meta-next/src/renderer/SpriteRenderer.js

import Engine from "../Engine"
import Renderer from "./Renderer"

class SpriteRenderer extends Renderer
{
	constructor() {
		super()
	}

	render(entity) 
	{
		if(entity.needUpdateOffset) {
			this.updateMesh(entity)
		}

		if(entity.needUpdateTransform) {
			entity.updateTransform()
		}
		super.render(entity.drawCommand)

		if(entity.children) {
			const children = entity.children
			for(let n = 0; n < children.length; n++) {
				this.render(children[n])
			}
		}		
	}

	updateMesh(entity)
	{
		entity.updateMesh()

		const pivot = entity._pivot
		const sizeX = entity._size.x
		const sizeY = entity._size.y
		const offsetX = -sizeX * pivot.x
		const offsetY = -sizeY * pivot.y
		
		tempBuffer[0] = sizeX + offsetX
		tempBuffer[1] = sizeY + offsetY
		tempBuffer[4] = offsetX
		tempBuffer[5] = sizeY + offsetY
		tempBuffer[8] = offsetX
		tempBuffer[9] = offsetY	
		tempBuffer[12] = sizeX + offsetX
		tempBuffer[13] = offsetY

		entity.drawCommand.mesh.upload(tempBuffer)
		entity.needUpdateOffset = false
	}
}

const tempBuffer = new Float32Array([
	1.0, 1.0, 1.0, 1.0,
	0.0, 1.0, 0.0, 1.0,
	0.0, 0.0, 0.0, 0.0,
	1.0, 0.0, 1.0, 0.0
])

const instance = new SpriteRenderer()
export default instance