function genData(count) {
    count = count|0;
    var verts = new Float32Array(count * 8);
    var mark_idx = new Float32Array(count * 4);

    var indices = new Uint32Array(count * 6);

    for (var i = 0; i < count; i++) {
        var vOff = i * 8;

        verts[vOff + 0] = -1.0;
        verts[vOff + 1] = -1.0;
        verts[vOff + 2] =  1.0;
        verts[vOff + 3] = -1.0;
        verts[vOff + 4] =  1.0;
        verts[vOff + 5] =  1.0;
        verts[vOff + 6] = -1.0;
        verts[vOff + 7] =  1.0;

        var iOff = i * 4;

        for (var b = 0; b < 4; b++) {
            mark_idx[iOff + b] = i;
        }

        var ixOff = i * 6;

        indices[ixOff + 0] = iOff + 0;
        indices[ixOff + 1] = iOff + 1;
        indices[ixOff + 2] = iOff + 2;
        indices[ixOff + 3] = iOff + 0;
        indices[ixOff + 4] = iOff + 2;
        indices[ixOff + 5] = iOff + 3;

    }

    return {verts: verts, mark_idx: mark_idx, indices: indices};
}