1 /* 2 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 /* 25 * @test 26 * @bug 8139183 27 * @summary Test verifies whether alpha channel of a translucent 28 * image is proper or not after scaling through drawImage. 29 * @run main ScaledImageAlphaTest 30 */ 31 32 import java.awt.*; 33 import java.awt.image.*; 34 35 public class ScaledImageAlphaTest { 36 37 public static void main(String[] args){ 38 39 int width = 50, height = 50; 40 // create BufferedImage of dimension (50,50) 41 BufferedImage img = new 42 BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB); 43 Graphics2D imgGraphics = (Graphics2D)img.getGraphics(); 44 45 int scaleX = 5, scaleY = 5, scaleWidth = 40, scaleHeight = 40; 46 int translucentAlpha = 128; 47 48 /* scale image to smaller dimension and set background color 49 * to green with translucent alpha. 50 */ 51 Color translucentGreen = new Color(0, 255, 0, translucentAlpha); 52 imgGraphics. 53 drawImage(img, scaleX, scaleY, scaleWidth, scaleHeight, 54 translucentGreen, null); 55 imgGraphics.dispose(); 56 57 /* get pixel information for background green color with 58 * scaled coordinates and extract alpha. 59 */ 60 Color c = new Color(img.getRGB(scaleX, scaleY), true); 61 int alpha = c.getAlpha(); 62 63 /* if alpha value is translucent, alpha channel is not lost 64 * while scaling otherwise we have lost alpha channel. 65 */ 66 if(alpha != translucentAlpha) { 67 throw new RuntimeException("Alpha channel is lost while scaling"); 68 } 69 } 70 }