are vertex arrays non-destructive?

i’m developing a realtime landscape renderer wich takes elevation data from a fractal, and since the fractal is quite complex (multifractal perlin noise) and it takes some time to sample, i’ve found a way to reduce sampling down to a minimum, by sampling only when is really needed.

the method i’ve implemented relys on a 2-dimensional wrappable buffer, and the data into the buffer MUST remain coherent all the time: my code stores values correctly, but sometime the polygons appear not as i expect.

since there are many shared vertex, every with position, color, normal, texture and fog coordinates, i use vertex arrays to let opengl do the calculation once.

to specify vertex arrays data i use gl___Pointer() family functions, and i dereference the arrays with glArrayElement().

now, does opengl leave unchanged the data into my arrays, after i have dereferenced?

i hope the answer will be yes…
…and i hope i was clear enough.


PS: just a note about how clever design can do for applications : before the renderer was running @25 fps, now it runs @130 !!

ok. i’ve fixed the bug, and as usual it was mine… but answer the same !