ts::DeBoorNet ts::BSpline::evaluate(const ts::rational u) const
{
DeBoorNet deBoorNet;
const tsError err = ts_bspline_evaluate(&bspline, u, deBoorNet.data());
if (err < 0)
throw std::runtime_error(ts_enum_str(err));
return deBoorNet;
}
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// draw spline
glColor3f(1.0, 1.0, 1.0);
glLineWidth(3);
gluBeginCurve(theNurb);
gluNurbsCurve(
theNurb,
spline.n_knots,
spline.knots,
spline.dim,
spline.ctrlp,
spline.order,
GL_MAP1_VERTEX_3
);
gluEndCurve(theNurb);
// draw control points
glColor3f(1.0, 0.0, 0.0);
glPointSize(5.0);
float j=0;
size_t i;
glBegin(GL_POINTS);
for (i = 0; i < spline.n_ctrlp; i++) {
j+=1.0/n_ctrlp;
glColor3f(0.0, j, 0.0);
glVertex3fv(&spline.ctrlp[i * spline.dim]);
}
glEnd();
// draw evaluation
glColor3f(0.0, 0.0, 1.0);
glPointSize(5.0);
tsDeBoorNet net;
ts_bspline_evaluate(&spline, u, &net);
glBegin(GL_POINTS);
glVertex3fv(net.result);
glEnd();
ts_deboornet_free(&net);
u += 0.001;
if (u > 4.f) {
u = 0.f;
}
glutSwapBuffers();
glutPostRedisplay();
}
