stride3d/stride · error · NotImplementedException

SamplerState parameter

Error message

SamplerState parameter '{parameter.Name}' not implemented

What it means

The SDSL-to-SPIR-V compiler supports only a fixed set of inline SamplerState parameters (e.g. MinLOD, MaxLOD, BorderColor). Any other parameter name hits Compile's switch default and throws NotImplementedException, meaning that sampler state option has no SPIR-V translation yet.

Solutions

1. Remove the unsupported inline parameter and configure that state at runtime via Parameters.Set().
2. Use only the parameter names supported by the compiler (see the switch in ShaderElements.MethodOrMember.cs).
3. Implement the equivalent behavior in shader code if no parameter equivalent exists.

Example fix

// before
SamplerState Sampler : MaxAnisotropy(8);
// after
SamplerState Sampler; // configure at runtime via Parameters.Set()

var supported = new HashSet<string> { "MinLOD", "MaxLOD", "BorderColor" };
foreach (var p in sampler.Parameters)
    if (!supported.Contains(p.Name)) Console.WriteLine($"Unsupported sampler parameter: {p.Name}");

try { sampler.Compile(); }
catch (NotImplementedException ex) when (ex.Message.StartsWith("SamplerState parameter"))
{
    // move that state to runtime Parameters.Set() and recompile
}

When it happens

Trigger: Declaring a sampler with an inline parameter that has no case in Compile's switch, e.g. `SamplerState Sampler : AddressU(CLAMP);` or MaxAnisotropy.

Common situations: Porting D3D11_SAMPLER_DESC fields (Filter, ComparisonFunc, MaxAnisotropy, addressing modes) into SDSL inline parameters unsupported by the SPIR-V backend.

Related errors

• Assign back to matrix swizzle is not implemented yet
• Unsupported interlocked operation
• BorderColor must be float4(r, g, b, a)
• Can't parse method attribute
• Exception of type 'System.NotImplementedException' was…

AI-assisted analysis of stride3d/stride@96fad776d2 (2026-09-14). Data as JSON: /api/errors/e977770edb85fa67. Report an issue: GitHub.

Appendix: source

Thrown at sources/shaders/Stride.Shaders.Parsers/Parsing/SDSL/AST/ShaderElements.MethodOrMember.cs:115

                    break;
                case "MinLOD":
                    minLOD = BitConverter.SingleToInt32Bits((float)((FloatLiteral)parameter.Value).Value);
                    break;
                case "MaxLOD":
                    maxLOD = BitConverter.SingleToInt32Bits((float)((FloatLiteral)parameter.Value).Value);
                    break;
                case "BorderColor":
                    {
                        if (parameter.Value is not VectorLiteral { TypeName.Name: "float4", Values: { Count: 4 } args })
                            throw new NotSupportedException($"BorderColor must be float4(r, g, b, a)");
                        borderR = BitConverter.SingleToInt32Bits((float)((NumberLiteral)args[0]).DoubleValue);
                        borderG = BitConverter.SingleToInt32Bits((float)((NumberLiteral)args[1]).DoubleValue);
                        borderB = BitConverter.SingleToInt32Bits((float)((NumberLiteral)args[2]).DoubleValue);
                        borderA = BitConverter.SingleToInt32Bits((float)((NumberLiteral)args[3]).DoubleValue);
                        break;
                    }
                default:
                    throw new NotImplementedException($"SamplerState parameter '{parameter.Name}' not implemented");
            }
        }
        // Only emit immutable sampler state when the declaration has explicit parameters.
        // Samplers without inline state (e.g. "stage SamplerState Sampler;") are dynamic
        // and set at runtime via Parameters.Set().
        if (Parameters.Count > 0)
        {
            context.Add(new OpDecorate(variableId, Specification.Decoration.SamplerStateSDSL, [
                filter, addressU, addressV, addressW, mipLODBias, maxAnisotropy, comparisonFunc, minLOD, maxLOD,
                borderR, borderG, borderB, borderA
            ]));
        }

        var variable = builder.Insert(new OpVariableSDSL(registeredType, variableId, Specification.StorageClass.UniformConstant, IsStaged ? Specification.VariableFlagsMask.Stage : Specification.VariableFlagsMask.None, null));
        context.AddName(variable.ResultId, Name);
        Symbol!.IdRef = variableId;

        RGroup.DecorateVariableLinkInfo(table, shader, context, Info, Name, Attributes, variable);

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