CNA-BUG-227: StubTextureRenderer's comment says GetData() is accepted and discarded, but the inherited default refuses the read

CNA snapshot 009d40f5  ·  Known Issues › Current bugs  ·  source links pinned to 009d40f5

The class comment on StubTextureRenderer says SetData()/GetData() are accepted no-op defaults, while the ITextureRenderer::GetData default it inherits returns false, which the shared Texture2D layer turns into NotSupportedException.

Identifier

CNA-BUG-227

Category

Bug

Subsystem

Documentation & release tooling

Status

Open

Verified against

CNA 009d40f5 (009d40f5dd085c4e674d3479675fac84b12b3e0a)

Severity

Low (a triage suggestion, not a project priority)

Evidence basis

Source-verified: read at TARGET, not executed

Tests touching this area

Yes: see Current tests

Affected contract

Maintainer comment on CNA::Internal::Renderers::Stub::StubTextureRenderer

Expected behaviour

The class comment describes what the STUB texture does with uploads and reads.

Actual behaviour at TARGET

StubRenderer.hpp: "Stores only width/height -- no pixel data of any kind; SetData()/GetData() are accepted (inherited no-op defaults) and simply discarded." Uploads are indeed discarded, but ITextureRenderer::GetData(level, x, y, w, h, data, dataLength) defaults to false ("this renderer read nothing back"), and Texture2D raises System::NotSupportedException on false wherever it needs the renderer's copy (render-target content, partial updates, block-compressed data). Reads are refused, not accepted.

Source locations

• modules/renderers/stub/include/CNA/Internal/Renderers/Stub/StubRenderer.hpp — StubTextureRenderer class comment
• modules/graphics/include/CNA/Internal/Renderers/Common/IGraphicsRenderer.hpp — ITextureRenderer::GetData default returns false, with its rationale
• modules/graphics/src/Xna/Texture2D.cpp — Texture2D raises NotSupportedException when the renderer read nothing back

Evidence

Checked by reading at 009d40f5; not executed. The interface comment explains why the default became a refusal: a silent no-op default "fabricated a complete, uniformly transparent-black frame". Only the STUB comment is stale; behaviour follows the interface.

Focused reproduction

No focused reproduction is known. Nothing has been invented here; the evidence above is what exists.

Current tests

Stub_Smoke uploads a texture but never reads one back; CNA's Stub lane records classify the shared suites' cube-texture refusals as the expected STUB taxonomy.

Regression test

No test is needed; correct the comment to say reads are refused through the interface default.

Blast radius

Maintainers reading the STUB renderer. No behaviour is affected.

Workaround

No workaround is known.