Architecture reference for the unified edit-mode transform gizmo (translation arrows + rotation rings, transform spaces, x-ray rendering). Required reading before implementing any task in todo.md whose ID begins with GIZMO-.
Reference for the two-color (orange/blue) boolean system where IsSubtractive classifies inputs into groups and boolean operations combine them into a parent-child tree. Required reading before implementing any task in todo_bool.md.
Standardized pattern for creating interactive SDF primitive tools in the Direct Modeling workbench.
Template and rules for creating new SDF primitive field classes in core/sdf/sdf/. Required reading before implementing any new SdfField subclass.
Reference for converting SVG path data (M L H V C S Q T A Z) and shape elements (rect, circle, ellipse, line, polyline, polygon) into cubic Bezier segments with no rasterization. Required reading before implementing svg_importer.py.
Convention for registering primitive-specific GLSL inside the primitive's own .py file. Required reading before editing any to_glsl/to_glsl_2d method.
FreeCAD BSpline API reference and to_glsl() contract for SdfNurbsCurveField and SdfNurbsSurfaceField — tasks NS-001..NS-008 in todo_arch_refactor.md.
Interface contract, data layout, and mesher integration patterns for SdfOctreeCache — the hierarchical CPU evaluator that replaces np.meshgrid.