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Diffstat (limited to 'gcc-4.4.3/libjava/classpath/gnu/java/awt/GradientPaintContext.java')
| -rw-r--r-- | gcc-4.4.3/libjava/classpath/gnu/java/awt/GradientPaintContext.java | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/gnu/java/awt/GradientPaintContext.java b/gcc-4.4.3/libjava/classpath/gnu/java/awt/GradientPaintContext.java new file mode 100644 index 000000000..5e1d62dd9 --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/gnu/java/awt/GradientPaintContext.java @@ -0,0 +1,164 @@ +/* GradientPaintContext.java -- + Copyright (C) 2005, Free Software Foundation, Inc. + +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 gnu.java.awt; + +import java.awt.geom.Point2D; +import java.awt.image.ColorModel; +import java.awt.image.Raster; +import java.awt.image.WritableRaster; +import java.awt.PaintContext; +import java.awt.Color; + +/** + * A {@link PaintContext} used by the {@link GradientPaint} class. + */ +public class GradientPaintContext implements PaintContext +{ + + // This implementation follows the technique described in + // "Java(tm) 2D Graphics" by Jonathan Knudsen (O'Reilly 1999). + + /** The x-coordinate of the anchor point for color 1. */ + private final float x1; + + /** The y-coordinate of the anchor point for color 1. */ + private final float y1; + + /** Color 1. */ + private final Color c1; + + /** The x-coordinate of the anchor point for color 2. */ + private final float x2; + + /** The y-coordinate of the anchor point for color 2. */ + private final float y2; + + /** Color 2. */ + private final Color c2; + + /** A flag indicating whether the gradient is cyclic or acyclic. */ + private final boolean cyclic; + + /** The length of the gradient line - computed from the two anchor points. */ + private final double length; + + /** + * Creates a new instance. + * + * @param x1 the x-coordinate for the anchor point for color 1. + * @param y1 the y-coordinate for the anchor point for color 1. + * @param c1 color 1. + * @param x2 the x-coordinate for the anchor point for color 2. + * @param y2 the y-coordinate for the anchor point for color 2. + * @param c2 color 2. + * @param cyclic a flag that determines whether the gradient is cyclic + * or acyclic. + */ + public GradientPaintContext(float x1, float y1, Color c1, + float x2, float y2, Color c2, boolean cyclic) + { + this.x1 = x1; + this.y1 = y1; + this.c1 = c1; + this.x2 = x2; + this.y2 = y2; + this.c2 = c2; + this.cyclic = cyclic; + length = Point2D.distance(x1, y1, x2, y2); + } + + /** + * Return the color model of this context. It may be different from the + * hint specified during createContext, as not all contexts can generate + * color patterns in an arbitrary model. + * + * @return the context color model + */ + public ColorModel getColorModel() + { + return ColorModel.getRGBdefault(); + } + + /** + * Return a raster containing the colors for the graphics operation. + * + * @param x the x-coordinate, in device space + * @param y the y-coordinate, in device space + * @param w the width, in device space + * @param h the height, in device space + * @return a raster for the given area and color + */ + public Raster getRaster(int x, int y, int w, int h) { + ColorModel cm = getColorModel(); + WritableRaster raster = cm.createCompatibleWritableRaster(w, h); + int[] data = new int[w * h * 4]; + double pd2 = (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2); + for (int r = 0; r < h; r++) { + for (int c = 0; c < w; c++) { + double u = 0.0; + if (pd2 != 0) + u = (((x + c) - x1) * (x2 - x1) + ((y + r) - y1) * (y2 - y1)) + / Math.sqrt(pd2); + double ratio = u / length; + if (cyclic) + ratio = Math.abs(ratio - Math.floor((ratio + 1.0) / 2.0) * 2.0); + else + ratio = Math.max(0.0, Math.min(1.0, ratio)); + int base = (r * w + c) * 4; + data[base] = (int) (c1.getRed() + ratio * (c2.getRed() - c1.getRed())); + data[base + 1] + = (int) (c1.getGreen() + ratio * (c2.getGreen() - c1.getGreen())); + data[base + 2] + = (int) (c1.getBlue() + ratio * (c2.getBlue() - c1.getBlue())); + data[base + 3] + = (int) (c1.getAlpha() + ratio * (c2.getAlpha() - c1.getAlpha())); + } + } + raster.setPixels(0, 0, w, h, data); + return raster; + } + + /** + * Release the resources allocated for the paint (none in this + * implementation). + */ + public void dispose() { + // nothing to do + } + +} |