ProtectedcanvasProtectedinnerProtectedrendererProtectedrules(Try to) free memory. Currently only relevant on iOS.
The general type of backend: Canvas or SVG. This is not used for now (only VexflowBackendType used), but it may be useful when we don't want to use a Vexflow class.
Initialize a canvas without attaching it to a DOM node. Can be used to draw in background
Width of the canvas
Height of the canvas
Optionalid: stringRenders a rectangle with the given style to the screen. It is given in screen coordinates.
the rect in screen coordinates
the style id
alpha value between 0 and 1
The GraphicalMusicPage the backend is drawing from. Each backend only renders one GraphicalMusicPage, to which the coordinates are relative.