cmake_minimum_required(VERSION 3.20)

set(CMAKE_CXX_STANDARD 20)

set(CMAKE_CXX_STANDARD_REQUIRED ON)

set(CMAKE_CXX_EXTENSIONS OFF)

project(tiny_bvh LANGUAGES CXX)

if (APPLE)

find_library(COCOA_LIBRARY Cocoa)

elseif (UNIX AND NOT EMSCRIPTEN)

find_package(X11)

elseif (EMSCRIPTEN)

# To auto generate test pages

set(CMAKE_EXECUTABLE_SUFFIX ".html")

# Enable clang's Address Sanitizer for WASM

option(enable_asan "Enable ASAN on the build (it'll slow down the app)" OFF)

# Enable wasm SIMD instructions

set(emcc_simd "fixed" CACHE STRING "SIMD type to use in the build (none, fixed, relaxed)")

set_property(CACHE emcc_simd PROPERTY STRINGS none fixed relaxed)

# Enable thread support for WASM (note that you need special http headers now https://emscripten.org/docs/porting/pthreads.html )

option(emcc_threads "Enable Threads in WASM (note that means you need to change your http headers)" OFF)

# Enable C/C++ main thread as a proxy thread to avoid blocking DOM/UI thread https://emscripten.org/docs/porting/pthreads.html

option(emcc_proxy_main "Enable C/C++ main thread as a proxy thread to avoid blocking DOM/UI thread" ${emcc_threads})

endif()

enable_testing()

add_executable(tiny_bvh_minimal tiny_bvh_minimal.cpp)

add_executable(tiny_bvh_renderer tiny_bvh_renderer.cpp)

add_executable(tiny_bvh_speedtest tiny_bvh_speedtest.cpp)

if (NOT EMSCRIPTEN)

# EMSCRIPTEN doesn't render anything by default (you would need WebGL/WebGPU)

add_executable(tiny_bvh_fenster tiny_bvh_fenster.cpp)

endif()

target_include_directories(tiny_bvh_speedtest PRIVATE ${CMAKE_CURRENT_LIST_DIR}/external/OpenCL/inc)

if (NOT MSVC)

# Produce debug symbols and set optimization level

set(common_cxx_flags

$<$<OR:$<CONFIG:RelWithDebInfo>,$<CONFIG:Debug>>:-g> $<$<OR:$<CONFIG:RelWithDebInfo>,$<CONFIG:Release>>:-O3>

)

set(common_link_flags

$<$<OR:$<CONFIG:RelWithDebInfo>,$<CONFIG:Debug>>:-g>

)

if (NOT EMSCRIPTEN)

# EMSCRIPTEN doesn't know about archs

set(common_cxx_flags

${common_cxx_flags} -march=native

)

else()

# EMSCRIPTEN flags:

# -sALLOW_MEMORY_GROWTH (allow runtime allocations) (for some reason cmake passes this as a linker flag when in theory it's a compiler one)

set(common_link_flags ${common_link_flags} -sALLOW_MEMORY_GROWTH=1)

# -fsanitize=address (enable ASAN)

# More at https://emscripten.org/docs/debugging/Sanitizers.html#address-sanitizer

if (enable_asan)

set(common_cxx_flags ${common_cxx_flags} -fsanitize=address)

set(common_link_flags ${common_link_flags} -fsanitize=address)

endif()

# Enable SIMD instructions and AVX intrinsics

string(TOLOWER "${emcc_simd}" emcc_simd_lower)

if (emcc_simd_lower STREQUAL fixed)

# Supported by all browsers https://webassembly.org/features/

set(common_cxx_flags ${common_cxx_flags} -msimd128 -mavx)

elseif (emcc_simd_lower STREQUAL relaxed)

# Supported some browsers https://webassembly.org/features/

set(common_cxx_flags ${common_cxx_flags} -mrelaxed-simd -mavx)

endif()

endif()

target_compile_options(tiny_bvh_minimal PRIVATE ${common_cxx_flags})

target_link_options(tiny_bvh_minimal PRIVATE ${common_link_flags})

target_compile_options(tiny_bvh_renderer PRIVATE ${common_cxx_flags})

target_link_options(tiny_bvh_renderer PRIVATE ${common_link_flags})

# No openmp support in default compiler

set(tiny_bvh_speedtest_cxx_flags ${common_cxx_flags})

set(tiny_bvh_speedtest_link_flags ${common_link_flags})

if (NOT APPLE AND NOT EMSCRIPTEN)

set(tiny_bvh_speedtest_cxx_flags ${tiny_bvh_speedtest_cxx_flags})

set(tiny_bvh_speedtest_link_flags ${tiny_bvh_speedtest_link_flags})

target_link_libraries(tiny_bvh_speedtest ${CMAKE_CURRENT_LIST_DIR}/external/OpenCL/lib/OpenCL.lib)

elseif (EMSCRIPTEN)

# Embed Sponza into the wasm to load it (in theory there are other methods, but this is the simplest)

# See https://emscripten.org/docs/porting/files/packaging_files.html#modifying-file-locations-in-the-virtual-file-system

set(tiny_bvh_speedtest_link_flags ${tiny_bvh_speedtest_link_flags} --preload-file "${CMAKE_CURRENT_LIST_DIR}/testdata@/testdata")

if (emcc_threads)

set(tiny_bvh_speedtest_cxx_flags ${tiny_bvh_speedtest_cxx_flags} -pthread)

set(tiny_bvh_speedtest_link_flags ${tiny_bvh_speedtest_link_flags} -pthread -sUSE_PTHREADS=1 -sPTHREAD_POOL_SIZE=navigator.hardwareConcurrency)

if (FALSE)

# From:

# - https://github.com/llvm/llvm-project/pull/95169

# - https://github.com/llvm/llvm-project/pull/71297

# - https://reviews.llvm.org/D142593?id=492403

# llvm's and clang's OpenMP has been ported to WASM around August 2024

# Sadly emcc's clang doesn't include a copy of the lib

# So you would need to do compile it yourself https://github.com/abrown/wasm-openmp-examples/blob/main/emscripten.sh

# Then link it here

set(tiny_bvh_speedtest_cxx_flags ${tiny_bvh_speedtest_cxx_flags} -fopenmp)

set(tiny_bvh_speedtest_link_flags ${tiny_bvh_speedtest_link_flags} -fopenmp)

endif()

if (emcc_proxy_main)

set(tiny_bvh_speedtest_link_flags ${tiny_bvh_speedtest_link_flags} -sPROXY_TO_PTHREAD=1)

endif()

endif()

endif()

target_compile_options(tiny_bvh_speedtest PRIVATE ${tiny_bvh_speedtest_cxx_flags})

target_link_options(tiny_bvh_speedtest PRIVATE ${tiny_bvh_speedtest_link_flags})

if (TARGET tiny_bvh_fenster)

# Not all platforms support all targets. E. g.:

# - EMSCRIPTEN doesn't render anything by default (you would need WebGL/WebGPU)

target_compile_options(tiny_bvh_fenster PRIVATE ${common_cxx_flags})

target_link_options(tiny_bvh_fenster PRIVATE ${common_link_flags})

if (WIN32)

target_link_libraries(tiny_bvh_fenster -mwindows)

elseif (APPLE)

target_link_libraries(tiny_bvh_fenster ${COCOA_LIBRARY})

elseif (X11_FOUND)

target_link_libraries(tiny_bvh_fenster ${X11_LIBRARIES})

endif()

endif()

else()

if (WIN32)

set_target_properties(tiny_bvh_fenster PROPERTIES WIN32_EXECUTABLE TRUE)

endif()

endif()

add_test(NAME "tiny_bvh_minimal" COMMAND tiny_bvh_minimal)