Function viewCoordSysUpdateRoamTrans

src/coord/View.ts:510–531

* NOTICE: It depends on `viewCoordSysUpdateRawTrans`.

(viewInner: ViewInner)

 * NOTICE: It depends on `viewCoordSysUpdateRawTrans`.
 */
function viewCoordSysUpdateRoamTrans(viewInner: ViewInner): void {
    const viewRectCenter = viewCoordSysGetViewRectCenter(viewInner);
    const roamViewCenter = parseCenterOption(tmpCenterURT, viewInner, viewInner.centerOption)
        ? vectorApplyTransform(tmpCenterURT, tmpCenterURT, viewInner.mtRaw)
        : viewRectCenter;

    const zoom = viewInner.zoom;
    const roamTrans = viewInner.trans[VIEW_COORD_SYS_TRANS_ROAM];
    roamTrans.x = viewRectCenter[0] - zoom * roamViewCenter[0];
    roamTrans.y = viewRectCenter[1] - zoom * roamViewCenter[1];
    roamTrans.scaleX = roamTrans.scaleY = zoom;
    // [VIEW_COORD_SYS_APPLY_ROAM_CENTER_AND_ZOOM]
    // Ordinarily, the definition is:
    //  roamTrans.originX = roamViewCenter[0];
    //  roamTrans.originY = roamViewCenter[1];
    //  roamTrans.x = viewRectCenter[0] - roamViewCenter[0];
    //  roamTrans.y = viewRectCenter[1] - roamViewCenter[1];
    //  roamTrans.scaleX = roamTrans.scaleY = zoom;
    // But `el.originX`/`originY` should not be set.
    // (see VIEW_COORD_SYS_ANIMATION_PROPS_CONSTRAINT for the reason),
    // so we use the above formula instead.
}
const tmpCenterURT: number[] = [];

/**