1 2 VisualStudio instructions 3 4 libpng version 1.6.22beta03 - February 8, 2016 5 6 Copyright (c) 2010,2013,2015 Glenn Randers-Pehrson 7 8 This code is released under the libpng license. 9 For conditions of distribution and use, see the disclaimer 10 and license in png.h 11 12 This directory contains support for building libpng under MicroSoft 13 VisualStudio 2010. It may also work under later versions of VisualStudio. 14 You should be familiar with VisualStudio before using this directory. 15 16 Initial preparations 17 ==================== 18 You must enter some information in zlib.props before attempting to build 19 with this 'solution'. Please read and edit zlib.props first. You will 20 probably not be familiar with the contents of zlib.props - do not worry, 21 it is mostly harmless. 22 23 This is all you need to do to build the 'release' and 'release library' 24 configurations. 25 26 Debugging 27 ========= 28 The release configurations default to /Ox optimization. Full debugging 29 information is produced (in the .pdb), but if you encounter a problem the 30 optimization may make it difficult to debug. Simply rebuild with a lower 31 optimization level (e.g. /Od.) 32 33 Linking your application 34 ======================== 35 Normally you should link against the 'release' configuration. This builds a 36 DLL for libpng with the default runtime options used by Visual Studio 2010. 37 In particular the runtime library is the "MultiThreaded DLL" version. 38 If you use Visual Studio defaults to build your application you will have no 39 problems. 40 41 If you don't use the Visual Studio defaults your application must still be 42 built with the default runtime option (/MD). If, for some reason, it is not 43 then your application will crash inside libpng16.dll as soon as libpng 44 tries to read from a file handle you pass in. 45 46 If you do not want to use the DLL, for example for a very small application, 47 the 'release library' configuration may be more appropriate. This is built 48 with a non-standard runtime library - the "MultiThreaded" version. When you 49 build your application it must be compiled with this option (/MT), otherwise 50 it will not build (if you are lucky) or crash (if you are not.) See the 51 WARNING file that is distributed along with this readme.txt. 52 53 Stop reading here 54 ================= 55 You have enough information to build a working application. 56 57 Debug versions have limited support 58 =================================== 59 This solution includes limited support for debug versions of libpng. You 60 do not need these unless your own solution itself uses debug builds (it is 61 far more effective to debug on the release builds, there is no point building 62 a special debug build unless you have heap corruption problems that you can't 63 track down.) 64 65 The debug build of libpng is minimally supported. Support for debug builds of 66 zlib is also minimal. You really don't want to do this. 67 68 WARNING 69 ======= 70 Libpng 1.6.x does not use the default run-time library when building static 71 library builds of libpng; instead of the shared DLL runtime it uses a static 72 runtime. If you need to change this make sure to change the setting on all the 73 relevant projects: 74 75 libpng 76 zlib 77 all the test programs 78 79 The runtime library settings for each build are as follows: 80 81 Release Debug 82 DLL /MD /MDd 83 Library /MT /MTd 84 85 NOTICE that libpng 1.5.x erroneously used /MD for Debug DLL builds; if you used 86 the debug builds in your app and you changed your app to use /MD you will need 87 to change it back to /MDd for libpng 1.6.0 and later. 88 89 The Visual Studio 2010 defaults for a Win32 DLL or Static Library project are 90 as follows: 91 92 Release Debug 93 DLL /MD /MDd 94 Static Library /MD /MDd 95 96
