new - * control point. - * - * @param x2 the <i>x</i> coordinate of the curve’s new - * end point. - * - * @param y2 the <i>y</i> coordinate of the curve’s new - * end point. - */ - public void setCurve(double x1, double y1, double cx, double cy, - double x2, double y2) - { - this.x1 = (float) x1; - this.y1 = (float) y1; - ctrlx = (float) cx; - ctrly = (float) cy; - this.x2 = (float) x2; - this.y2 = (float) y2; - } - - /** - * Changes the geometry of the curve, specifying coordinate values - * as single-precision floating-point numbers. - * - * @param x1 the <i>x</i> coordinate of the curve’s new - * start point. - * - * @param y1 the <i>y</i> coordinate of the curve’s new - * start point. - * - * @param cx the <i>x</i> coordinate of the curve’s new - * control point. - * - * @param cy the <i>y</i> coordinate of the curve’s new - * control point. - * - * @param x2 the <i>x</i> coordinate of the curve’s new - * end point. - * - * @param y2 the <i>y</i> coordinate of the curve’s new - * end point. - */ - public void setCurve(float x1, float y1, float cx, float cy, float x2, - float y2) - { - this.x1 = x1; - this.y1 = y1; - ctrlx = cx; - ctrly = cy; - this.x2 = x2; - this.y2 = y2; - } - - /** - * Determines the smallest rectangle that encloses the - * curve’s start, end and control point. As the - * illustration below shows, the invisible control point may cause - * the bounds to be much larger than the area that is actually - * covered by the curve. - * - * <p><img src="doc-files/QuadCurve2D-2.png" width="350" height="180" - * alt="An illustration of the bounds of a QuadCurve2D" /> - */ - public Rectangle2D getBounds2D() - { - float nx1 = (float) Math.min(Math.min(x1, ctrlx), x2); - float ny1 = (float) Math.min(Math.min(y1, ctrly), y2); - float nx2 = (float) Math.max(Math.max(x1, ctrlx), x2); - float ny2 = (float) Math.max(Math.max(y1, ctrly), y2); - return new Rectangle2D.Float(nx1, ny1, nx2 - nx1, ny2 - ny1); - } - } -} |
