@antv/g2/src/transform/maybeIdentityX.ts

the Grammar of Graphics in Javascript

import { deepMix } from '@antv/util';
import { TransformComponent as TC } from '../runtime';
import { column, columnOf } from './utils/helper';

export type MaybeIdentityXOptions = Record<string, never>;

/**
 * Add 3 constant encode for size channel.
 * This is useful for point geometry.
 */
export const MaybeIdentityX: TC<MaybeIdentityXOptions> = () => {
  return (I, mark) => {
    const { encode } = mark;
    const { x1 } = encode;
    if (x1) return [I, mark];
    const [X] = columnOf(encode, 'x');
    return [I, deepMix({}, mark, { encode: { x1: column([...X]) } })];
  };
};

MaybeIdentityX.props = {};