Mesh.textureRepeat mutates the shared per-image TextureAtlas.repeat (wrap mode is image-global)

[obiot]

Summary

Mesh's new textureRepeat setting (added with the glTF node-animation work) sets the wrap mode by mutating this.texture.repeat:

// packages/melonjs/src/renderable/mesh.js (constructor)
if (hasRealTexture && typeof settings.textureRepeat === "string") {
    this.texture.repeat = settings.textureRepeat;
}

this.texture comes from resolveTextureAtlas(...) → game.renderer.cache.get(image, …), which returns a single TextureAtlas shared per source image. So setting .repeat changes the wrap mode image-globally — every consumer of the same image object samples with that wrap.

Surfaced in the PR-2 code review; not a live bug today, but worth pinning before it bites.

How it's silent

• The only consumer that sets textureRepeat today is the glTF loader (GLTFScene / GLTFModel), driven by the material's sampler wrapS/wrapT.
• glTF decodes its own HTMLImageElement objects per asset, so the atlas is effectively private to that load.
• All primitives of a given material share one sampler → one wrap mode, so meshes sharing the image (e.g. all 6 parts of a Kenney blocky character share texture-a.png) all want the same wrap → mutating the shared atlas is consistent.
• The GL unit cache is keyed (source, repeat) (post-WebGL: createPattern cache-key collision invalidates earlier pattern handles for the same image #1448), so distinct wrap modes still get distinct GL units — but the TextureAtlas.repeat field the batcher reads at upload time is the shared one.

The trigger

Pointing two Meshes (or a Mesh and a Sprite) at the same image object but wanting different wrap modes: last-writer-wins, and the other consumer's wrap silently flips. Niche today, but it's unguarded shared-state mutation — same class as #1489.

Options

• A. Carry the wrap on the Mesh and thread it to uploadTexture / cache.getUnit per-draw, instead of mutating the atlas.
• B. Hand out a per-(image, repeat) TextureAtlas instance from the cache (so .repeat is never shared across wrap modes).
• C. Fold into the Refactor TextureCache and Batcher base class for renderer-agnostic abstraction #1410 TextureCache + batcher refactor, which already touches this whole surface.

Recommendation

Address as part of #1410 (the TextureCache/batcher renderer-agnostic refactor). Same root cause as #1489 (per-image atlas sharing); both should be resolved together there.

Cross-refs

• Refactor TextureCache and Batcher base class for renderer-agnostic abstraction #1410 (TextureCache refactor — where this should land)
• TextureCache.get(image, frame): framewidth/frameheight refinement is a no-op for every atlas format #1489 (sibling per-image atlas-sharing issue: framewidth/frameheight refinement no-op)