QQuickItem::clipRect clips QSGNode in QQuickItem::updatePaintNode()

posix

I made a QML component based on QQuickItem. I redefined the QQuickItem::clipRect() method in it in order to clip nested components (childrens) along a certain border, which is smaller than the size of the component itself. In the QQuickItem::updatePaintNode() method I paint a custom QSGNode based on QSGGeometryNode/QSGGeometry/QSGFlatColorMaterial. The problem is that when I need the geometry in QQuickItem::clipRect() and clip: true on the component, the rendered QSGNode is clipped along the boundary specified in QQuickItem::clipRect(). What needs to be done to get the QSGNode to be drawn outside of QQuickItem::clipRect()?

sierdzio

@posix said in QQuickItem::clipRect clips QSGNode in QQuickItem::updatePaintNode():

What needs to be done to get the QSGNode to be drawn outside of QQuickItem::clipRect()?

clip: false

posix

@sierdzio I need to draw a border and cut off the center, something like this:

+---------------+ QSGNode drawed border
| +-----------+ |
| |  Clipped  | |
| | childs at | |
| |  center   | |
| |           | |
| +-----------+ |
+---------------+

Is this impossible to do?

sierdzio

@posix definitely possible but I don't know how without some research. The only idea that comes to my head is to use 2 items for this.

posix

@sierdzio yes, I also thought that it would be possible to do this in QML using nested components, but I need to do it in C++.

The problem is that QSGNode, when clip: true, calculates its outer bounds from QQuickItem::clipRect(), and not from QQuickItem::boundingRect(). If there was a way to change this, the problem would be solved.