private static void DeclareSamplers(CodeGenContext context, TextureDescriptor[] descriptors)
{
foreach (var descriptor in descriptors)
{
var meta = new TextureMeta(descriptor.CbufSlot, descriptor.HandleIndex, descriptor.Format, descriptor.Type);
if (context.Samplers.ContainsKey(meta))
{
continue;
}
bool isBuffer = (descriptor.Type & SamplerType.Mask) == SamplerType.TextureBuffer;
int setIndex = context.Config.Options.TargetApi == TargetApi.Vulkan ? (isBuffer ? 4 : 2) : 0;
var dim = (meta.Type & SamplerType.Mask) switch
{
SamplerType.Texture1D => Dim.Dim1D,
SamplerType.Texture2D => Dim.Dim2D,
SamplerType.Texture3D => Dim.Dim3D,
SamplerType.TextureCube => Dim.Cube,
SamplerType.TextureBuffer => Dim.Buffer,
_ => throw new InvalidOperationException($"Invalid sampler type \"{meta.Type & SamplerType.Mask}\".")
};
var imageType = context.TypeImage(
context.TypeFP32(),
dim,
meta.Type.HasFlag(SamplerType.Shadow),
meta.Type.HasFlag(SamplerType.Array),
meta.Type.HasFlag(SamplerType.Multisample),
1,
ImageFormat.Unknown);
var nameSuffix = meta.CbufSlot < 0 ? $"_tcb_{meta.Handle:X}" : $"_cb{meta.CbufSlot}_{meta.Handle:X}";
var sampledImageType = context.TypeSampledImage(imageType);
var sampledImagePointerType = context.TypePointer(StorageClass.UniformConstant, sampledImageType);
var sampledImageVariable = context.Variable(sampledImagePointerType, StorageClass.UniformConstant);
context.Samplers.Add(meta, (imageType, sampledImageType, sampledImageVariable));
context.Name(sampledImageVariable, $"{GetStagePrefix(context.Config.Stage)}_tex{nameSuffix}");
context.Decorate(sampledImageVariable, Decoration.DescriptorSet, (LiteralInteger)setIndex);
context.Decorate(sampledImageVariable, Decoration.Binding, (LiteralInteger)descriptor.Binding);
context.AddGlobalVariable(sampledImageVariable);
}
}
