From: Nick Bowler <nbowler@draconx.ca>
Date: Fri, 14 Jun 2013 22:15:25 +0000 (-0400)
Subject: lbximg: Make libpng a soft dependency.
X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/commitdiff_plain/b54180ad4297cf2d3fd943bf78976f8d34d5eea9

lbximg: Make libpng a soft dependency.

Now that we have Netpbm output formats which do not depend on
any external libraries, we can make it possible to build lbximg
without libpng.  Adjust the build system so that lbximg is built
unconditionally and PNG output can be selectively disabled.
---

diff --git a/Makefile.am b/Makefile.am
index 48398a6..966ad2e 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -25,10 +25,7 @@ lib_LTLIBRARIES = liblbx.la
 liblbx_la_SOURCES = src/lbx.c src/fops.c src/image.c src/pack.c src/error.c
 liblbx_la_LDFLAGS = -export-symbols-regex '^lbx_'
 
-bin_PROGRAMS = lbxtool
-if BUILD_LBXIMG
-bin_PROGRAMS += lbximg
-endif
+bin_PROGRAMS = lbxtool lbximg
 if BUILD_LBXGUI
 bin_PROGRAMS += lbxgui
 endif
@@ -37,10 +34,14 @@ lbxtool_SOURCES = src/lbxtool.c src/tools.c
 lbxtool_LDADD = liblbx.la libgnu.la
 $(lbxtool_OBJECTS): $(gnulib_headers)
 
-lbximg_SOURCES = src/lbximg.c src/tools.c src/png.c src/pnm.c
+lbximg_SOURCES = src/lbximg.c src/tools.c src/pnm.c
 lbximg_LDADD = liblbx.la libgnu.la $(LIBPNG_LIBS)
 $(lbximg_OBJECTS): $(gnulib_headers)
 
+if HAVE_LIBPNG
+lbximg_SOURCES += src/png.c
+endif
+
 nodist_lbxgui_SOURCES = src/gui/lbxgui.glade.c
 lbxgui_SOURCES = src/gui/lbxgui.c src/gui/render.c src/gui/render.h \
 	src/gui/bg.xbm
diff --git a/configure.ac b/configure.ac
index 9ba3d42..224469a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,10 +1,10 @@
-dnl Copyright (C) 2009 Nick Bowler
-dnl Copying and distribution of this file, with or without modification,
-dnl are permitted in any medium without royalty provided the copyright
-dnl notice and this notice are preserved.  This file is offered as-is,
-dnl without any warranty.
+dnl Copyright © 2009, 2013 Nick Bowler
+dnl
+dnl License WTFPL2: Do What The Fuck You Want To Public License, version 2.
+dnl This is free software: you are free to do what the fuck you want to.
+dnl There is NO WARRANTY, to the extent permitted by law.
 
-AC_PREREQ([2.62])
+AC_PREREQ([2.68])
 AC_INIT([liblbx], [0.1], [toom-devel@lists.sourceforge.net])
 AC_CONFIG_SRCDIR([src/lbx.c])
 AC_CONFIG_HEADER([config.h])
@@ -23,22 +23,20 @@ gl_INIT
 
 m4_include([lib/gnulib.mk])
 
-PKG_PROG_PKG_CONFIG
+AC_ARG_WITH([libpng],
+	[AS_HELP_STRING([--with-libpng],
+		[build support for PNG output using libpng. [default=auto]])],
+	[with_libpng=$withval],
+	[with_libpng=auto])
 
-AC_ARG_ENABLE([lbximg],
-	[AS_HELP_STRING([--enable-lbximg],
-		[build the lbximg tool (requires libpng) [default=auto]])],
-	[enable_lbximg=$enableval],
-	[enable_lbximg=auto])
+AS_CASE([$with_libpng],
+	[no], [have_libpng=false],
+	[yes], [DX_CHECK_LIBPNG([1.5], [have_libpng=true])],
+	[DX_CHECK_LIBPNG([1.5], [have_libpng=true], [have_libpng=false])])
 
-have_libpng=no
-if test x"$enable_lbximg" = x"auto"; then
-DX_CHECK_LIBPNG([1.5], [have_libpng=yes], [have_libpng=no])
-fi
-if test x"$enable_lbximg" = x"yes"; then
-DX_CHECK_LIBPNG([1.5], [have_libpng=yes])
-fi
-AM_CONDITIONAL([BUILD_LBXIMG], [test x"$have_libpng" = x"yes"])
+AM_CONDITIONAL([HAVE_LIBPNG], [$have_libpng])
+AS_IF([$have_libpng], [AC_DEFINE([HAVE_LIBPNG], [1],
+	[Define to 1 if libpng support is available])])
 
 AC_ARG_ENABLE([lbxgui],
 	[AS_HELP_STRING([--enable-lbxgui],
@@ -46,14 +44,12 @@ AC_ARG_ENABLE([lbxgui],
 	[enable_lbxgui=$enableval],
 	[enable_lbxgui=auto])
 
-have_gtk=no
-if test x"$enable_lbxgui" = x"auto"; then
-DX_CHECK_GTK2([2.16], [have_gtk=yes], [have_gtk=no])
-fi
-if test x"$enable_lbxgui" = x"yes"; then
-DX_CHECK_GTK2([2.16], [have_gtk=yes])
-fi
-AM_CONDITIONAL([BUILD_LBXGUI], [test x"$have_gtk" = x"yes"])
+AS_CASE([$enable_lbxgui],
+	[no], [have_gtk=false],
+	[yes], [DX_CHECK_GTK2([2.16], [have_gtk=true])],
+	[DX_CHECK_GTK2([2.16], [have_gtk=true], [have_gtk=false])])
+
+AM_CONDITIONAL([BUILD_LBXGUI], [$have_gtk])
 
 AC_CONFIG_FILES([
 	Makefile
diff --git a/src/lbximg.c b/src/lbximg.c
index ada1692..b2c97f2 100644
--- a/src/lbximg.c
+++ b/src/lbximg.c
@@ -62,7 +62,9 @@ static const struct img_format {
 	char name[4];
 	bool enabled;
 } formats[] = {
+#if HAVE_LIBPNG
 	{ img_output_png, "png", 1 },
+#endif
 	{ img_output_pam, "pam", 1 },
 	{ img_output_ppm, "ppm", 1 },
 	{ img_output_pbm, "pbm", 1 },