app: clean compilation with external libmypaint.

The work-in-progress was using a source tree of libmypaint embedded
into GIMP tree. This is a cleaning with pkg-config test in configure,
and correct includes.

app/Makefile.am

@@ -165,7 +165,6 @@ gimpconsoleldadd = \
 	file/libappfile.a		\
 	text/libapptext.a		\
 	paint/libapppaint.a		\
-	paint/libmypaint.a		\
 	operations/libappoperations.a	\
 	gegl/libappgegl.a		\
 	config/libappconfig.a		\
@@ -189,6 +188,7 @@ gimpconsoleldadd = \
 	$(LCMS_LIBS)			\
 	$(Z_LIBS)			\
 	$(JSON_C_LIBS)			\
+	$(LIBMYPAINTGEGL_LIBS)		\
 	$(INTLLIBS)			\
 	$(RT_LIBS)			\
 	$(libm)

app/paint/Makefile.am

@@ -6,50 +6,13 @@ AM_CPPFLAGS = \
 	-I$(top_srcdir)				\
 	-I$(top_builddir)/app			\
 	-I$(top_srcdir)/app			\
-	-I$(top_srcdir)/app/paint/libmypaint	\
-	-std=c99				\
-	-DHAVE_JSON_C=1				\
-	$(JSON_C_CFLAGS)			\
 	$(CAIRO_CFLAGS)				\
 	$(GEGL_CFLAGS)				\
 	$(GDK_PIXBUF_CFLAGS)			\
+	$(LIBMYPAINTGEGL_CFLAGS)		\
 	-I$(includedir)
 
-noinst_LIBRARIES = libmypaint.a libapppaint.a
-
-libmypaint_a_SOURCES = \
-	libmypaint/mapping.c				\
-	libmypaint/mapping.h				\
-	libmypaint/helpers.c				\
-	libmypaint/helpers.h				\
-	libmypaint/brushmodes.c				\
-	libmypaint/brushmodes.h				\
-	libmypaint/fifo.c				\
-	libmypaint/fifo.h				\
-	libmypaint/operationqueue.c			\
-	libmypaint/operationqueue.h			\
-	libmypaint/rng-double.c				\
-	libmypaint/rng-double.h				\
-	libmypaint/utils.c				\
-	libmypaint/utils.h				\
-	libmypaint/tilemap.c				\
-	libmypaint/tilemap.h				\
-	libmypaint/mypaint.c				\
-	libmypaint/mypaint.h				\
-	libmypaint/mypaint-brush.c			\
-	libmypaint/mypaint-brush.h			\
-	libmypaint/mypaint-brush-settings.c		\
-	libmypaint/mypaint-brush-settings.h		\
-	libmypaint/mypaint-fixed-tiled-surface.c	\
-	libmypaint/mypaint-fixed-tiled-surface.h	\
-	libmypaint/mypaint-surface.c			\
-	libmypaint/mypaint-surface.h			\
-	libmypaint/mypaint-tiled-surface.c		\
-	libmypaint/mypaint-tiled-surface.h		\
-	libmypaint/mypaint-rectangle.c			\
-	libmypaint/mypaint-rectangle.h			\
-	libmypaint/gegl/mypaint-gegl-surface.c		\
-	libmypaint/gegl/mypaint-gegl-surface.h
+noinst_LIBRARIES = libapppaint.a
 
 libapppaint_a_sources = \
 	paint-enums.h			\

app/paint/gimpmybrush.c

@@ -23,9 +23,9 @@
 #include <gdk-pixbuf/gdk-pixbuf.h>
 #include <gegl.h>
 
-#include "libmypaint/mypaint-brush.h"
-#include "libmypaint/mypaint-tiled-surface.h"
-#include "libmypaint/gegl/mypaint-gegl-surface.h"
+#include <mypaint-brush.h>
+#include <mypaint-tiled-surface.h>
+#include <mypaint-gegl-surface.h>
 
 #include "libgimpmath/gimpmath.h"
 #include "libgimpcolor/gimpcolor.h"

configure.ac

@@ -66,6 +66,7 @@ m4_define([poppler_required_version], [0.12.4])
 m4_define([poppler_data_required_version], [0.4.7])
 m4_define([libgudev_required_version], [167])
 m4_define([gexiv2_required_version], [0.6.1])
+m4_define([libmypaint_required_version], [1.1])
 m4_define([lcms_required_version], [2.6])
 m4_define([libpng_required_version], [1.2.37])
 m4_define([liblzma_required_version], [5.0.0])
@@ -396,9 +397,8 @@ CFLAGS="$CFLAGS $extra_warnings"
 # can cause random behavior. If compile breaks due to the following,
 # come to us and we will point you to a newer version which works.
 #
-# Temporarily disabled -- mypaint brush
-# GIMP_DETECT_CFLAGS(extra_warnings, '-Werror=missing-prototypes')
-# CFLAGS="$CFLAGS $extra_warnings"
+GIMP_DETECT_CFLAGS(extra_warnings, '-Werror=missing-prototypes')
+CFLAGS="$CFLAGS $extra_warnings"
 
 GIMP_DETECT_CFLAGS(extra_warnings, '-Wstrict-prototypes')
 CFLAGS="$CFLAGS $extra_warnings"
@@ -725,6 +725,8 @@ PKG_CHECK_MODULES(HARFBUZZ, harfbuzz >= harfbuzz_required_version)
 
 PKG_CHECK_MODULES(GEXIV2, gexiv2 >= gexiv2_required_version)
 
+PKG_CHECK_MODULES(LIBMYPAINTGEGL, libmypaint-gegl >= libmypaint_required_version)
+
 ##########################################
 # Check for some special functions we need
 ##########################################
@@ -1630,13 +1632,6 @@ AC_SUBST(JP2_LIBS)
 PKG_CHECK_MODULES(LCMS, lcms2 >= lcms_required_version)
 
 
-##################
-# Check for json-c -- temporary for mypaint brush
-##################
-
-PKG_CHECK_MODULES(JSON_C, json-c)
-
-
 ######################
 # Check for libXcursor
 ######################