RenderTarget: Add resolveStencilBuffer.

[Mugen87]

Related issue: #27799 (comment)

Description

This PR introduces a new flag RenderTarget.resolveStencilBuffer. It can be used to control whether the stencil buffer should be resolved or not when rendering to a multisampled render target.

[Mugen87]

@Oletus Looking good?

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

Filesize dev	Filesize PR	Diff
672.9 kB (166.8 kB)	672.9 kB (166.8 kB)	+60 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

Filesize dev	Filesize PR	Diff
452.6 kB (109.3 kB)	452.6 kB (109.3 kB)	+59 B

[Oletus]

I didn't have time to test this yet, but looks great!

[gkjohnson]

Defines whether the stencil buffer should be resolved when rendering into a multisampled render target or not.

Can you clarify what this means? The description isn't super clear. Does this just mean "use the stencil buffer"? As in even if the render target has stencil enabled this flag can be set to false to disable it's use?

[Mugen87]

The flag is only relevant if you use a stencil buffer (when stencilBuffer is set to true) and only when doing RTT with multisampling. If you set resolveStencilBuffer to false, it disables the resolve meaning stencil data won't be transferred into the multisampled draw buffer. So it just controls the blit operation. You can still use stencil during the actual render pass.