Cosmin Truta f04c457a51 build: Remove the PNG_DEBUG option from CMake files and project files
Counter-intuitively, defining the PNG_DEBUG macro as 1 (i.e. setting
the debug verbosity level to 1) does *not* cause any of the existing
debug traces to show up. This setting would have worked if we had trace
statements like `png_debug(0, message)`, but we don't have any.

Debug traces do show up for verbosity levels from 2 to 5. The libpng
manual describes in detail how they are meant to be used.

According to the history of the CMake file, as well as the history of
other project files, PNG_DEBUG was never set to a numeric value larger
than 1. In other words, these debug settings inside these build files
never produced any output in any (unmodified) libpng version.

(As for the configure build, PNG_DEBUG has no special treatment there.)

Considering the plethora of alternative methods to pass C preprocessor
options through our build files, scripts and projects onto libpng, we'd
rather discontinue PNG_DEBUG as a dedicated build option.
2025-05-29 19:47:03 +03:00
..
2017-11-03 00:52:06 -04:00

Microsoft Developer Studio Project File, Format Version 7.10 for libpng.

Copyright (C) 2004 Simon-Pierre Cadieux.

This code is released under the libpng license.
For conditions of distribution and use, see copyright notice in png.h

NOTE: This project will be removed from libpng-1.5.0.  It has
been replaced with the "vstudio" project.

Assumptions:
* The libpng source files are in ..\..
* The zlib source files are in ..\..\..\zlib
* The zlib project file is in . /* Warning: This is until the zlib project
  files get integrated into the next zlib release. The final zlib project
  directory will then be ..\..\..\zlib\projects\visualc71. */

To use:

1) On the main menu, select "File | Open Solution".
   Open "libpng.sln".

2) Display the Solution Explorer view (Ctrl+Alt+L)

3) Set one of the project as the StartUp project. If you just want to build the
   binaries set "libpng" as the startup project (Select "libpng" tree view
   item + Project | Set as StartUp project). If you want to build and test the
   binaries set it to "pngtest" (Select "pngtest" tree view item +
   Project | Set as StartUp project)

4) Select "Build | Configuration Manager...".
   Choose the configuration you wish to build.

5) Select "Build | Clean Solution".

6) Select "Build | Build Solution (Ctrl-Shift-B)"

This project builds the libpng binaries as follows:

* Win32_DLL_Release\libpng16.dll      DLL build
* Win32_DLL_Debug\libpng16d.dll       DLL build (debug version)
* Win32_DLL_VB\libpng16vb.dll         DLL build for Visual Basic, using stdcall
* Win32_LIB_Release\libpng.lib        static build
* Win32_LIB_Debug\libpngd.lib         static build (debug version)

Notes:

If you change anything in the source files, or select different compiler
settings, please change the DLL name to something different than any of
the above names. Also, make sure that in your "pngusr.h" you define
PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX according to the
instructions provided in "pngconf.h".

All DLLs built by this project use the Microsoft dynamic C runtime library
MSVCR71.DLL (MSVCR71D.DLL for debug versions).  If you distribute any of the
above mentioned libraries you may have to include this DLL in your package.
For a list of files that are redistributable in Visual Studio see
$(VCINSTALLDIR)\redist.txt.