Moved finding of RSVG, Poppler-glib and GtkGl out into their own Find*.cmake modules to enable easier specialization.

CMakeModules/FindFLTK.cmake

@@ -1,4 +1,4 @@
-# Locate gdal
+# Locate FLTK
 # This module defines
 # FLTK_LIBRARY
 # FLTK_FOUND, if false, do not try to link to gdal 

CMakeModules/FindGtkGl.cmake

@@ -0,0 +1,16 @@
+#use pkg-config to find various modues
+INCLUDE(FindPkgConfig OPTIONAL)
+
+IF(PKG_CONFIG_FOUND)
+
+    INCLUDE(FindPkgConfig)
+
+    PKG_CHECK_MODULES(GTK gtk+-2.0)
+
+    IF(WIN32)
+        PKG_CHECK_MODULES(GTKGL gtkglext-win32-1.0)
+    ELSE()
+        PKG_CHECK_MODULES(GTKGL gtkglext-x11-1.0)
+    ENDIF()
+
+ENDIF()

CMakeModules/FindPoppler-glib.cmake

@@ -0,0 +1,41 @@
+#use pkg-config to find various modues
+INCLUDE(FindPkgConfig OPTIONAL)
+
+IF(PKG_CONFIG_FOUND)
+
+    INCLUDE(FindPkgConfig)
+
+    PKG_CHECK_MODULES(CAIRO cairo)
+    PKG_CHECK_MODULES(POPPLER poppler-glib)
+
+    IF (POPPLER_FOUND)
+
+        INCLUDE(CheckCXXSourceRuns)
+
+        SET(CMAKE_REQUIRED_INCLUDES ${POPPLER_INCLUDE_DIRS})
+
+        # Do step by step checking,
+        CHECK_CXX_SOURCE_RUNS("
+        #include <cstdlib>
+        #include <poppler.h>
+        int main()
+        {
+        #ifdef POPPLER_HAS_CAIRO
+           return EXIT_SUCCESS;
+        #else
+           return EXIT_FAILURE
+        #endif
+        }
+        " POPPLER_HAS_CAIRO)
+
+        IF (NOT POPPLER_HAS_CAIRO)
+            SET(POPPLER_FOUND FALSE)
+        ENDIF()
+
+    ENDIF()
+
+#    IF (POPPLER_FOUND AND (NOT POPPLER_LIBRARIES OR NOT POPPLER_INCLUDE_DIRS) )
+#        SET(POPPLER_FOUND FALSE)
+#    ENDIF()
+
+ENDIF()

CMakeModules/FindRSVG.cmake

@@ -0,0 +1,16 @@
+#use pkg-config to find various modues
+INCLUDE(FindPkgConfig OPTIONAL)
+
+IF(PKG_CONFIG_FOUND)
+
+    INCLUDE(FindPkgConfig)
+
+    PKG_CHECK_MODULES(RSVG librsvg-2.0)
+    PKG_CHECK_MODULES(CAIRO cairo)
+
+    IF (RSVG_FOUND AND NOT CAIRO_FOUND)
+       SET(RSVG_FOUND FALSE)
+    ENDIF()
+
+
+ENDIF()