meta-next/src/renderer/DebugRenderer.js

import Engine from "../Engine"
import Renderer from "./Renderer"
import DrawCommand from "./DrawCommand"
import Material from "../resources/Material"
import Mesh from "../mesh/Mesh"
import Vector3 from "../math/Vector3"
import debugVS from "../../shaders/debug.vs"
import debugFS from "../../shaders/debug.fs"

let material = null
const color = new Vector3(1, 1, 1)

class DebugRenderer extends Renderer
{
	constructor() 
	{
		super()

		this.mesh = null
		this.uniforms = { color }
		this.drawCommand = null
	}

	setup() 
	{
		if(!material) {
			material = new Material({ vertexSource: debugVS, fragmentSource: debugFS })
		}
		
		this.mesh = new Mesh(tempBuffer, null)
		this.drawCommand = new DrawCommand(null, this.mesh, material, this.uniforms, Engine.gl.LINE_STRIP)
	}

	render(entity, r, g, b) 
	{
		if(r === undefined) { r = 1 }
		if(g === undefined) { g = 1 }
		if(b === undefined) { b = 1 }

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

		color.set(r, g, b)

		this.drawCommand.transform = entity.transform
		this.drawCommand.mesh = entity.drawCommand.mesh
		super.render(this.drawCommand)

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

	updateMesh(entity)
	{
		const gl = Engine.gl

		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[2] = offsetX
		tempBuffer[3] = sizeY + offsetY
		tempBuffer[4] = offsetX
		tempBuffer[5] = offsetY	
		tempBuffer[6] = sizeX + offsetX
		tempBuffer[7] = offsetY
		this.mesh.upload(tempBuffer)		
	}
}

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

const instance = new DebugRenderer()
export default instance