src/png/projects/vstudio/readme.txt

   1
   2 VisualStudio instructions
   3
   4 libpng version 1.4.4 - September 23, 2010
   5
   6 Copyright (c) 1998-2010 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 This is a slightly modified copy of the 'vstudio' solution from libpng
  17 1.5; it is intended to provide compatibility for libpng 1.4 with later
  18 releases of zlib (from 1.2.4) and to provide a migration aid for 1.5.
  19
  20 A 'VB' DLL is no longer produced - use the standard 'Release' DLL.
  21
  22 Initial preparations
  23 ====================
  24 You should install the 'official' build of zlib on your system - follow the
  25 instructions provided on http://www.zlib.net.  When a new release is being
  26 made of zlib the instructions disappear for a while until the new official
  27 build is available.  You will have to wait.
  28
  29 You must enter some information in zlib.props before attempting to build
  30 with this 'solution'.  Please read and edit zlib.props first.  You will
  31 probably not be familiar with the contents of zlib.props - do not worry,
  32 it is mostly harmless.
  33
  34 Make sure that your official build layout matches the requirements listed
  35 in zlib.props.  Prior to zlib-1.2.4 the official build (1.2.3) placed
  36 include and library files in different directories - if you find this
  37 has happened just put them all in the same directory.
  38
  39 This is all you need to do to build the 'release' and 'release library'
  40 configurations.
  41
  42 Debugging
  43 =========
  44 The release configurations default to /Ox optimization.  Full debugging
  45 information is produced (in the .pdb), but if you encounter a problem the
  46 optimization may make it difficult to debug.  Simply rebuild with a lower
  47 optimization level (e.g. /Od.)
  48
  49 Stop reading here
  50 =================
  51 You have enough information to build a working application.
  52
  53 Debug versions have limited support
  54 ===================================
  55 This solution includes limited support for debug versions of libpng.  You
  56 do not need these unless your own solution itself uses debug builds (it is
  57 far more effective to debug on the release builds, there is no point building
  58 a special debug build.)
  59
  60 If, despite the previous paragraph, you still feel you need a debug build you
  61 will have to download the zlib source as well (http://www.zlib.net) and include
  62 the directory where you unpack it in zlib.props.  This solution will then be
  63 able to build a minimal zlib sufficient for libpng.  This build is only
  64 suitable for making a debug libpng.
  65
  66 The debug build of libpng is minimally supported.  Support for debug builds of
  67 zlib is also minimal.  You really don't want to do this.
  68
  69 This solution only supports the Multi-Threaded DLL C Runtime
  70 ============================================================
  71 If you examine the solution you will find that it very deliberately lists
  72 exactly which MicroSoft DLLs it is linking against.  It explicitly links
  73 against msvcrt.lib.  The debug version links against msvcrtd.lib (this is
  74 why it is a debug version - it's nothing to do with having any special
  75 debug support, it doesn't).
  76
  77 These versions of the MicroSoft C runtime correspond to the compiler flags
  78 /MD (release) and /MDd (debug) - the "Multi-Threaded DLL" implementation of the
  79 C runtime library.
  80
  81 If you need to change this then you will have to make sure that both the
  82 compiler flags and the ".lib" in the linker dependences match up.  Fortunately
  83 neither zlib nor libpng require libraries other than a C runtime and
  84 kernel32.
  85
  86 You cannot pass (FILE*) objects from a different runtime (including msvcrtd
  87 to msvcrt) to libpng.  If you do then your program will crash within libpng
  88 when it first makes a file read or write call.
  89
  90 It is likely if you have read this far that you have found you can't avoid
  91 having multiple C runtimes in your program.  This is OK, it does work, but
  92 you will have to implement the libpng file read/write callbacks rather than
  93 using the internal libpng default.  This is easy.