You only redraw when there’s interaction. In exchange you use basically no memory for state retention which frees up the real resource constraint.

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v1ne a day ago | parent | next [-]

Redrawing the whole thing consumes resources. That's power and resources not available to other tasks. There is value in being clever with what you draw.

	▲	piker 20 hours ago \| parent [-]
		Yes but it comes at the trade off persistent memory usage. It isn’t just free, and depending on the application in question that may be a lot better trade to make if, say, the app runs in the background or is rarely interacted with.

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codedokode 18 hours ago | parent | prev [-]

Moving the mouse is an interaction because there are hover effects.