| /* PathIterator.java -- describes a shape by iterating over its vertices |
| Copyright (C) 2000, 2002, 2003 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; |
| |
| /** |
| * This interface provides a directed path over the boundary of a shape. The |
| * path can contain 1st through 3rd order Bezier curves (lines, and quadratic |
| * and cubic splines). A shape can have multiple disjoint paths via the |
| * MOVETO directive, and can close a circular path back to the previos |
| * MOVETO via the CLOSE directive. |
| * |
| * @author Tom Tromey (tromey@cygnus.com) |
| * @author Eric Blake (ebb9@email.byu.edu) |
| * @see java.awt.Shape |
| * @see java.awt.Stroke |
| * @see FlatteningPathIterator |
| * @since 1.2 |
| * @status updated to 1.4 |
| */ |
| public interface PathIterator |
| { |
| /** |
| * The even-odd winding mode: a point is internal to the shape if a ray |
| * from the point to infinity (in any direction) crosses an odd number of |
| * segments. |
| */ |
| int WIND_EVEN_ODD = 0; |
| |
| /** |
| * The non-zero winding mode: a point is internal to the shape if a ray |
| * from the point to infinity (in any direction) crosses a different number |
| * of segments headed clockwise than those headed counterclockwise. |
| */ |
| int WIND_NON_ZERO = 1; |
| |
| /** |
| * Starts a new subpath. There is no segment from the previous vertex. |
| */ |
| int SEG_MOVETO = 0; |
| |
| /** |
| * The current segment is a line. |
| */ |
| int SEG_LINETO = 1; |
| |
| /** |
| * The current segment is a quadratic parametric curve. It is interpolated |
| * as t varies from 0 to 1 over the current point (CP), first control point |
| * (P1), and final interpolated control point (P2): |
| * <pre> |
| * P(t) = B(2,0)*CP + B(2,1)*P1 + B(2,2)*P2 |
| * 0 <= t <= 1 |
| * B(n,m) = mth coefficient of nth degree Bernstein polynomial |
| * = C(n,m) * t^(m) * (1 - t)^(n-m) |
| * C(n,m) = Combinations of n things, taken m at a time |
| * = n! / (m! * (n-m)!) |
| * </pre> |
| */ |
| int SEG_QUADTO = 2; |
| |
| /** |
| * The current segment is a cubic parametric curve (more commonly known as |
| * a Bezier curve). It is interpolated as t varies from 0 to 1 over the |
| * current point (CP), first control point (P1), the second control point |
| * (P2), and final interpolated control point (P3): |
| * <pre> |
| * P(t) = B(3,0)*CP + B(3,1)*P1 + B(3,2)*P2 + B(3,3)*P3 |
| * 0 <= t <= 1 |
| * B(n,m) = mth coefficient of nth degree Bernstein polynomial |
| * = C(n,m) * t^(m) * (1 - t)^(n-m) |
| * C(n,m) = Combinations of n things, taken m at a time |
| * = n! / (m! * (n-m)!) |
| * </pre> |
| */ |
| int SEG_CUBICTO = 3; |
| |
| /** |
| * The current segment closes a loop by an implicit line to the previous |
| * SEG_MOVETO coordinate. |
| */ |
| int SEG_CLOSE = 4; |
| |
| /** |
| * Returns the winding rule to determine which points are inside this path. |
| * |
| * @return the winding rule |
| * @see #WIND_EVEN_ODD |
| * @see #WIND_NON_ZERO |
| */ |
| int getWindingRule(); |
| |
| /** |
| * Tests if the iterator is exhausted. If this returns true, currentSegment |
| * and next may throw a NoSuchElementException (although this is not |
| * required). |
| * |
| * @return true if the iteration is complete |
| */ |
| boolean isDone(); |
| |
| /** |
| * Advance to the next segment in the iteration. It is not specified what |
| * this does if called when isDone() returns true. |
| * |
| * @throws java.util.NoSuchElementException optional when isDone() is true |
| */ |
| void next(); |
| |
| /** |
| * Returns the coordinates of the next point(s), as well as the type of |
| * line segment. The input array must be at least a float[6], to accomodate |
| * up to three (x,y) point pairs (although if you know the iterator is |
| * flat, you can probably get by with a float[2]). If the returned type is |
| * SEG_MOVETO or SEG_LINETO, the first point in the array is modified; if |
| * the returned type is SEG_QUADTO, the first two points are modified; if |
| * the returned type is SEG_CUBICTO, all three points are modified; and if |
| * the returned type is SEG_CLOSE, the array is untouched. |
| * |
| * @param coords the array to place the point coordinates in |
| * @return the segment type |
| * @throws NullPointerException if coords is null |
| * @throws ArrayIndexOutOfBoundsException if coords is too small |
| * @throws java.util.NoSuchElementException optional when isDone() is true |
| * @see #SEG_MOVETO |
| * @see #SEG_LINETO |
| * @see #SEG_QUADTO |
| * @see #SEG_CUBICTO |
| * @see #SEG_CLOSE |
| */ |
| int currentSegment(float[] coords); |
| |
| /** |
| * Returns the coordinates of the next point(s), as well as the type of |
| * line segment. The input array must be at least a double[6], to accomodate |
| * up to three (x,y) point pairs (although if you know the iterator is |
| * flat, you can probably get by with a double[2]). If the returned type is |
| * SEG_MOVETO or SEG_LINETO, the first point in the array is modified; if |
| * the returned type is SEG_QUADTO, the first two points are modified; if |
| * the returned type is SEG_CUBICTO, all three points are modified; and if |
| * the returned type is SEG_CLOSE, the array is untouched. |
| * |
| * @param coords the array to place the point coordinates in |
| * @return the segment type |
| * @throws NullPointerException if coords is null |
| * @throws ArrayIndexOutOfBoundsException if coords is too small |
| * @throws java.util.NoSuchElementException optional when isDone() is true |
| * @see #SEG_MOVETO |
| * @see #SEG_LINETO |
| * @see #SEG_QUADTO |
| * @see #SEG_CUBICTO |
| * @see #SEG_CLOSE |
| */ |
| int currentSegment(double[] coords); |
| } // interface PathIterator |
