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Diffstat (limited to 'src/main/java/com/kitfox/svg/batik/LinearGradientPaint.java')
| -rw-r--r-- | src/main/java/com/kitfox/svg/batik/LinearGradientPaint.java | 354 |
1 files changed, 354 insertions, 0 deletions
diff --git a/src/main/java/com/kitfox/svg/batik/LinearGradientPaint.java b/src/main/java/com/kitfox/svg/batik/LinearGradientPaint.java new file mode 100644 index 0000000..50ff7cc --- /dev/null +++ b/src/main/java/com/kitfox/svg/batik/LinearGradientPaint.java @@ -0,0 +1,354 @@ +/*****************************************************************************
+ * Copyright (C) The Apache Software Foundation. All rights reserved. *
+ * ------------------------------------------------------------------------- *
+ * This software is published under the terms of the Apache Software License *
+ * version 1.1, a copy of which has been included with this distribution in *
+ * the LICENSE file. *
+ *****************************************************************************/
+
+package com.kitfox.svg.batik;
+
+import java.awt.Color;
+import java.awt.PaintContext;
+import java.awt.Rectangle;
+import java.awt.RenderingHints;
+import java.awt.geom.AffineTransform;
+import java.awt.geom.NoninvertibleTransformException;
+import java.awt.geom.Point2D;
+import java.awt.geom.Rectangle2D;
+import java.awt.image.ColorModel;
+
+/**
+ * The <code>LinearGradientPaint</code> class provides a way to fill
+ * a {@link java.awt.Shape} with a linear color gradient pattern. The user may
+ * specify 2 or more gradient colors, and this paint will provide an
+ * interpolation between each color. The user also specifies start and end
+ * points which define where in user space the color gradient should begin
+ * and end.
+ * <p>
+ * The user must provide an array of floats specifying how to distribute the
+ * colors along the gradient. These values should range from 0.0 to 1.0 and
+ * act like keyframes along the gradient (they mark where the gradient should
+ * be exactly a particular color).
+ * <p>
+ * For example:
+ * <br>
+ * <code>
+ * <p>
+ * Point2D start = new Point2D.Float(0, 0);<br>
+ * Point2D end = new Point2D.Float(100,100);<br>
+ * float[] dist = {0.0, 0.2, 1.0};<br>
+ * Color[] colors = {Color.red, Color.white, Color.blue};<br>
+ * LinearGradientPaint p = new LinearGradientPaint(start, end, dist, colors);
+ * </code>
+ *<p>
+ * This code will create a LinearGradientPaint which interpolates between
+ * red and white for the first 20% of the gradient and between white and blue
+ * for the remaining 80%.
+ *
+ * <p> In the event that the user does not set the first keyframe value equal
+ * to 0 and the last keyframe value equal to 1, keyframes will be created at
+ * these positions and the first and last colors will be replicated there.
+ * So, if a user specifies the following arrays to construct a gradient:<br>
+ * {Color.blue, Color.red}, {.3, .7}<br>
+ * this will be converted to a gradient with the following keyframes:
+ * {Color.blue, Color.blue, Color.red, Color.red}, {0, .3, .7, 1}
+ *
+ * <p>
+ * The user may also select what action the LinearGradientPaint should take
+ * when filling color outside the start and end points. If no cycle method is
+ * specified, NO_CYCLE will be chosen by default, so the endpoint colors
+ * will be used to fill the remaining area.
+ *
+ * <p> The following image demonstrates the options NO_CYCLE and REFLECT.
+ *
+ * <p>
+ * <img src = "cyclic.jpg">
+ *
+ * <p> The colorSpace parameter allows the user to specify in which colorspace
+ * the interpolation should be performed, default sRGB or linearized RGB.
+ *
+ *
+ * @author Nicholas Talian, Vincent Hardy, Jim Graham, Jerry Evans
+ * @author <a href="mailto:vincent.hardy@eng.sun.com">Vincent Hardy</a>
+ * @version $Id: LinearGradientPaint.java,v 1.2 2004/09/27 09:27:27 kitfox Exp $
+ * @see java.awt.Paint
+ * @see java.awt.Graphics2D#setPaint
+ *
+ */
+
+public final class LinearGradientPaint extends MultipleGradientPaint {
+
+ /** Gradient start and end points. */
+ private Point2D start, end;
+
+ /**<p>
+ * Constructs an <code>LinearGradientPaint</code> with the default
+ * NO_CYCLE repeating method and SRGB colorspace.
+ *
+ * @param startX the x coordinate of the gradient axis start point
+ * in user space
+ *
+ * @param startY the y coordinate of the gradient axis start point
+ * in user space
+ *
+ * @param endX the x coordinate of the gradient axis end point
+ * in user space
+ *
+ * @param endY the y coordinate of the gradient axis end point
+ * in user space
+ *
+ * @param fractions numbers ranging from 0.0 to 1.0 specifying the
+ * distribution of colors along the gradient
+ *
+ * @param colors array of colors corresponding to each fractional value
+ *
+ *
+ * @throws IllegalArgumentException if start and end points are the
+ * same points, or if fractions.length != colors.length, or if colors
+ * is less than 2 in size.
+ *
+ */
+ public LinearGradientPaint(float startX, float startY,
+ float endX, float endY,
+ float[] fractions, Color[] colors) {
+
+ this(new Point2D.Float(startX, startY),
+ new Point2D.Float(endX, endY),
+ fractions,
+ colors,
+ NO_CYCLE,
+ SRGB);
+ }
+
+ /**<p>
+ * Constructs an <code>LinearGradientPaint</code> with default SRGB
+ * colorspace.
+ *
+ * @param startX the x coordinate of the gradient axis start point
+ * in user space
+ *
+ * @param startY the y coordinate of the gradient axis start point
+ * in user space
+ *
+ * @param endX the x coordinate of the gradient axis end point
+ * in user space
+ *
+ * @param endY the y coordinate of the gradient axis end point
+ * in user space
+ *
+ * @param fractions numbers ranging from 0.0 to 1.0 specifying the
+ * distribution of colors along the gradient
+ *
+ * @param colors array of colors corresponding to each fractional value
+ *
+ * @param cycleMethod either NO_CYCLE, REFLECT, or REPEAT
+ *
+ * @throws IllegalArgumentException if start and end points are the
+ * same points, or if fractions.length != colors.length, or if colors
+ * is less than 2 in size.
+ *
+ */
+ public LinearGradientPaint(float startX, float startY,
+ float endX, float endY,
+ float[] fractions, Color[] colors,
+ CycleMethodEnum cycleMethod) {
+ this(new Point2D.Float(startX, startY),
+ new Point2D.Float(endX, endY),
+ fractions,
+ colors,
+ cycleMethod,
+ SRGB);
+ }
+
+ /**<p>
+ * Constructs a <code>LinearGradientPaint</code> with the default
+ * NO_CYCLE repeating method and SRGB colorspace.
+ *
+ * @param start the gradient axis start <code>Point</code> in user space
+ *
+ * @param end the gradient axis end <code>Point</code> in user space
+ *
+ * @param fractions numbers ranging from 0.0 to 1.0 specifying the
+ * distribution of colors along the gradient
+ *
+ * @param colors array of colors corresponding to each fractional value
+ *
+ * @throws NullPointerException if one of the points is null
+ *
+ * @throws IllegalArgumentException if start and end points are the
+ * same points, or if fractions.length != colors.length, or if colors
+ * is less than 2 in size.
+ *
+ */
+ public LinearGradientPaint(Point2D start, Point2D end, float[] fractions,
+ Color[] colors) {
+
+ this(start, end, fractions, colors, NO_CYCLE, SRGB);
+ }
+
+ /**<p>
+ * Constructs a <code>LinearGradientPaint</code>.
+ *
+ * @param start the gradient axis start <code>Point</code> in user space
+ *
+ * @param end the gradient axis end <code>Point</code> in user space
+ *
+ * @param fractions numbers ranging from 0.0 to 1.0 specifying the
+ * distribution of colors along the gradient
+ *
+ * @param colors array of colors corresponding to each fractional value
+ *
+ * @param cycleMethod either NO_CYCLE, REFLECT, or REPEAT
+ *
+ * @param colorSpace which colorspace to use for interpolation,
+ * either SRGB or LINEAR_RGB
+ *
+ * @throws NullPointerException if one of the points is null
+ *
+ * @throws IllegalArgumentException if start and end points are the
+ * same points, or if fractions.length != colors.length, or if colors
+ * is less than 2 in size.
+ *
+ */
+ public LinearGradientPaint(Point2D start, Point2D end, float[] fractions,
+ Color[] colors,
+ CycleMethodEnum cycleMethod,
+ ColorSpaceEnum colorSpace) {
+
+ this(start, end, fractions, colors, cycleMethod, colorSpace,
+ new AffineTransform());
+
+ }
+
+ /**<p>
+ * Constructs a <code>LinearGradientPaint</code>.
+ *
+ * @param start the gradient axis start <code>Point</code> in user space
+ *
+ * @param end the gradient axis end <code>Point</code> in user space
+ *
+ * @param fractions numbers ranging from 0.0 to 1.0 specifying the
+ * distribution of colors along the gradient
+ *
+ * @param colors array of colors corresponding to each fractional value
+ *
+ * @param cycleMethod either NO_CYCLE, REFLECT, or REPEAT
+ *
+ * @param colorSpace which colorspace to use for interpolation,
+ * either SRGB or LINEAR_RGB
+ *
+ * @param gradientTransform transform to apply to the gradient
+ *
+ * @throws NullPointerException if one of the points is null,
+ * or gradientTransform is null
+ *
+ * @throws IllegalArgumentException if start and end points are the
+ * same points, or if fractions.length != colors.length, or if colors
+ * is less than 2 in size.
+ *
+ */
+ public LinearGradientPaint(Point2D start, Point2D end, float[] fractions,
+ Color[] colors,
+ CycleMethodEnum cycleMethod,
+ ColorSpaceEnum colorSpace,
+ AffineTransform gradientTransform) {
+ super(fractions, colors, cycleMethod, colorSpace, gradientTransform);
+
+ //
+ // Check input parameters
+ //
+ if (start == null || end == null) {
+ throw new NullPointerException("Start and end points must be" +
+ "non-null");
+ }
+
+ if (start.equals(end)) {
+ throw new IllegalArgumentException("Start point cannot equal" +
+ "endpoint");
+ }
+
+ //copy the points...
+ this.start = (Point2D)start.clone();
+
+ this.end = (Point2D)end.clone();
+
+ }
+
+ /**
+ * Creates and returns a PaintContext used to generate the color pattern,
+ * for use by the internal rendering engine.
+ *
+ * @param cm {@link ColorModel} that receives
+ * the <code>Paint</code> data. This is used only as a hint.
+ *
+ * @param deviceBounds the device space bounding box of the
+ * graphics primitive being rendered
+ *
+ * @param userBounds the user space bounding box of the
+ * graphics primitive being rendered
+ *
+ * @param transform the {@link AffineTransform} from user
+ * space into device space
+ *
+ * @param hints the hints that the context object uses to choose
+ * between rendering alternatives
+ *
+ * @return the {@link PaintContext} that generates color patterns.
+ *
+ * @see PaintContext
+ */
+ public PaintContext createContext(ColorModel cm,
+ Rectangle deviceBounds,
+ Rectangle2D userBounds,
+ AffineTransform transform,
+ RenderingHints hints) {
+
+ // Can't modify the transform passed in...
+ transform = new AffineTransform(transform);
+ //incorporate the gradient transform
+ transform.concatenate(gradientTransform);
+
+ try {
+ return new LinearGradientPaintContext(cm,
+ deviceBounds,
+ userBounds,
+ transform,
+ hints,
+ start,
+ end,
+ fractions,
+ this.getColors(),
+ cycleMethod,
+ colorSpace);
+ }
+
+ catch(NoninvertibleTransformException e) {
+ e.printStackTrace();
+ throw new IllegalArgumentException("transform should be" +
+ "invertible");
+ }
+ }
+
+ /**
+ * Returns a copy of the start point of the gradient axis
+ * @return a {@link Point2D} object that is a copy of the point
+ * that anchors the first color of this
+ * <code>LinearGradientPaint</code>.
+ */
+ public Point2D getStartPoint() {
+ return new Point2D.Double(start.getX(), start.getY());
+ }
+
+ /** Returns a copy of the end point of the gradient axis
+ * @return a {@link Point2D} object that is a copy of the point
+ * that anchors the last color of this
+ * <code>LinearGradientPaint</code>.
+ */
+ public Point2D getEndPoint() {
+ return new Point2D.Double(end.getX(), end.getY());
+ }
+
+}
+
+
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