bool areInYRange(const TQuadratic &q, double t0, double t1,
int(&solIdx)[2]) const
{
assert(0.0 <= t0 && t0 <= 1.0), assert(0.0 <= t1 && t1 <= 1.0);
const TPointD &p0 = q.getP0(), &p1 = q.getP1(), &p2 = q.getP2();
double der[2] = {y(p1) - y(p0), y(p0) - y(p1) + y(p2) - y(p1)},
s;
double y0 = getY(q, t0), y1 = getY(q, t1);
if (tcg::poly_ops::solve_1(der, &s, m_tol)) {
if (t0 <= s && s < t1) {
double ys = getY(q, s);
solIdx[0] = (ys < m_y && m_y <= y0 || y0 <= m_y && m_y < ys) ? 0 : -1;
solIdx[1] = (ys < m_y && m_y < y1 || y1 < m_y && m_y < ys) ? 1 : -1;
} else if (t1 < s && s <= t0) {
double ys = getY(q, s);
solIdx[0] = (ys < m_y && m_y <= y0 || y0 <= m_y && m_y < ys) ? 1 : -1;
solIdx[1] = (ys < m_y && m_y < y1 || y1 < m_y && m_y < ys) ? 0 : -1;
} else {
solIdx[0] = isInYRange(y0, y1) ? (t0 < s) ? 0 : 1
: -1;
solIdx[1] = -1;
}
} else
solIdx[1] = solIdx[0] = -1;
return (solIdx[0] >= 0 || solIdx[1] >= 0);
}
int leftScanlineIntersections(const TQuadratic &q, double t0, double t1,
bool &ascending)
{
const TPointD &p0 = q.getP0(), &p1 = q.getP1(), &p2 = q.getP2();
double y1_y0 = y(p1) - y(p0),
accel = y(p2) - y(p1) - y1_y0;
// Fallback to segment case whenever we have too flat quads
if (std::fabs(accel) < m_tol)
return leftScanlineIntersections(TSegment(q.getPoint(t0), q.getPoint(t1)), ascending);
// Calculate new ascension
int ascends = isAscending(q, t1, t0 < t1);
bool wasAscending = ascending;
ascending = (ascends > 0) ? true
: (ascends < 0) ? false
: (wasAscending = !ascending, ascending); // Couples with the cusps check below
// In case the y coords are not in range, quit
int solIdx[2];
if (!areInYRange(q, t0, t1, solIdx))
return 0;
// Identify coordinates for which q(t) == y
double poly[3] = {y(p0) - m_y, 2.0 * y1_y0, accel},
s[2];
int sCount = tcg::poly_ops::solve_2(poly, s); // Tolerance dealt at the first bailout above
if (sCount == 2) {
// Calculate result
int result = 0;
if (solIdx[0] >= 0) {
result += int(getX(q, s[solIdx[0]]) < m_x && (getY(q, t0) != m_y || ascending == wasAscending)); // Cusp check
}
if (solIdx[1] >= 0)
result += int(getX(q, s[solIdx[1]]) < m_x);
return result;
}
return (assert(sCount == 0), 0); // Should never happen, since m_y is in range. If it ever happens,
// it must be close to the extremal - so quit with no intersections.
}
void TQuadraticLengthEvaluator::setQuad(const TQuadratic &quad) {
const TPointD &p0 = quad.getP0();
const TPointD &p1 = quad.getP1();
const TPointD &p2 = quad.getP2();
TPointD speed0(2.0 * (p1 - p0));
TPointD accel(2.0 * (p2 - p1) - speed0);
double a = accel * accel;
double b = 2.0 * accel * speed0;
m_c = speed0 * speed0;
m_constantSpeed = isAlmostZero(a); // => b isAlmostZero, too
if (m_constantSpeed) {
m_c = sqrt(m_c);
return;
}
m_sqrt_a_div_2 = 0.5 * sqrt(a);
m_noSpeed0 = isAlmostZero(m_c); // => b isAlmostZero, too
if (m_noSpeed0) return;
m_tRef = 0.5 * b / a;
double d = m_c - 0.5 * b * m_tRef;
m_squareIntegrand = (d < TConsts::epsilon);
if (m_squareIntegrand) {
m_f = (b > 0) ? -sq(m_tRef) : sq(m_tRef);
return;
}
m_e = d / a;
double sqrt_part = sqrt(sq(m_tRef) + m_e);
double log_arg = m_tRef + sqrt_part;
m_squareIntegrand = (log_arg < TConsts::epsilon);
if (m_squareIntegrand) {
m_f = (b > 0) ? -sq(m_tRef) : sq(m_tRef);
return;
}
m_primitive_0 = m_sqrt_a_div_2 * (m_tRef * sqrt_part + m_e * log(log_arg));
}
double computeStep(const TQuadratic &quad, double pixelSize) {
double step = 2;
TPointD A = quad.getP0() - 2.0 * quad.getP1() +
quad.getP2(); // 2*A is the acceleration of the curve
double A_len = norm(A);
/*
A_len is equal to 2*norm(a)
pixelSize will be 0.5*pixelSize
now h is equal to sqrt( 8 * 0.5 * pixelSize / (2*norm(a)) ) = sqrt(2) * sqrt(
pixelSize/A_len )
*/
if (A_len > 0) step = sqrt(2 * pixelSize / A_len);
return step;
}
void makeOutline(const TStroke *stroke, int startQuad, int endQuad,
outlineBoundary &ob, double error2)
{
//std::ofstream cout("c:\\temp\\outline.txt");
assert(stroke);
assert(startQuad >= 0);
assert(endQuad < stroke->getChunkCount());
assert(startQuad <= endQuad);
TThickQuadratic *tq;
std::vector<TQuadratic *> arrayUp, arrayDown;
TQuadratic arc;
if (!stroke->getChunkCount())
return;
//if (startQuad==0)
{
const TThickQuadratic *tq = stroke->getChunk(startQuad);
// trova i punti sul cerchio che corrispondono
// a due fette di 90 gradi.
// Ritorna una quadratica invece di tre singoli punti solo per compattezza.
TQuadratic
arc = getCircleQuarter(tq, QUARTER_BEGIN);
// estrae le quadratiche che corrispondono ad i due archi...
splitCircularArcIntoQuadraticCurves(tq->getP0(), arc.getP0(), arc.getP1(), arrayUp);
// e le ordina in modo che l'outline sia composta sempre da
// una curva superiore ed una inferiore corrispondente
changeDirection(arrayUp);
splitCircularArcIntoQuadraticCurves(tq->getP0(), arc.getP1(), arc.getP2(), arrayDown);
changeDirection(arrayDown, true);
// copia le curve nell'outline; se gli array non hanno la stessa dimensione
// quello con meno curve viene riempito con curve improprie
// che hanno i punti di controllo coincidente con l'ultimo estremo valido
//cout<<"quads del semicerchio left:"<<std::endl;
copy(/*cout, */ arrayUp, arrayDown, ob);
}
for (int i = startQuad; i <= endQuad; ++i) {
tq = (TThickQuadratic *)stroke->getChunk(i);
TThickPoint p0 = tq->getThickP0();
TThickPoint p1 = tq->getThickP1();
TThickPoint p2 = tq->getThickP2();
if (p0.x == p1.x) {
if (p1.x == p2.x && ((p1.y > p0.y && p1.y > p2.y) || (p1.y < p0.y && p1.y < p2.y)))
tq = new TThickQuadratic(p0, 0.5 * (p0 + p1), p1);
} else if (p0.y == p1.y) {
if (p0.y == p2.y && ((p1.x > p0.x && p1.x > p2.x) || (p1.x < p0.x && p1.x < p2.x)))
tq = new TThickQuadratic(p0, 0.5 * (p0 + p1), p1);
} else {
double fac1 = 1.0 / (p0.x - p1.x);
double fac2 = 1.0 / (p0.y - p1.y);
double aux1 = fac1 * (p2.x - p1.x);
double aux2 = fac2 * (p2.y - p1.y);
double aux3 = fac1 * (p0.x - p2.x);
double aux4 = fac2 * (p0.y - p2.y);
if ((areAlmostEqual(aux1, aux2) && aux1 >= 0) ||
(areAlmostEqual(aux3, aux4) && aux3 >= 0 && aux3 <= 1))
tq = new TThickQuadratic(p0, 0.5 * (p0 + p1), p1);
}
//cout<<"quad# "<<i<<":" <<*tq<<std::endl;
makeOutline(/*cout, */ ob, *tq, error2);
if (tq != stroke->getChunk(i))
delete tq;
}
arrayUp.clear();
arrayDown.clear();
// come sopra ultimo pezzo di arco
// if (endQuad==stroke->getChunkCount()-1)
{
arc = getCircleQuarter(tq, QUARTER_END);
splitCircularArcIntoQuadraticCurves(tq->getP2(), arc.getP1(), arc.getP0(), arrayUp);
changeDirection(arrayUp);
splitCircularArcIntoQuadraticCurves(tq->getP2(), arc.getP2(), arc.getP1(), arrayDown);
changeDirection(arrayDown, true);
//cout<<"quads del semicerchio right:"<<std::endl;
copy(/*cout,*/ arrayUp, arrayDown, ob);
}
}
int intersect(const TQuadratic &q, const TSegment &s,
std::vector<DoublePair> &intersections, bool firstIsQuad) {
int solutionNumber = 0;
// Note the line `a*x+b*y+c = 0` we search for solutions
// di a*x(t)+b*y(t)+c=0 in [0,1]
double a = s.getP0().y - s.getP1().y, b = s.getP1().x - s.getP0().x,
c = -(a * s.getP0().x + b * s.getP0().y);
// se il segmento e' un punto
if (0.0 == a && 0.0 == b) {
double outParForQuad = q.getT(s.getP0());
if (areAlmostEqual(q.getPoint(outParForQuad), s.getP0())) {
if (firstIsQuad)
intersections.push_back(DoublePair(outParForQuad, 0));
else
intersections.push_back(DoublePair(0, outParForQuad));
return 1;
}
return 0;
}
if (q.getP2() - q.getP1() ==
q.getP1() - q.getP0()) { // the second is a segment....
if (firstIsQuad)
return intersect(TSegment(q.getP0(), q.getP2()), s, intersections);
else
return intersect(s, TSegment(q.getP0(), q.getP2()), intersections);
}
std::vector<TPointD> bez, pol;
bez.push_back(q.getP0());
bez.push_back(q.getP1());
bez.push_back(q.getP2());
bezier2poly(bez, pol);
std::vector<double> poly_1(3, 0), sol;
poly_1[0] = a * pol[0].x + b * pol[0].y + c;
poly_1[1] = a * pol[1].x + b * pol[1].y;
poly_1[2] = a * pol[2].x + b * pol[2].y;
if (!(rootFinding(poly_1, sol))) return 0;
double segmentPar, solution;
TPointD v10(s.getP1() - s.getP0());
for (UINT i = 0; i < sol.size(); ++i) {
solution = sol[i];
if ((0.0 <= solution && solution <= 1.0) ||
areAlmostEqual(solution, 0.0, 1e-6) ||
areAlmostEqual(solution, 1.0, 1e-6)) {
segmentPar = (q.getPoint(solution) - s.getP0()) * v10 / (v10 * v10);
if ((0.0 <= segmentPar && segmentPar <= 1.0) ||
areAlmostEqual(segmentPar, 0.0, 1e-6) ||
areAlmostEqual(segmentPar, 1.0, 1e-6)) {
TPointD p1 = q.getPoint(solution);
TPointD p2 = s.getPoint(segmentPar);
assert(areAlmostEqual(p1, p2, 1e-1));
if (firstIsQuad)
intersections.push_back(DoublePair(solution, segmentPar));
else
intersections.push_back(DoublePair(segmentPar, solution));
solutionNumber++;
}
}
}
return solutionNumber;
}
int intersectCloseControlPoints(const TQuadratic &c0, const TQuadratic &c1,
std::vector<DoublePair> &intersections) {
int ret = -2;
double dist1 = tdistance2(c0.getP0(), c0.getP1());
if (dist1 == 0) dist1 = 1e-20;
double dist2 = tdistance2(c0.getP1(), c0.getP2());
if (dist2 == 0) dist2 = 1e-20;
double val0 = std::max(dist1, dist2) / std::min(dist1, dist2);
double dist3 = tdistance2(c1.getP0(), c1.getP1());
if (dist3 == 0) dist3 = 1e-20;
double dist4 = tdistance2(c1.getP1(), c1.getP2());
if (dist4 == 0) dist4 = 1e-20;
double val1 = std::max(dist3, dist4) / std::min(dist3, dist4);
if (val0 > 1000000 &&
val1 > 1000000) // both c0 and c1 approximated by segments
{
TSegment s0 = TSegment(c0.getP0(), c0.getP2());
TSegment s1 = TSegment(c1.getP0(), c1.getP2());
ret = intersect(s0, s1, intersections);
for (UINT i = intersections.size() - ret; i < (int)intersections.size();
i++) {
intersections[i].first = (dist1 < dist2)
? sqrt(intersections[i].first)
: 1 - sqrt(1 - intersections[i].first);
intersections[i].second = (dist3 < dist4)
? sqrt(intersections[i].second)
: 1 - sqrt(1 - intersections[i].second);
}
// return ret;
} else if (val0 > 1000000) // c0 only approximated segment
{
TSegment s0 = TSegment(c0.getP0(), c0.getP2());
ret = intersect(s0, c1, intersections);
for (UINT i = intersections.size() - ret; i < (int)intersections.size();
i++)
intersections[i].first = (dist1 < dist2)
? sqrt(intersections[i].first)
: 1 - sqrt(1 - intersections[i].first);
// return ret;
} else if (val1 > 1000000) // only c1 approximated segment
{
TSegment s1 = TSegment(c1.getP0(), c1.getP2());
ret = intersect(c0, s1, intersections);
for (UINT i = intersections.size() - ret; i < (int)intersections.size();
i++)
intersections[i].second = (dist3 < dist4)
? sqrt(intersections[i].second)
: 1 - sqrt(1 - intersections[i].second);
// return ret;
}
/*
if (ret!=-2)
{
std::vector<DoublePair> intersections1;
int ret1 = intersect(c0, c1, intersections1, false);
if (ret1>ret)
{
intersections = intersections1;
return ret1;
}
}
*/
return ret;
}
int intersect(const TQuadratic &c0, const TQuadratic &c1,
std::vector<DoublePair> &intersections, bool checksegments) {
int ret;
// Works baddly, sometimes patch intersections...
if (checksegments) {
ret = intersectCloseControlPoints(c0, c1, intersections);
if (ret != -2) return ret;
}
double a = c0.getP0().x - 2 * c0.getP1().x + c0.getP2().x;
double b = 2 * (c0.getP1().x - c0.getP0().x);
double d = c0.getP0().y - 2 * c0.getP1().y + c0.getP2().y;
double e = 2 * (c0.getP1().y - c0.getP0().y);
double coeff = b * d - a * e;
int i = 0;
if (areAlmostEqual(coeff, 0.0)) // c0 is a Segment, or a single point!!!
{
TSegment s = TSegment(c0.getP0(), c0.getP2());
ret = intersect(s, c1, intersections);
if (a == 0 && d == 0) // values of t in s coincide with values of t in c0
return ret;
for (i = intersections.size() - ret; i < (int)intersections.size(); i++) {
intersections[i].first = c0.getT(s.getPoint(intersections[i].first));
}
return ret;
}
double c = c0.getP0().x;
double f = c0.getP0().y;
double g = c1.getP0().x - 2 * c1.getP1().x + c1.getP2().x;
double h = 2 * (c1.getP1().x - c1.getP0().x);
double k = c1.getP0().x;
double m = c1.getP0().y - 2 * c1.getP1().y + c1.getP2().y;
double p = 2 * (c1.getP1().y - c1.getP0().y);
double q = c1.getP0().y;
if (areAlmostEqual(h * m - g * p,
0.0)) // c1 is a Segment, or a single point!!!
{
TSegment s = TSegment(c1.getP0(), c1.getP2());
ret = intersect(c0, s, intersections);
if (g == 0 && m == 0) // values of t in s coincide with values of t in c0
return ret;
for (i = intersections.size() - ret; i < (int)intersections.size(); i++) {
intersections[i].second = c1.getT(s.getPoint(intersections[i].second));
}
return ret;
}
double a2 = (g * d - a * m);
double b2 = (h * d - a * p);
double c2 = ((k - c) * d + (f - q) * a);
coeff = 1.0 / coeff;
double A = (a * a + d * d) * coeff * coeff;
double aux = A * c2 + (a * b + d * e) * coeff;
std::vector<double> t;
std::vector<double> solutions;
t.push_back(aux * c2 + a * c + d * f - k * a - d * q);
aux += A * c2;
t.push_back(aux * b2 - h * a - d * p);
t.push_back(aux * a2 + A * b2 * b2 - g * a - d * m);
t.push_back(2 * A * a2 * b2);
t.push_back(A * a2 * a2);
rootFinding(t, solutions);
// solutions.push_back(0.0); //per convenzione; un valore vale l'altro....
for (i = 0; i < (int)solutions.size(); i++) {
if (solutions[i] < 0) {
if (areAlmostEqual(solutions[i], 0, 1e-6))
solutions[i] = 0;
else
continue;
} else if (solutions[i] > 1) {
if (areAlmostEqual(solutions[i], 1, 1e-6))
solutions[i] = 1;
else
continue;
}
DoublePair tt;
tt.second = solutions[i];
tt.first = coeff * (tt.second * (a2 * tt.second + b2) + c2);
if (tt.first < 0) {
if (areAlmostEqual(tt.first, 0, 1e-6))
tt.first = 0;
else
continue;
} else if (tt.first > 1) {
if (areAlmostEqual(tt.first, 1, 1e-6))
tt.first = 1;
else
continue;
}
intersections.push_back(tt);
assert(areAlmostEqual(c0.getPoint(tt.first), c1.getPoint(tt.second), 1e-1));
}
return intersections.size();
}
inline double get(const TQuadratic &q, double t, double(TPointD::*val)) const
{
double one_t = 1.0 - t;
return one_t * (one_t * q.getP0().*val + t * q.getP1().*val) + t * (one_t * q.getP1().*val + t * q.getP2().*val);
}
