# Visualization Library

A lightweight C++ OpenGL middleware for 2D/3D graphics

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# D:/VL/BuildSystem/VL_DISTRO/Visualization_Library_SDK/src/vlCore/MemoryFile.cpp

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    00001 /**************************************************************************************/
    00002 /*                                                                                    */
    00003 /*  Visualization Library                                                             */
    00004 /*  http://www.visualizationlibrary.org                                               */
    00005 /*                                                                                    */
    00006 /*  Copyright (c) 2005-2010, Michele Bosi                                             */
    00007 /*  All rights reserved.                                                              */
    00008 /*                                                                                    */
    00009 /*  Redistribution and use in source and binary forms, with or without modification,  */
    00010 /*  are permitted provided that the following conditions are met:                     */
    00011 /*                                                                                    */
    00012 /*  - Redistributions of source code must retain the above copyright notice, this     */
    00013 /*  list of conditions and the following disclaimer.                                  */
    00014 /*                                                                                    */
    00015 /*  - Redistributions in binary form must reproduce the above copyright notice, this  */
    00016 /*  list of conditions and the following disclaimer in the documentation and/or       */
    00017 /*  other materials provided with the distribution.                                   */
    00018 /*                                                                                    */
    00019 /*  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND   */
    00020 /*  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED     */
    00021 /*  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE            */
    00022 /*  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR  */
    00023 /*  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    */
    00024 /*  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;      */
    00025 /*  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON    */
    00026 /*  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT           */
    00027 /*  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS     */
    00028 /*  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.                      */
    00029 /*                                                                                    */
    00030 /**************************************************************************************/
    00031
    00032 #include <vlCore/MemoryFile.hpp>
    00033 #include <vlCore/Log.hpp>
    00034
    00035 using namespace vl;
    00036
    00037 //---------------------------------------------------------------------------
    00038 // MemoryFile
    00039 //---------------------------------------------------------------------------
    00040 MemoryFile::MemoryFile()
    00041 {
    00042   mBuffer = new Buffer;
    00043   mPtr = 0;
    00044   mIsOpen = false;
    00045 }
    00046 //---------------------------------------------------------------------------
    00047 bool MemoryFile::open(EOpenMode mode)
    00048 {
    00049   if ( isOpen() )
    00050   {
    00051     Log::error("MemoryFile::open(): file already open.\n");
    00052     return false;
    00053   }
    00054
    00055   // for now support only OM_ReadOnly mode
    00056   mIsOpen = (mode == OM_ReadOnly);
    00057   return mIsOpen;
    00058 }
    00059 //---------------------------------------------------------------------------
    00060 void MemoryFile::copy(VirtualFile* file)
    00061 {
    00062   if (file->isOpen())
    00063     file->close();
    00064
    00065   allocateBuffer(file->size());
    00066
    00067   file->open(OM_ReadOnly);
    00068
    00069   file->read( ptr(), size() );
    00070
    00071   file->close();
    00072 }
    00073 //---------------------------------------------------------------------------
    00074 long long MemoryFile::position_Implementation() const
    00075 {
    00076   if (!isOpen())
    00077     return -1;
    00078   return mPtr;
    00079 }
    00080 //---------------------------------------------------------------------------
    00081 long long MemoryFile::read_Implementation(void* buffer, long long byte_count)
    00082 {
    00083   if (!isOpen())
    00084     return 0;
    00085   if ( mBuffer->bytesUsed() )
    00086   {
    00087     long long bytes_left = mBuffer->bytesUsed() - mPtr;
    00088     byte_count = byte_count < bytes_left ? byte_count : bytes_left;
    00089     memcpy(buffer, ptr() + mPtr, (size_t)byte_count);
    00090     mPtr += byte_count;
    00091     return byte_count;
    00092   }
    00093   else
    00094   {
    00095     // no error is generated for an empty memory stream
    00096     return 0;
    00097   }
    00098 }
    00099 //---------------------------------------------------------------------------
    00100 bool MemoryFile::seekSet_Implementation(long long offset)
    00101 {
    00102   if (!isOpen())
    00103     return false;
    00104   mPtr = offset;
    00105   if (mPtr < 0) mPtr = 0;
    00106   if (mPtr > static_cast<long long>(mBuffer->bytesUsed()))
    00107       mPtr = mBuffer->bytesUsed();
    00108   return true;
    00109 }
    00110 //-----------------------------------------------------------------------------
    00111 ref<VirtualFile> MemoryFile::clone() const
    00112 {
    00113   ref<MemoryFile> file = new MemoryFile;
    00114   file->operator=(*this);
    00115   return file;
    00116 }
    00117 //---------------------------------------------------------------------------

Visualization Library v2011.09.1162 Reference Documentation
Copyright 2005-2011 Michele Bosi. All rights reserved.
Updated on Thu Jan 26 2012 00:43:29.
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