Appendix B Renderer Registry, Capabilities, and Evidence

CNA exposes 50 public renderer identities / 46 implementation families at the pinned revision. The four-count difference is exact: five EasyGL profiles share one implementation family, while every other identity has its own family. This appendix derives the registry from docs/renderer-registry.md and the source-owned factory paths, then reports a narrow set of capabilities from reachable implementation behavior. It does not copy the older central feature matrix, whose names and cells predate the current registry.

B.1 Canonical public identities

Cluster	Accepted CNA_GRAPHICS_RENDERER values	Count
OpenGL fixed function	OPENGLES1, OPENGL1, TINYGL	3
OpenGL programmable / portable	OPENGLES2, OPENGLES3, OPENGL33, WEBGL1, WEBGL2, OPENGL2, OPENGL4, PORTABLEGL	8
Native modern GPU	VULKAN, WEBGPU, SDL_GPU, METAL, IGL	5
Abstraction layers	BGFX, MAGNUM, LLGL, DILIGENT, SOKOL, WICKED, FNA3D	7
DirectX 1–3 / free-direct	DIRECTX1, DIRECTX2, DIRECTX3, FREEDIRECT	4
Retro ladder	DIRECTX5, DIRECTX6, DIRECTX7, DIRECTX8, GLIDE	5
Modern Direct3D	DIRECTX9, DIRECTX10, DIRECTX11, DIRECTX12	4
Windows 2D	DIRECT2D, GDI	2
2D / vector rasterizers	SDL_RENDERER, SKIA, BLEND2D, OPENVG, NANOVG	5
Web / DOM	CANVAS, HTML_DOM, SVG_DOM, PIXIJS	4
Diagnostic / non-GPU	HEADLESS, SOFTWARE, STUB	3
Total	50 identities / 46 families	50

ASCII is no longer a renderer identity; its reusable work lives in CNA::Graphics::AsciiPostProcessEffect. EASYGL, DX3, D3D9, D3D11, and D3D12 are not accepted selectors. FREEDIRECT selects the free-direct-backed family; DIRECTX3 selects the genuine DirectX 3 family. Defaults are WEBGL2 under Emscripten, OPENGLES3 on Linux, and SDL_RENDERER elsewhere.

B.2 Four implementation questions across all 46 families

The next matrix deliberately asks only four questions that can be answered uniformly from the pinned source. “Native” means the family owns both ordinary effect-aware Draw*Ex routes; it does not promise complete stock-effect fidelity. “Fallback–reject” means the shared parameter-dropping fallback reaches an explicit 3D refusal. “Hybrid” means a renderer-owned route still has a bounded coloured fallback. “Conditional” names a real profile/device/extension dependency. “Claims yes” exposes a public capability answer that contradicts the reachable factory or operation.

Family	Public identity / identities	Effect-aware draw	RT2D	MRT	Occlusion query
bgfx	BGFX	native	yes	yes	conditional
blend2d	BLEND2D	fallback–reject	yes	no	no
canvas	CANVAS	fallback–reject	yes	no	no
diligent	DILIGENT	native	yes	yes	conditional
direct2d	DIRECT2D	fallback–reject	yes	no	no
directx1	DIRECTX1	fallback–reject	yes	no	no
directx2	DIRECTX2	native fixed	yes	no	no
directx3	DIRECTX3	native fixed	yes	no	no
directx5	DIRECTX5	native fixed	yes	no	no
directx6	DIRECTX6	native fixed	yes	no	no
directx7	DIRECTX7	native fixed	yes	no	no
directx8	DIRECTX8	native fixed	yes	no	no
directx9	DIRECTX9	native	yes	yes	yes
directx10	DIRECTX10	fallback–coloured	yes	yes	no
directx11	DIRECTX11	native	yes	yes	yes
directx12	DIRECTX12	native	yes	yes	yes
easygl	OPENGLES2, OPENGLES3, OPENGL33, WEBGL1, WEBGL2	native	yes	profile	profile
fna3d	FNA3D	native	yes	yes	yes
freedirect	FREEDIRECT	fallback–reject	yes	no	no
gdi	GDI	reject	yes	no	no
glide	GLIDE	native fixed	throws	no	no
headless	HEADLESS	trace	trace	trace	trace; not a GPU query
html-dom	HTML_DOM	fallback–reject	yes	no	no
igl	IGL	native	yes	yes	no
llgl	LLGL	native	yes	yes	yes
magnum	MAGNUM	native	yes	conditional	yes
metal	METAL	native	yes	no	no
nanovg	NANOVG	fallback–reject	no	no	no
opengl1	OPENGL1	native fixed	conditional	no	conditional
opengl2	OPENGL2	native	yes	conditional	conditional
opengl4	OPENGL4	hybrid	yes	yes	yes
opengles1	OPENGLES1	hybrid fixed	yes	no	no
openvg	OPENVG	fallback–reject	no	no	no
pixijs	PIXIJS	fallback–reject	yes	no	no
portablegl	PORTABLEGL	native CPU	no	no	no
sdl-gpu	SDL_GPU	hybrid	yes	yes	no; claims yes
sdl-renderer	SDL_RENDERER	fallback–reject	yes	no	no
skia	SKIA	reject	yes	no	no
software	SOFTWARE	native CPU	yes	no	no; claims yes
sokol	SOKOL	native	yes	yes	GL build only
stub	STUB	fallback–no-op	no	no	no
svg-dom	SVG_DOM	fallback–reject	yes	no	no
tinygl	TINYGL	native CPU fixed	no	no	no
vulkan	VULKAN	native	yes	yes	yes
webgpu	WEBGPU	hybrid	yes	no; claims yes	no; claims yes
wicked	WICKED	native	yes	yes	yes

The table is a routing audit, not runtime certification. It is mechanically checked to contain 46 families; EasyGL contributes the remaining four public identities. New alpha.1 families IGL, NanoVG, PixiJS, and TinyGL are explicit rows rather than being inferred from their native libraries. Inherited refusal, deliberate no-op, CPU fixed-function, trace-only and hybrid colored-tail routes remain different outcomes even when the public method exists.

B.3 Capability answers require operation-level proof

GraphicsDevice::SupportsCapability is a useful preflight query, but its shared default is permissive. At the pin, WEBGPU reports MRT while rejecting every multi-target set. SDL_GPU, WEBGPU, and SOFTWARE report occlusion-query support while inheriting a null factory; HEADLESS returns a bookkeeping object with a constant pseudo-count rather than a real GPU query. These are tracked defects, not support.

Conversely, a false or absent high-level bit can hide a narrower usable path. Profile-gated GL queries, driver-gated wrapper capabilities, fixed-function rendering, CPU rasterization, and trace validation all need their own labels. The safe decision sequence is:

1.

filter by platform/dependency admissibility and the exact public selector;
2.

inspect the factory/resource operation and the draw route for the required feature;
3.

require renderer-owned tests or a retained host artifact at the needed evidence tier;
4.

use a second structurally independent family as a localization control;
5.

retain skips, refusals, and capability/reporting contradictions in the result.

Appendix G defines the evidence vocabulary. The renderer chapters own the narrower state, shader, texture, readback, and platform qualifications that cannot fit in this compact matrix.