void CurveLut::update() {
vector<float> sd = getSecondDerivative();
int m = controlPoints.size();
ofVec2f& first = controlPoints.front();
ofVec2f& last = controlPoints.back();
for(int x = 0; x < first.x; x++) {
lut[x] = first.y;
}
for(int i = 0; i < m - 1; i++) {
ofVec2f& cur = controlPoints[i];
ofVec2f& next = controlPoints[i+1];
for (int x = cur.x; x < next.x; x++) {
float t = (x-cur.x) / (next.x-cur.x);
float a = 1-t;
float b = t;
float h = next.x-cur.x;
lut[x] = (a*cur.y + b*next.y + (h*h/6)*((a*a*a-a)*sd[i]+(b*b*b-b)*sd[i+1]));
}
}
for(int x = last.x; x < n; x++) {
lut[x] = last.y;
}
for(int x = 0; x < n; x++) {
lut[x] = ofClamp(lut[x], 0, n - 1);
}
lutNew = true;
}
iSpline3D* otPolyLineSpline3::getNormal()
{
unsigned int count = getPointList().getCount();
otPolyLineSpline3* normalSpline = new otPolyLineSpline3(count);
otPolyLineSpline3* derivativeSpline = (otPolyLineSpline3 *)getDerivative();
otPolyLineSpline3* secondDerivativeSpline = (otPolyLineSpline3 *)getSecondDerivative();
normalSpline->setPoint(points[0].x,*(new otVector3));
for(unsigned int i=1;i<count-1;i++)
{
otVector3 derivative=derivativeSpline->getPointList()[i].y;
otVector3 secondDerivative=secondDerivativeSpline->getPointList()[i].y;
normalSpline->setPoint(points[i].x,(secondDerivative -derivative*((derivative|secondDerivative))).normalize() );
}
return normalSpline;
}
iSpline1D* otPolyLineSpline3::getCurvature()
{
unsigned int count = getPointList().getCount();
otPolyLineSpline* curvatureSpline = new otPolyLineSpline(count);
otPolyLineSpline3* secondDerivativeSpline = (otPolyLineSpline3 *)getSecondDerivative();
otPolyLineSpline3* normalSpline = (otPolyLineSpline3 *)getNormal();
curvatureSpline->setPoint(points[0].x,0);
for(unsigned int i=1;i<count-1;i++)
{
otVector3 normal=normalSpline->getPointList()[i].y;
otVector3 secondDerivative=secondDerivativeSpline->getPointList()[i].y;
curvatureSpline->setPoint(points[i].x,(normal|secondDerivative));
}
return curvatureSpline;
}
