Remove reduntant content from XRC format docs.

[wxWidgets.git] / docs / tech / tn0025.txt

diff --git a/docs/tech/tn0025.txt b/docs/tech/tn0025.txt
index f4635c9362eb3a6c0366b73ade0ddfb586bef610..058084a9c1d4478e0fdcfbdbde902e905f28ba3f 100644 (file)
--- a/docs/tech/tn0025.txt
+++ b/docs/tech/tn0025.txt
@@ -104,3 +104,24 @@ works.
 After testing and correcting the problems, simply commit your changes:
 
     svn commit -m 'Update $(LIB) to $(VERSION).' src/$(LIBDIR)
+
+
+4. Special instructions for libpng
+----------------------------------
+
+We use a special hack for libpng as we want to prefix all its symbols with
+"wx_" but don't want to use its build system which makes this easily possible
+(perhaps we should, but for now we don't). So, when upgrading libpng, you need
+to perform an extra step after merging the new version (and before committing
+your changes):
+
+Create a temporary build directory and run libpng configure from it using
+--with-libpng-prefix=wx_ option. Then run "make" (actually just "make png.lo"
+is sufficient as we don't really need to build the library) to create
+pnglibconf.h and pngprefix.h files in the build directory. And copy these
+files to src/png subdirectory of the wxWidgets source tree, overwriting the
+versions there.
+
+Notice that config.h generated by libpng configure is not used, we build it
+without -DHAVE_CONFIG_H as it works just fine without it on any ANSI C system
+(i.e. anywhere by now).