1. DomName('WebGLRenderingContext.copyTexImage2D')
  2. DocsEditable()
void copyTexImage2D(int target, int level, int internalformat, int x, int y, int width, int height, int border)

Source 

@DomName('WebGLRenderingContext.copyTexImage2D')
@DocsEditable()
void copyTexImage2D(int target, int level, int internalformat, int x, int y, int width, int height, int border) => _blink.BlinkWebGLRenderingContext.instance.copyTexImage2D_Callback_8_(this, target, level, internalformat, x, y, width, height, border);