private static AlignmentInfo Analyze(ITypeSymbol typeSymbol)
{
// Check if we already know this type
if (s_cachedSizes.TryGetValue(typeSymbol, out AlignmentInfo alignmentInfo))
{
return(alignmentInfo);
}
string symbolFullName = typeSymbol.GetFullMetadataName();
// Get any specific shader alignment
int?specificShaderAlignment = s_shaderAlignments.TryGetValue(symbolFullName, out int sa)
? (int?)sa
: null;
// Check if this in our list of known sizes
if (s_knownSizes.TryGetValue(symbolFullName, out int knownSize))
{
alignmentInfo = new AlignmentInfo(knownSize, knownSize, knownSize, specificShaderAlignment ?? knownSize);
s_cachedSizes.TryAdd(typeSymbol, alignmentInfo);
return(alignmentInfo);
}
// Check if enum
if (typeSymbol.TypeKind == TypeKind.Enum)
{
string enumBaseType = ((INamedTypeSymbol)typeSymbol).EnumUnderlyingType.GetFullMetadataName();
if (!s_knownSizes.TryGetValue(enumBaseType, out int enumSize))
{
throw new ShaderGenerationException($"Unknown enum base type: {enumBaseType}");
}
alignmentInfo = new AlignmentInfo(enumSize, enumSize, enumSize, specificShaderAlignment ?? enumSize);
s_cachedSizes.TryAdd(typeSymbol, alignmentInfo);
return(alignmentInfo);
}
// NOTE This check only works for known types accessible to ShaderGen, but it will pick up most non-blittable types.
if (BlittableHelper.IsBlittable(symbolFullName) == false)
{
throw new ShaderGenerationException($"Cannot use the {symbolFullName} type in a shader as it is not a blittable type.");
}
// Unknown type, get the instance fields.
var fields = typeSymbol.GetMembers()
.Where(symb => symb.Kind == SymbolKind.Field && !symb.IsStatic)
.Select(symb => (IFieldSymbol)symb)
.ToArray();
if (fields.Length == 0)
{
throw new ShaderGenerationException($"No fields on type {symbolFullName}, cannot assess size of structure.");
}
int csharpSize = 0;
int shaderSize = 0;
int csharpAlignment = 0;
int shaderAlignment = 0;
// Calculate size of struct from its fields alignment infos
foreach (IFieldSymbol field in fields)
{
// Determine if type is blittable
if (field.Type is IArrayTypeSymbol arrayType)
{
// We can only analyze array size as fields since the field has the attribute, not the type
var elementSizeAndAlignment = Get(arrayType.ElementType);
var arraySizeAttribute = field.GetAttributes().Single(a => a.AttributeClass.Name == nameof(ArraySizeAttribute));
var arraySize = (int)arraySizeAttribute.ConstructorArguments[0].Value;
var shaderAlign = Align(elementSizeAndAlignment.ShaderAlignment, 16);
alignmentInfo = new AlignmentInfo(
elementSizeAndAlignment.CSharpSize * arraySize,
Align(elementSizeAndAlignment.ShaderSize * arraySize, shaderAlign),
elementSizeAndAlignment.CSharpAlignment,
shaderAlign);
}
else
{
alignmentInfo = Analyze(field.Type);
}
// If specified, the field offset dictates the size of the csharp structure at the point where the field starts
csharpAlignment = Math.Max(csharpAlignment, alignmentInfo.CSharpAlignment);
var offset = GetOffset(field);
if (offset > 0)
{
csharpSize = offset;
}
else
{
csharpSize = Align(csharpSize, alignmentInfo.CSharpAlignment);
}
csharpSize += alignmentInfo.CSharpSize;
shaderAlignment = Math.Max(shaderAlignment, alignmentInfo.ShaderAlignment);
shaderSize = Align(shaderSize, alignmentInfo.ShaderAlignment);
shaderSize += alignmentInfo.ShaderSize;
}
// Structures always align to a multiple of 16
if (typeSymbol.TypeKind == TypeKind.Struct)
{
shaderAlignment = Align(specificShaderAlignment ?? shaderAlignment, 16);
}
else
{
shaderAlignment = specificShaderAlignment ?? shaderAlignment;
}
// The overall shader object size is always a multiple of its alignment
shaderSize = Align(shaderSize, shaderAlignment);
// If specified, the overall csharp object size is fixed
var sizeOf = GetSize(typeSymbol);
if (sizeOf > 0)
{
csharpSize = sizeOf;
}
// Return new alignment info after adding into cache.
alignmentInfo = new AlignmentInfo(csharpSize, shaderSize, csharpAlignment, shaderAlignment);
s_cachedSizes.TryAdd(typeSymbol, alignmentInfo);
return(alignmentInfo);
}
private static AlignmentInfo Analyze(ITypeSymbol typeSymbol)
{
// Check if we already know this type
if (s_cachedSizes.TryGetValue(typeSymbol, out AlignmentInfo alignmentInfo))
{
return(alignmentInfo);
}
string symbolFullName = typeSymbol.GetFullMetadataName();
// Get any specific shader alignment
int?specificShaderAlignment = s_shaderAlignments.TryGetValue(symbolFullName, out int sa)
? (int?)sa
: null;
// Check if this in our list of known sizes
if (s_knownSizes.TryGetValue(symbolFullName, out int knownSize))
{
alignmentInfo = new AlignmentInfo(knownSize, knownSize, knownSize, specificShaderAlignment ?? knownSize);
s_cachedSizes.TryAdd(typeSymbol, alignmentInfo);
return(alignmentInfo);
}
// Check if enum
if (typeSymbol.TypeKind == TypeKind.Enum)
{
string enumBaseType = ((INamedTypeSymbol)typeSymbol).EnumUnderlyingType.GetFullMetadataName();
if (!s_knownSizes.TryGetValue(enumBaseType, out int enumSize))
{
throw new ShaderGenerationException($"Unknown enum base type: {enumBaseType}");
}
alignmentInfo = new AlignmentInfo(enumSize, enumSize, enumSize, specificShaderAlignment ?? enumSize);
s_cachedSizes.TryAdd(typeSymbol, alignmentInfo);
return(alignmentInfo);
}
// NOTE This check only works for known types accessible to ShaderGen, but it will pick up most non-blittable types.
if (BlittableHelper.IsBlittable(symbolFullName) == false)
{
throw new ShaderGenerationException($"Cannot use the {symbolFullName} type in a shader as it is not a blittable type.");
}
// Unknown type, get the instance fields.
ITypeSymbol[] fields = typeSymbol.GetMembers()
.Where(symb => symb.Kind == SymbolKind.Field && !symb.IsStatic)
.Select(symb => ((IFieldSymbol)symb).Type)
.ToArray();
if (fields.Length == 0)
{
throw new ShaderGenerationException($"No fields on type {symbolFullName}, cannot assess size of structure.");
}
int csharpSize = 0;
int shaderSize = 0;
int csharpAlignment = 0;
int shaderAlignment = 0;
// Calculate size of struct from its fields alignment infos
foreach (ITypeSymbol fieldType in fields)
{
// Determine if type is blittable
alignmentInfo = Analyze(fieldType);
csharpAlignment = Math.Max(csharpAlignment, alignmentInfo.CSharpAlignment);
csharpSize += alignmentInfo.CSharpSize + csharpSize % alignmentInfo.CSharpAlignment;
shaderAlignment = Math.Max(shaderAlignment, alignmentInfo.ShaderAlignment);
shaderSize += alignmentInfo.ShaderSize + shaderSize % alignmentInfo.ShaderAlignment;
}
// Return new alignment info after adding into cache.
alignmentInfo = new AlignmentInfo(csharpSize, shaderSize, csharpAlignment, specificShaderAlignment ?? shaderAlignment);
s_cachedSizes.TryAdd(typeSymbol, alignmentInfo);
return(alignmentInfo);
}
