Refresh stale depth bounds after geometry edits, allow orbiting through camera poles, and preserve hidden-line occlusion for selected solids.\n\nFixes #957
Model space appearance now follows the active UI theme instead of a
hardcoded dark background. Canvas mode is user-selectable (Match Theme /
Classic CAD Dark / Custom RGB), with matching controls for the paper
sheet and desk surround backgrounds and grid opacity.
Implements industry-standard CAD system variables, all settable via
command name, SETVAR, and the Options dialog:
- COLORTHEME (0/1 dark/light UI scheme, preserves custom palettes)
- COLORSCHEME (interactive named-theme selection)
- BACKGROUND (THEME/CLASSIC/DEFAULT/DESK presets, RGB triplets)
- SELECTIONAREA, SELECTIONAREAOPACITY (translucent marquee fill)
- WINDOWSAREACOLOR/WINDOWAREACOLOR, CROSSINGAREACOLOR (ACI or theme)
- SELECTIONEFFECT, SELECTIONEFFECTCOLOR (GPU highlight pass, driven by
selection_generation invalidation — no retessellation)
- SELECTIONPREVIEW (bit 0 = idle rollover, bit 1 = in-command hover)
- GRIPSIZE, GRIPCOLOR, GRIPHOT, GRIPHOVER (grip overlay styling)
Scene.selection was Rc<RefCell<SelectionState>> (31 fields, ~1.6KB
with poly_points) cloned deep per view_main per pane via
(*sel_ref).clone() at view/mod.rs:760. Replace with
Arc<RefCell<SelectionState>> (Arc::new(RefCell::new(...)) at
scene/mod.rs:1436,1868), SelectionCanvas holds Arc<RefCell> and
selection_overlay takes Arc<RefCell> (overlay.rs:365,415),
view_main does Arc::clone(&tab.scene.selection) (atomic bump)
instead of deep clone. sel_ref stays borrowed for field reads
(vp_size etc.).
Bench (release, n=5000): SelectionState::clone 39-68ns (64pts) /
11-22ns (0pts) vs Arc::clone 7ns — 5-9x on the hot path.
Tests:
- selection_is_arc_not_refcell: asserts type_name contains Arc
- bench_selection_state_clone / bench_selection_arc_clone / bench_selection_state_clone_empty (ignored, release)
Resolve ByBlock alpha independently from color and keep explicit opaque values from falling back to layer transparency.
Pin the matching cadcodec API across desktop, plugin, and web targets.
Refs HakanSeven12/cadcodec#2