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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.graphics;
public class RadialGradient extends GradientShader {
private RadialGradientPaint mPaint;
/**
* Create a shader that draws a radial gradient given the center and radius.
*
* @param x The x-coordinate of the center of the radius
* @param y The y-coordinate of the center of the radius
* @param radius Must be positive. The radius of the circle for this
* gradient
* @param colors The colors to be distributed between the center and edge of
* the circle
* @param positions May be NULL. The relative position of each corresponding
* color in the colors array. If this is NULL, the the colors are
* distributed evenly between the center and edge of the circle.
* @param tile The Shader tiling mode
*/
public RadialGradient(float x, float y, float radius, int colors[], float positions[],
TileMode tile) {
super(colors, positions);
if (radius <= 0) {
throw new IllegalArgumentException("radius must be > 0");
}
mPaint = new RadialGradientPaint(x, y, radius, mColors, mPositions, tile);
}
/**
* Create a shader that draws a radial gradient given the center and radius.
*
* @param x The x-coordinate of the center of the radius
* @param y The y-coordinate of the center of the radius
* @param radius Must be positive. The radius of the circle for this
* gradient
* @param color0 The color at the center of the circle.
* @param color1 The color at the edge of the circle.
* @param tile The Shader tiling mode
*/
public RadialGradient(float x, float y, float radius, int color0, int color1, TileMode tile) {
this(x, y, radius, new int[] { color0, color1 }, null /* positions */, tile);
}
@Override
java.awt.Paint getJavaPaint() {
return mPaint;
}
private static class RadialGradientPaint extends GradientPaint {
private final float mX;
private final float mY;
private final float mRadius;
public RadialGradientPaint(float x, float y, float radius, int[] colors, float[] positions, TileMode mode) {
super(colors, positions, mode);
mX = x;
mY = y;
mRadius = radius;
}
public java.awt.PaintContext createContext(
java.awt.image.ColorModel colorModel,
java.awt.Rectangle deviceBounds,
java.awt.geom.Rectangle2D userBounds,
java.awt.geom.AffineTransform xform,
java.awt.RenderingHints hints) {
precomputeGradientColors();
return new RadialGradientPaintContext(colorModel);
}
private class RadialGradientPaintContext implements java.awt.PaintContext {
private final java.awt.image.ColorModel mColorModel;
public RadialGradientPaintContext(java.awt.image.ColorModel colorModel) {
mColorModel = colorModel;
}
public void dispose() {
}
public java.awt.image.ColorModel getColorModel() {
return mColorModel;
}
public java.awt.image.Raster getRaster(int x, int y, int w, int h) {
java.awt.image.BufferedImage image = new java.awt.image.BufferedImage(w, h,
java.awt.image.BufferedImage.TYPE_INT_ARGB);
int[] data = new int[w*h];
// compute distance from each point to the center, and figure out the distance from
// it.
int index = 0;
for (int iy = 0 ; iy < h ; iy++) {
for (int ix = 0 ; ix < w ; ix++) {
float _x = x + ix - mX;
float _y = y + iy - mY;
float distance = (float) Math.sqrt(_x * _x + _y * _y);
data[index++] = getGradientColor(distance / mRadius);
}
}
image.setRGB(0 /*startX*/, 0 /*startY*/, w, h, data, 0 /*offset*/, w /*scansize*/);
return image.getRaster();
}
}
}
}
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