From 44bda93154ed1444cb3d3148f1187bd1511e8c4a Mon Sep 17 00:00:00 2001 From: Glenn Randers-Pehrson Date: Thu, 18 Sep 2014 09:25:50 -0500 Subject: [PATCH] [libpng16] Updated INSTALL info about pnglibconf.h --- INSTALL | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/INSTALL b/INSTALL index f4df80a8b..1b66d89ac 100644 --- a/INSTALL +++ b/INSTALL @@ -333,7 +333,7 @@ built. pngconf.h no longer includes pngusr.h; therefore, pngusr.h is ignored after the build of pnglibconf.h and it is never included in an application build. -The rarely used alternative of adding a list of feature macros to the +The formerly used alternative of adding a list of feature macros to the CPPFLAGS setting in the build also still works; however, the macros will be copied to pnglibconf.h and this may produce macro redefinition warnings when the individual C files are compiled. @@ -349,12 +349,19 @@ functioning awk called 'nawk'. Configuration options are now documented in scripts/pnglibconf.dfa. This file also includes dependency information that ensures a configuration is -consistent; that is, if a feature is switched off dependent features are -also removed. As a recommended alternative to using feature macros in +consistent; that is, if a feature is switched off, dependent features are +also switched off. As a recommended alternative to using feature macros in pngusr.h a system builder may also define equivalent options in pngusr.dfa (or, indeed, any file) and add that to the configuration by setting DFA_XTRA to the file name. The makefiles in contrib/pngminim illustrate -how to do this, and illustrate a case where pngusr.h is still required. +how to do this, and also illustrate a case where pngusr.h is still required. + +After you have built libpng, the definitions that were recorded in +pnglibconf.h are available to your application (pnglibconf.h is included +in png.h and gets installed alongside png.h and pngconf.h in your +$PREFIX/include directory). Do not edit pnglibconf.h after you have built +libpng, because than the settings would not accurately reflect the settings +that were used to build libpng. XV. Configuring libpng for multiprocessing