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beziercurve.cpp
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#include "beziercurve.h"
BezierCurve::BezierCurve() :
closed(true),
samples_per_segment(15),
tests_sample_rate(200),
selected(-1)
{
}
// does this show up in the commit
void BezierCurve::AddPoint(const QVector2D & v)
{
pts.push_back(v);
}
void BezierCurve::SetPoints(const QList <QVector2D> & ps)
{
pts = ps;
}
void BezierCurve::SetPointsFromPolyline(const QList <QVector2D> & polyline)
{
pts.clear();
for (int i=0; i<polyline.size()-1; ++i) {
if (i == 0) {
pts.push_back(polyline[i]);
}
pts.push_back(polyline[i] * 0.6666f + polyline[i+1] * 0.3333f);
pts.push_back(polyline[i] * 0.3333f + polyline[i+1] * 0.6666f);
pts.push_back(polyline[i+1]);
}
}
void BezierCurve::SetPoint(const int index, const QVector2D & v)
{
if (index < 0 || index >= pts.size()) {
qDebug() << "BezierCurve::SetPoint - Warning, index" << index << "out of range";
return;
}
pts[index] = v;
}
void BezierCurve::TranslateControlPoints(const QVector2D & v)
{
for (int i=0; i<pts.size(); ++i) {
pts[i] += v;
}
}
void BezierCurve::RotateControlPoints(const float rotate_radians)
{
const float cos_rad = cosf(rotate_radians);
const float sin_rad = sinf(rotate_radians);
for (int i=0; i<pts.size(); ++i) {
const float pt_x = cos_rad*pts[i].x() - sin_rad*pts[i].y();
const float pt_y = sin_rad*pts[i].x() + cos_rad*pts[i].y();
pts[i] = QVector2D(pt_x, pt_y);
}
}
void BezierCurve::ScaleControlPoints(const float x, const float y)
{
for (int i=0; i<pts.size(); ++i) {
pts[i].setX( pts[i].x() * x);
pts[i].setY( pts[i].y() * y);
}
}
int BezierCurve::GetNumControlPoints() const
{
return pts.size();
}
QVector2D BezierCurve::GetControlPointCentroid() const
{
QVector2D centroid(0, 0);
for (int i=0; i<pts.size(); ++i) {
centroid += pts[i];
}
centroid *= 1.0f / float(pts.size());
return centroid;
}
void BezierCurve::ClearPoints()
{
pts.clear();
samples.clear();
}
void BezierCurve::LoadFromSVGData(const QString & s)
{
pts.clear();
samples.clear();
QString s_filtered = s;
s_filtered.replace(QString(","), QString(" "));
QStringList path_data_tokens = s_filtered.split(" ");
QVector2D current_pos(0, 0);
QString last_command("");
while (path_data_tokens.size() > 0) {
//examine next token
QString token = path_data_tokens.first();
//qDebug() << "Parsing token" << path_data_tokens.size() << ":" << token;
//check if token is a command token
if (QString::compare(token, "M") == 0 || QString::compare(token, "m") == 0 || //M - "moveto" (absolute), m (relative)
QString::compare(token, "Z") == 0 || QString::compare(token, "z") == 0 || //Z - close the curve
QString::compare(token, "C") == 0 || QString::compare(token, "c") == 0 || //C - cubic Bezier "curveto" (absolute), c (relative)
QString::compare(token, "S") == 0 || QString::compare(token, "s") == 0 || //S - cubic Bezier "shorthand curveto" (absolute), s (relative)
QString::compare(token, "L") == 0 || QString::compare(token, "l") == 0) { //L - line (absolute), l (relative)
last_command = token;
path_data_tokens.pop_front(); //discard the command token
}
//parse the coordinates that come after a command token
if (QString::compare(last_command, "M") == 0 || QString::compare(last_command, "m") == 0) { //M - "moveto" (absolute), m (relative)
QString tok1 = path_data_tokens.first(); path_data_tokens.pop_front();
QString tok2 = path_data_tokens.first(); path_data_tokens.pop_front();
if (QString::compare(last_command, "M") == 0) {
current_pos = QVector2D(tok1.toFloat(), tok2.toFloat());
}
else {
current_pos = current_pos + QVector2D(tok1.toFloat(), tok2.toFloat());
}
}
else if (QString::compare(last_command, "Z") == 0 || QString::compare(last_command, "z") == 0) { //Z/z - close the curve
/*
QVector2D first_pos = pts.first();
QVector2D tan1 = current_pos + (first_pos - current_pos) * 0.25;
QVector2D tan2 = current_pos + (first_pos - current_pos) * 0.75;
//add a bezier segment which closes this path
pts.push_back(current_pos);
pts.push_back(tan1);
pts.push_back(tan2);
pts.push_back(first_pos);
*/
}
else if (QString::compare(last_command, "C") == 0 || QString::compare(last_command, "c") == 0 || //C - cubic Bezier "curveto" (absolute), c (relative)
QString::compare(last_command, "S") == 0 || QString::compare(last_command, "s") == 0) { //S - cubic Bezier "shorthand curveto" (absolute), s (relative)
QVector2D tan1;
QVector2D tan2;
QVector2D pos;
if (QString::compare(last_command, "C") == 0 || QString::compare(last_command, "c") == 0) {
//expect 3 params total
QString tok1_tan1 = path_data_tokens.first(); path_data_tokens.pop_front();
QString tok2_tan1 = path_data_tokens.first(); path_data_tokens.pop_front();
QString tok1_tan2 = path_data_tokens.first(); path_data_tokens.pop_front();
QString tok2_tan2 = path_data_tokens.first(); path_data_tokens.pop_front();
QString tok1 = path_data_tokens.first(); path_data_tokens.pop_front();
QString tok2 = path_data_tokens.first(); path_data_tokens.pop_front();
tan1 = QVector2D(tok1_tan1.toFloat(), tok2_tan1.toFloat());
tan2 = QVector2D(tok1_tan2.toFloat(), tok2_tan2.toFloat());
pos = QVector2D(tok1.toFloat(), tok2.toFloat());
}
else {
//expect only 2 params
QString tok1_tan2 = path_data_tokens.first(); path_data_tokens.pop_front();
QString tok2_tan2 = path_data_tokens.first(); path_data_tokens.pop_front();
QString tok1 = path_data_tokens.first(); path_data_tokens.pop_front();
QString tok2 = path_data_tokens.first(); path_data_tokens.pop_front();
//http://www.w3.org/TR/SVG/paths.html#PathDataCubicBezierCommands
//"The first control point is assumed to be the reflection of the second
//control point on the previous command relative to the current point. "
if (QString::compare(token, "S") == 0) {
tan1 = current_pos + (current_pos - pts[pts.size()-2]);
}
else {
tan1 = current_pos - pts[pts.size()-2];
}
tan2 = QVector2D(tok1_tan2.toFloat(), tok2_tan2.toFloat());
pos = QVector2D(tok1.toFloat(), tok2.toFloat());
}
if (QString::compare(last_command, "C") == 0 || QString::compare(last_command, "S") == 0) { //absolute
//add a bezier segment
qDebug() << "Adding absolute Bezier segment" << current_pos << tan1 << tan2 << pos;
if (pts.empty()) {
pts.push_back(current_pos);
}
pts.push_back(tan1);
pts.push_back(tan2);
pts.push_back(pos);
current_pos = pos;
}
else { //relative
//add a bezier segment
qDebug() << "Adding relative Bezier segment" << current_pos << current_pos+tan1 << current_pos+tan2 << current_pos+pos;
if (pts.empty()) {
pts.push_back(current_pos);
}
pts.push_back(current_pos + tan1);
pts.push_back(current_pos + tan2);
pts.push_back(current_pos + pos);
current_pos = current_pos + pos;
}
}
else if (QString::compare(last_command, "L") == 0 || QString::compare(last_command, "l") == 0) { //L - line (absolute), l (relative)
QString tok1 = path_data_tokens.first(); path_data_tokens.pop_front();
QString tok2 = path_data_tokens.first(); path_data_tokens.pop_front();
QVector2D last_pos = current_pos;
if (QString::compare(last_command, "L") == 0) {
current_pos = QVector2D(tok1.toFloat(), tok2.toFloat());
}
else {
current_pos = current_pos + QVector2D(tok1.toFloat(), tok2.toFloat());
}
QVector2D tan1 = last_pos + (current_pos - last_pos) * 0.25;
QVector2D tan2 = last_pos + (current_pos - last_pos) * 0.75;
//add a bezier segment which closes this path
pts.push_back(last_pos);
pts.push_back(tan1);
pts.push_back(tan2);
pts.push_back(current_pos);
}
};
//qDebug() << "Loaded curve" << pts;
//next we normalize this
QVector2D bmin(FLT_MAX, FLT_MAX);
QVector2D bmax(-FLT_MAX, -FLT_MAX);
for (int i=0; i<pts.size(); ++i) {
bmin.setX(qMin(bmin.x(), pts[i].x()));
bmin.setY(qMin(bmin.y(), pts[i].y()));
bmax.setX(qMax(bmax.x(), pts[i].x()));
bmax.setY(qMax(bmax.y(), pts[i].y()));
}
const float scale_fac = 4.0f;
const float scale_val = qMax(bmax.x() - bmin.x(), bmax.y() - bmin.y()); //scale both X and Y with same val to preserve aspect ratio
for (int i=0; i<pts.size(); ++i) {
pts[i] = (pts[i] - bmin);
pts[i] /= scale_val;
pts[i].setX(pts[i].x() * scale_fac - scale_fac/2.0f);
pts[i].setY(scale_fac - (pts[i].y() * scale_fac));
}
//qDebug() << "Loaded curve" << pts;
}
int BezierCurve::GetPreviousSegmentIndex(const int i) const
{
int next = i - 3;
if (next < 0) {
next = pts.size() - 4;
}
return next;
}
int BezierCurve::GetNextSegmentIndex(const int i) const
{
int next = i + 3;
if (next >= pts.size()-1) {
next = 0;
}
return next;
}
void BezierCurve::SetClosed(bool b)
{
closed = b;
}
void BezierCurve::Draw2D()
{
glColor3f(0.75f, 0.75f, 0.75f);
glBegin(GL_LINES);
for (int i=0; i+3<pts.size(); i+=3) {
glVertex2f(pts[i].x(), pts[i].y());
glVertex2f(pts[i+1].x(), pts[i+1].y());
glVertex2f(pts[i+2].x(), pts[i+2].y());
glVertex2f(pts[i+3].x(), pts[i+3].y());
}
glEnd();
glColor3f(0.5f, 0.5f, 0.5f);
closed ? glBegin(GL_LINE_LOOP) : glBegin(GL_LINE_STRIP);
for (int i=0; i<samples.size(); ++i) {
glVertex2f(samples[i].x(), samples[i].y());
}
glEnd();
glColor3f(0.25f, 1.0f, 0.25f);
glPointSize(6.0f);
glBegin(GL_POINTS);
for (int i=0; i<pts.size(); ++i) {
glVertex2f(pts[i].x(), pts[i].y());
}
glColor3f(0.25f, 0.25f, 1.0f);
if (selected >= 0) {
glVertex2f(pts[selected].x(), pts[selected].y());
}
glEnd();
}
bool BezierCurve::IsClosed()
{
return closed;
}
void BezierCurve::SetSamplesPerSegment(const int i)
{
samples_per_segment = i;
}
void BezierCurve::UpdateSamples()
{
samples.clear();
for (int i=0; i+3<pts.size(); i+=3) {
for (int j=0; j<samples_per_segment; ++j) {
QVector2D p;
SamplePoint(pts[i], pts[i+1], pts[i+2], pts[i+3], float(j) / float(samples_per_segment), p);
samples.push_back(p);
}
}
}
const QList <QVector2D> & BezierCurve::Samples() const
{
return samples;
}
const QList <QVector2D> & BezierCurve::Points() const
{
return pts;
}
const QVector2D BezierCurve::Point(const int i) const
{
return pts[i];
}
void BezierCurve::SelectPoint(const QVector2D & p, const float select_size)
{
selected = -1;
float min_dist = select_size;
for (int i=0; i<pts.size(); ++i) {
float each_dist = (pts[i] - p).lengthSquared();
if (each_dist < min_dist) {
min_dist = each_dist;
selected = i;
}
}
}
void BezierCurve::SetSelectedPoint(const int index)
{
selected = index;
}
int BezierCurve::SelectedPoint() const
{
return selected;
}
void BezierCurve::MoveSelectedPoint(const QVector2D & p, const bool keep_g1, const bool equal_lengths)
{
if (selected == -1) {
qDebug() << "BezierCurve::MoveSelectedPoint - Warning, trying to move no selected point";
return;
}
else if (selected >= pts.size()) {
qDebug() << "BezierCurve::MoveSelectedPoint - Warning, selected point index >= size of points";
}
if (selected % 3 != 0) { //if there is a tangent point we may need to keep collinear
int other_index = -1;
int ctrl_pt = -1;
if (selected % 3 == 1) {
ctrl_pt = selected-1;
if (selected == 1) { //it's the first segment
other_index = closed ? pts.size()-2 : -1;
}
else {
other_index = selected-2;
}
}
else if (selected % 3 == 2) {
ctrl_pt = selected+1;
if (selected == pts.size()-2) { //it's the last segment
other_index = closed ? 1 : -1;
}
else {
other_index = selected+2;
}
}
//make other_index point collinear
if (keep_g1 && other_index >= 0) {
float dist = (pts[other_index]-pts[ctrl_pt]).length();
if(equal_lengths)
pts[other_index] = pts[ctrl_pt] - (p-pts[ctrl_pt]);
else
pts[other_index] = pts[ctrl_pt] + (p-pts[ctrl_pt]).normalized() * (-dist);
}
pts[selected] = p;
}
else if (selected % 3 == 0) {
QVector2D movement = p - pts[selected];
if (closed && (selected == 0 || selected == pts.size()-1)) {
pts[0] += movement;
pts[pts.size()-1] += movement;
if(keep_g1)
{
pts[1] += movement;
pts[pts.size()-2] += movement;
}
}
else {
if(keep_g1)
{
if (selected > 0) {
pts[selected-1] += movement;
}
if (selected < pts.size()-1) {
pts[selected+1] += movement;
}
}
pts[selected] += movement;
}
}
}
void BezierCurve::DeletePoint(const int segment_index)
{
if (closed && pts.size() <= 7) {
qDebug() << "BezierCurve::DeleteSelectedPoint() - Warning, not deleting since curve closed and only" << pts.size() << "pts.";
return;
}
if (!closed && pts.size() <= 4) {
qDebug() << "BezierCurve::DeleteSelectedPoint() - Warning, not deleting since curve not closed and only" << pts.size() << "pts.";
return;
}
//move to nearest endpoint
int index = segment_index;
if (index % 3 == 1) {
--index;
}
if (index % 3 == 2) {
++index;
}
//now we remove the endpoint, plus the tangent before and after
//TODO: this could be more optimal in that the shape is better preserved following removal
if (index > 0 && index < pts.size()-1) {
pts.removeAt(index-1);
pts.removeAt(index-1);
pts.removeAt(index-1);
}
else {
if (!closed && index == 0) {
pts.removeFirst();
pts.removeFirst();
pts.removeFirst();
}
else if (!closed && index == pts.size()-1) {
pts.removeLast();
pts.removeLast();
pts.removeLast();
}
else { //closed and at the endpoint
QVector2D t2 = pts[2];
pts.removeLast();
pts.removeLast();
pts.removeFirst();
pts.removeFirst();
pts.removeFirst();
pts.push_back(t2);
pts.push_back(pts.first());
}
}
}
void BezierCurve::DeleteSelectedPoint()
{
DeletePoint(selected);
selected = -1;
}
void BezierCurve::InsertPoint(const int segment_index)
{
if (segment_index < 0 || segment_index >= pts.size()) {
qDebug() << "BezierCurve::InsertPoint() - Warning, selected is" << segment_index;
return;
}
int index = segment_index;
index -= (index % 3);
QList <QVector2D> subdiv_pts;
Subdivide(index, 0.5f);
}
void BezierCurve::InsertSelectedPoint()
{
InsertPoint(selected);
}
void BezierCurve::UnselectPoint()
{
selected = -1;
}
void BezierCurve::SamplePoint(const QVector2D & p1, const QVector2D & t1, const QVector2D & t2, const QVector2D & p2, const float t, QVector2D & point)
{
const float omt = 1.0f - t;
const float omt_2 = omt * omt;
const float t_2 = t * t;
const float a0 = omt_2 * omt;
const float a1 = 3 * omt_2 * t;
const float a2 = 3 * omt * t_2;
const float a3 = t_2 * t;
point = (p1 * a0) + (t1 * a1) + (t2 * a2) + (p2 * a3);
}
void BezierCurve::SampleTangent(const QVector2D & p1, const QVector2D & t1, const QVector2D & t2, const QVector2D & p2, const float t, QVector2D & tangent)
{
const float omt = 1.0f - t;
const QVector2D p10 = p1 * omt + t1 * t;
const QVector2D p11 = t1 * omt + t2 * t;
const QVector2D p12 = t2 * omt + p2 * t;
const QVector2D p20 = p10 * omt + p11 * t;
const QVector2D p21 = p11 * omt + p12 * t;
tangent = (p21 - p20).normalized();
}
bool BezierCurve::IsPointInside(const QVector2D & p)
{
//use ray casting algorithm, count intersection points with x value less than p.x
int intersects_left_of_p = 0;
for (int i=0; i<samples.size(); ++i) {
int i1 = i;
int i2 = (i+1)%samples.size();
QVector2D intersect;
if (samples[i1].x() < p.x() || samples[i2].x() < p.x()) {
if (GLutils::LineRayIntersection(samples[i1], samples[i2], p, QVector2D(1, 0), intersect)) {
if (intersect.x() < p.x()) {
++intersects_left_of_p;
}
}
}
}
return (intersects_left_of_p % 2) == 1;
}
void BezierCurve::Subdivide(const int i, const float t)
{
const float omt = 1.0f - t;
const QVector2D p00 = pts[i];
const QVector2D p01 = pts[i+1];
const QVector2D p02 = pts[i+2];
const QVector2D p03 = pts[i+3];
const QVector2D p10 = p00 * omt + p01 * t;
const QVector2D p11 = p01 * omt + p02 * t;
const QVector2D p12 = p02 * omt + p03 * t;
const QVector2D p20 = p10 * omt + p11 * t;
const QVector2D p21 = p11 * omt + p12 * t;
const QVector2D p30 = p20 * omt + p21 * t;
//Use these:
//first ctrl point - p00
//start tangent - p10
//end tangent - p20
//new endpoint - p30
//start tangent - p21
//end tangent - p12
//end ctrl point - p03
//add in the middle ctrl points
pts.removeAt(i+1);
pts.removeAt(i+1);
pts.insert(i+1, p10);
pts.insert(i+2, p20);
pts.insert(i+3, p30);
pts.insert(i+4, p21);
pts.insert(i+5, p12);
}
void BezierCurve::Subdivide(const BezierCurve & c, const int i, const float t, QList <QVector2D> & subdiv_pts)
{
const float omt = 1.0f - t;
const QVector2D p00 = c.pts[i];
const QVector2D p01 = c.pts[i+1];
const QVector2D p02 = c.pts[i+2];
const QVector2D p03 = c.pts[i+3];
const QVector2D p10 = p00 * omt + p01 * t;
const QVector2D p11 = p01 * omt + p02 * t;
const QVector2D p12 = p02 * omt + p03 * t;
const QVector2D p20 = p10 * omt + p11 * t;
const QVector2D p21 = p11 * omt + p12 * t;
const QVector2D p30 = p20 * omt + p21 * t;
//Use these:
//first ctrl point - p00
//start tangent - p10
//end tangent - p20
//new endpoint - p30
//start tangent - p21
//end tangent - p12
//end ctrl point - p03
subdiv_pts.push_back(p00);
subdiv_pts.push_back(p10);
subdiv_pts.push_back(p20);
subdiv_pts.push_back(p30);
subdiv_pts.push_back(p21);
subdiv_pts.push_back(p12);
subdiv_pts.push_back(p03);
}
void BezierCurve::GetLineIntersections(const QVector2D & line_p, const QVector2D & line_d, QList <BezierCurvePoint> & intersects)
{
intersects.clear();
QVector <float> segment_line_dists = QVector <float> (tests_sample_rate+1);
QVector2D line_n(-line_d.y(), line_d.x());
//qDebug() << "pts size" << pts.size();
for (int i=0; i+3<pts.size(); i+=3) {
QVector <QVector2D> segment_samples;
SamplePointsForSegment(i, segment_samples);
for (int t=0; t<=tests_sample_rate; ++t) {
//compute distance from line along direction split_n (ortho to split_d)
const float each_dist = QVector2D::dotProduct(segment_samples[t] - line_p, line_n);
segment_line_dists[t] = each_dist;
}
//now we iterate through and observe changes in signed distance
for (int t=0; t<tests_sample_rate; ++t) {
if (segment_line_dists[t] * segment_line_dists[t+1] > 0.0f) {
continue;
}
BezierCurvePoint bcp;
bcp.segment = i;
bcp.point = (segment_samples[t] + segment_samples[t+1]) * 0.5f;
bcp.t = (float(t) + 0.5f)/float(tests_sample_rate);
intersects.push_back(bcp);
}
}
//sort intersections along the ray direction
for (int i=0; i<intersects.size(); ++i) {
for (int j=i+1; j<intersects.size(); ++j) {
if (QVector2D::dotProduct(intersects[i].point, line_d) > QVector2D::dotProduct(intersects[j].point, line_d)) {
intersects.swap(i, j);
}
}
}
}
void BezierCurve::GetLineSegmentIntersections(const QVector2D & line_p1, const QVector2D & line_p2, QList <BezierCurvePoint> & intersects)
{
for (int i=0; i+3<pts.size(); i+=3) {
QVector <QVector2D> segment_samples;
SamplePointsForSegment(i, segment_samples);
for (int t=0; t<tests_sample_rate; ++t) {
QVector2D intersect;
if (GLutils::LineLineIntersection(line_p1, line_p2, segment_samples[t], segment_samples[t+1], intersect)) {
BezierCurvePoint bcp;
bcp.segment = i;
bcp.point = (segment_samples[t] + segment_samples[t+1]) * 0.5f;
bcp.t = (float(t) + 0.5f)/float(tests_sample_rate);
intersects.push_back(bcp);
}
}
}
}
void BezierCurve::SplitAlongLine(const QVector2D & split_p, const QVector2D & split_d, QList <BezierCurve> & curves)
{
//1. compute the intersections with the bezier curve
QList <BezierCurvePoint> split;
GetLineIntersections(split_p, split_d, split);
//2. go through making loops starting at each split segment (in both directions)
//qDebug() << "Splitting info:";
//qDebug() << "---------------";
//qDebug() << split_segment;
//qDebug() << split_point;
//qDebug() << split_t;
//if the line didn't split this curve, we just return
if (split.empty()) {
return;
}
//if there's an odd number of intersections, we return
if (split.size() % 2 == 1) {
qDebug() << "BezierCurve::SplitAlongLine() - Problem, grid line made odd number of intersections";
return;
}
//subdivide if two adjacent split point share the same segment
//TODO!!!: special case where split_segment[start] and split_segment[start+1] are the same
//(i.e. no position ctrl points on one side, but interpolated curve crosses)
for (int i=0; i+1<split.size(); i+=2) {
if (split[i].segment == split[i+1].segment) {
Subdivide(split[i].segment, (split[i].t + split[i+1].t) * 0.5f);
//reprocess intersections (since curve parameterization changed)
GetLineIntersections(split_p, split_d, split);
}
}
//create a new curve which follows this split
QVector <bool> visited_forward = QVector <bool> (split.size(), false);
QVector <bool> visited_backward = QVector <bool> (split.size(), false);
//visit all split lines twice (in both directions)
while (true) {
int start = -1;
bool go_forward = false;
//figure out split to start at and direction
for (int i=0; i<visited_backward.size(); i+=2) {
if (!visited_forward[i]) {
start = i;
go_forward = true;
break;
}
if (!visited_backward[i]) {
start = i;
go_forward = false;
break;
}
}
if (start == -1) {
break;
}
//ok, now we go through making a new bezier curve
int i;
int i0;
BezierCurve new_curve;
new_curve.SetClosed(true);
QList <QVector2D> subdiv_pts;
Subdivide((*this), split[start].segment, split[start].t, subdiv_pts);
QList <QVector2D> next_subdiv_pts;
Subdivide((*this), split[start+1].segment, split[start+1].t, next_subdiv_pts);
if (go_forward) {
new_curve.AddPoint(subdiv_pts[0]);
new_curve.AddPoint(subdiv_pts[1]);
new_curve.AddPoint(subdiv_pts[2]);
new_curve.AddPoint(subdiv_pts[3]);
new_curve.AddPoint(subdiv_pts[3] * 0.75 + next_subdiv_pts[3] * 0.25);
new_curve.AddPoint(subdiv_pts[3] * 0.25 + next_subdiv_pts[3] * 0.75);
new_curve.AddPoint(next_subdiv_pts[3]);
new_curve.AddPoint(next_subdiv_pts[4]);
new_curve.AddPoint(next_subdiv_pts[5]);
new_curve.AddPoint(next_subdiv_pts[6]);
visited_forward[start] = true;
visited_forward[start+1] = true;
i0 = split[start].segment;
i = split[start+1].segment;
}
else {
new_curve.AddPoint(next_subdiv_pts[0]);
new_curve.AddPoint(next_subdiv_pts[1]);
new_curve.AddPoint(next_subdiv_pts[2]);
new_curve.AddPoint(next_subdiv_pts[3]);
new_curve.AddPoint(subdiv_pts[3] * 0.25 + next_subdiv_pts[3] * 0.75);
new_curve.AddPoint(subdiv_pts[3] * 0.75 + next_subdiv_pts[3] * 0.25);
new_curve.AddPoint(subdiv_pts[3]);
new_curve.AddPoint(subdiv_pts[4]);
new_curve.AddPoint(subdiv_pts[5]);
new_curve.AddPoint(subdiv_pts[6]);
visited_backward[start] = true;
visited_backward[start+1] = true;
i0 = split[start+1].segment;
i = split[start].segment;
}
i = GetNextSegmentIndex(i);
//halt when the curve is closed
while (i0 != i) {
//qDebug() << "tracing through forward?" << go_forward << "i0?" << i0 << "i?" << i;
//qDebug() << "Curve" << curves.size() << ":" << go_forward << i << i0;
//check if this segment is in the split list
int ind = -1;
for (int j=0; j<split.size(); ++j) {
if (i == split[j].segment) {
ind = j;
break;
}
}
if (ind == -1) { //the segment is NOT in the split_list
//no subdivision
//qDebug() << "adding pts" << i+1 << i+2 << i+3;
new_curve.AddPoint(pts[i+1]);
new_curve.AddPoint(pts[i+2]);
new_curve.AddPoint(pts[i+3]);
}
else { //the segment IS in the split_list
if (go_forward && visited_forward[ind]) {
//qDebug() << "already been here?";
break;
}
else if (!go_forward && visited_backward[ind]) {
//qDebug() << "already been here?";
break;
}
//int next_ind = go_forward ? ind+1 : ind-1;
int next_ind = (ind % 2) == 0 ? ind+1 : ind-1;