[Rendering] Adds support for DrawAuto and DrawIndirect to MeshDraw

[tebjan]

PR Details

Adds a DrawAuto flag and ArgumentBufferBinding to MeshDraw.

Description

The new arguments will be read by the MeshRenderFeature to select the right draw call method.

Related Issue

Fixes #1481

Motivation and Context

Generate geometry on the GPU.

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.

[johang88]

Feels like it could be ignored by serialization as it's runtime only? Perhaps DrawIndirect instead of DrawAuto?

[tebjan]

Feels like it could be ignored by serialization as it's runtime only?

You are right, it is a runtime technique. So then it needs the [DataMemberIgnore] attribute, is that correct?

Perhaps DrawIndirect instead of DrawAuto?

Yes, sorry didn't specify that correctly. The way I thought about it is that DrawAuto uses a vertex buffer from the stream out stage of another shader and with ArgumentBuffer I meant DrawIndirect, which takes the draw args like vertex count, instance count, and vertex buffer offsets as a buffer. I've corrected the title.