Namely, I want to write a vertex shader something akin to this:
in vec3 vertex;
void main()
{
vertex.x = gl_VertexID % vertexWidth;
vertex.y = gl_VertexID / vertexWidth;
//vertex.z = someProceduralFunction(...);
gl_Position = projection * modelview * vec4(vertex, 1.0);
}
Ignoring the question of whether the code even compiles, it's abundantly clear that I don't actually need any VBOs in the theoretical sense, so is it possible to just pump some kind of shadow vertices to this shader? Or do I need to allocate the space in the buffer regardless?