NormalMapFiltering.ps.glsl not compiling

[nbentyNV]

Effect/NormalMapFiltering sample (default settings)

The error I'm getting is from glslang - perturbNormal is missing the definition. The definition is actually missing from the GLSL string we send even though _MS_USER_NORMAL_MAPPING is defined.

[tangent-vector-personal]

Where is the user definition? Is if in a Slang file or user code?

[nbentyNV]

User code. I'm using #import

[tangent-vector-personal]

The fact that we aren't emitting a definition in user code is worrying: we are supposed to emit those unconditionally.

My best theory right now is that the semantic checking is deciding the user definition is a redeclaration, but in that case we should still emit whatever redeclaration has a body.

[tangent-vector-personal]

My understanding is that this issue has been worked around in the original codbase.

I don't think this is something Slang should support long-term (interfaces and generics should cover most of what we want), so I'd like to close this as a "will not fix" if possible.

[tangent-vector]

Closing this as "will not fix." We will not support the case of a Slang file declaring a function that then gets defined in user HLSL or GLSL.

The basic rules of Slang will be:

• A Slang "module" (one or more .slang files that get compiled as a unit) can explicitly depend on another module via import, but these can only be other Slang modules.

• An HLSL/GLSL module (one translation unit_ can explicitly depend on Slang modules, via import

• Any dependencies in the other direction ("I want this library code to call my code") need to be expressed as explicit parameterization (e.g., a library function takes a parameter of interface type, and the client passes in an instance which implements its members).