Function rotateNodeLabel

src/chart/graph/circularLayoutHelper.ts:193–234

(
    node: GraphNode,
    circularRotateLabel: boolean,
    cx: number,
    cy: number
)

};

export function rotateNodeLabel(
    node: GraphNode,
    circularRotateLabel: boolean,
    cx: number,
    cy: number
) {
    const el = node.getGraphicEl() as Symbol;
    // need to check if el exists. '-' value may not create node element.
    if (!el) {
        return;
    }
    const nodeModel = node.getModel<GraphNodeItemOption>();
    let labelRotate = nodeModel.get(['label', 'rotate']) || 0;
    const symbolPath = el.getSymbolPath();
    if (circularRotateLabel) {
        const pos = node.getLayout();
        let rad = Math.atan2(pos[1] - cy, pos[0] - cx);
        if (rad < 0) {
            rad = Math.PI * 2 + rad;
        }
        const isLeft = pos[0] < cx;
        if (isLeft) {
            rad = rad - Math.PI;
        }
        const textPosition = isLeft ? 'left' as const : 'right' as const;

        symbolPath.setTextConfig({
            rotation: -rad,
            position: textPosition,
            origin: 'center'
        });
        const emphasisState = symbolPath.ensureState('emphasis');
        zrUtil.extend(emphasisState.textConfig || (emphasisState.textConfig = {}), {
            position: textPosition
        });
    }
    else {
        symbolPath.setTextConfig({
            rotation: labelRotate *= Math.PI / 180
        });
    }
}