This page gives a high-level map of the main subsystems in wx_BGI_Graphics.

Public API Layers

Header	Role
`src/wx_bgi.h`	Classic BGI-compatible C API
`src/wx_bgi_ext.h`	Modern extension helpers (`wxbgi_*`)
`src/wx_bgi_3d.h`	Cameras, UCS, world-coordinate drawing
`src/wx_bgi_dds.h`	DDS/CHDOP retained scene API
`src/wx_bgi_openlb.h`	Header-only OpenLB live-loop helpers
`src/bgi_types.h`	Shared types and constants

Core Runtime Areas

Area	Main Files	Notes
Global state	`src/bgi_state.cpp`, `src/bgi_state.h`	Owns global state, buffers, and lifecycle helpers
Immediate drawing	`src/bgi_api.cpp`, `src/bgi_draw.cpp`, `src/bgi_font.cpp`, `src/bgi_image.cpp`	Classic BGI drawing path and pixel-buffer rendering
Modern extension API	`src/bgi_modern_api.cpp`	Polling, frame control, wx helpers, and advanced runtime features
Cameras	`src/bgi_camera.cpp`, `src/bgi_camera_api.cpp`	View/projection math and camera API wrappers
UCS/world	`src/bgi_ucs.cpp`, `src/bgi_ucs_api.cpp`, `src/bgi_world_api.cpp`	Coordinate systems, extents, and world/UCS draw wrappers
DDS retained scene	`src/bgi_dds.cpp`, `src/bgi_dds_api.cpp`, `src/bgi_dds_render.cpp`, `src/bgi_dds_serial.cpp`	Scene graph, traversal, rendering, and JSON/YAML round-trips
3D solids	`src/bgi_solid_api.cpp`, `src/bgi_solid_render.cpp`	Solid primitive API and tessellation/rendering
Overlays	`src/bgi_overlay.cpp`, `src/bgi_overlay_api.cpp`	Grid, UCS axes, cursors, and visual aids
wx integration	`src/wx/wx_bgi_canvas.cpp`, `src/wx/wx_bgi_canvas.h`	Embedded `WxBgiCanvas` rendering surface

Immediate mode + retained mode together: most draw calls both render immediately and append a replayable DDS object.
Camera additive model: classic BGI behavior remains intact while cameras, UCS, and world coordinates add a separate engineering/3D layer.
Retained composition: retained transform and set-operation nodes wrap existing DDS IDs instead of mutating source objects.
Exact retained 3D booleans: supported solids use the Manifold backend for retained union/intersection/difference.
Single shared state mutex: internal state changes are guarded centrally.