Isolate Qt and GLFW ImGui frontends

.github/workflows/system-packages.yml

@@ -139,6 +139,39 @@ jobs:
       - name: Build
         run: meson compile -C build/
 
+      - name: Verify Qt-only frontend
+        if: matrix.build_type == 'debug'
+        env:
+          CC: ccache ${{ matrix.platform.cc }}
+          CXX: ccache ${{ matrix.platform.cxx }}
+        run: |
+          meson setup build-qt-only/ \
+            --buildtype=debug \
+            --wrap-mode=forcefallback \
+            -Dtesting=false -Dexamples=false \
+            -Dqt=true -Dglfw=false -Dimgui=false
+          ninja -C build-qt-only/ \
+            visualization/libbalsaVisualization.so.p/src_qt_vulkan_film.cpp.o \
+            visualization/libbalsaVisualization.so.p/src_qt_vulkan_window.cpp.o \
+            visualization/tools/mesh_viewer_qt.p/mesh_viewer_qt.cpp.o
+
+      - name: Verify GLFW ImGui frontend
+        if: matrix.build_type == 'debug'
+        env:
+          CC: ccache ${{ matrix.platform.cc }}
+          CXX: ccache ${{ matrix.platform.cxx }}
+        run: |
+          meson setup build-glfw-imgui/ \
+            --buildtype=debug \
+            --wrap-mode=forcefallback \
+            -Dtesting=false -Dexamples=false \
+            -Dqt=false -Dglfw=true -Dimgui=true
+          ninja -C build-glfw-imgui/ \
+            visualization/libbalsaVisualization.so.p/src_glfw_vulkan_film.cpp.o \
+            visualization/libbalsaVisualization.so.p/src_glfw_vulkan_window.cpp.o \
+            visualization/libbalsaVisualization.so.p/src_vulkan_imgui_integration.cpp.o \
+            visualization/tools/mesh_viewer_glfw.p/mesh_viewer_glfw.cpp.o
+
       - name: ccache stats
         run: ccache -s
 

meson_options.txt

@@ -6,10 +6,10 @@ option('openvdb', type : 'boolean', value : false, description : 'Build openvdb
 option('json', type : 'boolean', value : true, description : 'Use json')
 option('protobuf', type : 'boolean', value : false, description : 'Use protobuf')
 option('partio', type : 'boolean', value : false, description : 'Use partio')
-option('imgui', type : 'boolean', value : true, description : 'Use imgui')
+option('imgui', type : 'boolean', value : true, description : 'Build the ImGui UI frontend (currently requires GLFW)')
 option('alembic', type : 'boolean', value : false, description : 'Use alembic')
 option('perfetto', type : 'boolean', value : false, description : 'Use perfetto')
 
 option('visualization', type : 'boolean', value : true, description : 'Build visualization library')
-option('glfw', type : 'boolean', value : true, description : 'Use glfw')
-option('qt', type : 'boolean', value : true, description : 'Use qt')
+option('glfw', type : 'boolean', value : true, description : 'Build the GLFW window backend')
+option('qt', type : 'boolean', value : true, description : 'Build the Qt window and widget frontend')

visualization/examples/meson.build

@@ -1,5 +1,16 @@
 
-test_example_scene_dep = static_library('vulkan_scene', 'vulkan_scene.cpp', dependencies: [visualization_dep])
-executable('vulkan_window', 'vulkan_window.cpp', 'vulkan_scene.cpp', dependencies: [visualization_dep])
-#executable('test_vulkan_window', 'test_vulkan_window.cpp', 'example_vulkan_scene.cpp', dependencies: [visualization_dep])
-executable('vulkan_window_glfw', 'vulkan_window_glfw.cpp', dependencies: [visualization_dep], link_with: [test_example_scene_dep])
+# The existing example scene includes an ImGui overlay, so only build it for
+# the GLFW + ImGui frontend. Qt-only examples should not acquire ImGui.
+if get_option('glfw') and get_option('imgui')
+  test_example_scene_dep = static_library(
+    'vulkan_scene',
+    'vulkan_scene.cpp',
+    dependencies: [visualization_dep],
+  )
+  executable(
+    'vulkan_window_glfw',
+    'vulkan_window_glfw.cpp',
+    dependencies: [visualization_dep],
+    link_with: [test_example_scene_dep],
+  )
+endif

visualization/meson.build

@@ -6,6 +6,10 @@ vulkan_dep = dependency('vulkan', required: false)
 
 shaderc_dep = dependency('shaderc')
 
+if get_option('imgui') and not get_option('glfw')
+  error('The ImGui frontend currently requires GLFW; enable -Dglfw=true or disable -Dimgui')
+endif
+
 # Shader source files are part of the dependency contract, so a binary system
 # package cannot satisfy it. Always use the pinned source subproject.
 colormap_proj = subproject('colormap_shaders')
@@ -42,7 +46,28 @@ endif
 imgui_backend_sources = []
 imgui_backend_inc = []
 if get_option('imgui')
-  imgui_dep = dependency('imgui')
+  imgui_dep = dependency(
+    'imgui',
+    default_options: [
+      'dx9=disabled',
+      'dx10=disabled',
+      'dx11=disabled',
+      'dx12=disabled',
+      'metal=disabled',
+      'opengl=disabled',
+      'sdl2_renderer=disabled',
+      'sdl3_renderer=disabled',
+      'sdl3_gpu=disabled',
+      'vulkan=enabled',
+      'webgpu=disabled',
+      'glfw=enabled',
+      'sdl2=disabled',
+      'sdl3=disabled',
+      'osx=disabled',
+      'win=disabled',
+      'allegro5=disabled',
+    ],
+  )
   if imgui_dep.type_name() != 'internal'
     imgui_prefix = imgui_dep.get_variable(pkgconfig: 'prefix')
     imgui_bd = imgui_prefix / 'res' / 'bindings'
@@ -148,7 +173,7 @@ meson.override_dependency('balsaVisualization', visualization_dep)
 if get_option('testing')
   subdir('tests')
 endif
-if get_option('examples')
+if get_option('examples') and get_option('glfw') and get_option('imgui')
   subdir('examples')
 endif
 subdir('tools')

visualization/tools/meson.build

@@ -1,35 +1,41 @@
 
-cli11_dep = dependency('CLI11', required: false, allow_fallback: true)
-
-# ── mesh_viewer_glfw ─────────────────────────────────────────────────
-mesh_viewer_glfw_deps = [visualization_dep]
-mesh_viewer_glfw_args = []
-if cli11_dep.found()
-  mesh_viewer_glfw_deps += cli11_dep
-  mesh_viewer_glfw_args += '-DBALSA_HAS_CLI11=1'
+if get_option('qt') or (get_option('glfw') and get_option('imgui'))
+  cli11_dep = dependency('CLI11', required: false, allow_fallback: true)
 endif
-executable('mesh_viewer_glfw', 'mesh_viewer_glfw.cpp',
-  dependencies: mesh_viewer_glfw_deps,
-  cpp_args: mesh_viewer_glfw_args)
 
-# ── mesh_viewer_qt ───────────────────────────────────────────────────
-mesh_viewer_qt_deps = [visualization_dep]
-mesh_viewer_qt_args = []
-if cli11_dep.found()
-  mesh_viewer_qt_deps += cli11_dep
-  mesh_viewer_qt_args += '-DBALSA_HAS_CLI11=1'
+if get_option('glfw') and get_option('imgui')
+  # ── mesh_viewer_glfw ───────────────────────────────────────────────
+  mesh_viewer_glfw_deps = [visualization_dep]
+  mesh_viewer_glfw_args = []
+  if cli11_dep.found()
+    mesh_viewer_glfw_deps += cli11_dep
+    mesh_viewer_glfw_args += '-DBALSA_HAS_CLI11=1'
+  endif
+  executable('mesh_viewer_glfw', 'mesh_viewer_glfw.cpp',
+    dependencies: mesh_viewer_glfw_deps,
+    cpp_args: mesh_viewer_glfw_args)
+
+  # ── image_viewer_glfw ──────────────────────────────────────────────
+  image_viewer_glfw_deps = [visualization_dep]
+  image_viewer_glfw_args = []
+  if cli11_dep.found()
+    image_viewer_glfw_deps += cli11_dep
+    image_viewer_glfw_args += '-DBALSA_HAS_CLI11=1'
+  endif
+  executable('image_viewer_glfw', 'image_viewer_glfw.cpp',
+    dependencies: image_viewer_glfw_deps,
+    cpp_args: image_viewer_glfw_args)
 endif
-executable('mesh_viewer_qt', 'mesh_viewer_qt.cpp',
-  dependencies: mesh_viewer_qt_deps,
-  cpp_args: mesh_viewer_qt_args)
 
-# ── image_viewer_glfw ────────────────────────────────────────────────
-image_viewer_glfw_deps = [visualization_dep]
-image_viewer_glfw_args = []
-if cli11_dep.found()
-  image_viewer_glfw_deps += cli11_dep
-  image_viewer_glfw_args += '-DBALSA_HAS_CLI11=1'
+if get_option('qt')
+  # ── mesh_viewer_qt ─────────────────────────────────────────────────
+  mesh_viewer_qt_deps = [visualization_dep]
+  mesh_viewer_qt_args = []
+  if cli11_dep.found()
+    mesh_viewer_qt_deps += cli11_dep
+    mesh_viewer_qt_args += '-DBALSA_HAS_CLI11=1'
+  endif
+  executable('mesh_viewer_qt', 'mesh_viewer_qt.cpp',
+    dependencies: mesh_viewer_qt_deps,
+    cpp_args: mesh_viewer_qt_args)
 endif
-executable('image_viewer_glfw', 'image_viewer_glfw.cpp',
-  dependencies: image_viewer_glfw_deps,
-  cpp_args: image_viewer_glfw_args)