Dynamic mover

.github/workflows/build.yml

@@ -5,6 +5,7 @@ on:
     branches: [ main ]
   pull_request:
     branches: [ main ]
+  workflow_dispatch:
 
 env:
   BUILD_TYPE: Debug
@@ -14,7 +15,7 @@ jobs:
     name: ${{ matrix.name }}
     runs-on: ${{ matrix.os }}
     timeout-minutes: ${{ matrix.timeout || 4 }}
-    if: github.event_name == 'push' || github.event.pull_request.draft == false
+    if: github.event_name != 'pull_request' || github.event.pull_request.draft == false
     strategy:
       fail-fast: false
       matrix:
@@ -50,6 +51,17 @@ jobs:
             os: windows-11-arm
             args: -A arm64 -DBOX2D_DISABLE_SIMD=TRUE -DBOX2D_SANITIZE=ON
             test: ./bin/Debug/test
+          # Optimized runs. The determinism golden hash is otherwise only checked at -O0,
+          # and -O2 is where a value changing float transform would first show up.
+          - name: windows-relwithdebinfo
+            os: windows-latest
+            msvc: true
+            config: RelWithDebInfo
+            test: ./bin/RelWithDebInfo/test
+          - name: macos-relwithdebinfo
+            os: macos-latest
+            config: RelWithDebInfo
+            test: ./bin/test
           - name: ubuntu-gcc-double
             os: ubuntu-latest
             args: -DBOX2D_DOUBLE_PRECISION=ON
@@ -69,23 +81,27 @@ jobs:
         arch: x64
 
     - name: Configure CMake
-      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DBOX2D_SAMPLES=OFF -DBUILD_SHARED_LIBS=OFF -DBOX2D_VALIDATE=ON -DCMAKE_COMPILE_WARNING_AS_ERROR=ON ${{ matrix.args }}
+      run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{ matrix.config || env.BUILD_TYPE }} -DBOX2D_SAMPLES=OFF -DBUILD_SHARED_LIBS=OFF -DBOX2D_VALIDATE=ON -DCMAKE_COMPILE_WARNING_AS_ERROR=ON ${{ matrix.args }}
 
     - name: Build
-      run: cmake --build ${{github.workspace}}/build --config ${{env.BUILD_TYPE}}
+      run: cmake --build ${{github.workspace}}/build --config ${{ matrix.config || env.BUILD_TYPE }}
 
     - name: Test
       working-directory: ${{github.workspace}}/build
       env:
         MSAN_OPTIONS: ${{ matrix['msan-options'] || '' }}
+        UBSAN_OPTIONS: print_stacktrace=1
       run: ${{ matrix.test }}
 
   # mingw needs some extra setup so keeping it separate from the matrix.
+  # Debug -O0 copies whole structs and can hide padding bugs. RelWithDebInfo tests
+  # -O2 codegen while B2_ENABLE_ASSERT keeps asserts alive, heavy validation stays
+  # Debug only.
   build-windows-mingw:
     name: windows-mingw
     runs-on: windows-latest
     timeout-minutes: 4
-    if: github.event_name == 'push' || github.event.pull_request.draft == false
+    if: github.event_name != 'pull_request' || github.event.pull_request.draft == false
     defaults:
       run:
         shell: msys2 {0}
@@ -103,20 +119,38 @@ jobs:
           mingw-w64-ucrt-x86_64-ninja
 
     - name: Configure CMake
-      run: cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DBOX2D_SAMPLES=OFF -DBUILD_SHARED_LIBS=OFF -DBOX2D_VALIDATE=ON -DCMAKE_COMPILE_WARNING_AS_ERROR=ON
+      run: cmake -B build -G Ninja -DCMAKE_BUILD_TYPE=RelWithDebInfo -DBOX2D_SAMPLES=OFF -DBUILD_SHARED_LIBS=OFF -DBOX2D_VALIDATE=ON -DCMAKE_COMPILE_WARNING_AS_ERROR=ON
 
     - name: Build
-      run: cmake --build build --config ${{env.BUILD_TYPE}}
+      run: cmake --build build --config RelWithDebInfo
 
     - name: Test
       working-directory: build
       run: ./bin/test
 
+  # Build-only: running the wasm test needs a node + pthread/SharedArrayBuffer harness.
+  # This still catches compile breaks in the box2d library and the test target.
+  emscripten:
+    name: emscripten
+    runs-on: ubuntu-latest
+    timeout-minutes: 8
+    if: github.event_name != 'pull_request' || github.event.pull_request.draft == false
+    steps:
+    - uses: actions/checkout@v6
+
+    - uses: mymindstorm/setup-emsdk@v14
+
+    - name: Configure CMake
+      run: emcmake cmake -B build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}} -DBOX2D_SAMPLES=OFF -DBUILD_SHARED_LIBS=OFF -DBOX2D_VALIDATE=ON
+
+    - name: Build
+      run: cmake --build build --config ${{env.BUILD_TYPE}}
+
   samples:
     name: ${{ matrix.name }}
     runs-on: ${{ matrix.os }}
     timeout-minutes: 8
-    if: github.event_name == 'push' || github.event.pull_request.draft == false
+    if: github.event_name != 'pull_request' || github.event.pull_request.draft == false
     strategy:
       fail-fast: false
       matrix:

.gitignore

@@ -11,8 +11,4 @@ CMakeUserPresets.json
 .idea/
 .claude/
 .tmp/
-AGENTS.md
-GEMINI.md
 *.b2rec
-build-dp/
-build_float/

CMakeLists.txt

@@ -30,8 +30,13 @@ if (MSVC OR APPLE OR (UNIX AND NOT APPLE))
 			add_compile_options("$<$<CONFIG:Debug>:/fsanitize=address>")
 			add_link_options("$<$<CONFIG:Debug>:/INCREMENTAL:NO>")
 		elseif(APPLE)
-			add_compile_options(-fsanitize=address -fsanitize-address-use-after-scope -fsanitize=undefined)
+			# UBSan recovers by default, no-recover makes the first report fatal so CI fails
+			add_compile_options(-fsanitize=address -fsanitize-address-use-after-scope -fsanitize=undefined -fno-sanitize-recover=all)
 			add_link_options(-fsanitize=address -fsanitize-address-use-after-scope -fsanitize=undefined)
+		elseif(UNIX)
+			# use-after-scope is clang only, leave it off so gcc builds work
+			add_compile_options(-fsanitize=address -fsanitize=undefined -fno-sanitize-recover=all -fno-omit-frame-pointer)
+			add_link_options(-fsanitize=address -fsanitize=undefined)
 		endif()
 	else()
 		if(MSVC AND CMAKE_CXX_COMPILER_ID STREQUAL "MSVC" AND PROJECT_IS_TOP_LEVEL)
@@ -44,12 +49,17 @@ endif()
 
 # Deterministic math
 # https://box2d.org/posts/2024/08/determinism/
-if (MINGW OR UNIX)
-	add_compile_options(-ffp-contract=off)
-elseif (MSVC AND CMAKE_C_COMPILER_ID STREQUAL "Clang")
-	# clang-cl contracts multiply add into FMA under AVX2, diverging from non FMA builds.
-	# The plain driver flag is dropped, so force it through to the frontend.
-	add_compile_options(/clang:-ffp-contract=off)
+# Contraction into FMA is the one value changing transform enabled by default, and whether
+# it fires depends on the target. Test the compiler, not the platform, so every gcc and
+# clang gets the flag including a clang that is neither MinGW nor clang-cl.
+if (CMAKE_C_COMPILER_ID MATCHES "GNU|Clang")
+	if (CMAKE_C_COMPILER_FRONTEND_VARIANT STREQUAL "MSVC")
+		# clang-cl contracts multiply add into FMA under AVX2, diverging from non FMA builds.
+		# The plain driver flag is dropped, so force it through to the frontend.
+		add_compile_options(/clang:-ffp-contract=off)
+	else()
+		add_compile_options(-ffp-contract=off)
+	endif()
 endif()
 
 option(BOX2D_DISABLE_SIMD "Disable SIMD math (slower)" OFF)
@@ -60,37 +70,46 @@ if(CMAKE_SYSTEM_PROCESSOR MATCHES "x86_64|AMD64")
 	cmake_dependent_option(BOX2D_AVX2 "Enable AVX2" OFF "NOT BOX2D_DISABLE_SIMD" OFF)
 endif()
 
+# These are read by the library build, so they must precede add_subdirectory(src),
+# otherwise the first configure and a re-configure produce different libraries.
+# Top level only, so they stay hidden from FetchContent consumers.
+if(PROJECT_IS_TOP_LEVEL)
+	option(BOX2D_PROFILE "Enable profiling with Tracy" OFF)
+	option(BOX2D_VALIDATE "Enable heavy validation" ON)
+endif()
+
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
 # Leaving this here for testing
 # set(CMAKE_VERBOSE_MAKEFILE ON)
 
+# Emscripten pthread support. Must precede add_subdirectory(src) so the box2d library
+# objects are built with the same atomics/bulk-memory features as the executables that
+# link them, otherwise wasm-ld rejects --shared-memory. Top level only, so a FetchContent
+# consumer keeps control of its own threading model.
+if (EMSCRIPTEN AND PROJECT_IS_TOP_LEVEL)
+	set(EMSCRIPTEN_PTHREADS_COMPILER_FLAGS "-pthread -s USE_PTHREADS=1")
+	set(EMSCRIPTEN_PTHREADS_LINKER_FLAGS "${EMSCRIPTEN_PTHREADS_COMPILER_FLAGS} -s ALLOW_MEMORY_GROWTH")
+	string(APPEND CMAKE_C_FLAGS " ${EMSCRIPTEN_PTHREADS_COMPILER_FLAGS}")
+	string(APPEND CMAKE_CXX_FLAGS " ${EMSCRIPTEN_PTHREADS_COMPILER_FLAGS}")
+	string(APPEND CMAKE_EXE_LINKER_FLAGS " ${EMSCRIPTEN_PTHREADS_LINKER_FLAGS}")
+endif()
+
 add_subdirectory(src)
 
 # This hides samples, test, and doxygen from apps that use box2d via FetchContent
 if(PROJECT_IS_TOP_LEVEL)
 	option(BOX2D_SAMPLES "Build the Box2D samples" ON)
 	option(BOX2D_BENCHMARKS "Build the Box2D benchmarks" OFF)
 	option(BOX2D_DOCS "Build the Box2D documentation" OFF)
-	option(BOX2D_PROFILE "Enable profiling with Tracy" OFF)
-	option(BOX2D_VALIDATE "Enable heavy validation" ON)
 	option(BOX2D_UNIT_TESTS "Build the Box2D unit tests" ON)
 
 	# Needed for samples.exe to find box2d.dll
 	set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/bin")
 	set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/bin")
 
 	if(BOX2D_UNIT_TESTS OR BOX2D_SAMPLES OR BOX2D_BENCHMARKS)
-		# Emscripten pthread support
-		if(EMSCRIPTEN)
-			set(EMSCRIPTEN_PTHREADS_COMPILER_FLAGS "-pthread -s USE_PTHREADS=1")
-			set(EMSCRIPTEN_PTHREADS_LINKER_FLAGS "${EMSCRIPTEN_PTHREADS_COMPILER_FLAGS} -s ALLOW_MEMORY_GROWTH")
-			string(APPEND CMAKE_C_FLAGS " ${EMSCRIPTEN_PTHREADS_COMPILER_FLAGS}")
-			string(APPEND CMAKE_CXX_FLAGS " ${EMSCRIPTEN_PTHREADS_COMPILER_FLAGS}")
-			string(APPEND CMAKE_EXE_LINKER_FLAGS " ${EMSCRIPTEN_PTHREADS_LINKER_FLAGS}")
-		endif()
-
 		add_subdirectory(shared)
 	endif()
 

README.md

@@ -136,6 +136,19 @@ Support development of Box2D through [Github Sponsors](https://github.com/sponso
 
 Please consider starring this repository and subscribing to my [YouTube channel](https://www.youtube.com/@erin_catto).
 
+## LLM Usage
+
+LLMs are used in the following areas:
+
+- unit tests
+- samples app
+- migrating code between Box2D and Box3D
+- build configuration
+- code reviews
+- benchmarking
+
+Elsewhere all code is developed and written by me. I take responsibility for every line of code in Box2D/3D.
+
 ## External ports, wrappers, and bindings (unsupported)
 
 - Beef bindings - https://github.com/EnokViking/Box2DBeef