https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/copyTexSubImage2D
WebGLRenderingContext: copyTexSubImage2D() method - Web APIs | MDN
The copyTexSubImage2D() method of the WebGLRenderingContext interface of the WebGL API copies pixels from the current WebGLFramebuffer into a 2D texture...
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