Imported Upstream version 1.6.21

[platform/upstream/libpng.git] / projects / vstudio / README.txt

diff --git a/projects/vstudio/readme.txt b/projects/vstudio/README.txt
similarity index 63%
rename from projects/vstudio/readme.txt
rename to projects/vstudio/README.txt
index 5b0035d..642a42b 100644 (file)
--- a/projects/vstudio/readme.txt
+++ b/projects/vstudio/README.txt
@@ -1,9 +1,9 @@
 
 VisualStudio instructions
 
-libpng version 1.6.13 - August 21, 2014
+libpng version 1.6.21 - January 15, 2016
 
-Copyright (c) 1998-2010 Glenn Randers-Pehrson
+Copyright (c) 2010,2013,2015 Glenn Randers-Pehrson
 
 This code is released under the libpng license.
 For conditions of distribution and use, see the disclaimer
@@ -38,16 +38,17 @@ In particular the runtime library is the "MultiThreaded DLL" version.
 If you use Visual Studio defaults to build your application you will have no
 problems.
 
-If you don't use the Visual Studio defaults your application must still be built
-with the default runtime option (/MD).  If, for some reason, it is not then your
-application will crash inside libpng16.dll as soon as libpng tries to read
-from a file handle you pass in.
+If you don't use the Visual Studio defaults your application must still be
+built with the default runtime option (/MD).  If, for some reason, it is not
+then your application will crash inside libpng16.dll as soon as libpng
+tries to read from a file handle you pass in.
 
 If you do not want to use the DLL, for example for a very small application,
 the 'release library' configuration may be more appropriate.  This is built
 with a non-standard runtime library - the "MultiThreaded" version.  When you
 build your application it must be compiled with this option (/MT), otherwise
-it will not build (if you are lucky) or crash (if you are not.)
+it will not build (if you are lucky) or crash (if you are not.) See the
+WARNING file that is distributed along with this readme.txt.
 
 Stop reading here
 =================
@@ -63,3 +64,32 @@ track down.)
 
 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.
+
+WARNING
+=======
+Libpng 1.6.x does not use the default run-time library when building static
+library builds of libpng; instead of the shared DLL runtime it uses a static
+runtime.  If you need to change this make sure to change the setting on all the
+relevant projects:
+
+    libpng
+    zlib
+    all the test programs
+
+The runtime library settings for each build are as follows:
+
+               Release        Debug
+    DLL         /MD            /MDd
+    Library     /MT            /MTd
+
+NOTICE that libpng 1.5.x erroneously used /MD for Debug DLL builds; if you used
+the debug builds in your app and you changed your app to use /MD you will need
+to change it back to /MDd for libpng 1.6.0 and later.
+
+The Visual Studio 2010 defaults for a Win32 DLL or Static Library project are
+as follows:
+
+                     Release     Debug
+    DLL               /MD         /MDd
+    Static Library    /MD         /MDd
+