CNA-VGAP-001: Matrix camera builders have no XNA oracle and no full-matrix value test

CNA snapshot 009d40f5  ·  Known Issues › Verification gaps  ·  source links pinned to 009d40f5

CreateLookAt and the perspective and orthographic builders are asserted only on single terms and covered indirectly by consumer tests; CNA's XNA matrix oracle does not include them.

Identifier

CNA-VGAP-001

Category

Verification gap

Subsystem

Math & geometry

Status

Open

Verified against

CNA 009d40f5 (009d40f5dd085c4e674d3479675fac84b12b3e0a)

Evidence basis

Source-verified: read at TARGET, not executed

Tests touching this area

Yes: see Current tests

Affected contract

Matrix::CreateLookAt, CreatePerspective, CreatePerspectiveFieldOfView, CreatePerspectiveOffCenter, CreateOrthographic and CreateOrthographicOffCenter

Expected behaviour

The evidence standard CNA applies to the rest of Matrix: bit comparison with the genuine XNA runtime through matrix-oracle.txt and MatrixOracleTests, or at least value tests of all sixteen terms for representative inputs.

Actual behaviour at TARGET

At TARGET the direct evidence is:

• in MatrixTests.cpp: CreateLookAtM44IsOne (M44 only), CreateOrthographicM11 (M11, M22, M44), CreateOrthographicOffCenterM44 (M44, M11), three …M34IsMinusOne cases for the perspective builders, and the thrown cases;
• in the C ABI MatrixSmoke.c: one input per builder, checking LookAt M43, orthographic M11, M22 and M33, perspective M11 and M34, and M11 and M22 of the field-of-view and off-centre forms;
• the oracle corpus families are multiply, invert, rotationx/y/z, transform3, transformnormal3, toradians and todegrees; no builder is included.

The remaining terms (LookAt's rotation block, the perspective depth terms M33 and M43) are exercised only indirectly, by ViewportTests.cpp (projection and unprojection derived by hand), the bounding-frustum tests and graphics-ext consumers. Nothing is known to be wrong apart from the field-of-view guard recorded as CNA-BUG-026.

Source locations

• modules/math/src/Matrix.cpp — CreateLookAt, CreatePerspective, CreatePerspectiveFieldOfView, CreatePerspectiveOffCenter, CreateOrthographic, CreateOrthographicOffCenter
• modules/math/tests/Microsoft/Xna/Framework/MatrixTests.cpp — the builder tests listed above
• modules/math/tests/Microsoft/Xna/Framework/MatrixOracleTests.cpp — asserts the oracle family counts; no builder family
• tests/reference/xna40/framework/matrix-oracle.txt — the recorded XNA corpus
• modules/c-api/tests/pure_c/MatrixSmoke.c — one value check per builder
• modules/graphics/tests/Microsoft/Xna/Framework/Graphics/ViewportTests.cpp — indirect coverage through Project and Unproject

Evidence

Checked by reading at 009d40f5; nothing was built or executed for this entry. The test inventory and the corpus families were read; no test was run, so this entry says nothing about whether the existing tests pass.

Focused reproduction

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

Current tests

As listed under actual behaviour: single-term unit tests, one C ABI smoke value per builder, and indirect consumer tests.

Regression test

Add the six builders to the framework oracle's matrix cases and regenerate the corpus with CNA's oracle tool, then extend MatrixOracleTests to compare all sixteen words; failing that, add full-matrix value tests derived independently of the implementation.

Blast radius

Every 3D camera and projection built with these functions; a last-bit difference from XNA would propagate into projection, depth and picking. No incorrect output is known.

Workaround

No workaround is known.