Function unionExtentFromExtent

src/util/model.ts:1258–1264

(tarExtent: number[], srcExtent: number[])

 *  - `extent` should be initialized as `initExtentForUnion()`.
 */
export function unionExtentFromExtent(tarExtent: number[], srcExtent: number[]): void {
    // Accept both or neither.
    if (isValidBoundsForExtent(srcExtent[0], srcExtent[1])) {
        srcExtent[0] < tarExtent[0] && (tarExtent[0] = srcExtent[0]);
        srcExtent[1] > tarExtent[1] && (tarExtent[1] = srcExtent[1]);
    }
}

/**
 * PENDING: `Infinity` from user data is not necessarily meaningless, but visualizing it requires