I’m currently using quads as source input for a vertex program to produce billboards. Right now, I’m calling glDrawArrays (), and I was wondering if by switching over to using triangle fans/strips using glDrawElements () I could attain better performance. My gut feeling is that there is no performance diffrence, am I right?
Most hardware will draw it as a tristrip. I’d recommend you move over to tristrips/fans because you dont know how the driver will divide the rectangle intro tris. There is more than one way and it may not be the way you want it.
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Fixed it for ya.
-SirKnight
[This message has been edited by SirKnight (edited 09-26-2002).]
Use GL_TRIANGLES, more fastest.
No, GL_TRIANGLES will not be faster.
For a single quad drawn with GL_TRIANGLES you’d have to send either 6 vertices, or 4 vertices and 6 indices - compare that to the 4 vertices and 4 indices for GL_TRIANGLE_STRIP, or the 4 vertices and 4 indices for GL_QUAD.