Issue when play is triggered after sceneEl renderstart event

[jeromeetienne]

Thanks for your work, really appreciated :)

in the component play function, one can find the following code

this.sceneEl.addEventListener('renderstart', this.onRenderTargetLoaded, false);
// ...
// and later ...
onRenderTargetLoaded: function () {
	console.log('component onRenderTargetLoaded')
	this.sceneEl.removeEventListener('renderstart', this.onRenderTargetLoaded, false);
	this.canvasEl = this.sceneEl.canvas;
	this.addEventListeners();
},

But if play is called after renderstart is triggered, then onRenderTargetLoaded is never called, and .addEventListeners either.

this.sceneEl.addEventListener('renderstart', this.onRenderTargetLoaded, false);
// test if renderstart has already been triggered
if( this.sceneEl.renderStarted ){
	this.onRenderTargetLoaded()
}

• https://github.com/aframevr/aframe/blob/master/docs/core/scene.md#properties
• https://github.com/aframevr/aframe/blob/master/docs/core/scene.md#events

Thanks