void convex_hull_marching(Bezier src_bz, Bezier bz,
std::vector<double> &solutions,
double left_t,
double right_t)
{
while(bz.order() > 0 and bz[0] == 0) {
std::cout << "deflate\n";
bz = bz.deflate();
solutions.push_back(left_t);
}
if (bz.order() > 0) {
int old_sign = SGN(bz[0]);
int sign;
double left_bound = 0;
double dt = 0;
for (size_t i = 1; i < bz.size(); i++)
{
sign = SGN(bz[i]);
if (sign != old_sign)
{
dt = double(i) / bz.order();
left_bound = dt * bz[0] / (bz[0] - bz[i]);
break;
}
old_sign = sign;
}
if (dt == 0) return;
std::cout << bz << std::endl;
std::cout << "dt = " << dt << std::endl;
std::cout << "left_t = " << left_t << std::endl;
std::cout << "right_t = " << right_t << std::endl;
std::cout << "left bound = " << left_bound
<< " = " << bz(left_bound) << std::endl;
double new_left_t = left_bound * (right_t - left_t) + left_t;
std::cout << "new_left_t = " << new_left_t << std::endl;
Bezier bzr = subRight(src_bz, new_left_t);
while(bzr.order() > 0 and bzr[0] == 0) {
std::cout << "deflate\n";
bzr = bzr.deflate();
solutions.push_back(new_left_t);
}
if (left_t < new_left_t) {
convex_hull_marching(src_bz, bzr,
solutions,
new_left_t, right_t);
} else {
std::cout << "epsilon reached\n";
while(bzr.order() > 0 and fabs(bzr[0]) <= 1e-10) {
std::cout << "deflate\n";
bzr = bzr.deflate();
std::cout << bzr << std::endl;
solutions.push_back(new_left_t);
}
}
}
}
void
Bezier::find_bezier_roots(std::vector<double> &solutions,
double left_t, double right_t) const {
Bezier bz = *this;
//convex_hull_marching(bz, bz, solutions, left_t, right_t);
//return;
// a constant bezier, even if identically zero, has no roots
if (bz.isConstant()) {
return;
}
while(bz[0] == 0) {
debug(std::cout << "deflate\n");
bz = bz.deflate();
solutions.push_back(0);
}
if (bz.degree() == 1) {
debug(std::cout << "linear\n");
if (SGN(bz[0]) != SGN(bz[1])) {
double d = bz[0] - bz[1];
if(d != 0) {
double r = bz[0] / d;
if(0 <= r && r <= 1)
solutions.push_back(r);
}
}
return;
}
//std::cout << "initial = " << bz << std::endl;
Bernsteins B(solutions);
B.find_bernstein_roots(bz, 0, left_t, right_t);
//std::cout << solutions << std::endl;
}
for(int i = 0; i < a.size(); i++) {
EXPECT_FLOAT_EQ(a[i], b[i]);
}
}
vector<double> find_all_roots(Bezier b) {
vector<double> rts = b.roots();
if(b.at0() == 0) rts.push_back(0);
if(b.at1() == 0) rts.push_back(1);
return rts;
}
TEST_F(ChainTest, Deflate) {
Bezier b = array_roots(vector_from_array((const double[]){0,0.25,0.5}));
EXPECT_FLOAT_EQ(0, b.at0());
b = b.deflate();
EXPECT_FLOAT_EQ(0, b.valueAt(0.25));
b = b.subdivide(0.25).second;
EXPECT_FLOAT_EQ(0, b.at0());
b = b.deflate();
const double rootposition = (0.5-0.25) / (1-0.25);
EXPECT_FLOAT_EQ(0, b.valueAt(rootposition));
b = b.subdivide(rootposition).second;
EXPECT_FLOAT_EQ(0, b.at0());
}
TEST_F(ChainTest, Roots) {
expect_array((const double[]){0.5}, wiggle.roots());
Bezier bigun(Bezier::Order(30));
for(unsigned i = 0; i < bigun.size(); i++) {
