Move Rust crate to src/libslic3r/Support/TreeSupportRust/ and add CMake integration

Co-authored-by: cochcoder <103969142+cochcoder@users.noreply.github.com>

Author: Copilot

.gitignore

@@ -43,4 +43,4 @@ test.js
 /.cache/
 .clangd
 internal_docs/
-orca-tree-supports/target/
+src/libslic3r/Support/TreeSupportRust/target/

src/libslic3r/CMakeLists.txt

@@ -486,6 +486,9 @@ add_library(libslic3r STATIC ${lisbslic3r_sources}
     ${OpenVDBUtils_SOURCES})
 source_group(TREE ${CMAKE_CURRENT_SOURCE_DIR} FILES ${lisbslic3r_sources})
 
+# Rust tree support library (optional — requires cargo/Rust toolchain)
+add_subdirectory(Support/TreeSupportRust)
+
 if (SLIC3R_STATIC)
     set(CGAL_Boost_USE_STATIC_LIBS ON CACHE BOOL "" FORCE)
 endif ()
@@ -603,6 +606,13 @@ target_link_libraries(libslic3r
         OpenSSL::Crypto
     )
 
+# Link Rust tree support library if cargo/Rust toolchain is available
+if(TARGET orca_tree_supports)
+    target_link_libraries(libslic3r PRIVATE orca_tree_supports)
+    target_compile_definitions(libslic3r PRIVATE HAS_RUST_TREE_SUPPORTS=1)
+    message(STATUS "Rust tree support library enabled")
+endif()
+
 if(NOT WIN32)
     # Link freetype for OCCT dependency (CAD operations need font rendering)
     target_link_libraries(libslic3r PRIVATE ${FREETYPE_LIBRARIES})

src/libslic3r/Support/TreeSupportRust/CMakeLists.txt

@@ -0,0 +1,104 @@
+# CMakeLists.txt for the Rust tree support library (orca-tree-supports)
+#
+# This file integrates the Rust crate into the CMake build system.
+# It invokes `cargo build` to compile the Rust static library and
+# creates an IMPORTED target that can be linked by libslic3r.
+#
+# Requirements:
+#   - Rust toolchain (rustc, cargo) must be installed and on PATH
+#   - Minimum Rust version: 1.70 (2021 edition)
+
+# Detect cargo
+find_program(CARGO_EXECUTABLE cargo HINTS $ENV{HOME}/.cargo/bin)
+if(NOT CARGO_EXECUTABLE)
+    message(WARNING "cargo not found — Rust tree support library will NOT be built. "
+                    "Install Rust from https://rustup.rs/ to enable.")
+    return()
+endif()
+
+message(STATUS "Found cargo: ${CARGO_EXECUTABLE}")
+
+# Determine build type for cargo
+if(CMAKE_BUILD_TYPE STREQUAL "Debug")
+    set(CARGO_BUILD_TYPE "debug")
+    set(CARGO_BUILD_FLAGS "")
+else()
+    set(CARGO_BUILD_TYPE "release")
+    set(CARGO_BUILD_FLAGS "--release")
+endif()
+
+# Paths
+set(RUST_CRATE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
+set(RUST_TARGET_DIR "${CMAKE_CURRENT_SOURCE_DIR}/target")
+set(RUST_HEADER "${CMAKE_CURRENT_SOURCE_DIR}/include/orca_tree_supports.h")
+
+# Determine the static library filename (platform-dependent)
+if(WIN32)
+    set(RUST_LIB_NAME "orca_tree_supports.lib")
+elseif(APPLE)
+    set(RUST_LIB_NAME "liborca_tree_supports.a")
+else()
+    set(RUST_LIB_NAME "liborca_tree_supports.a")
+endif()
+
+set(RUST_LIB_PATH "${RUST_TARGET_DIR}/${CARGO_BUILD_TYPE}/${RUST_LIB_NAME}")
+
+# Custom command: build the Rust crate
+add_custom_command(
+    OUTPUT "${RUST_LIB_PATH}"
+    COMMAND ${CARGO_EXECUTABLE} build ${CARGO_BUILD_FLAGS}
+            --manifest-path "${RUST_CRATE_DIR}/Cargo.toml"
+            --target-dir "${RUST_TARGET_DIR}"
+    WORKING_DIRECTORY "${RUST_CRATE_DIR}"
+    DEPENDS
+        "${RUST_CRATE_DIR}/Cargo.toml"
+        "${RUST_CRATE_DIR}/Cargo.lock"
+        "${RUST_CRATE_DIR}/src/lib.rs"
+        "${RUST_CRATE_DIR}/src/config.rs"
+        "${RUST_CRATE_DIR}/src/mesh.rs"
+        "${RUST_CRATE_DIR}/src/overhang_detection.rs"
+        "${RUST_CRATE_DIR}/src/branch_generation.rs"
+        "${RUST_CRATE_DIR}/src/collision.rs"
+        "${RUST_CRATE_DIR}/src/interface_layers.rs"
+        "${RUST_CRATE_DIR}/src/placement.rs"
+        "${RUST_CRATE_DIR}/src/ffi.rs"
+        "${RUST_CRATE_DIR}/src/utils.rs"
+    COMMENT "Building Rust tree support library (${CARGO_BUILD_TYPE})..."
+)
+
+# Custom target that triggers the build
+add_custom_target(orca_tree_supports_build
+    DEPENDS "${RUST_LIB_PATH}"
+)
+
+# Create an IMPORTED static library target
+add_library(orca_tree_supports STATIC IMPORTED GLOBAL)
+set_target_properties(orca_tree_supports PROPERTIES
+    IMPORTED_LOCATION "${RUST_LIB_PATH}"
+    INTERFACE_INCLUDE_DIRECTORIES "${RUST_CRATE_DIR}/include"
+)
+add_dependencies(orca_tree_supports orca_tree_supports_build)
+
+# On Unix, Rust static libs need to link against system threading and dl libs
+if(UNIX AND NOT APPLE)
+    set_target_properties(orca_tree_supports PROPERTIES
+        INTERFACE_LINK_LIBRARIES "pthread;dl;m"
+    )
+elseif(APPLE)
+    set_target_properties(orca_tree_supports PROPERTIES
+        INTERFACE_LINK_LIBRARIES "-framework Security;-framework CoreFoundation"
+    )
+elseif(WIN32)
+    set_target_properties(orca_tree_supports PROPERTIES
+        INTERFACE_LINK_LIBRARIES "ws2_32;userenv;bcrypt;ntdll"
+    )
+endif()
+
+# Custom target to run Rust tests
+add_custom_target(orca_tree_supports_test
+    COMMAND ${CARGO_EXECUTABLE} test
+            --manifest-path "${RUST_CRATE_DIR}/Cargo.toml"
+            --target-dir "${RUST_TARGET_DIR}"
+    WORKING_DIRECTORY "${RUST_CRATE_DIR}"
+    COMMENT "Running Rust tree support tests..."
+)

orca-tree-supports/Cargo.lock …lic3r/Support/TreeSupportRust/Cargo.lockorca-tree-supports/Cargo.lock renamed to src/libslic3r/Support/TreeSupportRust/Cargo.lock orca-tree-supports/Cargo.lock renamed to src/libslic3r/Support/TreeSupportRust/Cargo.lock

@@ -65,21 +65,31 @@ for FDM 3D printing. It is designed as a drop-in replacement for the C++
 
 ### Build the library
 
+The Rust library is automatically built by CMake when a Rust toolchain is available.
+It integrates into the standard OrcaSlicer build process:
+
 ```bash
-cd orca-tree-supports
+# Standard OrcaSlicer build (includes Rust tree support if cargo is available)
+cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
+cmake --build build
+
+# Or build standalone for development:
+cd src/libslic3r/Support/TreeSupportRust
 cargo build --release
 ```
 
 This produces:
 - `target/release/liborca_tree_supports.a` (static library)
-- `target/release/liborca_tree_supports.so` (shared library on Linux)
-- `target/release/liborca_tree_supports.dylib` (shared library on macOS)
 - `include/orca_tree_supports.h` (C header, generated by cbindgen)
 
 ### Run tests
 
 ```bash
+cd src/libslic3r/Support/TreeSupportRust
 cargo test
+
+# Or via CMake:
+cmake --build build --target orca_tree_supports_test
 ```
 
 ### Generate documentation
@@ -90,28 +100,13 @@ cargo doc --open
 
 ## Integration with OrcaSlicer C++
 
-### 1. Link the Rust library
-
-Add to your CMakeLists.txt:
-
-```cmake
-# Build the Rust crate
-add_custom_command(
-    OUTPUT ${CMAKE_BINARY_DIR}/liborca_tree_supports.a
-    COMMAND cargo build --release --manifest-path ${CMAKE_SOURCE_DIR}/orca-tree-supports/Cargo.toml
-    WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}/orca-tree-supports
-)
-
-# Link against the static library
-target_link_libraries(libslic3r PRIVATE
-    ${CMAKE_BINARY_DIR}/liborca_tree_supports.a
-)
-target_include_directories(libslic3r PRIVATE
-    ${CMAKE_SOURCE_DIR}/orca-tree-supports/include
-)
-```
+The Rust tree support library is automatically integrated into the build when a
+Rust toolchain (cargo) is detected. CMake will:
+1. Build the Rust static library via `cargo build`
+2. Link it into `libslic3r`
+3. Define `HAS_RUST_TREE_SUPPORTS=1` when available
 
-### 2. Call from C++
+### Call from C++
 
 ```cpp
 #include "orca_tree_supports.h"

orca-tree-supports/Cargo.toml …lic3r/Support/TreeSupportRust/Cargo.tomlorca-tree-supports/Cargo.toml renamed to src/libslic3r/Support/TreeSupportRust/Cargo.toml orca-tree-supports/Cargo.toml renamed to src/libslic3r/Support/TreeSupportRust/Cargo.toml

@@ -298,7 +298,7 @@ fn drop_single_branch(
         nodes.push(node);
     }
 
-    let reaches_buildplate = !nodes.is_empty() && nodes.last().is_some_and(|n| n.layer_index == 0);
+    let reaches_buildplate = nodes.last().is_some_and(|n| n.layer_index == 0);
 
     Branch {
         nodes,