Modernise Existing CMakeLists.txt

- Added to .gitignore CMakeUserPresets.json

### Configuration:
- Changed python command to use single quotes to make build output log more legible.
- Added GODOT_DEV_BUILD to allow differentiation of debug or Release builds.
- Added find logic for macos Cocoa library

### godot-cpp Changes
- godot-cpp-test is changed to be incorporated into the cmake build as a target.
- Duplicated godot-cpp target into [template_release, template_debug, editor]
- Created {platform}.cmake files mirroring the style of the SCons build.

CMake has a feature called generator expressions for its configuration variables that are evaluated at build time. This allows multi-configuration build systems to properly evaulate options. for msvc, xcode and nijna multi-config.

- Moved configuration options to generator expressions with the notable exclusion of OSX_ARCHITECTURES.
- Remove CMAKE_BUILD_TYPE from msvc CI target as Multi-Config generators ignore it

### godot-cpp-test Changes
- Removed majority of the cmake code, now that the godot-cpp project is setup, the majority of the flags will be propagated as transient dependencies
- Marked with EXCLUDE_FROM_ALL so that it isn't built as part of the 'all' target
- Updated ci to build the godot-cpp-test target from the root directory using cmake
- Tests passing for Windows, Linux, and Macos builds.

### Documentation
Updated with new information
Added Emscripten example
Added Android example

Author: enetheru

.github/workflows/ci.yml

@@ -207,30 +207,6 @@ jobs:
           path: ${{ matrix.artifact-path }}
           if-no-files-found: error
 
-  linux-cmake:
-    name: 🐧 Build (Linux, GCC, CMake)
-    runs-on: ubuntu-22.04
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-        with:
-          submodules: recursive
-
-      - name: Install dependencies
-        run: |
-          sudo apt-get update -qq
-          sudo apt-get install -qqq build-essential pkg-config cmake
-
-      - name: Build godot-cpp
-        run: |
-          cmake -DCMAKE_BUILD_TYPE=Release .
-          make -j $(nproc) VERBOSE=1
-
-      - name: Build test GDExtension library
-        run: |
-          cd test && cmake -DCMAKE_BUILD_TYPE=Release -DGODOT_HEADERS_PATH="../godot-headers" -DCPP_BINDINGS_PATH=".." .
-          make -j $(nproc) VERBOSE=1
-
   linux-cmake-ninja:
     name: 🐧 Build (Linux, GCC, CMake Ninja)
     runs-on: ubuntu-22.04
@@ -245,15 +221,12 @@ jobs:
           sudo apt-get update -qq
           sudo apt-get install -qqq build-essential pkg-config cmake ninja-build
 
-      - name: Build godot-cpp
-        run: |
-          cmake -DCMAKE_BUILD_TYPE=Release -GNinja .
-          cmake --build . -j $(nproc) --verbose
-
       - name: Build test GDExtension library
         run: |
-          cd test && cmake -DCMAKE_BUILD_TYPE=Release -DGODOT_HEADERS_PATH="../godot-headers" -DCPP_BINDINGS_PATH=".." -GNinja .
-          cmake --build . -j $(nproc) --verbose
+          mkdir cmake-build
+          cd cmake-build
+          cmake ../ -DTEST_TARGET=template_release
+          cmake --build . --verbose -j $(nproc) -t godot-cpp-test --config Release
 
   windows-msvc-cmake:
     name: 🏁 Build (Windows, MSVC, CMake)
@@ -264,12 +237,9 @@ jobs:
         with:
           submodules: recursive
 
-      - name: Build godot-cpp
-        run: |
-          cmake -DCMAKE_BUILD_TYPE=Release -G"Visual Studio 16 2019" .
-          cmake --build . --verbose --config Release
-
       - name: Build test GDExtension library
         run: |
-          cd test && cmake -DCMAKE_BUILD_TYPE=Release -DGODOT_HEADERS_PATH="../godot-headers" -DCPP_BINDINGS_PATH=".." -G"Visual Studio 16 2019" .
-          cmake --build . --verbose --config Release
+          mkdir cmake-build
+          cd cmake-build
+          cmake ../ -DTEST_TARGET=template_release
+          cmake --build . --verbose -t godot-cpp-test --config Release

.gitignore

@@ -198,4 +198,7 @@ venv
 
 # Clion Configuration
 .idea/
-cmake-build-*
+cmake-build*/
+
+# CMake related
+CMakeUserPresets.json

CMakeLists.txt

@@ -1,24 +1,98 @@
-cmake_minimum_required(VERSION 3.13)
-project(godot-cpp LANGUAGES CXX)
-
-# Configure CMake
-# https://discourse.cmake.org/t/how-do-i-remove-compile-options-from-target/5965
-# https://stackoverflow.com/questions/74426638/how-to-remove-rtc1-from-specific-target-or-file-in-cmake
-if(${CMAKE_CXX_COMPILER_ID} STREQUAL MSVC)
-    if(NOT CMAKE_BUILD_TYPE MATCHES Debug)
-        STRING(REGEX REPLACE "/RTC(su|[1su])" "" CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS}")
-        string(REPLACE "/RTC1" "" CMAKE_CXX_FLAGS_DEBUG ${CMAKE_CXX_FLAGS_DEBUG})
-    endif ()
-endif ()
+cmake_minimum_required(VERSION 3.17)
+
+#[=======================================================================[.rst:
+
+CMake Version requirements
+--------------------------
+
+To enable use of the emscripten emsdk hack for pseudo shared library support
+without polluting options for consumers we need to use the
+CMAKE_PROJECT_<PROJECT-NAME>_INCLUDE which was introduced in version 3.17
+
+Scons Compatibility
+-------------------
+
+As we are attempting to maintain feature parity, and ease of maintenance, these
+CMake scripts are built to resemble the SCons build system.
 
-include( ${PROJECT_SOURCE_DIR}/cmake/godotcpp.cmake )
+The file structure and file content are made to match, if not in content then
+in spirit. The closer the two build systems look the easier they will be to
+maintain.
 
-# I know this doesn't look like a typical CMakeLists.txt, but as we are
-# attempting mostly feature parity with SCons, and easy maintenance, the closer
-# the two build systems look the easier they will be to keep in lockstep.
+Where the SCons additional scripts in the tools directory, The CMake scripts
+are in the cmake directory.
 
-# The typical target definitions are in ${PROJECT_SOURCE_DIR}/cmake/godotcpp.cmake
+For example, the tools/godotcpp.py is sourced into SCons, and the 'options'
+function is run.
 
+.. highlight:: python
+
+    cpp_tool = Tool("godotcpp", toolpath=["tools"])
+    cpp_tool.options(opts, env)
+
+
+The CMake equivalent is below.
+]=======================================================================]
+
+include( cmake/godotcpp.cmake )
 godotcpp_options()
 
+#[=======================================================================[.rst:
+
+Configurations
+--------------
+
+There are two build main configurations, 'Debug' and 'Release', these are not
+related to godot's DEBUG_FEATURES flag. Build configurations change the default
+compiler and linker flags present when building the library, things like debug
+symbols, optimization.
+
+The Scons build scripts don't have this concept, you can think of it like the
+SCons solution has a single default configuration. In both cases overriding the
+defaults is controlled by options on the command line, or in preset files.
+
+Because of this added configuration and that it can be undefined, it becomes
+important to set a default, considering the SCons solution that does not enable
+debug symbols by default, it seemed appropriate to set the default to 'Release'
+if unspecified. This can always be overridden like below.
+
+.. highlight:: shell
+
+    cmake <source> -DCMAKE_BUILD_TYPE:STRING=Debug
+
+.. caution::
+
+A complication arises from `Multi-Config Generators`_ that cannot have
+their configuration set at configure time. This means that the configuration
+must be set on the build command. This is especially important for Visual
+Studio Generators which default to 'Debug'
+
+.. highlight:: shell
+
+    cmake --build . --config Release
+
+.. _Multi-Config Generators:https://cmake.org/cmake/help/latest/prop_gbl/GENERATOR_IS_MULTI_CONFIG.html
+]=======================================================================]
+get_property( IS_MULTI_CONFIG GLOBAL PROPERTY GENERATOR_IS_MULTI_CONFIG )
+if( NOT IS_MULTI_CONFIG AND NOT CMAKE_BUILD_TYPE )
+    if( GODOT_DEV_BUILD )
+        set( CMAKE_BUILD_TYPE Debug )
+    else ()
+        set( CMAKE_BUILD_TYPE Release )
+    endif ()
+endif ()
+
+#[[ Python is required for code generation ]]
+find_package(Python3 3.4 REQUIRED) # pathlib should be present
+
+# Define our project.
+project( godot-cpp
+        VERSION 4.4
+        DESCRIPTION "C++ bindings for the Godot Engine's GDExtensions API."
+        HOMEPAGE_URL "https://github.com/godotengine/godot-cpp"
+        LANGUAGES CXX)
+
 godotcpp_generate()
+
+# Test Example
+add_subdirectory( test )

cmake/android.cmake

@@ -0,0 +1,41 @@
+#[=======================================================================[.rst:
+Android
+-------
+
+This file contains functions for options and configuration for targeting the
+Android platform
+
+Configuration of the Android toolchain is done using toolchain files,
+CMakePresets, or variables on the command line.
+
+The `Android SDK`_ provides toolchain files to help with configuration.
+
+CMake has its own `built-in support`_ for cross compiling to the
+Android platforms.
+
+.. warning::
+
+    Android does not support or test the CMake built-in workflow, recommend
+    using their toolchain file.
+
+.. _Android SDK:https://developer.android.com/ndk/guides/cmake
+
+.. _built-in support:https://cmake.org/cmake/help/latest/manual/cmake-toolchains.7.html#cross-compiling-for-android
+
+There is further information and examples in the doc/cmake.rst file.
+
+]=======================================================================]
+function( android_options )
+    # Android Options
+endfunction()
+
+function( android_generate TARGET_NAME )
+
+    target_compile_definitions(${TARGET_NAME}
+            PUBLIC
+            ANDROID_ENABLED
+            UNIX_ENABLED
+    )
+
+    common_compiler_flags( ${TARGET_NAME} )
+endfunction()