1 /*
2  * Copyright (c) 2009-2010 jMonkeyEngine
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are
7  * met:
8  *
9  * * Redistributions of source code must retain the above copyright
10  *   notice, this list of conditions and the following disclaimer.
11  *
12  * * Redistributions in binary form must reproduce the above copyright
13  *   notice, this list of conditions and the following disclaimer in the
14  *   documentation and/or other materials provided with the distribution.
15  *
16  * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
17  *   may be used to endorse or promote products derived from this software
18  *   without specific prior written permission.
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20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  */
32 package com.jme3.scene.plugins.blender.file;
33 
34 import com.jme3.scene.plugins.blender.BlenderContext;
35 import com.jme3.scene.plugins.blender.exceptions.BlenderFileException;
36 
37 /**
38  * A class that holds the header data of a file block. The file block itself is not implemented. This class holds its
39  * start position in the stream and using this the structure can fill itself with the proper data.
40  * @author Marcin Roguski
41  */
42 public class FileBlockHeader {
43 
44     public static final int BLOCK_TE00 = 'T' << 24 | 'E' << 16;					//TE00
45     public static final int BLOCK_ME00 = 'M' << 24 | 'E' << 16;					//ME00
46     public static final int BLOCK_SR00 = 'S' << 24 | 'R' << 16;					//SR00
47     public static final int BLOCK_CA00 = 'C' << 24 | 'A' << 16;					//CA00
48     public static final int BLOCK_LA00 = 'L' << 24 | 'A' << 16;					//LA00
49     public static final int BLOCK_OB00 = 'O' << 24 | 'B' << 16;					//OB00
50     public static final int BLOCK_MA00 = 'M' << 24 | 'A' << 16;					//MA00
51     public static final int BLOCK_SC00 = 'S' << 24 | 'C' << 16;					//SC00
52     public static final int BLOCK_WO00 = 'W' << 24 | 'O' << 16;					//WO00
53     public static final int BLOCK_TX00 = 'T' << 24 | 'X' << 16;					//TX00
54     public static final int BLOCK_IP00 = 'I' << 24 | 'P' << 16;					//IP00
55     public static final int BLOCK_AC00 = 'A' << 24 | 'C' << 16;					//AC00
56     public static final int BLOCK_GLOB = 'G' << 24 | 'L' << 16 | 'O' << 8 | 'B';	//GLOB
57     public static final int BLOCK_REND = 'R' << 24 | 'E' << 16 | 'N' << 8 | 'D';	//REND
58     public static final int BLOCK_DATA = 'D' << 24 | 'A' << 16 | 'T' << 8 | 'A';	//DATA
59     public static final int BLOCK_DNA1 = 'D' << 24 | 'N' << 16 | 'A' << 8 | '1';	//DNA1
60     public static final int BLOCK_ENDB = 'E' << 24 | 'N' << 16 | 'D' << 8 | 'B';	//ENDB
61     /** Identifier of the file-block [4 bytes]. */
62     private int code;
63     /** Total length of the data after the file-block-header [4 bytes]. */
64     private int size;
65     /**
66      * Memory address the structure was located when written to disk [4 or 8 bytes (defined in file header as a pointer
67      * size)].
68      */
69     private long oldMemoryAddress;
70     /** Index of the SDNA structure [4 bytes]. */
71     private int sdnaIndex;
72     /** Number of structure located in this file-block [4 bytes]. */
73     private int count;
74     /** Start position of the block's data in the stream. */
75     private int blockPosition;
76 
77     /**
78      * Constructor. Loads the block header from the given stream during instance creation.
79      * @param inputStream
80      *        the stream we read the block header from
81      * @param blenderContext
82      *        the blender context
83      * @throws BlenderFileException
84      *         this exception is thrown when the pointer size is neither 4 nor 8
85      */
FileBlockHeader(BlenderInputStream inputStream, BlenderContext blenderContext)86     public FileBlockHeader(BlenderInputStream inputStream, BlenderContext blenderContext) throws BlenderFileException {
87         inputStream.alignPosition(4);
88         code = inputStream.readByte() << 24 | inputStream.readByte() << 16
89                 | inputStream.readByte() << 8 | inputStream.readByte();
90         size = inputStream.readInt();
91         oldMemoryAddress = inputStream.readPointer();
92         sdnaIndex = inputStream.readInt();
93         count = inputStream.readInt();
94         blockPosition = inputStream.getPosition();
95         if (FileBlockHeader.BLOCK_DNA1 == code) {
96             blenderContext.setBlockData(new DnaBlockData(inputStream, blenderContext));
97         } else {
98             inputStream.setPosition(blockPosition + size);
99             blenderContext.addFileBlockHeader(Long.valueOf(oldMemoryAddress), this);
100         }
101     }
102 
103     /**
104      * This method returns the structure described by the header filled with appropriate data.
105      * @param blenderContext
106      *        the blender context
107      * @return structure filled with data
108      * @throws BlenderFileException
109      */
getStructure(BlenderContext blenderContext)110     public Structure getStructure(BlenderContext blenderContext) throws BlenderFileException {
111         blenderContext.getInputStream().setPosition(blockPosition);
112         Structure structure = blenderContext.getDnaBlockData().getStructure(sdnaIndex);
113         structure.fill(blenderContext.getInputStream());
114         return structure;
115     }
116 
117     /**
118      * This method returns the code of this data block.
119      * @return the code of this data block
120      */
getCode()121     public int getCode() {
122         return code;
123     }
124 
125     /**
126      * This method returns the size of the data stored in this block.
127      * @return the size of the data stored in this block
128      */
getSize()129     public int getSize() {
130         return size;
131     }
132 
133     /**
134      * This method returns the memory address.
135      * @return the memory address
136      */
getOldMemoryAddress()137     public long getOldMemoryAddress() {
138         return oldMemoryAddress;
139     }
140 
141     /**
142      * This method returns the sdna index.
143      * @return the sdna index
144      */
getSdnaIndex()145     public int getSdnaIndex() {
146         return sdnaIndex;
147     }
148 
149     /**
150      * This data returns the number of structure stored in the data block after this header.
151      * @return the number of structure stored in the data block after this header
152      */
getCount()153     public int getCount() {
154         return count;
155     }
156 
157     /**
158      * This method returns the start position of the data block in the blend file stream.
159      * @return the start position of the data block
160      */
getBlockPosition()161     public int getBlockPosition() {
162         return blockPosition;
163     }
164 
165     /**
166      * This method indicates if the block is the last block in the file.
167      * @return true if this block is the last one in the file nad false otherwise
168      */
isLastBlock()169     public boolean isLastBlock() {
170         return FileBlockHeader.BLOCK_ENDB == code;
171     }
172 
173     /**
174      * This method indicates if the block is the SDNA block.
175      * @return true if this block is the SDNA block and false otherwise
176      */
isDnaBlock()177     public boolean isDnaBlock() {
178         return FileBlockHeader.BLOCK_DNA1 == code;
179     }
180 
181     @Override
toString()182     public String toString() {
183         return "FILE BLOCK HEADER [" + this.codeToString(code) + " : " + size + " : " + oldMemoryAddress + " : " + sdnaIndex + " : " + count + "]";
184     }
185 
186     /**
187      * This method transforms the coded bloch id into a string value.
188      * @param code
189      *        the id of the block
190      * @return the string value of the block id
191      */
codeToString(int code)192     protected String codeToString(int code) {
193         char c1 = (char) ((code & 0xFF000000) >> 24);
194         char c2 = (char) ((code & 0xFF0000) >> 16);
195         char c3 = (char) ((code & 0xFF00) >> 8);
196         char c4 = (char) (code & 0xFF);
197         return String.valueOf(c1) + c2 + c3 + c4;
198     }
199 }
200