Source: Add dataReady flag.

[Mugen87]

Fixed #25133.

Description

This is an alternative implementation to #27572. It introduces a new flag Source.dataReady that allows to prevent the engine from uploading texture data. The texture will still be allocated though so it's possible to allocate the image/buffer and gradually fill/stream data into it.

This PR should also solve the use case mentioned in #27572 (comment).

Since the flag is true by default, it should not affect existing apps.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

Filesize dev	Filesize PR	Diff
673.6 kB (167.3 kB)	673.7 kB (167.3 kB)	+94 B

🌳 Bundle size after tree-shaking

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

Filesize dev	Filesize PR	Diff
454.4 kB (110.2 kB)	454.5 kB (110.2 kB)	+94 B

[mrdoob]

What do you think of naming it dataReady instead? (true by default too)

[Mugen87]

Sounds good as well! 👍

I'll update the PR.

[Mugen87]

It seems after I have regenerated the E2E screenshot for webgl_camera, testes in different PRs fail. Regenerating it on my macOS system does not show a new diff so maybe someone else can update it?

[mrdoob]

@Mugen87 Done! 16c15ef

[Oletus]

Sorry about the slow reply, this is great! I didn't get to integrating this yet, but this looks like it will solve our use case. Thank you!

[Oletus]

One note how this could be improved: Maybe copyTextureToTexture functions should warn in case the dataReady flag of the source texture is set to false? People might think that the copy is happening from the buffer on the GPU, when it is in fact doing a texture upload:

three.js/src/renderers/WebGLRenderer.js

Line 2391 in 841d2e7

this.copyTextureToTexture = function ( position, srcTexture, dstTexture, level = 0 ) {