Thick lines

I'm guessing you meant LINELIST and not POINTLIST?

ID3DXLine allows you to specify the line width.

Sorry, yes, LINELIST. And thanks for your reply.

In my app, I need to be able to draw lines around selected objects.

Is it better to do this by:

a) drawing the object normally and then drawing in wireframe with, say, a plain white texture. Problem with this is that for a cube, for example, you get lines making up the diagonal parts of the polys.

b) maintaining a list of lines and drawing using a LINELIST.

Does anyone know anything about the performance of drawing LINELISTs? Is it comparable to drawing the object in wireframe? Without doing any tests, I'm inclined to think it'll be quicker to draw the object.

Thanks

You'd have to benchmark it. If you're drawing wireframe triangles, you can backface cull, but you'll be drawing diagonals on planar faces made up of multiple triangles that you wouldn't do when drawing a list of lines that make up the outline of the mesh.

I wrote some code a while back that generated an index buffer comprising a line list from an indexed list of triangles just to draw the outline of a mesh (removed diagonals). More on that can be found here.