I’m trying to create a simple x/y line graph, I’m very confused on how to managed multiple nodes, ie, x axis line, y axis line, and the actual real line. If the code just returns x_axis, or y_axis, and not calling the AppendChildNode works OK for the line.
Also, noticed that once all the nodes are added the application crashes on closing. Is there a special method to dispose of the Node objects?
QSGNode *VtyGraphQT::updatePaintNode(QSGNode *oldNode, UpdatePaintNodeData *)
{
QSGGeometryNode *background, *x_axis, *y_axis, *line = 0;
QSGGeometry *geometry=0, *x_axisGeo=0, *y_axisGeo=0, *lineGeo = 0;
if (!oldNode) {
background = new QSGGeometryNode;
x_axis = new QSGGeometryNode;
y_axis = new QSGGeometryNode;
line = new QSGGeometryNode;
x_axisGeo = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 2);
y_axisGeo = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 2);
lineGeo = new QSGGeometry(QSGGeometry::defaultAttributes_Point2D(), 1024);
x_axisGeo->setLineWidth(2);
x_axisGeo->setDrawingMode(GL_LINE_STRIP);
x_axis->setGeometry(x_axisGeo);
x_axis->setFlag(QSGNode::OwnsGeometry);
y_axisGeo->setLineWidth(2);
y_axisGeo->setDrawingMode(GL_LINE_STRIP);
y_axis->setGeometry(y_axisGeo);
y_axis->setFlag(QSGNode::OwnsGeometry);
lineGeo->setLineWidth(2);
lineGeo->setDrawingMode(GL_LINE_STRIP);
line->setGeometry(lineGeo);
line->setFlag(QSGNode::OwnsGeometry);
QSGFlatColorMaterial *material = new QSGFlatColorMaterial;
material->setColor(QColor(255, 0, 0));
x_axis->setMaterial(material);
x_axis->setFlag(QSGNode::OwnsMaterial);
y_axis->setMaterial(material);
y_axis->setFlag(QSGNode::OwnsMaterial);
line->setMaterial(material);
line->setFlag(QSGNode::OwnsMaterial);
background->setMaterial(material);
background->setFlag(QSGNode::OwnsMaterial);
background->appendChildNode(x_axis);
background->appendChildNode(y_axis);
background->appendChildNode(line);
x_axisGeo->allocate(2);
x_axisGeo->vertexDataAsPoint2D()[0].set(0,0);
x_axisGeo->vertexDataAsPoint2D()[1].set(width(),0);
y_axisGeo->allocate(2);
y_axisGeo->vertexDataAsPoint2D()[0].set(0,0);
y_axisGeo->vertexDataAsPoint2D()[1].set(0,height());
}else
{
background = static_cast<QSGGeometryNode *>(oldNode);
}
return background;
}
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