33 {
36
38
39
40 for (int dy = -1; dy <= 1; ++dy) {
41 for (int dx = -1; dx <= 1; ++dx) {
42 i32 gx = cell_x + dx;
43 i32 gy = cell_y + dy;
44
45 i32 fx, fy;
46 feature_point(gx, gy, fx, fy);
47
48 i32 feature_x = (gx << 15) + fx;
49 i32 feature_y = (gy << 15) + fy;
50
51 i32 dx_q15 =
x - feature_x;
52 i32 dy_q15 =
y - feature_y;
53
54
55
56 i32 dist =
57 q15_abs(dx_q15) + q15_abs(dy_q15);
58
59 if (dist < min_dist)
60 min_dist = dist;
61 }
62 }
63
64
65 return (min_dist << 15) / (2 *
Q15_ONE);
66}