setMouseScreenDownPosition(screenLocation) {
    if (screenLocation != null) {
      this.mouseScreenDownPosition = cc.p(screenLocation.x, screenLocation.y);
      this.mouseGlobalScaleInvertedScreenDownPosition = UtilsEngine.transformPositionFromGlobalScale(this.mouseScreenDownPosition);
      this.mouseBoardDownPosition = UtilsEngine.transformTileMapToBoardIndex(this.mouseGlobalScaleInvertedScreenDownPosition);
      this.mouseBoardUnroundedDownPosition = UtilsEngine.transformTileMapToBoard(this.mouseGlobalScaleInvertedScreenDownPosition);
      this.mouseDown = true;
      this.mouseDragging = false;
      this.mouseDownAt = Date.now();
    }
  }
Sets mouse screen down position, board down index position, and board down position.
@param {Vec2} screenLocation