Skills: NineSliceSprite in the UI skill, the audio skill brought up to the implementation, and open 20.9.0

[obiot]

Description

Two skill updates, plus the version bump that opens 20.9.0 for them. No engine code changes.

UI skill (melonjs-ui-and-text): its description listed "NineSliceSprite panels" among what it covers, but the body never mentioned them. New section, "Panels and boxes that stretch: NineSliceSprite":

• both ways to make one, each taken from a shipped example: createSpriteFromName(name, { width, height }, true) from an atlas (the UI example's draggable panel), and the constructor from an image (the Text example's dialogue box)
• the three things that trip people up: width / height are the size to stretch to and the constructor throws without them; insetx / insety default to a quarter of the image, not its border; the anchor is the centre
• it resizes live through the width / height setters (checked in nineslicesprite.js: both write nss_width / nss_height, which draw() reads)

Audio skill (melonjs-audio): checked against every export of the audio module and the vendored backend. Added what positional sound needs and the skill did not say:

• the listener is fixed at the origin: the backend has a listener pos() but nothing public reaches it, so positions must be passed relative to the player, every frame
• the panner defaults assume metres: inverse / refDistance: 1 puts a source 100 px away at ~1%, so a sound positioned in pixels is near silent a few tiles out; set refDistance in pixels or scale positions down
• stereo() and position() are exclusive per instance: both create the instance's one panner if it doesn't exist, and each only updates a panner of its own type (spatial.ts), so whichever runs first makes the other a silent no-op
• new section "Effects on all game audio": reverb, echo, a compressor etc. inserted after getMasterGain(). Notes that setVolume / muteAll still apply, that a stream: true clip plays through an <audio> element and bypasses the master gain (voice.ts), and that per-clip effects are not reachable
• hasAudio(), hasFormat(), runtime audio.load(), and the rate (0.5..4.0) and fade ranges
• four symptom-table rows and new triggers (reverb, compressor, listener, refDistance, getMasterGain, ...); the description stays under the 1024-character limit (795)

Version: packages/melonjs/package.json and .claude-plugin/plugin.json both move to 20.9.0 together, with an unreleased [20.9.0] changelog section carrying both entries under Fixed.

Type of change

• Bug fix
• New feature
• Documentation update
• Performance improvement
• Refactoring (no functional changes)

Checklist

• I have read the Contributing Guide
• My code follows the existing code style (pnpm lint passes)
• I have tested my changes locally (pnpm test passes): not run; no source or test changes
• I have added tests that cover my changes (if applicable): not applicable, documentation only
• The build succeeds (pnpm build), as part of pnpm lint

Related issues

None. The audio audit surfaced two engine gaps that are not fixed here: the listener cannot be moved through the public API, and stereo() / position() fail silently on an instance whose panner is the other type.

🤖 Generated with Claude Code

https://claude.ai/code/session_0146cnBA4Z2zLzWYa3wjnYaW

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Generated by Claude Code

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