I need to draw a lot of polygons consisting of 6 vertices's (two triangles).
Without any texture coordinates, normals etc., both approaches result in 72 bytes. In the future I would definitely also need texture coordinates and normals, which would make index drawing consume less memory. Not a lot though.
So my question is: For VAOs with few vertex overlaps, which approach is faster? I don't care about the extra memory consumed by non-index drawing, only speed.
Edit: To make it clear.
Non-index approach:
float[18] vertices = {
//Triangle 1
1,1,0,
1,0,0,
0,0,0,
//Triangle 2
1,0,0,
0,1,0,
0,0,0,
};
Index approach:
float[12] vertices = {
1,1,0,
1,0,0,
0,0,0,
0,1,0,
};
int[6] indices = {
//Triangle 1
0,1,2,
//Triangle 2
0,3,2
};