1 /* 2 * Copyright (C) 2007 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 com.example.android.apis.graphics; 18 19 import com.example.android.apis.R; 20 21 import android.app.Activity; 22 import android.content.Context; 23 import android.graphics.*; 24 import android.graphics.drawable.*; 25 import android.os.Bundle; 26 import android.view.KeyEvent; 27 import android.view.*; 28 29 import java.nio.IntBuffer; 30 import java.nio.ShortBuffer; 31 32 public class BitmapPixels extends GraphicsActivity { 33 34 @Override 35 protected void onCreate(Bundle savedInstanceState) { 36 super.onCreate(savedInstanceState); 37 setContentView(new SampleView(this)); 38 } 39 40 private static class SampleView extends View { 41 private Bitmap mBitmap1; 42 private Bitmap mBitmap2; 43 private Bitmap mBitmap3; 44 private Bitmap mBitmap4; 45 46 // access the red component from a premultiplied color 47 private static int getR32(int c) { return (c >> 0) & 0xFF; } 48 // access the red component from a premultiplied color 49 private static int getG32(int c) { return (c >> 8) & 0xFF; } 50 // access the red component from a premultiplied color 51 private static int getB32(int c) { return (c >> 16) & 0xFF; } 52 // access the red component from a premultiplied color 53 private static int getA32(int c) { return (c >> 24) & 0xFF; } 54 55 /** 56 * This takes components that are already in premultiplied form, and 57 * packs them into an int in the correct device order. 58 */ 59 private static int pack8888(int r, int g, int b, int a) { 60 return (r << 0) | ( g << 8) | (b << 16) | (a << 24); 61 } 62 63 private static short pack565(int r, int g, int b) { 64 return (short)((r << 11) | ( g << 5) | (b << 0)); 65 } 66 67 private static short pack4444(int r, int g, int b, int a) { 68 return (short)((a << 0) | ( b << 4) | (g << 8) | (r << 12)); 69 } 70 71 private static int mul255(int c, int a) { 72 int prod = c * a + 128; 73 return (prod + (prod >> 8)) >> 8; 74 } 75 76 /** 77 * Turn a color int into a premultiplied device color 78 */ 79 private static int premultiplyColor(int c) { 80 int r = Color.red(c); 81 int g = Color.green(c); 82 int b = Color.blue(c); 83 int a = Color.alpha(c); 84 // now apply the alpha to r, g, b 85 r = mul255(r, a); 86 g = mul255(g, a); 87 b = mul255(b, a); 88 // now pack it in the correct order 89 return pack8888(r, g, b, a); 90 } 91 92 private static void makeRamp(int from, int to, int n, 93 int[] ramp8888, short[] ramp565, 94 short[] ramp4444) { 95 int r = getR32(from) << 23; 96 int g = getG32(from) << 23; 97 int b = getB32(from) << 23; 98 int a = getA32(from) << 23; 99 // now compute our step amounts per componenet (biased by 23 bits) 100 int dr = ((getR32(to) << 23) - r) / (n - 1); 101 int dg = ((getG32(to) << 23) - g) / (n - 1); 102 int db = ((getB32(to) << 23) - b) / (n - 1); 103 int da = ((getA32(to) << 23) - a) / (n - 1); 104 105 for (int i = 0; i < n; i++) { 106 ramp8888[i] = pack8888(r >> 23, g >> 23, b >> 23, a >> 23); 107 ramp565[i] = pack565(r >> (23+3), g >> (23+2), b >> (23+3)); 108 ramp4444[i] = pack4444(r >> (23+4), g >> (23+4), b >> (23+4), 109 a >> (23+4)); 110 r += dr; 111 g += dg; 112 b += db; 113 a += da; 114 } 115 } 116 117 private static IntBuffer makeBuffer(int[] src, int n) { 118 IntBuffer dst = IntBuffer.allocate(n*n); 119 for (int i = 0; i < n; i++) { 120 dst.put(src); 121 } 122 dst.rewind(); 123 return dst; 124 } 125 126 private static ShortBuffer makeBuffer(short[] src, int n) { 127 ShortBuffer dst = ShortBuffer.allocate(n*n); 128 for (int i = 0; i < n; i++) { 129 dst.put(src); 130 } 131 dst.rewind(); 132 return dst; 133 } 134 135 public SampleView(Context context) { 136 super(context); 137 setFocusable(true); 138 139 final int N = 100; 140 int[] data8888 = new int[N]; 141 short[] data565 = new short[N]; 142 short[] data4444 = new short[N]; 143 144 makeRamp(premultiplyColor(Color.RED), premultiplyColor(Color.GREEN), 145 N, data8888, data565, data4444); 146 147 mBitmap1 = Bitmap.createBitmap(N, N, Bitmap.Config.ARGB_8888); 148 mBitmap2 = Bitmap.createBitmap(N, N, Bitmap.Config.RGB_565); 149 mBitmap3 = Bitmap.createBitmap(N, N, Bitmap.Config.ARGB_4444); 150 151 mBitmap1.copyPixelsFromBuffer(makeBuffer(data8888, N)); 152 mBitmap2.copyPixelsFromBuffer(makeBuffer(data565, N)); 153 mBitmap3.copyPixelsFromBuffer(makeBuffer(data4444, N)); 154 } 155 156 @Override protected void onDraw(Canvas canvas) { 157 canvas.drawColor(0xFFCCCCCC); 158 159 int y = 10; 160 canvas.drawBitmap(mBitmap1, 10, y, null); 161 y += mBitmap1.getHeight() + 10; 162 canvas.drawBitmap(mBitmap2, 10, y, null); 163 y += mBitmap2.getHeight() + 10; 164 canvas.drawBitmap(mBitmap3, 10, y, null); 165 } 166 } 167 } 168 169
