1/*
 2    Copyright 2018 0KIMS association.
 3
 4    This file is part of circom (Zero Knowledge Circuit Compiler).
 5
 6    circom is a free software: you can redistribute it and/or modify it
 7    under the terms of the GNU General Public License as published by
 8    the Free Software Foundation, either version 3 of the License, or
 9    (at your option) any later version.
10
11    circom is distributed in the hope that it will be useful, but WITHOUT
12    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
14    License for more details.
15
16    You should have received a copy of the GNU General Public License
17    along with circom. If not, see <https://www.gnu.org/licenses/>.
18*/
19
20function pointAdd(x1,y1,x2,y2) {
21    var a = 168700;
22    var d = 168696;
23
24    var res[2];
25    res[0] = (x1*y2 + y1*x2) / (1 + d*x1*x2*y1*y2);
26    res[1] = (y1*y2 - a*x1*x2) / (1 - d*x1*x2*y1*y2);
27    return res;
28}
29
30function EscalarMulW4Table(base, k) {
31    var out[16][2];
32
33    var i;
34    var p[2];
35
36    var dbl[2] = base;
37
38    for (i=0; i<k*4; i++) {
39        dbl = pointAdd(dbl[0], dbl[1], dbl[0], dbl[1]);
40    }
41
42    out[0][0] = 0;
43    out[0][1] = 1;
44    for (i=1; i<16; i++) {
45        p = pointAdd(out[i-1][0], out[i-1][1], dbl[0], dbl[1]);
46        out[i][0] = p[0];
47        out[i][1] = p[1];
48    }
49
50    return out;
51}