attrib[4 * index + 0].tex_coord[2] = tex;
attrib[4 * index + 1].position[(surface + 0) % 3] = x + 0 - offset;
attrib[4 * index + 1].position[(surface + 1) % 3] = y + 1 - offset;
attrib[4 * index + 1].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;
attrib[4 * index + 0].tex_coord[2] = tex;
attrib[4 * index + 1].position[(surface + 0) % 3] = x + 0 - offset;
attrib[4 * index + 1].position[(surface + 1) % 3] = y + 1 - offset;
attrib[4 * index + 1].position[(surface + 2) % 3] = surface < 3 ? offset : -offset;