CNA-GAP-015: Only BasicEffect exposes XNA's parameter graph and technique name; the other stock effects still lack texture or light parameters and carry a Default technique

CNA snapshot 3b43bd86  ·  Known Issues › Functional gaps  ·  source links pinned to 3b43bd86

AlphaTestEffect lacks Texture, DualTextureEffect lacks Texture/Texture2, EnvironmentMapEffect lacks DirLight*, SkinnedEffect lacks Texture/DirLight*; these effects carry a Default technique and WorldInverseTranspose keeps a 4x4 shape.

Identifier

CNA-GAP-015

Category

Functional gap

Subsystem

Graphics & renderers

Status

Narrowed (partially fixed; describes only what survives)

Verified against

CNA 3b43bd86 (3b43bd8687ed46523d873f9bec4b32bd8481dcb5)

Evidence basis

Source-verified: read at TARGET, not executed

Tests touching this area

Yes: see Current tests

Affected contract

Effect::getParametersProperty() and CurrentTechnique of AlphaTestEffect, DualTextureEffect, EnvironmentMapEffect, SkinnedEffect

Expected behaviour

XNA 4.0's stock effects cache the parameters of their compiled effect (IL of each CacheEffectParameters): Texture for AlphaTest; Texture and Texture2 for DualTexture; Texture, EnvironmentMap and DirLight0..2 for EnvironmentMap; Texture and DirLight0..2 (with specular) for Skinned. Code can read or set them through Parameters[name].

Actual behaviour at TARGET

CNA's AlphaTestEffect.cpp, DualTextureEffect.cpp, EnvironmentMapEffect.cpp and SkinnedEffect.cpp declare their parameters with AddStockParameterInternal: AlphaTest and DualTexture publish only numeric parameters (no Texture, no Texture2), EnvironmentMap publishes Texture and EnvironmentMap but no DirLight0..2, and Skinned publishes Bones and the numeric parameters but no Texture or DirLight0..2, so Parameters["Texture"] on AlphaTest, DualTexture or Skinned returns null. These effects are built on Effect(GraphicsDevice&), whose single technique is named "Default" (BasicEffect alone passes a stock technique name). WorldInverseTranspose is still declared 4x4 where XNA's .fx uses float3x3.

Fixed since first recorded: d650554a8 (CNA-DEMOS-ISSUE-034/035) added Texture and EnvironmentMap to EnvironmentMapEffect and made SkinnedEffect's Bones 72 coherent 4x3 matrix views, as XNA's float4x3[72], pinned by StockBoneParameterTest in StockParameterContractTests.cpp.

Source locations

• modules/graphics/src/Xna/AlphaTestEffect.cpp — AlphaTestEffect::CacheEffectParameters
• modules/graphics/src/Xna/EnvironmentMapEffect.cpp — EnvironmentMapEffect::CacheEffectParameters
• modules/graphics/src/Xna/SkinnedEffect.cpp — SkinnedEffect::CacheEffectParameters (Bones rows)
• modules/graphics/src/Xna/BasicEffect.cpp — BasicEffect uses the stock-technique constructor

Evidence

Checked by reading the named sources at 3b43bd86; nothing was built or executed for this entry. XNA parameter names read from the genuine XNA 4.0 Graphics IL. The typed properties (Texture, EnvironmentMap, lights) work; only the generic parameter surface is incomplete.

Re-verified at c6dec91f: the four CacheEffectParameters functions were re-read after d650554a8; the parameters named above are still absent and the copy constructors still use Effect(*src.device_). Not executed.

Focused reproduction

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

Current tests

StockParameterContractTests.cpp pins scalar shapes and the Bones views; stock-effect tests otherwise use the typed properties, and none enumerates Parameters against XNA's list.

Regression test

A table-driven test per stock effect comparing parameter names, classes, types and shapes with XNA's (a generated list from the XNA IL).

Blast radius

Code that manipulates stock effects generically through Parameters (editors, material systems, serializers).

Workaround

Use the typed properties.