Chooses a CSS cursor colour that contrasts with the canvas background.
Returns 'black' on light backgrounds and 'white' on dark backgrounds so
the crosshair and other SVG/CSS cursors remain visible. The decision is
delegated to isLightBackground.
Parameters
backgroundColor: number
Current renderer clear colour as packed
0xRRGGBB RGB.
Returns "white"|"black"
'black' or 'white' for use as a CSS colour keyword.
Chooses a CSS cursor colour that contrasts with the canvas background.
Returns
'black'on light backgrounds and'white'on dark backgrounds so the crosshair and other SVG/CSS cursors remain visible. The decision is delegated to isLightBackground.