Implement 2D graphic API (#87)

* Implement 2D graphic library based on LittlevGL

* Add lvgl license file

samples/gui/lvgl-native-ui-app/CMakeLists.txt

@@ -0,0 +1,56 @@
+# Copyright (C) 2019 Intel Corporation.  All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+cmake_minimum_required (VERSION 2.8.2)
+message ("lvgl_native_ui_app...")
+project (lvgl_native_ui_app)
+
+#################################################################
+#SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -m32 -g)
+
+set(lv_name lvgl)
+set(lv_drivers_name lv_drivers)
+set(LVGL_SOURCE_DIR ${CMAKE_CURRENT_SOURCE_DIR}/${lv_name})
+set(LVGL_DRIVER_DIR ${CMAKE_CURRENT_SOURCE_DIR}/${lv_drivers_name})
+
+if ((NOT EXISTS ${LVGL_SOURCE_DIR}) OR (NOT EXISTS ${LVGL_DRIVER_DIR}))
+        configure_file(${CMAKE_CURRENT_SOURCE_DIR}/CMakeLists.txt.in ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl/CMakeLists.txt)
+
+        execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
+                RESULT_VARIABLE result
+                WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl )
+        if(result)
+                message(FATAL_ERROR "CMake step for lvgl failed: ${result}")
+        endif()
+        execute_process(COMMAND ${CMAKE_COMMAND} --build .
+                RESULT_VARIABLE result
+                WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/download_lvgl )
+        if(result)
+                message(FATAL_ERROR "Build step for lvgl failed: ${result}")
+        endif()
+endif()
+
+#################################
+set(CMAKE_C_STANDARD 11)#C11
+set(CMAKE_CXX_STANDARD 17)#C17
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+INCLUDE_DIRECTORIES(${PROJECT_SOURCE_DIR})
+
+file(GLOB_RECURSE INCLUDES "${LVGL_DRIVER_DIR}/*.h" "${LVGL_SOURCE_DIR}/*.h"  "./*.h" )
+file(GLOB_RECURSE SOURCES  "${LVGL_DRIVER_DIR}/*.c" "${LVGL_SOURCE_DIR}/*.c" )
+
+add_executable(lvgl_native_ui_app main.c get_time.c ${SOURCES} ${INCLUDES})
+target_link_libraries(lvgl_native_ui_app PRIVATE SDL2 )
+