CMakeLists.txt

cmake_minimum_required(VERSION 3.16 FATAL_ERROR)

project(JoltC CXX)

# Use solution folders to organize projects
set_property(GLOBAL PROPERTY USE_FOLDERS ON)

# Requires C++ 17
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_CXX_EXTENSIONS OFF)
set(CMAKE_INSTALL_MESSAGE LAZY)

set(CMAKE_OSX_DEPLOYMENT_TARGET "10.15" CACHE STRING "Minimum OS X deployment version")
set(CMAKE_OSX_ARCHITECTURES "x86_64;arm64" CACHE STRING "Build architectures for OS X")

# Determine if engine is built as a subproject (using add_subdirectory)
# or if it is the master project.
if (NOT DEFINED JPH_MASTER_PROJECT)
    set(JPH_MASTER_PROJECT OFF)
    if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
        set(JPH_MASTER_PROJECT ON)
        message(STATUS "CMake version: ${CMAKE_VERSION}")
    endif ()
endif ()

if (JPH_MASTER_PROJECT)
	# Configure CMake global variables
	set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
	set(CMAKE_LIBRARY_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
	set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/lib)
endif()

include(CMakeDependentOption)
include(GNUInstallDirs)
include(FetchContent)

# When turning this option on, the library will be compiled using assertions. By default asserts are enabled in Debug build.
option(USE_ASSERTS "Enable asserts" OFF)

# When turning this option on, the library will be compiled using doubles for positions. This allows for much bigger worlds.
option(DOUBLE_PRECISION "Use double precision math" OFF)

# When turning this option on, the library will be compiled with debug symbols
option(GENERATE_DEBUG_SYMBOLS "Generate debug symbols" OFF)

# When turning this option on, the library will override the default CMAKE_CXX_FLAGS_DEBUG/RELEASE values, otherwise they will use the platform defaults
option(OVERRIDE_CXX_FLAGS "Override CMAKE_CXX_FLAGS_DEBUG/RELEASE" ON)

# When turning this option on, the library will be compiled in such a way to attempt to keep the simulation deterministic across platforms
option(CROSS_PLATFORM_DETERMINISTIC "Cross platform deterministic" OFF)

# When turning this option on, the library will be compiled for ARM (aarch64-linux-gnu), requires compiling with clang
option(CROSS_COMPILE_ARM "Cross compile to aarch64-linux-gnu" OFF)

# When turning this option on, Jolt will be compiled as a shared library and public symbols will be exported.
option(BUILD_SHARED_LIBS "Compile Jolt as a shared library" OFF)

# When turning this option on, the library will be compiled with interprocedural optimizations enabled, also known as link-time optimizations or link-time code generation.
# Note that if you turn this on you need to use SET_INTERPROCEDURAL_OPTIMIZATION() or set(CMAKE_INTERPROCEDURAL_OPTIMIZATION ON) to enable LTO specifically for your own project as well.
# If you don't do this you may get an error: /usr/bin/ld: libJolt.a: error adding symbols: file format not recognized
option(INTERPROCEDURAL_OPTIMIZATION "Enable interprocedural optimizations" ON)

# When turning this on, in Debug and Release mode, the library will emit extra code to ensure that the 4th component of a 3-vector is kept the same as the 3rd component
# and will enable floating point exceptions during simulation to detect divisions by zero.
# Note that this currently only works using MSVC. Clang turns Float2 into a SIMD vector sometimes causing floating point exceptions (the option is ignored).
option(FLOATING_POINT_EXCEPTIONS_ENABLED "Enable floating point exceptions" ON)

# Number of bits to use in ObjectLayer. Can be 16 or 32.
option(OBJECT_LAYER_BITS "Number of bits in ObjectLayer" 16)

# Select X86 processor features to use (if everything is off it will be SSE2 compatible)
option(USE_SSE4_1 "Enable SSE4.1" ON)
option(USE_SSE4_2 "Enable SSE4.2" ON)
option(USE_AVX "Enable AVX" ON)
option(USE_AVX2 "Enable AVX2" ON)
option(USE_AVX512 "Enable AVX512" OFF)
option(USE_LZCNT "Enable LZCNT" ON)
option(USE_TZCNT "Enable TZCNT" ON)
option(USE_F16C "Enable F16C" ON)
option(USE_FMADD "Enable FMADD" ON)

# Enable SIMD for the WASM build. Note that this is currently off by default since not all browsers support this.
# See: https://caniuse.com/?search=WebAssembly%20SIMD (Safari got support in March 2023 and was the last major browser to get support).
option(USE_WASM_SIMD "Enable SIMD for WASM" OFF)

# Enable all warnings
option(ENABLE_ALL_WARNINGS "Enable all warnings and warnings as errors" OFF)

# Setting to periodically trace broadphase stats to help determine if the broadphase layer configuration is optimal
option(TRACK_BROADPHASE_STATS "Track Broadphase Stats" OFF)

# Setting to periodically trace narrowphase stats to help determine which collision queries could be optimized
option(TRACK_NARROWPHASE_STATS "Track Narrowphase Stats" OFF)

# Enable the debug renderer in the Debug and Release builds. Note that DEBUG_RENDERER_IN_DISTRIBUTION will override this setting.
option(DEBUG_RENDERER_IN_DEBUG_AND_RELEASE "Enable debug renderer in Debug and Release builds" ON)

# Setting to enable the debug renderer in all builds.
# Note that enabling this reduces the performance of the library even if you're not drawing anything.
option(DEBUG_RENDERER_IN_DISTRIBUTION "Enable debug renderer in all builds" OFF)

# Enable the profiler in Debug and Release builds. Note that PROFILER_IN_DISTRIBUTION will override this setting.
option(PROFILER_IN_DEBUG_AND_RELEASE "Enable the profiler in Debug and Release builds" ON)

# Enable the profiler in all builds.
# Note that enabling this reduces the performance of the library.
option(PROFILER_IN_DISTRIBUTION "Enable the profiler in all builds" OFF)

# Setting this option will force the library to use malloc/free instead of allowing the user to override the memory allocator
option(DISABLE_CUSTOM_ALLOCATOR "Disable support for a custom memory allocator" OFF)

# Setting this option will force the library to use the STL vector instead of the custom Array class
option(USE_STD_VECTOR "Use std::vector instead of own Array class" OFF)

# Setting this option will compile the ObjectStream class and RTTI attribute information
option(ENABLE_OBJECT_STREAM "Compile the ObjectStream class and RTTI attribute information" ON)

# Ability to toggle between the static and DLL versions of the MSVC runtime library
# Windows Store only supports the DLL version
cmake_dependent_option(USE_STATIC_MSVC_RUNTIME_LIBRARY "Use the static MSVC runtime library" ON "MSVC;NOT WINDOWS_STORE" OFF)

option(JPH_SAMPLES "Build samples" ${JPH_MASTER_PROJECT})

# Determine which configurations exist
if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR) # Only do this when we're at the top level, see: https://gitlab.kitware.com/cmake/cmake/-/issues/24181
	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC" OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
		set(CMAKE_CONFIGURATION_TYPES "Debug;Release;Distribution")
	elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang" OR "${CMAKE_CXX_COMPILER_ID}" STREQUAL "AppleClang")
		set(CMAKE_CONFIGURATION_TYPES "Debug;Release;ReleaseASAN;ReleaseUBSAN;ReleaseCoverage;Distribution")
	endif()
endif()

FetchContent_Declare(
        JoltPhysics
        GIT_REPOSITORY "https://github.com/pfeodrippe/JoltPhysics"
        GIT_TAG "9578adf25dc2334d67ed89c85c6f263596475efd"
		SOURCE_SUBDIR "Build"
)
FetchContent_MakeAvailable(JoltPhysics)

if (XCODE)
	# Ensure that we enable SSE4.2 for the x86_64 build, XCode builds multiple architectures
	set_property(TARGET Jolt PROPERTY XCODE_ATTRIBUTE_OTHER_CPLUSPLUSFLAGS[arch=x86_64] "$(inherited) -msse4.2 -mpopcnt")
endif()

if (MSVC)
	# Fill in the path to the asan libraries
	set(CLANG_LIB_PATH "\"$(VSInstallDir)\\VC\\Tools\\Llvm\\x64\\lib\\clang\\${CMAKE_CXX_COMPILER_VERSION}\\lib\\windows\"")

	# 64 bit architecture
	set(CMAKE_VS_PLATFORM_TOOLSET_HOST_ARCHITECTURE "x64")

	# Set runtime library
	if (USE_STATIC_MSVC_RUNTIME_LIBRARY)
		set(CMAKE_MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
	endif()

	# Set general compiler flags
	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Zc:__cplusplus /Gm- /MP /nologo /diagnostics:classic /FC /fp:except- /Zc:inline")

	# Enable warnings
	if (ENABLE_ALL_WARNINGS)
		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Wall -fno-access-control")
	endif()

    # Optionally generate debug symbols
	if (GENERATE_DEBUG_SYMBOLS)
		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Zi")
	endif()

	# Remove any existing compiler flag that enables RTTI
	string(REPLACE "/GR" "" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})

	# Set compiler flag for disabling RTTI
	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /GR-")

	if ("${CMAKE_VS_PLATFORM_NAME}" STREQUAL "ARM")
		# On ARM the exception handling flag is missing which causes warnings
		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /EHsc")
	endif()

	# Set compiler flags for various configurations
	if (OVERRIDE_CXX_FLAGS)
		set(CMAKE_CXX_FLAGS_DEBUG "/GS /Od /Ob0 /RTC1")
		set(CMAKE_CXX_FLAGS_RELEASE "/GS- /Gy /O2 /Oi /Ot")
		set(CMAKE_CXX_FLAGS_DISTRIBUTION "/GS- /Gy /O2 /Oi /Ot")
	endif()

	set(CMAKE_CXX_FLAGS_DISTRIBUTION "${CMAKE_CXX_FLAGS_RELEASE}")
	set(CMAKE_CXX_FLAGS_RELEASEASAN "-fsanitize=address /Od")
	set(CMAKE_CXX_FLAGS_RELEASEUBSAN "-fsanitize=undefined,implicit-conversion,float-divide-by-zero,local-bounds -fno-sanitize-recover=all")
	set(CMAKE_CXX_FLAGS_RELEASECOVERAGE "-fprofile-instr-generate -fcoverage-mapping")

	# Set linker flags
	set(CMAKE_EXE_LINKER_FLAGS "/SUBSYSTEM:WINDOWS /ignore:4221")
	if (GENERATE_DEBUG_SYMBOLS)
		set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} /DEBUG")
	endif()
	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
		if (CROSS_PLATFORM_DETERMINISTIC)
			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /fp:precise")
		else()
			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /fp:fast") # Clang doesn't use fast math because it cannot be turned off inside a single compilation unit
		endif()
	elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "Clang")
		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /showFilenames")
		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Qunused-arguments") # Clang emits warnings about unused arguments such as /MP and /GL
		set(CMAKE_EXE_LINKER_FLAGS_RELEASEASAN "/SUBSYSTEM:CONSOLE /LIBPATH:${CLANG_LIB_PATH} clang_rt.asan-x86_64.lib -wholearchive:clang_rt.asan-x86_64.lib clang_rt.asan_cxx-x86_64.lib -wholearchive:clang_rt.asan_cxx-x86_64.lib")
		set(CMAKE_EXE_LINKER_FLAGS_RELEASEUBSAN "${CMAKE_EXE_LINKER_FLAGS_RELEASE} /LIBPATH:${CLANG_LIB_PATH}")
		set(CMAKE_EXE_LINKER_FLAGS_RELEASECOVERAGE "${CMAKE_EXE_LINKER_FLAGS_RELEASE} /LIBPATH:${CLANG_LIB_PATH}")
	endif()
else()
	# Enable warnings
	if (ENABLE_ALL_WARNINGS)
		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Werror")
	endif()

    # Optionally generate debug symbols
	if (GENERATE_DEBUG_SYMBOLS)
		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -g")
	endif()

	if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
		# Also disable -Wstringop-overflow or it will generate false positives that can't be disabled from code when link-time optimizations are enabled
		# Also turn off automatic fused multiply add contractions, there doesn't seem to be a way to do this selectively through the macro JPH_PRECISE_MATH_OFF
		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-stringop-overflow -ffp-contract=off")
	else()
		# Do not use -ffast-math since it cannot be turned off in a single compilation unit under clang, see Core.h
		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -ffp-model=precise")

		# On clang 14 and later we can turn off float contraction through a pragma, older versions and deterministic versions need it off always, see Core.h
		if (CMAKE_CXX_COMPILER_VERSION LESS 14 OR CROSS_PLATFORM_DETERMINISTIC)
			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -ffp-contract=off")
		endif()
	endif()

	# See https://github.com/jrouwe/JoltPhysics/issues/922. When compiling with DOUBLE_PRECISION=YES and CMAKE_OSX_DEPLOYMENT_TARGET=10.12 clang triggers a warning that we silence here.
	if ("${CMAKE_SYSTEM_NAME}" MATCHES "Darwin" AND "${CMAKE_CXX_COMPILER_ID}" STREQUAL "AppleClang")
		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -faligned-allocation")
	endif()

	# Cross compiler flags
	if (CROSS_COMPILE_ARM)
		set(CMAKE_CXX_FLAGS "--target=aarch64-linux-gnu ${CMAKE_CXX_FLAGS}")
	endif()

	# Set compiler flags for various configurations
	if (OVERRIDE_CXX_FLAGS)
		set(CMAKE_CXX_FLAGS_DEBUG "")
		set(CMAKE_CXX_FLAGS_RELEASE "-O3")
	endif()
	set(CMAKE_CXX_FLAGS_DISTRIBUTION "${CMAKE_CXX_FLAGS_RELEASE}")
	set(CMAKE_CXX_FLAGS_RELEASEASAN "-fsanitize=address")
	set(CMAKE_CXX_FLAGS_RELEASEUBSAN "-fsanitize=undefined,implicit-conversion,float-divide-by-zero,local-bounds -fno-sanitize-recover=all")
	set(CMAKE_CXX_FLAGS_RELEASECOVERAGE "-fprofile-instr-generate -fcoverage-mapping")

	# Set linker flags
	if (NOT ("${CMAKE_SYSTEM_NAME}" STREQUAL "Windows"))
		set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -pthread")
	endif()
endif()

# Set linker flags
set(CMAKE_EXE_LINKER_FLAGS_DISTRIBUTION "${CMAKE_EXE_LINKER_FLAGS_RELEASE}")
set(CMAKE_SHARED_LINKER_FLAGS_DISTRIBUTION "${CMAKE_SHARED_LINKER_FLAGS_RELEASE}")

SET_INTERPROCEDURAL_OPTIMIZATION()

set(PHYSICS_REPO_ROOT ${CMAKE_CURRENT_SOURCE_DIR}/src/joltc)
set(BUILD_SHARED_LIBS OFF CACHE BOOL "Disable shared library when building Jolt" FORCE)

# Options
if (IOS OR EMSCRIPTEN)
    set(BUILD_SHARED_LIBS OFF CACHE BOOL "Always Disable shared library on (IOS, WEB)" FORCE)
else()
    set(BUILD_SHARED_LIBS ON CACHE BOOL "Always build shared library" FORCE)
endif()

add_subdirectory(src/joltc)

if (CMAKE_GENERATOR_PLATFORM)
    message(STATUS "CMAKE_GENERATOR_PLATFORM: ${CMAKE_GENERATOR_PLATFORM}")
endif()

message(STATUS "CMAKE_SYSTEM_PROCESSOR: ${CMAKE_SYSTEM_PROCESSOR}")
if (CMAKE_OSX_ARCHITECTURES)
    message(STATUS "CMAKE_OSX_ARCHITECTURES: ${CMAKE_OSX_ARCHITECTURES}")
endif ()