/// <summary>
/// Creates a new instance of the <see cref="D2DInputDescriptionAttribute"/> type with the specified arguments.
/// </summary>
/// <param name="index">The index of the resource to declare the description for.</param>
/// <param name="filter">The type of filter to apply to the input texture.</param>
public D2DInputDescriptionAttribute(int index, D2D1Filter filter)
{
Index = index;
Filter = filter;
}
/// <summary>
/// Extracts the input descriptions for the current shader.
/// </summary>
/// <param name="structDeclarationSymbol">The input <see cref="INamedTypeSymbol"/> instance to process.</param>
/// <param name="inputDescriptions">The produced input descriptions for the shader.</param>
/// <param name="diagnostics">The collection of produced <see cref="Diagnostic"/> instances.</param>
public static void GetInfo(
INamedTypeSymbol structDeclarationSymbol,
out ImmutableArray <InputDescription> inputDescriptions,
out ImmutableArray <Diagnostic> diagnostics)
{
int inputCount = 0;
ImmutableArray <InputDescription> .Builder inputDescriptionsBuilder = ImmutableArray.CreateBuilder <InputDescription>();
ImmutableArray <Diagnostic> .Builder diagnosticsBuilder = ImmutableArray.CreateBuilder <Diagnostic>();
foreach (AttributeData attributeData in structDeclarationSymbol.GetAttributes())
{
switch (attributeData.AttributeClass?.GetFullMetadataName())
{
case "ComputeSharp.D2D1.D2DInputCountAttribute":
inputCount = (int)attributeData.ConstructorArguments[0].Value !;
break;
case "ComputeSharp.D2D1.D2DInputDescriptionAttribute":
if (attributeData.ConstructorArguments.Length == 2)
{
int index = (int)attributeData.ConstructorArguments[0].Value !;
D2D1Filter filter = (D2D1Filter)attributeData.ConstructorArguments[1].Value !;
_ = attributeData.TryGetNamedArgument("LevelOfDetailCount", out int levelOfDetailCount);
inputDescriptionsBuilder.Add(new InputDescription((uint)index, filter, levelOfDetailCount));
}
break;
default:
break;
}
}
inputDescriptions = ImmutableArray <InputDescription> .Empty;
// Validate the input count (ignore if invalid, this will be validated by the HLSL source generator)
if (inputCount is not(>= 0 and <= 8))
{
goto End;
}
// All simple indices must be in range
if (inputDescriptionsBuilder.Any(description => description.Index >= inputCount))
{
diagnosticsBuilder.Add(OutOfRangeInputDescriptionIndex, structDeclarationSymbol, structDeclarationSymbol);
goto End;
}
HashSet <uint> inputDescriptionIndices = new(inputDescriptionsBuilder.Select(description => description.Index));
// All input description indices must be unique
if (inputDescriptionIndices.Count != inputDescriptionsBuilder.Count)
{
diagnosticsBuilder.Add(RepeatedD2DInputDescriptionIndices, structDeclarationSymbol, structDeclarationSymbol);
goto End;
}
inputDescriptions = inputDescriptionsBuilder.ToImmutable();
End:
diagnostics = diagnosticsBuilder.ToImmutable();
}
/// <summary>
/// Creates a new <see cref="D2D1InputDescription"/> instance with the specified parameters.
/// </summary>
/// <param name="index">The index of the resource the description belongs to.</param>
/// <param name="filter">The type of filter to apply to the input texture.</param>
/// <param name="levelOfDetailCount">The mip level to retrieve from the upstream transform, if specified.</param>
internal D2D1InputDescription(int index, D2D1Filter filter, int levelOfDetailCount)
{
Index = index;
Filter = filter;
LevelOfDetailCount = levelOfDetailCount;
}
