WebGLRTMgr is a manager for creating and recycling WebGLRenderTarget. TODO The demand is not high and the management cost is high. Remove it first.
WebGLRTMgr 管理WebGLRenderTarget的创建和回收 TODO 需求不大，管理成本高。先去掉。
静态
The width of the render target.
The height of the render target.
A RenderTexture2D instance.
Retrieves a render target with the specified width and height. For now, the search is based strictly on size.
根据指定的宽度和高度获得一个渲染目标。目前，搜索是基于严格大小判断的。
The RenderTexture2D instance to be recycled.
Releases a render target back to the manager for recycling.
将渲染目标回收至管理器以供循环使用。
En
WebGLRTMgr is a manager for creating and recycling WebGLRenderTarget. TODO The demand is not high and the management cost is high. Remove it first.
Zh
WebGLRTMgr 管理WebGLRenderTarget的创建和回收 TODO 需求不大，管理成本高。先去掉。