Fix pkgconfig file and add CMake module files

This commit fixes the pkgconfig file so that opengl and fltk
libraries and include directories are added to stage.pc, so that
third-party packages can use stage.pc to link with stage without any
other code.

This commit also adds stage-config and stage-config-version cmake module
files, so that find_package(stage) will work.  These cmake modules also
include the opengl and fltk libraries and include directories, so that
third-party packages can link against stage without any other code.

CMakeLists.txt

@@ -127,10 +127,31 @@ ELSE( PLAYER_FOUND )
   MESSAGE(STATUS ${INDENT} "Player not detected. If Player is installed but not detected, check your PKG_CONFIG_PATH." )
 ENDIF( PLAYER_FOUND )
 
+# Format the fltk libraries for inclusion in stage.pc
+SET(PC_LIBRARIES ${FLTK_LIBRARIES} ${OPENGL_LIBRARIES})
+SET(PC_INCLUDE_DIRS ${FLTK_INCLUDE_DIR} ${OPENGL_INCLUDE_DIR})
+
+SET(PC_LINK_FLAGS "")
+FOREACH(LIB ${PC_LIBRARIES})
+  GET_FILENAME_COMPONENT(LIBNAME ${LIB} NAME_WE)
+  STRING(REGEX REPLACE "^lib" "" LINKLIB ${LIBNAME})
+  SET(PC_LINK_FLAGS "${PC_LINK_FLAGS} -l${LINKLIB}")
+ENDFOREACH(LIB ${FLTK_LIBRARIES})
+
+SET(PC_INCLUDE_FLAGS "")
+FOREACH(INC ${PC_INCLUDE_DIRS})
+  SET(PC_INCLUDE_FLAGS "${PC_INCLUDE_FLAGS} -I${INC}")
+ENDFOREACH(INC ${PC_INCLUDE_DIRS})
+
 # Create the pkgconfig file
 CONFIGURE_FILE (${CMAKE_CURRENT_SOURCE_DIR}/stage.pc.in ${CMAKE_CURRENT_BINARY_DIR}/stage.pc @ONLY)
 INSTALL (FILES ${CMAKE_CURRENT_BINARY_DIR}/stage.pc DESTINATION ${PROJECT_LIB_DIR}/pkgconfig/)
 
+# Create the CMake module files
+CONFIGURE_FILE (${CMAKE_CURRENT_SOURCE_DIR}/stage-config.cmake.in ${CMAKE_CURRENT_BINARY_DIR}/stage-config.cmake @ONLY)
+CONFIGURE_FILE (${CMAKE_CURRENT_SOURCE_DIR}/stage-config-version.cmake.in ${CMAKE_CURRENT_BINARY_DIR}/stage-config-version.cmake @ONLY)
+INSTALL (FILES ${CMAKE_CURRENT_BINARY_DIR}/stage-config.cmake ${CMAKE_CURRENT_BINARY_DIR}/stage-config-version.cmake DESTINATION ${PROJECT_LIB_DIR}/cmake/${PROJECT_NAME})
+
 MESSAGE( STATUS "Installation path CMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}" )
 
 # all targets need these include directories

stage-config-version.cmake.in

@@ -0,0 +1,11 @@
+set(PACKAGE_VERSION "@VERSION@")
+
+# Check whether the requested PACKAGE_FIND_VERSION is compatible
+if("${PACKAGE_VERSION}" VERSION_LESS "${PACKAGE_FIND_VERSION}")
+  set(PACKAGE_VERSION_COMPATIBLE FALSE)
+else()
+  set(PACKAGE_VERSION_COMPATIBLE TRUE)
+  if ("${PACKAGE_VERSION}" VERSION_EQUAL "${PACKAGE_FIND_VERSION}")
+    set(PACKAGE_VERSION_EXACT TRUE)
+  endif()
+endif()

stage-config.cmake.in

@@ -0,0 +1,14 @@
+# - Config file for Stage
+# It defines the following variables:
+#    STAGE_INCLUDE_DIRS - Stage Include directories
+#    STAGE_LIBRARIES    - Stage link libraries
+
+set(STAGE_INCLUDE_DIRS "@CMAKE_INSTALL_PREFIX@/include/@PROJECT_NAME@-@APIVERSION@" 
+  "@FLTK_INCLUDE_DIR@"
+  "@OPENGL_INCLUDE_DIR@")
+list(REMOVE_DUPLICATES STAGE_INCLUDE_DIRS)
+set(STAGE_LIBRARIES 
+  "@CMAKE_INSTALL_PREFIX@/@PROJECT_LIB_DIR@/libstage.so"
+  "@FLTK_LIBRARIES@"
+  "@OPENGL_gl_LIBRARIES@")
+

stage.pc.in

@@ -10,5 +10,5 @@ Version: @VERSION@
 # add the incantations to the flags and libs lines below 
 Requires:
 
-Libs: -L${prefix}/@PROJECT_LIB_DIR@ -lstage @FLTK_LDFLAGS@
-Cflags: -I${prefix}/include/Stage-@APIVERSION@ @FLTK_CFLAGS@ 
+Libs: -L${prefix}/@PROJECT_LIB_DIR@ -lstage @PC_LINK_FLAGS@
+Cflags: -I${prefix}/include/Stage-@APIVERSION@ @PC_INCLUDE_FLAGS@