Review CMake / backend selection

pthom · Feb 6, 2024 · 3fd23b5 · 3fd23b5
1 parent a279bdf
commit 3fd23b5
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Showing 6 changed files with 55 additions and 46 deletions.
diff --git a/.github/workflows/cpp_lib.yml b/.github/workflows/cpp_lib.yml
@@ -36,5 +36,5 @@ jobs:
       run: |
         mkdir build
         cd build
-        cmake .. -DHELLOIMGUI_USE_GLFW_OPENGL3=ON -DHELLOIMGUI_USE_SDL_OPENGL3=ON -DCMAKE_BUILD_TYPE=Release -DHELLOIMGUI_DOWNLOAD_FREETYPE_IF_NEEDED=ON
+        cmake .. -DHELLOIMGUI_USE_GLFW3=ON -DHELLOIMGUI_USE_SDL2=ON  -DHELLOIMGUI_HAS_OPENGL3=ON -DCMAKE_BUILD_TYPE=Release -DHELLOIMGUI_DOWNLOAD_FREETYPE_IF_NEEDED=ON
         cmake --build . --config Release -j 3
diff --git a/.github/workflows/ios.yml b/.github/workflows/ios.yml
@@ -35,7 +35,6 @@ jobs:
         cmake .. \
           -GXcode \
           -DCMAKE_TOOLCHAIN_FILE=../external/imgui_bundle/external/hello_imgui/hello_imgui/hello_imgui_cmake/ios-cmake/ios.toolchain.cmake \
-          -DHELLOIMGUI_USE_SDL_OPENGL3=ON \
           -DPLATFORM=SIMULATOR64
 
     - name: Build for simulator

diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -38,6 +38,47 @@ include(${CMAKE_CURRENT_LIST_DIR}/external/hello_imgui/hello_imgui/hello_imgui_c
 include(${HELLOIMGUI_CMAKE_PATH}/hello_imgui_build_lib.cmake)
 
 
+# Backends
+# -----------------------------------------------------------------------------
+# <Backends> # do not remove this line (used by the script that generates the documentation)
+# (this part is a direct copy from HelloImGui CmakeList, reproduced here for convenience)
+# You need to select at least two backends:
+#
+#     - At least one (or more) rendering backend (OpenGL3, Metal, Vulkan, DirectX11, DirectX12)
+#       Make your choice according to your needs and your target platforms, between:
+#          -DHELLOIMGUI_HAS_OPENGL3=ON    # This is the recommended choice, especially for beginners
+#          -DHELLOIMGUI_HAS_METAL=ON      # Apple only, advanced users only
+#          -DHELLOIMGUI_HAS_VULKAN=ON     # Advanced users only
+#          -DHELLOIMGUI_HAS_DIRECTX11=ON  # Windows only, still experimental
+#          -DHELLOIMGUI_HAS_DIRECTX12=ON  # Windows only, advanced users only, still experimental
+#
+#     - At least one (or more) platform backend (SDL2, Glfw3):
+#      Make your choice according to your needs and your target platforms, between:
+#          -DHELLOIMGUI_USE_SDL2=ON
+#          -DHELLOIMGUI_USE_GLFW3=ON
+#
+# If you make no choice, the default will be selected:
+#     HELLOIMGUI_USE_GLFW3 + HELLOIMGUI_HAS_OPENGL3
+#
+# Note about rendering backends:
+#   OpenGL3 is the recommended choice as a starting point, especially for beginners.
+#   Vulkan, Metal, and DirectX11, DirectX12 do work, but you may need to customize the rendering code inside HelloImGui:
+#   see src/hello_imgui/internal/backend_impls/rendering_xxxx.[h,cpp]
+#   (using those backends probably implies that you want to heavily customize the rendering code)
+#
+################################################################################
+# Platform backends:
+option(HELLOIMGUI_USE_GLFW3 "Use Glfw3 as a platform backend" OFF)
+option(HELLOIMGUI_USE_SDL2 "Use Sdl2 as a platform backend" OFF)
+# Rendering backends
+option(HELLOIMGUI_HAS_OPENGL3 "Use OpenGL3 as a rendering backend" OFF)
+option(HELLOIMGUI_HAS_METAL "Use Metal as a rendering backend" OFF)
+option(HELLOIMGUI_HAS_VULKAN "Use Vulkan as a rendering backend" OFF)
+option(HELLOIMGUI_HAS_DIRECTX11 "Use DirectX11 as a rendering backend" OFF)
+option(HELLOIMGUI_HAS_DIRECTX12 "Use DirectX12 as a rendering backend" OFF)
+# </Backends>  # do not remove this line (used by the script that generates the documentation)
+
+
 # IMGUI_BUNDLE_BUILD_PYTHON: include python support
 # -----------------------------------------------------------------------------
 # (OFF when building the cpp library; ON by default when using pip install.
@@ -51,47 +92,16 @@ else()
     set(IMGUI_BUNDLE_BUILD_CPP ON)
 endif()
 
-
-# -----------------------------------------------------------------------------
-# BACKENDS
-# Backends are defined by a combination of a platform backend (Sdl2, Glfw3),
-# and a renderer backend (OpenGL3, Vulkan, Metal, etc)
-#
-# By default, imgui_bundle will use
-# - Glfw+OpenGL3 on desktop platforms (Windows, Linux, macOS):
-#       -DHELLOIMGUI_USE_GLFW_OPENGL3=ON
-# - SDL+OpenGl3 on emscripten, iOS and Android:
-#       -DHELLOIMGUI_USE_SDL_OPENGL3=ON
-#
-# Notes:
-# - For python bindings:
-#       we force the usage of Glfw+OpenGL3 (HELLOIMGUI_USE_GLFW_OPENGL3), but you can use SDL via a pure python backend.
-#       glfw will be built from the submodule external/glfw/glfw
-# - Glfw3 may be downloaded automatically if not found as a system library:
-#    set HELLOIMGUI_DOWNLOAD_GLFW_IF_NEEDED to OFF to disable this behavior
-#    (HELLOIMGUI_DOWNLOAD_GLFW_IF_NEEDED is OFF by default under Linux)
-# - SDL2 may be downloaded automatically if not found as a system library:
-#    set HELLOIMGUI_DOWNLOAD_SDL_IF_NEEDED to OFF to disable this behavior.
-#    (HELLOIMGUI_DOWNLOAD_SDL_IF_NEEDED is OFF by default under Linux)
-# -----------------------------------------------------------------------------
-_him_check_if_no_backend_selected(no_backend_selected)
-# Select default backend if none selected
-if (no_backend_selected)
-    if (EMSCRIPTEN OR ANDROID OR IOS)
-        set(default_use_glfw_opengl3 OFF)
-        set(default_use_sdl_opengl3 ON)
-    else()
-        set(default_use_glfw_opengl3 ON)
-        set(default_use_sdl_opengl3 OFF)
-    endif()
-    option(HELLOIMGUI_USE_GLFW_OPENGL3 "Use GLFW+OpenGL3 backend" ${default_use_glfw_opengl3})
-    option(HELLOIMGUI_USE_SDL_OPENGL3 "Use SDL+OpenGL3 backend" ${default_use_sdl_opengl3})
-endif()
-
 # For python bindings, we force the usage of Glfw+OpenGL3
 if(IMGUI_BUNDLE_BUILD_PYTHON)
-    set(HELLOIMGUI_USE_GLFW_OPENGL3 ON CACHE BOOL "" FORCE)
-    set(HELLOIMGUI_USE_SDL_OPENGL3 OFF CACHE BOOL "" FORCE)
+    set(HELLOIMGUI_USE_GLFW3 ON CACHE BOOL "" FORCE)
+    set(HELLOIMGUI_HAS_OPENGL3 ON CACHE BOOL "" FORCE)
+
+    set(HELLOIMGUI_USE_SDL2 OFF CACHE BOOL "" FORCE)
+    set(HELLOIMGUI_HAS_METAL OFF CACHE BOOL "" FORCE)
+    set(HELLOIMGUI_HAS_VULKAN OFF CACHE BOOL "" FORCE)
+    set(HELLOIMGUI_HAS_DIRECTX11 OFF CACHE BOOL "" FORCE)
+    set(HELLOIMGUI_HAS_DIRECTX12 OFF CACHE BOOL "" FORCE)
 endif()
 
 # -----------------------------------------------------------------------------

diff --git a/_example_integration b/_example_integration
diff --git a/bindings/imgui_bundle/demos_cpp/demos_immapp/imgui_example_glfw_opengl3.cpp b/bindings/imgui_bundle/demos_cpp/demos_immapp/imgui_example_glfw_opengl3.cpp
@@ -1,4 +1,4 @@
-#ifdef HELLOIMGUI_USE_GLFW_OPENGL3
+#if defined(HELLOIMGUI_HAS_OPENGL3) && defined(HELLOIMGUI_USE_GLFW3)
 
 #ifndef __EMSCRIPTEN__ // to keep the build process simple, this demo is currently disabled with emscripten (although ImGui and Imgui Bundle are perfectly compatible with emscripten)
 
@@ -222,7 +222,7 @@ int main(int, char**)
 int main(int, char**) {}
 #endif
 
-#else // #ifdef HELLOIMGUI_USE_GLFW_OPENGL3
+#else // #if defined(HELLOIMGUI_HAS_OPENGL3) && defined(HELLOIMGUI_USE_GLFW3)
 #include <stdio.h>
 int main() { printf("Glfw not found!"); }
 #endif
diff --git a/imgui_bundle_cmake/imgui_bundle_build_lib.cmake b/imgui_bundle_cmake/imgui_bundle_build_lib.cmake
@@ -65,10 +65,10 @@ endfunction()
 
 function(ibd_shout_on_deprecated_options)
     if (DEFINED IMGUI_BUNDLE_WITH_GLFW)
-        message(FATAL_ERROR "IMGUI_BUNDLE_WITH_GLFW is deprecated. Please use HELLOIMGUI_USE_GLFW_OPENGL3 instead")
+        message(FATAL_ERROR "IMGUI_BUNDLE_WITH_GLFW is deprecated. Please use HELLOIMGUI_USE_GLFW3 + HELLOIMGUI_HAS_OPENGL3 instead")
     endif()
     if (DEFINED IMGUI_BUNDLE_WITH_SDL)
-        message(FATAL_ERROR "IMGUI_BUNDLE_WITH_SDL is deprecated. Please use HELLOIMGUI_USE_SDL_OPENGL3 instead")
+        message(FATAL_ERROR "IMGUI_BUNDLE_WITH_SDL is deprecated. Please use HELLOIMGUI_USE_SDL2 + HELLOIMGUI_HAS_OPENGL3 instead")
     endif()
 endfunction()