[Interest] Are there limits to the number of vertices that can be allocated on a QSGGeometry?

[Shawn Rutledge]

> On 2021 Oct 20, at 17:36, Nuno Santos <nuno.santos at imaginando.pt> wrote:
> 
> Hi,
> 
> I have a custom QSGGeometryNode that renders several elements using triangles.
> 
> Each element is composed by 4 rectangles, this means that each element needs 6x4=24 vertices.
> 
> If there are more than a certain number of elements to be drawn, artefacts pop up. This artefacts are characterised by lines that connect to the origin, or with vertices on other elements.
> 
> I have stumbled on this issue when rendering a scene with roughly 3800 elements, which require 91200 vertices. I’m using colored point 2d vertices. 
> 
> 
> Are there limits to the number of vertices that can be allocated on a QSGGeometry?

Yes: it uses 16-bit indices, and the last index is reserved to indicate primitive restart.  So you can have up to 65534 vertices per node.