Standalone player

[mrdoob]

What do you think about taking the viewer code out of xm.js into viewer.js so xm.js can be used as standalone player? (You know, for demos and stuff 😉)

[a1k0n]

Definitely a good idea, though I'd need to introduce some sort of viewer callback mechanism from the player. Hmm.

[luckcolors]

You could use https://github.com/nwjs or https://github.com/atom/electron for the standalone client.

[mrdoob]

@luckcolors I meant a library that only cares about reproducing the file, without the visualisation part.

[a1k0n]

Yeah. I'll work on splitting it out. The code needs a bunch of cleanup first, and a unit test suite before that, because it's sort of fragile, since so many mods rely on various corner cases. Trackers didn't have linters back then :/

[luckcolors]

@mrdoob Ah ok. I will make a separate issue for the native app.

[a1k0n]

oops, bumped the button. A native app sort of defeats the purpose...

[luckcolors]

Well it will be just packaged in a differen way. The app will be the same as the one inside the browser.

[a1k0n]

With 8e114a16da95a5fea14e75a32180d32dcb7d79a3 it's now possible to play without a viewer, though you still need to create a few XMView stubs to do it. I'll have to add a few checks so that isn't necessary.

[a1k0n]

The code which defines what the buttons do and downloads songs and so forth are now completely separated from the player, which has the following API:

• XMPlayer.initAudio -> starts up audio context; it's available as XMPlayer.audioctx
• XMPlayer.loadXM(ArrayBuffer) -> returns true if loaded, otherwise barfs randomly
• XMPlayer.playXM() -> starts playing
• XMPlayer.pauseXM() -> obvious
• XMPlayer.stopXM() -> obvious; call this before loading a new one

Loading trackview.js is now optional; without it, the player won't do any visualizations. Or, you can override the following to get callbacks:

• XMView.pushEvent(e) -> push an audio event onto the queue. Called once per tick (about 50Hz, controlled by song). e contains fields:
  • t - audio timestamp
  • vu - Float32Array of RMS power (volume) for each channel
  • scopes - [Float32Array] of oscilloscope data, one array per channel; XMView.scope_width contains # of samples to produce here
  • songpos - position in the song (# patterns played)
  • pat - pattern number currently playing
  • row - row within pattern
• XMView.pause() - pause visualization
• XMView.stop() - stop/reset visualization

[mrdoob]

May I suggest... XMPlayer.init(), XMPlayer.load(ArrayBuffer), XMPlayer.play(), XMPlayer.pause() and XMPlayer.stop()?

[a1k0n]

Heh, yeah, now that those functions moved into the namespace, that makes more sense...