Loading a model whose first placement sits at the world origin
stack-overflowed BonsaiViewer instantly on Windows (and macOS).
WinDbg trace was a 5-frame Qt signal-slot cycle hitting the guard
page ~1400 levels deep; Linux escaped only because that machine's
iterator order put a non-origin instance first, which made the guess
return a non-default value and naturally terminated the recursion
after one step.
Root cause is the architecture, not the specific guard inside the
guess function. `ViewportView::refresh()` was connected to six
SessionState signals (projectReset, projectOpened, modelsChanged,
federationChanged, visibilityChanged, modelGeometryReady) and was
calling `maybeGuessFederatedFalseOrigin` on every model on every
fire. That helper called `session_state_->notifyFederationChanged()`
unconditionally after the mutation, which re-emitted
SessionState::federationChanged, which re-entered refresh(), which
re-entered the guess — a hidden emit-in-slot loop. The "current ==
defaults" guard at the top of the guess prevented further mutations
once the value moved off defaults, but on machines where the guess
itself returned defaults the guard never fired and the loop ran
forever.
Cleanup:
* refresh() is now terminal: it reads federation state, pushes it to
the viewport, and returns. No mutations, no signal emissions.
maybeGuessFederatedFalseOrigin is removed from its for-loop.
* The guess is renamed to `tryGuessFirstModelFalseOrigin(uint32_t)`
and is now invoked only from the modelGeometryReady connection,
not from refresh(). Conditions:
1. modelIds().size() == 1 (the just-loaded model is the only
model — i.e. this is the "first model added" edge)
2. federation->federatedFalseOrigin() == defaults (nobody has
set the origin yet — possibly because the previous attempt
guessed defaults and no-op'd, in which case we deliberately
want to retry next time a model lands)
No one-shot flag: add→remove→add cycles re-attempt the guess
precisely while the origin is still default, which is the right
semantics.
* SessionState now relays Federation::federatedFalseOriginChanged
onto its own bus via notifyFederationChanged. This replaces the
manual `session_state_->notifyFederationChanged()` call the old
guess made post-mutation. With the relay in place, any future
mutation site (commands, settings dialog, project load) will
propagate to views automatically — the emit point lives at the
data change, not at every caller. Views still subscribe to
SessionState only; Federation stays a back-end detail.
Reproduced with ISSUE_053_20181220Holter_Tower_10.ifcview on
Windows (build 21d3945, WinDbg `kn30` showed the recurring cycle
explicitly). Diagnosis confirmed on Linux by adding tracing prints
in refresh() and the guess body: same model, same code, but the
iterator's first-placement happened to be non-origin so the loop
terminated after one step.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Bonsai now drives the wgpu viewport for both sidecar and direct-IFC
loads. The GL viewer and its supporting state classes are gone.
SceneLoader rewire:
- Takes WgpuViewportWindow* instead of ViewportWindow*.
- Sidecar path reads metadata only (readSidecarMetadataOnly) and hands
the StreamingSidecar off to the new applyCachedModel. Field accesses
inside applySidecarData go through .meta.
- Direct-IFC path uses the wgpu A-path (upload{Mesh,Instance}Chunk +
finalizeModel). The applyLodExtension call is dropped — wgpu has no
live LOD1 splice; LOD1 still lands in the on-disk sidecar for the
next open.
Bonsai migration:
- ViewportWindow → WgpuViewportWindow across MainWindow, Measurement,
SessionState, and every modules/*/{Commands,Panel,View}.{h,cpp} —
116 sites total. Same s/OverlayRenderer::/WgpuOverlayRenderer::/
rename, 12 sites.
- Includes flipped from ../ifcviewer/ViewportWindow.h to
../ifcviewer-wgpu/WgpuViewportWindow.h. OverlayRenderer.h include
dropped (transitively reached via the viewport header).
- BonsaiViewer links IfcViewerWgpu in addition to IfcViewer for the
duration of the migration; the GL-side IfcViewer also publicly links
IfcViewerWgpu so SceneLoader can resolve WgpuViewportWindow.
GL backend deletion:
- src/ifcviewer/ViewportWindow.{cpp,h}, BvhAccel.*, OverlayRenderer.*,
Selection.*, Visibility.* all gone.
- src/ifcviewer-minimal/ removed entirely (MinimalWindow drove the GL
viewport).
- src/ifcviewer/tests: test_bvh_accel, test_selection, test_visibility
removed. The first has no replacement (wgpu doesn't use a per-instance
BVH); the latter two are ported separately. test_lod_builder,
test_sidecar_cache, test_instanced_geometry, test_federation remain
(backend-agnostic).
- IfcViewer's CMakeLists drops OpenGL, Qt::OpenGL, Qt::Widgets — none
of the surviving translation units reach for them.
Build flag plumbing:
- BUILD_BONSAIVIEWER now auto-enables BUILD_BONSAIVIEWER_WGPU since
SceneLoader requires the wgpu lib for its WgpuViewportWindow* arg.
- The wgpu subprojects add_subdirectory ahead of the GL one so
IfcViewerWgpu exists when IfcViewer's link evaluates.
- src/ifcviewer-minimal subdir reference removed from cmake/CMakeLists.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Directory src/ifcviewer-full -> src/bonsaiviewer, CMake target
IfcViewerFull -> BonsaiViewer, namespace ifcviewerfull -> bonsaiviewer,
QApplication / window titles / connector path now use the new brand.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Dion Moult