MaterialRecords

Remarks

What replaces a descriptor set per material. A draw that binds a set per material cannot be merged with a draw that binds a different one, which is the sentence everything in docs/plan/23-bindless-materials.md follows from. A buffer of records is bound once and subscripted by a number the draw carries, so two materials' draws differ in their data and in nothing a command list can see.

Per effect, and that is a correction to the plan. The sketch said one buffer per variant, which turns out to be one buffer per material: a variant is a (material, flags, shader) triple, so there is exactly one material in each. What several materials genuinely share is their effect — same shader, same composition, same permutation — and that is what a record buffer is keyed by. The layout is the effect's, so every record in one buffer has the same shape by construction rather than by a check.

Written once, not once a frame. A record is rewritten when its material's values change and the buffer goes to the device when any of them did. A settled scene uploads nothing, which is the same economy EffectConstants has and the same reason: the bytes are the expensive part, not the bookkeeping.

An index, once given out, does not move. Same argument as BindlessTable's: it is written into a per-object block the host has already filled, and there is nothing to go back and renumber. So the buffer grows and a released record leaves a hole, which is what Count counts and what a caller trades against.

Fields and properties (5)

• public int Stride

  How many bytes one record occupies.

• public int Count

  How many records have been handed out.

• public BufferHandle Buffer

  The buffer, invalid until something has been written.

• public int UploadCount

  How many times the records have actually gone to the GPU.

• public ReadOnlySpan<byte> Bytes

  The records as they were last filled.

Methods (5)

• public MaterialRecords(IGraphicsDevice device, int stride, string name = "MaterialRecords")

  Creates a record buffer for one effect.

• public int IndexOf(int variant)

  The record one variant occupies, giving it one if it has none.

• public bool Write(int index, ReadOnlySpan<byte> bytes)

  Fills one record, and answers whether the bytes were different from last time.

• public BufferHandle Upload()

  Puts the records on the device, if any of them changed.

• public void Dispose()

  Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

Used by (2)

• MaterialRecordBufferTestsVixen.Rendering.Tests
• MaterialRenderFeatureVixen.Rendering