Add JS/WASM bindings for libnest2d via Emscripten

saumyaj3 · saumyaj3 · commit 314d021d371a · 2025-09-11T14:43:38.000+02:00
NP-1172
diff --git a/.github/workflows/package.yml b/.github/workflows/package.yml
@@ -0,0 +1,37 @@
+name: package
+
+on:
+  workflow_dispatch:
+  repository_dispatch:
+    types: [build]
+  push:
+    paths:
+      - 'src/**'
+      - 'include/**'
+      - 'test_package/**'
+      - 'conanfile.py'
+      - 'conandata.yml'
+      - 'CMakeLists.txt'
+      - 'tools/**'
+      - 'tests/**'
+      - '.github/workflows/package.yml'
+    branches:
+      - main
+      - dev
+      - 'CURA-*'
+      - 'PP-*'
+      - 'NP-*'
+      - 'GH-*'
+      - '[0-9].[0-9]*'
+      - '[0-9].[0-9][0-9]*'
+
+jobs:
+  conan-package:
+    uses: ./.github/workflows/conan-package.yml
+
+  npm-package:
+    needs: [ conan-package ]
+    uses: ultimaker/cura-workflows/.github/workflows/npm-package.yml@main
+    with:
+      package_version_full: ${{ needs.conan-package.outputs.package_version_full }}
+    secrets: inherit
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -6,6 +6,7 @@ find_package(standardprojectsettings REQUIRED)
 option(BUILD_SHARED_LIBS "Build shared libs instead of static (applies for dependencies as well)" OFF)
 option(HEADER_ONLY "If enabled static library will not be built." ON)
 option(ENABLE_TESTING "Build with Google unittest" OFF)
+option(WITH_JS_BINDINGS "Build JS/WASM bindings for npm package" OFF)
 set(GEOMETRIES clipper CACHE STRING "Geometry backend, available options: 'clipper' (default), 'boost'")
 set(OPTIMIZER nlopt CACHE STRING "Optimization backend, available options: 'nlopt' (default), 'optimlib'")
 set(THREADING std CACHE STRING "Multithreading, available options: 'std' (default), 'tbb', 'omp', 'none'")
@@ -89,34 +90,56 @@ endif()
 target_compile_definitions(project_options INTERFACE LIBNEST2D_THREADING_${THREADING})
 
 set(libnest2d_SRCS
-        src/libnest2d.cpp
-        )
+    src/libnest2d.cpp
+)
+
+if(WITH_JS_BINDINGS OR EMSCRIPTEN)
+    list(APPEND libnest2d_SRCS src/libnest2d_js.cpp)
+endif()
+
 
 if(HEADER_ONLY)
     add_library(nest2d INTERFACE ${libnest2d_HDRS})
     target_link_libraries(nest2d INTERFACE project_options)
     target_include_directories(nest2d
-            INTERFACE
+        INTERFACE
+            $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include/>
+            $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
+    )
+else()
+    if(WITH_JS_BINDINGS OR EMSCRIPTEN)
+        add_library(nest2d_js SHARED ${libnest2d_SRCS} ${libnest2d_HDRS})
+        target_link_libraries(nest2d_js PUBLIC project_options)
+        target_include_directories(nest2d_js
+            PUBLIC
                 $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include/>
                 $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
-            )
-else()
-    if(BUILD_SHARED_LIBS)
-        add_library(nest2d SHARED ${libnest2d_SRCS} ${libnest2d_HDRS})
-        if(WIN32)
-            set_target_properties(nest2d PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS ON)
+            PRIVATE
+                $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src>
+        )
+        set_target_properties(nest2d_js PROPERTIES OUTPUT_NAME "libnest2d_js")
+        # Emscripten-specific properties for npm packaging
+        if(EMSCRIPTEN)
+            set_target_properties(nest2d_js PROPERTIES SUFFIX ".js")
         endif()
     else()
-        add_library(nest2d STATIC ${libnest2d_SRCS} ${libnest2d_HDRS})
-    endif()
-    target_link_libraries(nest2d PUBLIC project_options)
-    target_include_directories(nest2d
+        if(BUILD_SHARED_LIBS)
+            add_library(nest2d SHARED ${libnest2d_SRCS} ${libnest2d_HDRS})
+            if(WIN32)
+                set_target_properties(nest2d PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS ON)
+            endif()
+        else()
+            add_library(nest2d STATIC ${libnest2d_SRCS} ${libnest2d_HDRS})
+        endif()
+        target_link_libraries(nest2d PUBLIC project_options)
+        target_include_directories(nest2d
             PUBLIC
                 $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include/>
                 $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
             PRIVATE
                 $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src>
-            )
+        )
+    endif()
 endif()
 
 if(ENABLE_TESTING)
diff --git a/conanfile.py b/conanfile.py
@@ -22,21 +22,24 @@ class Nest2DConan(ConanFile):
     package_type = "library"
     implements = ["auto_header_only"]
 
+    python_requires = "npmpackage/[>=1.0.0]"
     options = {
         "shared": [True, False],
         "fPIC": [True, False],
         "header_only": [True, False],
         "geometries": ["clipper", "boost"],
         "optimizer": ["nlopt", "optimlib"],
-        "threading": ["std", "tbb", "omp", "none"]
+        "threading": ["std", "tbb", "omp", "none"],
+        "with_js_bindings": [True, False]
     }
     default_options = {
         "shared": True,
         "fPIC": True,
         "header_only": False,
         "geometries": "clipper",
         "optimizer": "nlopt",
-        "threading": "std"
+        "threading": "std",
+        "with_js_bindings": False
     }
 
     def set_version(self):
@@ -133,6 +136,7 @@ def generate(self):
         tc.variables["GEOMETRIES"] = self.options.geometries
         tc.variables["OPTIMIZER"] = self.options.optimizer
         tc.variables["THREADING"] = self.options.threading
+        tc.variables["WITH_JS_BINDINGS"] = self.options.get_safe("with_js_bindings", False)
 
         tc.generate()
 
@@ -162,3 +166,7 @@ def package_info(self):
         self.cpp_info.defines.append(f"LIBNEST2D_THREADING_{self.options.threading}")
         if self.settings.os in ["Linux", "FreeBSD", "Macos"] and self.options.threading == "std":
             self.cpp_info.system_libs.append("pthread")
+
+        # npm package json for Emscripten builds
+        if self.settings.os == "Emscripten" or self.options.get_safe("with_js_bindings", False):
+            self.python_requires["npmpackage"].module.conf_package_json(self)
diff --git a/src/libnest2d_js.cpp b/src/libnest2d_js.cpp
@@ -0,0 +1,50 @@
+// Expose libnest2d API to JavaScript via Emscripten
+#ifndef LIBNEST2D_JS_H
+#define LIBNEST2D_JS_H
+
+#include <libnest2d/libnest2d.hpp>
+#include <libnest2d/nester.hpp>
+#include <libnest2d/optimizer.hpp>
+#include <libnest2d/geometry_traits.hpp>
+#include <emscripten/bind.h>
+#include <vector>
+#include <string>
+
+using namespace libnest2d;
+using namespace emscripten;
+
+EMSCRIPTEN_BINDINGS(libnest2d_js) {
+    // Expose Point type
+    value_object<Point>("Point")
+        .field("x", &Point::x)
+        .field("y", &Point::y);
+
+    // Expose Polygon type
+    value_object<Polygon>("Polygon")
+        .field("points", &Polygon::points);
+
+    // Expose NesterConfig
+    value_object<NesterConfig>("NesterConfig")
+        .field("iterations", &NesterConfig::iterations)
+        .field("time_limit", &NesterConfig::time_limit);
+
+    // Expose Nester class
+    class_<Nester>("Nester")
+        .constructor<>()
+        .function("nest", &Nester::nest);
+
+    // Expose OptimizerConfig
+    value_object<OptimizerConfig>("OptimizerConfig")
+        .field("max_evals", &OptimizerConfig::max_evals)
+        .field("tolerance", &OptimizerConfig::tolerance);
+
+    // Expose Optimizer class
+    class_<Optimizer>("Optimizer")
+        .constructor<>()
+        .function("optimize", &Optimizer::optimize);
+
+    // Expose utility functions (example)
+    function("polygonArea", &polygon_area);
+}
+
+#endif // LIBNEST2D_JS_H
