The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2008 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package android.graphics; |
| 18 | |
Xavier Ducrohet | 45a7c28 | 2010-01-19 10:20:43 -0800 | [diff] [blame^] | 19 | public class RadialGradient extends GradientShader { |
Xavier Ducrohet | 63b2e61 | 2010-01-13 20:30:26 -0800 | [diff] [blame] | 20 | |
Xavier Ducrohet | 45a7c28 | 2010-01-19 10:20:43 -0800 | [diff] [blame^] | 21 | private RadialGradientPaint mPaint; |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 22 | |
Xavier Ducrohet | 45a7c28 | 2010-01-19 10:20:43 -0800 | [diff] [blame^] | 23 | /** |
| 24 | * Create a shader that draws a radial gradient given the center and radius. |
| 25 | * |
| 26 | * @param x The x-coordinate of the center of the radius |
| 27 | * @param y The y-coordinate of the center of the radius |
| 28 | * @param radius Must be positive. The radius of the circle for this |
| 29 | * gradient |
| 30 | * @param colors The colors to be distributed between the center and edge of |
| 31 | * the circle |
| 32 | * @param positions May be NULL. The relative position of each corresponding |
| 33 | * color in the colors array. If this is NULL, the the colors are |
| 34 | * distributed evenly between the center and edge of the circle. |
| 35 | * @param tile The Shader tiling mode |
| 36 | */ |
| 37 | public RadialGradient(float x, float y, float radius, int colors[], float positions[], |
| 38 | TileMode tile) { |
| 39 | super(colors, positions); |
| 40 | if (radius <= 0) { |
| 41 | throw new IllegalArgumentException("radius must be > 0"); |
| 42 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 43 | |
Xavier Ducrohet | 45a7c28 | 2010-01-19 10:20:43 -0800 | [diff] [blame^] | 44 | mPaint = new RadialGradientPaint(x, y, radius, mColors, mPositions, tile); |
| 45 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 46 | |
Xavier Ducrohet | 45a7c28 | 2010-01-19 10:20:43 -0800 | [diff] [blame^] | 47 | /** |
| 48 | * Create a shader that draws a radial gradient given the center and radius. |
| 49 | * |
| 50 | * @param x The x-coordinate of the center of the radius |
| 51 | * @param y The y-coordinate of the center of the radius |
| 52 | * @param radius Must be positive. The radius of the circle for this |
| 53 | * gradient |
| 54 | * @param color0 The color at the center of the circle. |
| 55 | * @param color1 The color at the edge of the circle. |
| 56 | * @param tile The Shader tiling mode |
| 57 | */ |
| 58 | public RadialGradient(float x, float y, float radius, int color0, int color1, TileMode tile) { |
| 59 | this(x, y, radius, new int[] { color0, color1 }, null /* positions */, tile); |
| 60 | } |
Xavier Ducrohet | 63b2e61 | 2010-01-13 20:30:26 -0800 | [diff] [blame] | 61 | |
| 62 | @Override |
Xavier Ducrohet | 45a7c28 | 2010-01-19 10:20:43 -0800 | [diff] [blame^] | 63 | java.awt.Paint getJavaPaint() { |
| 64 | return mPaint; |
Xavier Ducrohet | 63b2e61 | 2010-01-13 20:30:26 -0800 | [diff] [blame] | 65 | } |
The Android Open Source Project | 9066cfe | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 66 | |
Xavier Ducrohet | 45a7c28 | 2010-01-19 10:20:43 -0800 | [diff] [blame^] | 67 | private static class RadialGradientPaint extends GradientPaint { |
| 68 | |
| 69 | private final float mX; |
| 70 | private final float mY; |
| 71 | private final float mRadius; |
| 72 | |
| 73 | public RadialGradientPaint(float x, float y, float radius, int[] colors, float[] positions, TileMode mode) { |
| 74 | super(colors, positions, mode); |
| 75 | mX = x; |
| 76 | mY = y; |
| 77 | mRadius = radius; |
| 78 | } |
| 79 | |
| 80 | public java.awt.PaintContext createContext( |
| 81 | java.awt.image.ColorModel colorModel, |
| 82 | java.awt.Rectangle deviceBounds, |
| 83 | java.awt.geom.Rectangle2D userBounds, |
| 84 | java.awt.geom.AffineTransform xform, |
| 85 | java.awt.RenderingHints hints) { |
| 86 | precomputeGradientColors(); |
| 87 | return new RadialGradientPaintContext(colorModel); |
| 88 | } |
| 89 | |
| 90 | private class RadialGradientPaintContext implements java.awt.PaintContext { |
| 91 | |
| 92 | private final java.awt.image.ColorModel mColorModel; |
| 93 | |
| 94 | public RadialGradientPaintContext(java.awt.image.ColorModel colorModel) { |
| 95 | mColorModel = colorModel; |
| 96 | } |
| 97 | |
| 98 | public void dispose() { |
| 99 | } |
| 100 | |
| 101 | public java.awt.image.ColorModel getColorModel() { |
| 102 | return mColorModel; |
| 103 | } |
| 104 | |
| 105 | public java.awt.image.Raster getRaster(int x, int y, int w, int h) { |
| 106 | java.awt.image.BufferedImage image = new java.awt.image.BufferedImage(w, h, |
| 107 | java.awt.image.BufferedImage.TYPE_INT_ARGB); |
| 108 | |
| 109 | int[] data = new int[w*h]; |
| 110 | |
| 111 | // compute distance from each point to the center, and figure out the distance from |
| 112 | // it. |
| 113 | int index = 0; |
| 114 | for (int iy = 0 ; iy < h ; iy++) { |
| 115 | for (int ix = 0 ; ix < w ; ix++) { |
| 116 | float _x = x + ix - mX; |
| 117 | float _y = y + iy - mY; |
| 118 | float distance = (float) Math.sqrt(_x * _x + _y * _y); |
| 119 | |
| 120 | data[index++] = getGradientColor(distance / mRadius); |
| 121 | } |
| 122 | } |
| 123 | |
| 124 | image.setRGB(0 /*startX*/, 0 /*startY*/, w, h, data, 0 /*offset*/, w /*scansize*/); |
| 125 | |
| 126 | return image.getRaster(); |
| 127 | } |
| 128 | |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | } |