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| VisualStudio instructions |
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| libpng version 1.4.3 - June 26, 2010 |
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| Copyright (c) 1998-2010 Glenn Randers-Pehrson |
| |
| This code is released under the libpng license. |
| For conditions of distribution and use, see the disclaimer |
| and license in png.h |
| |
| This directory contains support for building libpng under MicroSoft |
| VisualStudio 2010. It may also work under later versions of VisualStudio. |
| You should be familiar with VisualStudio before using this directory. |
| |
| This is a slightly modified copy of the 'vstudio' solution from libpng |
| 1.5; it is intended to provide compatibility for libpng 1.4 with later |
| releases of zlib (from 1.2.4) and to provide a migration aid for 1.5. |
| |
| A 'VB' DLL is no longer produced - use the standard 'Release' DLL. |
| |
| Initial preparations |
| ==================== |
| You should install the 'official' build of zlib on your system - follow the |
| instructions provided on http://www.zlib.net. When a new release is being |
| made of zlib the instructions disappear for a while until the new official |
| build is available. You will have to wait. |
| |
| You must enter some information in zlib.props before attempting to build |
| with this 'solution'. Please read and edit zlib.props first. You will |
| probably not be familiar with the contents of zlib.props - do not worry, |
| it is mostly harmless. |
| |
| Make sure that your official build layout matches the requirements listed |
| in zlib.props. Prior to zlib-1.2.4 the official build (1.2.3) placed |
| include and library files in different directories - if you find this |
| has happened just put them all in the same directory. |
| |
| This is all you need to do to build the 'release' and 'release library' |
| configurations. |
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| Debugging |
| ========= |
| The release configurations default to /Ox optimization. Full debugging |
| information is produced (in the .pdb), but if you encounter a problem the |
| optimization may make it difficult to debug. Simply rebuild with a lower |
| optimization level (e.g. /Od.) |
| |
| Stop reading here |
| ================= |
| You have enough information to build a working application. |
| |
| Debug versions have limited support |
| =================================== |
| This solution includes limited support for debug versions of libpng. You |
| do not need these unless your own solution itself uses debug builds (it is |
| far more effective to debug on the release builds, there is no point building |
| a special debug build.) |
| |
| If, despite the previous paragraph, you still feel you need a debug build you |
| will have to download the zlib source as well (http://www.zlib.net) and include |
| the directory where you unpack it in zlib.props. This solution will then be |
| able to build a minimal zlib sufficient for libpng. This build is only |
| suitable for making a debug libpng. |
| |
| The debug build of libpng is minimally supported. Support for debug builds of |
| zlib is also minimal. You really don't want to do this. |
| |
| This solution only supports the Multi-Threaded DLL C Runtime |
| ============================================================ |
| If you examine the solution you will find that it very deliberately lists |
| exactly which MicroSoft DLLs it is linking against. It explicitly links |
| against msvcrt.lib. The debug version links against msvcrtd.lib (this is |
| why it is a debug version - it's nothing to do with having any special |
| debug support, it doesn't). |
| |
| These versions of the MicroSoft C runtime correspond to the compiler flags |
| /MD (release) and /MDd (debug) - the "Multi-Threaded DLL" implementation of the |
| C runtime library. |
| |
| If you need to change this then you will have to make sure that both the |
| compiler flags and the ".lib" in the linker dependences match up. Fortunately |
| neither zlib nor libpng require libraries other than a C runtime and |
| kernel32. |
| |
| You cannot pass (FILE*) objects from a different runtime (including msvcrtd |
| to msvcrt) to libpng. If you do then your program will crash within libpng |
| when it first makes a file read or write call. |
| |
| It is likely if you have read this far that you have found you can't avoid |
| having multiple C runtimes in your program. This is OK, it does work, but |
| you will have to implement the libpng file read/write callbacks rather than |
| using the internal libpng default. This is easy. |
