ProcessVertices example anyone?

[dalchri]

I've got a set of 1-8 CustomVertex.PositionColored vertices that I am rendering as a point list. Once I've rendered them, I need to label the points using transformed viewport coordinates and a call to DrawText.

Is there a way to get the transformed viewport coordinates of these vertices from directx w/o doing the math myself?

I assume that Device.ProcessVertices is the way to get the job done but I can't figure out how to make it work. In DirectX 9 C#, I keep getting System.InvalidArgumentException. I created the destBuffer with TransformedColored vertices.

Does anyone have a working example?

Thanks for any links or such!

 

[joekrahn]

I have also been looking for a good example. The difficult
part of ProcessVertices is setting up the vertex buffers
correctly. There is a complicated set of rules to get
the target buffer to match. It would be nice if there were
simply a function to get the necessary target FVF.

The only way I can find to get it right is to use the debug
driver for DirectX and tweak things based on the debug
messages. If rendering with a vertex shader, it seems even
more complex. I'm trying to get that working now, with no
success so far.

 

[dalchri]

In C#, I was trying to come up with a valid vertexDeclaration parameter having no idea what information it encapsulated. In the end, if I remember right, the trick was to pass that parameter as null.

So what I did (since I don't use a mesh) was set the StreamSource (using an untransformed vertex buffer), VertexFormat, Texture, and Transform as though I was going to call DrawPrimitives. Then I called ProcessVertices with a second vertex buffer that was to contain transformed coordinates.

Let me know if you keep having trouble, I've gotten it to work!