# Algorithm to auto generate vertex/index data for tri strip object?

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I have been given the the task of quantifying the frame rate of an app as a function of scene complexity. Something like finding FPS(#triangles in scene). Objects for this app are specified by vertex data for tri strips. For example to specify a quad, you specify that it has a total 4 unique vertices, then give the vertex data, then you have to specify the indices used.... e.g. an input file might look like this # Number of vertices 4 1. 1. 0. # V1 -1. 1. 0. # V2 1. -1. 0. # V3 -1. -1. 0. # V4 # Coordinate Indices 2 # 2 Tri-strips 0 1 2 # use vertices 0,1,2 2 1 3 # use vertices 2,1,3 I want to generate input files with varying numbers of tri-strip vertices for a quad to test the FPS vs. tris. But I don't want to have to manually create each file, so I was curious if there was an alorithm I could use to generate the verts and indices. Maybe something that will let me specify x and y extent and the number of verts horiztonally and vertically, the the output being a list of vertices and a list of index triples. Maybe someone knows of an example that does this sort of thing? Thanks, CB

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You mean something like this?:
7--8--9|\ |\ || \| \|4--5--6|\ |\ || \| \|1--2--3

For this just build each row or column as a trilist, i.e. alternating one up/down and one right/left:

1,4,2,5,3,6 and 9,6,8,5,7,4

To create a single strip you need to stitch them together with degenerate triangles, i.e. triangles with no area (they have only 2 distinct vertices):

3,6,6 + 6,6,9 + 6,9,6, so basically, just add one more index between the rows:

1,4,2,5,3,6,6,9,6,8,5,7,4

Or use NvTriStrip for that purpose. That programm works on arbitrary polygon soups.

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