https://developer.mozilla.org/en-US/docs/Web/API/WebGLRenderingContext/copyTexImage2D
WebGLRenderingContext: copyTexImage2D() method - Web APIs | MDN
The copyTexImage2D() method of the WebGLRenderingContext interface of the WebGL API copies pixels from the current WebGLFramebuffer into a 2D texture image.
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https://bugzilla.mozilla.org/show_bug.cgi?id=944238
944238 - WebGL copyTexImage2D hits nsTArrayInfallibleAllocator::SizeTooBig
RESOLVED (wlitwinczyk) in Core - Graphics: CanvasWebGL. Last updated 2014-08-19.
webglhits