Java tutorial
/* ** Copyright 2011, 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 com.android.glesv2debugger; import com.google.protobuf.ByteString; import org.eclipse.jface.dialogs.MessageDialog; import org.eclipse.swt.graphics.ImageData; import org.eclipse.swt.graphics.PaletteData; import java.nio.ByteBuffer; import java.util.Arrays; public class MessageProcessor { static void showError(final String message) { // need to call SWT from UI thread MessageDialog.openError(null, "MessageProcessor", message); } /** * data layout: uint32 total decompressed length, (chunks: uint32 chunk * decompressed size, uint32 chunk compressed size, chunk data)+. 0 chunk * compressed size means chunk is not compressed */ public static byte[] lzfDecompressChunks(final ByteString data) { ByteBuffer in = data.asReadOnlyByteBuffer(); in.order(SampleView.targetByteOrder); ByteBuffer out = ByteBuffer.allocate(in.getInt()); byte[] inChunk = new byte[0]; byte[] outChunk = new byte[0]; while (in.remaining() > 0) { int decompressed = in.getInt(); int compressed = in.getInt(); if (decompressed > outChunk.length) outChunk = new byte[decompressed]; if (compressed == 0) { in.get(outChunk, 0, decompressed); out.put(outChunk, 0, decompressed); } else { if (compressed > inChunk.length) inChunk = new byte[compressed]; in.get(inChunk, 0, compressed); int size = org.liblzf.CLZF.lzf_decompress(inChunk, compressed, outChunk, outChunk.length); assert size == decompressed; out.put(outChunk, 0, size); } } assert !out.hasRemaining(); return out.array(); } /** same data layout as LZFDecompressChunks */ public static byte[] lzfCompressChunks(final byte[] in, final int inSize) { byte[] chunk = new byte[256 * 1024]; // chunk size is arbitrary final ByteBuffer out = ByteBuffer .allocate(4 + (inSize + chunk.length - 1) / chunk.length * (chunk.length + 4 * 2)); out.order(SampleView.targetByteOrder); out.putInt(inSize); for (int i = 0; i < inSize; i += chunk.length) { int chunkIn = chunk.length; if (i + chunkIn > inSize) chunkIn = inSize - i; final byte[] inChunk = java.util.Arrays.copyOfRange(in, i, i + chunkIn); final int chunkOut = org.liblzf.CLZF.lzf_compress(inChunk, chunkIn, chunk, chunk.length); out.putInt(chunkIn); out.putInt(chunkOut); if (chunkOut == 0) // compressed bigger than chunk (uncompressed) out.put(inChunk); else out.put(chunk, 0, chunkOut); } return Arrays.copyOf(out.array(), out.position()); } /** * returns new ref, which is also the decoded image; ref could be bigger * than pixels, in which case the first pixels.length bytes form the image */ public static byte[] decodeReferencedImage(byte[] ref, byte[] pixels) { if (ref.length < pixels.length) ref = new byte[pixels.length]; for (int i = 0; i < pixels.length; i++) ref[i] ^= pixels[i]; for (int i = pixels.length; i < ref.length; i++) ref[i] = 0; // clear unused ref to maintain consistency return ref; } public static ImageData receiveImage(int width, int height, int format, int type, final ByteString data) { assert width > 0 && height > 0; int bpp = 0; int redMask = 0, blueMask = 0, greenMask = 0; switch (GLEnum.valueOf(type)) { case GL_UNSIGNED_SHORT_5_6_5: case GL_UNSIGNED_SHORT_4_4_4_4: case GL_UNSIGNED_SHORT_5_5_5_1: format = type; break; case GL_UNSIGNED_BYTE: break; default: showError("unsupported texture type " + type); return null; } switch (GLEnum.valueOf(format)) { case GL_ALPHA: case GL_LUMINANCE: redMask = blueMask = greenMask = 0xff; bpp = 8; break; case GL_LUMINANCE_ALPHA: blueMask = 0xff; redMask = 0xff00; bpp = 16; break; case GL_RGB: blueMask = 0xff; greenMask = 0xff00; redMask = 0xff0000; bpp = 24; break; case GL_RGBA: blueMask = 0xff00; greenMask = 0xff0000; redMask = 0xff000000; bpp = 32; break; case GL_UNSIGNED_SHORT_5_6_5: blueMask = ((1 << 5) - 1) << 0; greenMask = ((1 << 6) - 1) << 5; redMask = ((1 << 5) - 1) << 11; bpp = 16; break; case GL_UNSIGNED_SHORT_4_4_4_4: blueMask = ((1 << 4) - 1) << 4; greenMask = ((1 << 4) - 1) << 8; redMask = ((1 << 4) - 1) << 12; bpp = 16; break; case GL_UNSIGNED_SHORT_5_5_5_1: blueMask = ((1 << 5) - 1) << 1; greenMask = ((1 << 5) - 1) << 6; redMask = ((1 << 5) - 1) << 11; bpp = 16; break; default: showError("unsupported texture format: " + format); return null; } byte[] pixels = lzfDecompressChunks(data); assert pixels.length == width * height * (bpp / 8); PaletteData palette = new PaletteData(redMask, greenMask, blueMask); return new ImageData(width, height, bpp, palette, 1, pixels); } }