deps: gather backends under imgui/backends directory

stay consistent with upstream

CMakeLists.txt

@@ -1147,8 +1147,8 @@ if(USE_OPENGL)
 
 	if(NOT LIBRETRO)
 		target_sources(${PROJECT_NAME} PRIVATE
-				core/rend/gles/imgui_impl_opengl3.cpp
-				core/rend/gles/imgui_impl_opengl3.h
+				core/deps/imgui/backends/imgui_impl_opengl3.cpp
+				core/deps/imgui/backends/imgui_impl_opengl3.h
 				core/rend/gles/opengl_driver.cpp
 				core/rend/gles/opengl_driver.h)
 	endif()
@@ -1282,8 +1282,8 @@ if(USE_VULKAN)
 		target_sources(${PROJECT_NAME} PRIVATE
 				core/rend/vulkan/vulkan_driver.h
 				core/rend/vulkan/vulkan_context.cpp
-				core/rend/vulkan/imgui_impl_vulkan.cpp
-				core/rend/vulkan/imgui_impl_vulkan.h)
+				core/deps/imgui/backends/imgui_impl_vulkan.cpp
+				core/deps/imgui/backends/imgui_impl_vulkan.h)
 		if(CMAKE_SIZEOF_VOID_P EQUAL 4)
 			target_compile_definitions(${PROJECT_NAME} PRIVATE ImTextureID=ImU64)
 		endif()
@@ -1303,8 +1303,8 @@ if(WIN32 AND USE_DX9 AND NOT LIBRETRO AND NOT WINDOWS_STORE AND ("x86" IN_LIST A
 		core/rend/dx9/dx9_driver.h
 		core/rend/dx9/dxcontext.cpp
 		core/rend/dx9/dxcontext.h
-		core/rend/dx9/imgui_impl_dx9.h
-		core/rend/dx9/imgui_impl_dx9.cpp)
+		core/deps/imgui/backends/imgui_impl_dx9.h
+		core/deps/imgui/backends/imgui_impl_dx9.cpp)
 	target_sources(${PROJECT_NAME} PRIVATE ${REND_DX9_FILES})
 
 	if(NOT MINGW)
@@ -1323,8 +1323,8 @@ endif()
 if(WIN32 AND USE_DX11)
 	if(NOT LIBRETRO)
 		target_sources(${PROJECT_NAME} PRIVATE
-			core/rend/dx11/imgui_impl_dx11.cpp
-			core/rend/dx11/imgui_impl_dx11.h)
+			core/deps/imgui/backends/imgui_impl_dx11.cpp
+			core/deps/imgui/backends/imgui_impl_dx11.h)
 	endif()
 	target_sources(${PROJECT_NAME} PRIVATE
 		core/rend/dx11/dx11_driver.h

core/deps/imgui/backends/imgui_impl_opengl3.cpp

@@ -67,7 +67,7 @@
 #endif
 
 #include "wsi/gl_context.h"
-#include "glcache.h"
+#include "rend/gles/glcache.h"
 #include "hw/pvr/Renderer_if.h"
 
 // OpenGL Data

core/rend/dx11/dx11_driver.h

@@ -18,7 +18,7 @@
 */
 #pragma once
 #include "rend/imgui_driver.h"
-#include "imgui_impl_dx11.h"
+#include "imgui/backends/imgui_impl_dx11.h"
 #include "dx11context.h"
 #include "rend/gui.h"
 #include <unordered_map>

core/rend/dx11/dx11context.cpp

@@ -25,7 +25,7 @@
 #include "hw/pvr/Renderer_if.h"
 #include "emulator.h"
 #include "dx11_driver.h"
-#include "imgui_impl_dx11.h"
+#include "imgui/backends/imgui_impl_dx11.h"
 #ifdef TARGET_UWP
 #include <windows.h>
 #include <gamingdeviceinformation.h>

core/rend/dx9/dx9_driver.h

@@ -18,7 +18,7 @@
 */
 #pragma once
 #include "rend/imgui_driver.h"
-#include "imgui_impl_dx9.h"
+#include "imgui/backends/imgui_impl_dx9.h"
 #include "dxcontext.h"
 #include <unordered_map>
 

core/rend/dx9/dxcontext.cpp

@@ -25,7 +25,7 @@
 #include "hw/pvr/Renderer_if.h"
 #include "emulator.h"
 #include "dx9_driver.h"
-#include "imgui_impl_dx9.h"
+#include "imgui/backends/imgui_impl_dx9.h"
 
 DXContext theDXContext;
 

core/rend/gles/opengl_driver.cpp

@@ -17,7 +17,7 @@
     along with Flycast.  If not, see <https://www.gnu.org/licenses/>.
 */
 #include "opengl_driver.h"
-#include "imgui_impl_opengl3.h"
+#include "imgui/backends/imgui_impl_opengl3.h"
 #include "wsi/gl_context.h"
 #include "rend/osd.h"
 #include "rend/gui.h"

core/rend/gui.cpp

@@ -22,7 +22,7 @@
 #include "hw/maple/maple_if.h"
 #include "hw/maple/maple_devs.h"
 #include "imgui/imgui.h"
-#include "imgui/roboto_medium.h"
+#include "roboto_medium.h"
 #include "network/net_handshake.h"
 #include "network/ggpo.h"
 #include "wsi/context.h"

core/rend/vulkan/vulkan_context.cpp

@@ -20,7 +20,7 @@
 */
 #include "vulkan_context.h"
 #include "imgui/imgui.h"
-#include "imgui_impl_vulkan.h"
+#include "imgui/backends/imgui_impl_vulkan.h"
 #include "../gui.h"
 #ifdef USE_SDL
 #include <sdl/sdl.h>

core/rend/vulkan/vulkan_driver.h

@@ -18,7 +18,7 @@
 */
 #pragma once
 #include "rend/imgui_driver.h"
-#include "imgui_impl_vulkan.h"
+#include "imgui/backends/imgui_impl_vulkan.h"
 #include "vulkan_context.h"
 #include "texture.h"
 #include <unordered_map>