Add cmake stuff for retrieving argagg include path

Concerns issue #1

CMakeLists.txt

@@ -98,6 +98,7 @@ set (CMAKE_INCLUDE_PATH ${CMAKE_INSTALL_PREFIX}/include)
 set (CMAKE_LIBRARY_PATH ${CMAKE_INSTALL_PREFIX}/lib)
 find_package (Intl REQUIRED)
 find_package (Iconv REQUIRED)
+find_package (Argagg REQUIRED)
 
 find_package (PkgConfig REQUIRED)
 pkg_search_module (SDL2 REQUIRED sdl2)

cmake/FindArgagg.cmake

@@ -0,0 +1,37 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+#.rst:
+# FindArgagg
+# --------
+#
+# Find the libargagg headers and libraries.
+#
+# This module reports information about the libargagg
+# installation in several variables.  General variables::
+#
+#   Argagg_FOUND - true if the libargagg headers and libraries were found
+#   Argagg_INCLUDE_DIRS - the directory containing the libargagg headers
+#
+# The following cache variables may also be set::
+#
+#   Argagg_INCLUDE_DIR - the directory containing the libargagg headers
+
+
+# Based on FindIconv written by Roger Leigh <rleigh@codelibre.net>
+
+# Find include directory
+find_path(Argagg_INCLUDE_DIR
+          NAMES "argagg/argagg.hpp"
+          DOC "libargagg include directory")
+mark_as_advanced(Argagg_INCLUDE_DIR)
+
+include(${CMAKE_ROOT}/Modules/FindPackageHandleStandardArgs.cmake)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(Argagg
+                                  FOUND_VAR Argagg_FOUND
+                                  REQUIRED_VARS Argagg_INCLUDE_DIR
+                                  FAIL_MESSAGE "Failed to find libargagg")
+
+if(Argagg_FOUND)
+  set(Argagg_INCLUDE_DIRS "${Argagg_INCLUDE_DIR}")
+endif()