examples(wasm): wasm-enable the Ariadne host + ship the DSL volume bunny demos to the web gallery

.github/workflows/deploy-pages.yml

@@ -44,7 +44,7 @@ jobs:
       # grl-snam-weights lands here; --preload-file bakes the trained CoefMLP into
       # nav_city_swarm.data so the browser swarm drives with the published policy.
       CVC_WASM_NAV_WEIGHTS: /opt/cvc-wasm/deps-wasm-mt/share/grl-snam-weights/coef_sdf.cvcnav
-      DEMOS: 'terrain_lab lsystem_forest lsystem_coast volren_bunny volslice_bunny nav_city_swarm nav_city_drive nav_fog_ghost'
+      DEMOS: 'terrain_lab lsystem_forest lsystem_coast volren_bunny volren_bunny_ari volslice_bunny volslice_bunny_ari nav_city_swarm nav_city_drive nav_fog_ghost'
     steps:
       - name: Checkout master
         uses: actions/checkout@v4

src/cvcGL/examples/CMakeLists.txt

@@ -124,6 +124,24 @@ endif()
 if(EMSCRIPTEN)
   set(_wasm_demos lsystem_forest lsystem_coast terrain_lab bunny_shadow volren_bunny volslice_bunny nav_city_swarm nav_city_drive nav_fog_ghost)
   set(_wasm_extra_demos ariadne_hello)
+
+  # Ariadne (.ari) demos as wasm: build the generic ariadne_hello host once per document, with that
+  # .ari baked in as the default doc (CVC_ARIADNE_WASM_DOC) and the shared component library embedded
+  # in MEMFS (--embed-file), so a pure-DSL demo runs in the browser with no argv. Distinct slugs
+  # (<name>_ari) so they sit ALONGSIDE the C++ volren_bunny/volslice_bunny demos, not replacing them.
+  # This is also the path for every future .ari demo (A/V, lsystem, …) to reach the web gallery.
+  get_filename_component(_CVC_ARIADNE_COMPONENTS
+    "${CMAKE_CURRENT_SOURCE_DIR}/../../cvc/ariadne/components" ABSOLUTE)
+  foreach(_ari volren_bunny volslice_bunny)
+    add_executable(${_ari}_ari ariadne_hello.cpp)
+    target_link_libraries(${_ari}_ari PRIVATE cvcGL ${VTK_LIBRARIES})
+    vtk_module_autoinit(TARGETS ${_ari}_ari MODULES ${VTK_LIBRARIES})
+    target_compile_definitions(${_ari}_ari PRIVATE CVC_ARIADNE_WASM_DOC="/${_ari}.ari")
+    target_link_options(${_ari}_ari PRIVATE
+      "--embed-file=${CMAKE_CURRENT_SOURCE_DIR}/${_ari}.ari@/${_ari}.ari"
+      "--embed-file=${_CVC_ARIADNE_COMPONENTS}@/components")
+    list(APPEND _wasm_demos ${_ari}_ari)
+  endforeach()
   # Optional runtime asset bundle for nav_city_swarm (Austin: terrain.json +
   # buildings.glb + satellite.png). When CVC_WASM_BUNDLE is set to a scene dir,
   # its contents are preloaded to /bundle and, if the sibling shared/Humvee.glb

src/cvcGL/examples/ariadne_hello.cpp

@@ -17,6 +17,9 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h> // emscripten_sleep — yield the asyncify main loop to the browser
+#endif
 #include <cvc/ariadne/ariadne.h>
 #include <cvc/ariadne/loader.h>
 #include <cvc/ariadne/uri.h> // register_cvc_uri_handler — the cvc:// component-library import path
@@ -76,6 +79,16 @@ int main(int argc, char **argv) {
     else if (a[0] != '-' && docPath.empty())
       docPath = a;
   }
+  // A wasm demo build bakes in its own .ari (CVC_ARIADNE_WASM_DOC) and embeds the component library
+  // in MEMFS (see the examples CMake --embed-file). With no argv in the browser, default to that
+  // doc and add the MEMFS root to the search path so `cvc://components/*.ari` resolves at
+  // /components.
+#ifdef CVC_ARIADNE_WASM_DOC
+  if (docPath.empty()) {
+    docPath = CVC_ARIADNE_WASM_DOC;
+    componentPaths.push_back("/");
+  }
+#endif
   // The cvc:// component-library import path (import: cvc://components/foo.ari), resolved against
   // CVC_ARIADNE_PATH + any --component-path dirs + the install datadir + cwd. Register before load.
   cvc::ariadne::register_cvc_uri_handler(componentPaths);

src/cvcGL/examples/wasm/build-wasm-demo.sh

@@ -74,6 +74,42 @@ EOF_EMCFG
     echo "build-wasm-demo: shared emsdk cache not writable by $(id -un); using seeded per-user cache ${_em_cache}"
 fi
 
+# yaml-cpp for wasm — the Ariadne .ari loader's only extra dependency (src/cvc/
+# CMakeLists.txt: find_package(yaml-cpp) → CVC_ARIADNE_HAVE_YAML). It is NOT in
+# the cvcpkg wasm catalog (published linux/macos/win/bsd only), so without this
+# the loader silently compiles to a stub and the .ari demos (volren_bunny_ari,
+# volslice_bunny_ari) deploy BLANK. Build it from the pinned upstream tarball
+# into CVC_WASM_DEPS, STATIC, and pthread-matched to the module so the emscripten
+# link doesn't reject mixed -pthread objects. Idempotent: skipped once installed.
+if [ ! -f "${CVC_WASM_DEPS}/lib/cmake/yaml-cpp/yaml-cpp-config.cmake" ] \
+   && [ ! -f "${CVC_WASM_DEPS}/share/cmake/yaml-cpp/yaml-cpp-config.cmake" ]; then
+    echo "build-wasm-demo: yaml-cpp not in ${CVC_WASM_DEPS}; building it for wasm from source"
+    _yc_ver=0.8.0
+    _yc_sha=fbe74bbdcee21d656715688706da3c8becfd946d92cd44705cc6098bb23b3a16
+    _yc_work="${BUILD_DIR}/_yaml-cpp"
+    _yc_src="${_yc_work}/yaml-cpp-${_yc_ver}"
+    _yc_tar="${_yc_work}/yaml-cpp-${_yc_ver}.tar.gz"
+    mkdir -p "${_yc_work}"
+    if [ ! -d "${_yc_src}" ]; then
+        curl -fL "https://github.com/jbeder/yaml-cpp/archive/refs/tags/${_yc_ver}.tar.gz" \
+            -o "${_yc_tar}"
+        echo "${_yc_sha}  ${_yc_tar}" | sha256sum -c -
+        tar -xzf "${_yc_tar}" -C "${_yc_work}"
+    fi
+    _yc_pthread=""
+    [[ "${PTHREAD}" == "ON" ]] && _yc_pthread="-pthread"
+    emcmake cmake -G Ninja -S "${_yc_src}" -B "${_yc_work}/build" \
+        -DCMAKE_BUILD_TYPE=Release \
+        -DCMAKE_INSTALL_PREFIX="${CVC_WASM_DEPS}" \
+        -DYAML_CPP_BUILD_TESTS=OFF \
+        -DYAML_CPP_BUILD_TOOLS=OFF \
+        -DYAML_CPP_BUILD_CONTRIB=OFF \
+        -DYAML_BUILD_SHARED_LIBS=OFF \
+        -DCMAKE_CXX_FLAGS="${_yc_pthread}" \
+        -DCMAKE_C_FLAGS="${_yc_pthread}"
+    cmake --build "${_yc_work}/build" --target install
+fi
+
 emcmake cmake -G Ninja -S "${REPO_ROOT}" -B "${BUILD_DIR}" \
     -DCMAKE_BUILD_TYPE=Release \
     -DCMAKE_FIND_ROOT_PATH="${CVC_WASM_DEPS}" \

src/cvcGL/examples/wasm/demos.json

@@ -6,7 +6,9 @@
     "lsystem_forest",
     "lsystem_coast",
     "volren_bunny",
+    "volren_bunny_ari",
     "volslice_bunny",
+    "volslice_bunny_ari",
     "nav_city_swarm",
     "nav_city_drive",
     "nav_fog_ghost",
@@ -66,6 +68,18 @@
       "blurb":
           "The classic view-aligned slice compositor from VolumeRover2, ported to cvc::volslice: the bunny's signed-distance volume windowed into a byte texture and colored by a 256-entry transfer function, hundreds of camera-facing slices blended back to front. Add up to nine bunnies — each is its own scene-graph volume node, depth-sorted per frame — and drive quality, near-plane peel, the value window and spacing-corrected opacity live in the panel.",
       "thumb": "img/volslice_bunny.jpg"
+    },
+    "volren_bunny_ari": {
+      "desc": "the volren bunny, built entirely in the Ariadne UI DSL (.ari)",
+      "blurb":
+          "The same CPU-raycast bunny, rebuilt in the Ariadne UI DSL: the scene, lighting rig and raycast control panel are all declared in one .ari document — no demo-specific C++, just the generic host. The volume is computed live as the signed distance field of the embedded Stanford mesh via a single DSL source (source: { sdf: { mesh } }), and the controls are reusable .ari components shared with the other bunny demos.",
+      "thumb": "img/volren_bunny_ari.jpg"
+    },
+    "volslice_bunny_ari": {
+      "desc": "the volslice bunny, built entirely in the Ariadne UI DSL (.ari)",
+      "blurb":
+          "The slice-based bunny, rebuilt in the Ariadne UI DSL: scene, transfer function, lighting and the slice control panel declared in one .ari document, driven by the generic host — no demo-specific C++. The volume is the signed distance field of the embedded Stanford mesh (source: { sdf: { mesh } }), and the controls are reusable .ari components.",
+      "thumb": "img/volslice_bunny_ari.jpg"
     }
   }
 }