README.txt
1
2 VisualStudio instructions
3
4 libpng version 1.6.22beta03 - February 8, 2016
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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
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96