Add cairo interface.

src/graphics/CMakeLists.txt

@@ -1,8 +1,46 @@
-list(APPEND graphics_LIB_INCLUDES OpenGlInterface.cpp)
-list(APPEND graphics_HEADERS OpenGlInterface.h)
+list(APPEND graphics_LIB_INCLUDES 
+    DrawingContext.cpp
+    DrawingManager.cpp
+    DrawingSurface.cpp
+    opengl/OpenGlInterface.cpp
+    cairo/CairoInterface.cpp
+    cairo/CairoDrawingSurface.cpp
+    cairo/CairoDrawingContext.cpp)
+    
+list(APPEND graphics_HEADERS 
+    opengl/OpenGlInterface.h
+    cairo/CairoInterface.h
+    INativeDrawingSurface.h
+    INativeDrawingContext.h)
 
-add_library(graphics SHARED ${graphics_LIB_INCLUDES} ${graphics_HEADERS})
+find_package(PkgConfig)
+PKG_CHECK_MODULES(PC_CAIRO cairo)
+FIND_PATH(CAIRO_INCLUDE_DIRS
+    NAMES cairo.h
+    HINTS ${PC_CAIRO_INCLUDEDIR}
+          ${PC_CAIRO_INCLUDE_DIRS}
+    PATH_SUFFIXES cairo
+)
+
+FIND_LIBRARY(CAIRO_LIBRARIES
+    NAMES cairo
+    HINTS ${PC_CAIRO_LIBDIR}
+          ${PC_CAIRO_LIBRARY_DIRS}
+)
+
+add_library(graphics SHARED 
+    ${graphics_LIB_INCLUDES} 
+    ${graphics_HEADERS})
+    
+target_include_directories(graphics PUBLIC
+                          ${CAIRO_INCLUDE_DIRS}
+                          "${CMAKE_CURRENT_SOURCE_DIR}"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/cairo"
+                          "${CMAKE_CURRENT_SOURCE_DIR}/opengl"
+                          "${PROJECT_SOURCE_DIR}/src/geometry/"
+                          "${PROJECT_SOURCE_DIR}/src/visual_elements/"
+                          )
                           
-target_link_libraries(graphics PUBLIC GL)
+target_link_libraries(graphics PUBLIC visual_elements GL ${CAIRO_LIBRARIES})
 
 set_property(TARGET graphics PROPERTY FOLDER src)