RadialGradientPaint.java revision 2965
2965N/A * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved. 0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 0N/A * This code is free software; you can redistribute it and/or modify it 0N/A * under the terms of the GNU General Public License version 2 only, as 2362N/A * published by the Free Software Foundation. Oracle designates this 0N/A * particular file as subject to the "Classpath" exception as provided 2362N/A * by Oracle in the LICENSE file that accompanied this code. 0N/A * This code is distributed in the hope that it will be useful, but WITHOUT 0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 0N/A * version 2 for more details (a copy is included in the LICENSE file that 0N/A * accompanied this code). 0N/A * You should have received a copy of the GNU General Public License version 0N/A * 2 along with this work; if not, write to the Free Software Foundation, 0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 2362N/A * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 2362N/A * or visit www.oracle.com if you need additional information or have any 0N/A * The {@code RadialGradientPaint} class provides a way to fill a shape with 0N/A * a circular radial color gradient pattern. The user may specify 2 or more 0N/A * gradient colors, and this paint will provide an interpolation between 0N/A * The user must specify the circle controlling the gradient pattern, 0N/A * which is described by a center point and a radius. The user can also 0N/A * specify a separate focus point within that circle, which controls the 0N/A * location of the first color of the gradient. By default the focus is 0N/A * set to be the center of the circle. 0N/A * This paint will map the first color of the gradient to the focus point, 0N/A * and the last color to the perimeter of the circle, interpolating 0N/A * smoothly for any in-between colors specified by the user. Any line drawn 0N/A * from the focus point to the circumference will thus span all the gradient 0N/A * Specifying a focus point outside of the circle's radius will result in the 0N/A * focus being set to the intersection point of the focus-center line and the 0N/A * perimeter of the circle. 0N/A * The user must provide an array of floats specifying how to distribute the 0N/A * colors along the gradient. These values should range from 0.0 to 1.0 and 0N/A * act like keyframes along the gradient (they mark where the gradient should 0N/A * be exactly a particular color). 0N/A * In the event that the user does not set the first keyframe value equal 0N/A * to 0 and/or the last keyframe value equal to 1, keyframes will be created 0N/A * at these positions and the first and last colors will be replicated there. 0N/A * So, if a user specifies the following arrays to construct a gradient:<br> 0N/A * {Color.BLUE, Color.RED}, {.3f, .7f} 0N/A * this will be converted to a gradient with the following keyframes:<br> 0N/A * {Color.BLUE, Color.BLUE, Color.RED, Color.RED}, {0f, .3f, .7f, 1f} 0N/A * The user may also select what action the {@code RadialGradientPaint} 0N/A * should take when filling color outside the bounds of the circle's radius. 0N/A * If no cycle method is specified, {@code NO_CYCLE} will be chosen by 0N/A * default, which means the the last keyframe color will be used to fill the 0N/A * The colorSpace parameter allows the user to specify in which colorspace 0N/A * the interpolation should be performed, default sRGB or linearized RGB. 0N/A * The following code demonstrates typical usage of 0N/A * {@code RadialGradientPaint}, where the center and focus points are 0N/A * Point2D center = new Point2D.Float(50, 50); 0N/A * float radius = 25; 0N/A * float[] dist = {0.0f, 0.2f, 1.0f}; 0N/A * Color[] colors = {Color.RED, Color.WHITE, Color.BLUE}; 0N/A * RadialGradientPaint p = 0N/A * new RadialGradientPaint(center, radius, dist, colors); 0N/A * This image demonstrates the example code above, with default 0N/A * (centered) focus for each of the three cycle methods: 0N/A * It is also possible to specify a non-centered focus point, as 0N/A * in the following code: 0N/A * Point2D center = new Point2D.Float(50, 50); 0N/A * float radius = 25; 0N/A * Point2D focus = new Point2D.Float(40, 40); 0N/A * float[] dist = {0.0f, 0.2f, 1.0f}; 0N/A * Color[] colors = {Color.RED, Color.WHITE, Color.BLUE}; 0N/A * RadialGradientPaint p = 0N/A * new RadialGradientPaint(center, radius, focus, 0N/A * CycleMethod.NO_CYCLE); 0N/A * This image demonstrates the previous example code, with non-centered 0N/A * focus for each of the three cycle methods: 0N/A * @see java.awt.Paint 0N/A * @see java.awt.Graphics2D#setPaint 0N/A * @author Nicholas Talian, Vincent Hardy, Jim Graham, Jerry Evans 0N/A /** Focus point which defines the 0% gradient stop X coordinate. */ 0N/A /** Center of the circle defining the 100% gradient stop X coordinate. */ 0N/A /** Radius of the outermost circle defining the 100% gradient stop. */ 0N/A * Constructs a {@code RadialGradientPaint} with a default 0N/A * {@code NO_CYCLE} repeating method and {@code SRGB} color space, 0N/A * using the center as the focus point. 0N/A * @param cx the X coordinate in user space of the center point of the 0N/A * circle defining the gradient. The last color of the 0N/A * gradient is mapped to the perimeter of this circle. 0N/A * @param cy the Y coordinate in user space of the center point of the 0N/A * circle defining the gradient. The last color of the 0N/A * gradient is mapped to the perimeter of this circle. 0N/A * @param radius the radius of the circle defining the extents of the 0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the 0N/A * distribution of colors along the gradient 0N/A * @param colors array of colors to use in the gradient. The first color 0N/A * is used at the focus point, the last color around the 0N/A * perimeter of the circle. 0N/A * @throws NullPointerException 0N/A * if {@code fractions} array is null, 0N/A * or {@code colors} array is null 0N/A * @throws IllegalArgumentException 0N/A * if {@code radius} is non-positive, 0N/A * or {@code fractions.length != colors.length}, 0N/A * or {@code colors} is less than 2 in size, 0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0, 0N/A * or the {@code fractions} are not provided in strictly increasing order 0N/A * Constructs a {@code RadialGradientPaint} with a default 0N/A * {@code NO_CYCLE} repeating method and {@code SRGB} color space, 0N/A * using the center as the focus point. 0N/A * @param center the center point, in user space, of the circle defining 0N/A * @param radius the radius of the circle defining the extents of the 0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the 0N/A * distribution of colors along the gradient 0N/A * @param colors array of colors to use in the gradient. The first color 0N/A * is used at the focus point, the last color around the 0N/A * perimeter of the circle. 0N/A * @throws NullPointerException 0N/A * if {@code center} point is null, 0N/A * or {@code fractions} array is null, 0N/A * or {@code colors} array is null 0N/A * @throws IllegalArgumentException 0N/A * if {@code radius} is non-positive, 0N/A * or {@code fractions.length != colors.length}, 0N/A * or {@code colors} is less than 2 in size, 0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0, 0N/A * or the {@code fractions} are not provided in strictly increasing order 0N/A * Constructs a {@code RadialGradientPaint} with a default 0N/A * {@code SRGB} color space, using the center as the focus point. 0N/A * @param cx the X coordinate in user space of the center point of the 0N/A * circle defining the gradient. The last color of the 0N/A * gradient is mapped to the perimeter of this circle. 0N/A * @param cy the Y coordinate in user space of the center point of the 0N/A * circle defining the gradient. The last color of the 0N/A * gradient is mapped to the perimeter of this circle. 0N/A * @param radius the radius of the circle defining the extents of the 0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the 0N/A * distribution of colors along the gradient 0N/A * @param colors array of colors to use in the gradient. The first color 0N/A * is used at the focus point, the last color around the 0N/A * perimeter of the circle. 0N/A * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, 0N/A * @throws NullPointerException 0N/A * if {@code fractions} array is null, 0N/A * or {@code colors} array is null, 0N/A * or {@code cycleMethod} is null 0N/A * @throws IllegalArgumentException 0N/A * if {@code radius} is non-positive, 0N/A * or {@code fractions.length != colors.length}, 0N/A * or {@code colors} is less than 2 in size, 0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0, 0N/A * or the {@code fractions} are not provided in strictly increasing order 0N/A * Constructs a {@code RadialGradientPaint} with a default 0N/A * {@code SRGB} color space, using the center as the focus point. 0N/A * @param center the center point, in user space, of the circle defining 0N/A * @param radius the radius of the circle defining the extents of the 0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the 0N/A * distribution of colors along the gradient 0N/A * @param colors array of colors to use in the gradient. The first color 0N/A * is used at the focus point, the last color around the 0N/A * perimeter of the circle. 0N/A * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, 0N/A * @throws NullPointerException 0N/A * if {@code center} point is null, 0N/A * or {@code fractions} array is null, 0N/A * or {@code colors} array is null, 0N/A * or {@code cycleMethod} is null 0N/A * @throws IllegalArgumentException 0N/A * if {@code radius} is non-positive, 0N/A * or {@code fractions.length != colors.length}, 0N/A * or {@code colors} is less than 2 in size, 0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0, 0N/A * or the {@code fractions} are not provided in strictly increasing order 0N/A * Constructs a {@code RadialGradientPaint} with a default 0N/A * {@code SRGB} color space. 0N/A * @param cx the X coordinate in user space of the center point of the 0N/A * circle defining the gradient. The last color of the 0N/A * gradient is mapped to the perimeter of this circle. 0N/A * @param cy the Y coordinate in user space of the center point of the 0N/A * circle defining the gradient. The last color of the 0N/A * gradient is mapped to the perimeter of this circle. 0N/A * @param radius the radius of the circle defining the extents of the 0N/A * @param fx the X coordinate of the point in user space to which the 0N/A * first color is mapped 0N/A * @param fy the Y coordinate of the point in user space to which the 0N/A * first color is mapped 0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the 0N/A * distribution of colors along the gradient 0N/A * @param colors array of colors to use in the gradient. The first color 0N/A * is used at the focus point, the last color around the 0N/A * perimeter of the circle. 0N/A * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, 0N/A * @throws NullPointerException 0N/A * if {@code fractions} array is null, 0N/A * or {@code colors} array is null, 0N/A * or {@code cycleMethod} is null 0N/A * @throws IllegalArgumentException 0N/A * if {@code radius} is non-positive, 0N/A * or {@code fractions.length != colors.length}, 0N/A * or {@code colors} is less than 2 in size, 0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0, 0N/A * or the {@code fractions} are not provided in strictly increasing order 0N/A * Constructs a {@code RadialGradientPaint} with a default 0N/A * {@code SRGB} color space. 0N/A * @param center the center point, in user space, of the circle defining 0N/A * the gradient. The last color of the gradient is mapped 0N/A * to the perimeter of this circle. 0N/A * @param radius the radius of the circle defining the extents of the color 0N/A * @param focus the point in user space to which the first color is mapped 0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the 0N/A * distribution of colors along the gradient 0N/A * @param colors array of colors to use in the gradient. The first color 0N/A * is used at the focus point, the last color around the 0N/A * perimeter of the circle. 0N/A * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, 0N/A * @throws NullPointerException 0N/A * if one of the points is null, 0N/A * or {@code fractions} array is null, 0N/A * or {@code colors} array is null, 0N/A * or {@code cycleMethod} is null 0N/A * @throws IllegalArgumentException 0N/A * if {@code radius} is non-positive, 0N/A * or {@code fractions.length != colors.length}, 0N/A * or {@code colors} is less than 2 in size, 0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0, 0N/A * or the {@code fractions} are not provided in strictly increasing order 0N/A * Constructs a {@code RadialGradientPaint}. 0N/A * @param center the center point in user space of the circle defining the 0N/A * gradient. The last color of the gradient is mapped to 0N/A * the perimeter of this circle. 0N/A * @param radius the radius of the circle defining the extents of the 0N/A * @param focus the point in user space to which the first color is mapped 0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the 0N/A * distribution of colors along the gradient 0N/A * @param colors array of colors to use in the gradient. The first color 0N/A * is used at the focus point, the last color around the 0N/A * perimeter of the circle. 0N/A * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, 0N/A * @param colorSpace which color space to use for interpolation, 0N/A * either {@code SRGB} or {@code LINEAR_RGB} 0N/A * @param gradientTransform transform to apply to the gradient 0N/A * @throws NullPointerException 0N/A * if one of the points is null, 0N/A * or {@code fractions} array is null, 0N/A * or {@code colors} array is null, 0N/A * or {@code cycleMethod} is null, 0N/A * or {@code colorSpace} is null, 0N/A * or {@code gradientTransform} is null 0N/A * @throws IllegalArgumentException 0N/A * if {@code radius} is non-positive, 0N/A * or {@code fractions.length != colors.length}, 0N/A * or {@code colors} is less than 2 in size, 0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0, 0N/A * or the {@code fractions} are not provided in strictly increasing order 0N/A // check input arguments 0N/A * Constructs a {@code RadialGradientPaint} with a default 0N/A * {@code SRGB} color space. 0N/A * The gradient circle of the {@code RadialGradientPaint} is defined 0N/A * by the given bounding box. 0N/A * This constructor is a more convenient way to express the 0N/A * following (equivalent) code:<br> 0N/A * double gw = gradientBounds.getWidth(); 0N/A * double gh = gradientBounds.getHeight(); 0N/A * double cx = gradientBounds.getCenterX(); 0N/A * double cy = gradientBounds.getCenterY(); 0N/A * Point2D center = new Point2D.Double(cx, cy); 0N/A * AffineTransform gradientTransform = new AffineTransform(); 0N/A * gradientTransform.translate(cx, cy); 0N/A * gradientTransform.scale(gw / 2, gh / 2); 0N/A * gradientTransform.translate(-cx, -cy); 0N/A * RadialGradientPaint gp = 0N/A * new RadialGradientPaint(center, 1.0f, center, 0N/A * fractions, colors, 0N/A * ColorSpaceType.SRGB, 0N/A * gradientTransform); 0N/A * @param gradientBounds the bounding box, in user space, of the circle 0N/A * defining the outermost extent of the gradient 0N/A * @param fractions numbers ranging from 0.0 to 1.0 specifying the 0N/A * distribution of colors along the gradient 0N/A * @param colors array of colors to use in the gradient. The first color 0N/A * is used at the focus point, the last color around the 0N/A * perimeter of the circle. 0N/A * @param cycleMethod either {@code NO_CYCLE}, {@code REFLECT}, 0N/A * @throws NullPointerException 0N/A * if {@code gradientBounds} is null, 0N/A * or {@code fractions} array is null, 0N/A * or {@code colors} array is null, 0N/A * or {@code cycleMethod} is null 0N/A * @throws IllegalArgumentException 0N/A * if {@code gradientBounds} is empty, 0N/A * or {@code fractions.length != colors.length}, 0N/A * or {@code colors} is less than 2 in size, 0N/A * or a {@code fractions} value is less than 0.0 or greater than 1.0, 0N/A * or the {@code fractions} are not provided in strictly increasing order 0N/A // radius is set to 1.0, and then we set a scale transform 0N/A // to achieve an elliptical gradient defined by the bounding box 213N/A * Creates and returns a {@link PaintContext} used to 213N/A * generate a circular radial color gradient pattern. 213N/A * See the description of the {@link Paint#createContext createContext} method 213N/A * for information on null parameter handling. 213N/A * @param cm the preferred {@link ColorModel} which represents the most convenient 213N/A * format for the caller to receive the pixel data, or {@code null} 213N/A * if there is no preference. 213N/A * @param deviceBounds the device space bounding box 213N/A * of the graphics primitive being rendered. 213N/A * @param userBounds the user space bounding box 213N/A * of the graphics primitive being rendered. 213N/A * @param transform the {@link AffineTransform} from user 213N/A * space into device space. 213N/A * @param hints the set of hints that the context object can use to 213N/A * choose between rendering alternatives. 213N/A * @return the {@code PaintContext} for 213N/A * generating color patterns. 0N/A // avoid modifying the user's transform... 0N/A // incorporate the gradient transform 0N/A * Returns a copy of the center point of the radial gradient. 0N/A * @return a {@code Point2D} object that is a copy of the center point 0N/A * Returns a copy of the end point of the gradient axis. 0N/A * @return a {@code Point2D} object that is a copy of the focus point 0N/A * Returns the radius of the circle defining the radial gradient. 0N/A * @return the radius of the circle defining the radial gradient