New OverlayRenderer module owns every client-supplied overlay primitive
drawn after the main pass: tinted, depth-aware highlight triangles via
its own GL shader, and top-left HUD text via QPainter on a
QOpenGLPaintDevice. Public surface on ViewportWindow is just two
forwarders (setHighlightTriangles, setHudText).
ViewportWindow's MeshLocalPick now exposes the instance's composed
transform so consumers can map mesh-local geometry back to world
space without re-querying. AreaMeasurement uses both: its selection
key is now (object_id, tri) so per-instance highlighting works for
two distinct walls sharing a mesh, and on every pick it rebuilds the
world-space tri list and the HUD readout.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Adds a click-to-measure area mode triggered by Ctrl+Shift+A. Each LMB
click expands the picked triangle into its connected coplanar patch
(BFS over shared edges, dot(normal, seed) > 0.9999); re-clicking
removes that patch; Alt+LMB skips expansion for a single triangle.
Picks across different meshes accumulate as separate patches.
ViewportWindow gains pickMeshLocalAt (screen pick → mesh-local hit
via inverse composed transform) and a tool-mode pattern mirroring
the section tool (toggleAreaTool, surfacePickedInTool signal,
areaToolToggled signal, Esc to exit). Per-mesh adjacency is built
lazily on first pick of each mesh and dropped on tool toggle.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Adds neutral primitives on ViewportWindow (readbackMeshTriangles,
findInstance) so consumers can compute per-object geometry queries
without the library retaining a CPU triangle copy. Measurement.cpp in
ifcviewer-full uses them to sum signed-tetrahedra in mesh-local space,
weighted by |det(placement_3x3)| per instance for mapped-item scaling.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Dion Moult