removeOneLeastError()

template<typename NumberT = float>

template<typename VectorType>

static void fl::LineSimplifier< NumberT >::removeOneLeastError ( VectorType * _poly )

inlinestatic

Definition at line 64 of file line_simplification.h.

                                                       {
        bitset<256> keep;
        VectorType &poly = *_poly;
        keep.assign(poly.size(), 1);
        const int n = poly.size();
        NumberT bestErr = INFINITY_DOUBLE;
        int bestIdx = -1;
 
        // scan all interior “alive” points
        for (int i = 1; i + 1 < n; ++i) {
            if (!keep[i])
                continue;
 
            // find previous alive
            int L = i - 1;
            while (L >= 0 && !keep[L])
                --L;
            // find next alive
            int R = i + 1;
            while (R < n && !keep[R])
                ++R;
 
            if (L < 0 || R >= n)
                continue; // endpoints
 
            // compute perp‐distance² to the chord L→R
            NumberT dx = poly[R].x - poly[L].x;
            NumberT dy = poly[R].y - poly[L].y;
            NumberT vx = poly[i].x - poly[L].x;
            NumberT vy = poly[i].y - poly[L].y;
            NumberT len2 = dx * dx + dy * dy;
            NumberT err =
                (len2 > NumberT(0))
                    ? ((dx * vy - dy * vx) * (dx * vy - dy * vx) / len2)
                    : (vx * vx + vy * vy);
 
            if (err < bestErr) {
                bestErr = err;
                bestIdx = i;
            }
        }
 
        // now “remove” that one point
        if (bestIdx >= 0)
            // keep[bestIdx] = 0;
            poly.erase(poly.begin() + bestIdx);
    }

References INFINITY_DOUBLE, and keep.