add example cmake file for win32 directx11 backend

examples/example_win32_directx11/CMakeLists.txt

@@ -0,0 +1,58 @@
+# CMakeLists for building imgui example app
+# To build: $ cd example_win32_directx11
+#			$ mkdir build && cd build
+#			$ cmake .. (Generator flag optional: eg -G 'MSYS Makefiles')
+#			$ make OR ninja OR .sln (depends on your cmake-generator)
+
+cmake_minimum_required(VERSION 3.12) # requires 3.12 for the list(TRANSFORM ...) shortcut
+
+project(imgui_win32_directx11 LANGUAGES CXX VERSION 0.0.1)
+
+# set the path of imgui top-level folder here
+set(IMGUI_DIR ../../)
+
+# add platform-agnostic sources...
+set(IMGUI_SRC
+        imgui_draw.cpp
+        imgui_demo.cpp
+        imgui_tables.cpp
+        imgui_widgets.cpp
+        imgui.cpp)
+# add platform-specific sources...
+set(IMGUI_BACKEND_SRC
+        backends/imgui_impl_dx11.cpp
+        backends/imgui_impl_win32.cpp)
+
+# prepend imgui top-level path to src files
+list(TRANSFORM IMGUI_SRC PREPEND ${IMGUI_DIR})
+list(TRANSFORM IMGUI_BACKEND_SRC PREPEND ${IMGUI_DIR})
+
+# compiler flags
+set(CFLAGS 
+        -Wall 
+        -Werror 
+        -Wnarrowing
+        -O3
+        -DNDEBUG)
+# necessary graphics libraries
+set(LDLIBS 
+        d3d11 
+        d3dcompiler 
+        dwmapi)
+
+# add library with the imgui sources
+add_library(imgui_win32_directx11  ${IMGUI_SRC} ${IMGUI_BACKEND_SRC})
+# set compiler flags
+target_compile_options(imgui_win32_directx11  PRIVATE ${CFLAGS})
+# link against necessary graphics libraries
+target_link_libraries(imgui_win32_directx11  PRIVATE ${LDLIBS})
+# include headers from the IMGUI_DIR
+target_include_directories(imgui_win32_directx11  PRIVATE ${IMGUI_DIR})
+
+# finally, build the example main.cpp 
+add_executable(imgui_win32_directx11_example main.cpp)
+# link example exe against the imgui library
+target_link_libraries(imgui_win32_directx11_example PRIVATE imgui_win32_directx11)
+# include headers from the IMGUI_DIR and backends
+target_include_directories(imgui_win32_directx11_example  PRIVATE ${IMGUI_DIR} ${IMGUI_DIR}/backends)
+