Does HLSL implement Shader Model LOD instruction?

Question

The DX Shader Model 5.0 has a lod instruction. It returns "the LOD (level of detail) that would be used for texture filtering".

Does HLSL have a built-in intrinsic that can do the same? I know I could evaluate the LOD manually, but I'm wondering if there's a better way.

What? You refer to a hlsl instruction and then ask if the same one is available? could you clear up your question abit? — Tordin, Nov 15, 2013 at 13:35
@Tordin They seem to be referring to an existing DX Shader Model instruction and want to know if GLSL has a similar one. I've edited to clarify. — Anko, Nov 15, 2013 at 13:40
@Anko No, there is Shader Model Assembly and HLSL. The first one is like x86 assembly and HLSL is like C language. So we generally write shaders in HLSL and it is compiled to asm code by DirectX (which can be viewed using Shader Dump feature). — michalo2882, Nov 15, 2013 at 15:17
Finally found it! It's Object.CalculateLevelOfDetail not listed under Shader Model 5 Reference, but under 4. — michalo2882, Nov 15, 2013 at 15:58
@michalo2882 Yeah, the organization of the MSDN docs is kind of annoying - SM5 includes everything in SM4, so the SM5 docs only have the stuff that was new in SM5. Anyway, you should post an answer to your question and accept it. — Nathan Reed, Nov 15, 2013 at 17:40

michalo2882 · Accepted Answer · 2013-11-16 19:40:14Z

2

Finally found it! It's Object.CalculateLevelOfDetail. It's not listed under Shader Model 5 Reference, but under 4.

answered Nov 16, 2013 at 19:40

michalo2882

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