Reflection file format

The build task writes one reflection file per shader; the source generator reads it without loading the compiler. The model is OneShader.Reflection.ShaderReflection; ReflectionFormat.Write and TryRead implement this format. Version 1.

Rules

• UTF-8, no byte-order mark, \n line ends, one record per line, ending with a newline.
• First line: oneshader-reflection 1. A reader must reject other versions. Additive changes (new records or new attributes) keep version 1; readers ignore unknown records and attributes.
• A record is keyword key=value key=value .... Values are bare tokens (no spaces) or double-quoted strings with \\, \", \n, \r, \t and \uXXXX escapes. Numbers are invariant-culture decimals; all counts, sizes, strides, offsets, locations and workgroup sizes are unsigned. Enum values use the member names of the C# enums. Lists are comma-separated; an empty list is -.
• Nesting is by indentation: two spaces per level.
• Order is the model's order (declaration order). Equal models give identical bytes.

Records

source name="Shaders/Sprite.hlsl"
targets list=SpirV,Wgsl
resource name="Frame" kind=ConstantBuffer count=1 stages=Vertex,Pixel rtype=ConstantBuffer hlsl=""
  slot target=SpirV set=0 binding=0
  layout
    type kind=Struct scalar=Bool rows=0 cols=0 name="Frame" size=128 align=16 length=0 stride=0 mstride=0 packing=ColumnMajor
      member name="ViewProjection" offset=0
        type kind=Matrix ... mstride=16 packing=ColumnMajor
      member name="Weights" offset=80
        type kind=Array ... length=3 stride=16
          element
            type kind=Scalar scalar=Float ...
entry name="VSMain" stage=Vertex workgroup=0,0,0 stride=32
  input name="Position" semantic="POSITION" index=0 location=0 builtin=None scalar=Float components=2 format=Float32x2 offset=0 interp=Default
  output name="Position" semantic="SV_Position" index=0 location=- builtin=Position scalar=Float components=4 format=None offset=0 interp=Default
  uses name="Frame"

• resource: an optional format attribute holds the [[vk::image_format]] name of a read-write texture; kind is ResourceKind; stages a list of Vertex, Pixel, Compute (- for none); rtype is ResourceTypeKind; hlsl the type as written. Child slot records give one slot per target (target is SpirV, Msl or Wgsl; Metal uses the argument index as binding and 0 as set). count is the array size (1 for a single resource); an array occupies one slot. A layout child holds a type tree.
• counter (child of resource, append and consume buffers only): target, set, binding of the hidden counter buffer, one record per target like slot. Readers that do not know it ignore it.
• push: a push-constant block (not a resource): name, stages, a layout child with a type tree, and slot children for the targets that deliver it as a bound buffer: Msl (binding is the [[buffer(n)]] index, set 0) and Wgsl (set is the bind group, binding the binding). SPIR-V has no slot. An entry names the block it reads with a pushuse name=... child.
• features (child of entry, written only when non-zero): bits, the DeviceFeatures flags the entry point needs for 16-bit and 64-bit types (1 Float16, 2 Int16, 4 Float64, 8 Int64, 16 StorageBuffer16, 32 UniformBuffer16, 64 PushConstant16, 128 InputOutput16, 256 Int64Atomics).
• spec: a specialization constant: name, id (the constant_id), scalar (Bool, Int, UInt or Float) and default (the 32-bit pattern, as a number). Child slot records (target, index, name) give the SPIR-V SpecId, the Metal function-constant index and variable, and the WGSL @id and override name per target. Written only for files that have constants; it follows the push records. An entry lists the constants it reads with specuse name=... children.
• type: kind is Scalar, Vector, Matrix, Array or Struct. rows is the vector component count or matrix rows; cols matrix columns; size, align in bytes; length/stride for arrays (length 0 = unsized); mstride/packing for matrices (the stride is between stored columns for ColumnMajor, rows for RowMajor). An Array has one element child holding a type; a Struct has member children (name, offset) each holding one type.
• entry: workgroup is x,y,z (zeros unless compute); stride the interleaved vertex size (vertex stage only). input/output are stage variables; location=- means built-in; format is a VertexFormat name for vertex inputs and None elsewhere. uses lists resource names the entry point touches.

Layouts are the single buffer layout shared by all targets (see BufferLayout).