visitNode(node) {
    const gl = cc._renderContext;
    const anchorPoint = node.getAnchorPoint();
    const position = node.getPosition();

    // flipped stack matrix for nodes so they draw correctly
    const ox = (position.x || 0);
    const oy = (position.y || 0);
    const ax = this.width * (anchorPoint.x || 0);
    const ay = this.height * (anchorPoint.y || 0);
    const stackMat = this._stackMatrix.mat;
    stackMat[5] = -1.0;
    stackMat[12] = ax - ox;
    stackMat[13] = this.height - ay + oy;

    // visit node
    node.visit(this);

    // reset self to normal
    stackMat[12] = stackMat[13] = 0;
    stackMat[5] = 1.0;
  }
Resets projection / modelview matrices for visiting a node and then visits the node.
@param node