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Diffstat (limited to 'src/toys/normal-bundle.cpp')
| -rw-r--r-- | src/toys/normal-bundle.cpp | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/src/toys/normal-bundle.cpp b/src/toys/normal-bundle.cpp new file mode 100644 index 0000000..efe7536 --- /dev/null +++ b/src/toys/normal-bundle.cpp @@ -0,0 +1,230 @@ +#include <2geom/d2.h> +#include <2geom/sbasis.h> +#include <2geom/sbasis-2d.h> +#include <2geom/sbasis-geometric.h> +#include <2geom/bezier-to-sbasis.h> + +#include <toys/path-cairo.h> +#include <toys/toy-framework-2.h> + +#include <vector> +using std::vector; +using namespace Geom; + +class NormalBundle : public std::vector<D2<SBasis2d> >{ +public: + vector<double> lengths; + NormalBundle(){lengths.push_back(0.);} + void setBase(D2<SBasis> const &B, double tol); + void draw(cairo_t* cr, unsigned NbSections =5,unsigned NbFibre=5); +}; +vector<D2<SBasis> > compose(NormalBundle const &NB, + D2<SBasis> const &Binit, + Geom::Point Origin=Geom::Point(0,0)); + +//-------------------------------------------- + +void SBasis1d_to_2d(D2<SBasis> C0, + D2<SBasis> C1, + D2<SBasis2d> &S){ + for(unsigned dim = 0; dim < 2; dim++) { +//**** C0 and C1 should have the same size... + for (unsigned i=C0[dim].size();i<C1[dim].size(); i++) + C0[dim].push_back(Linear(0)); + for (unsigned i=C1[dim].size();i<C0[dim].size(); i++) + C1[dim].push_back(Linear(0)); + S[dim].clear(); + S[dim].us = C0[dim].size(); + S[dim].vs = 1; + for(unsigned v = 0; v < S[dim].vs; v++) + for(unsigned u = 0; u < S[dim].us; u++) + S[dim].push_back(Linear2d(C0[dim][u][0],C0[dim][u][1], + C1[dim][u][0],C1[dim][u][1])); + } +} + +void NormalBundle::setBase(D2<SBasis> const &B, double tol=0.01) { + + D2<SBasis> dB = derivative(B); + vector<double> cuts; + Piecewise<D2<SBasis> > unitV=unitVector(dB); + + //TODO: clean this up, use arc_length_parametrization... + cuts=unitV.cuts; + double t0=0,t1,L=0; + for(unsigned i=1;i<cuts.size();i++){ + t1=cuts[i]; + D2<SBasis> subB=compose(B,Linear(t0,t1)); + D2<SBasis2d> S; + SBasis1d_to_2d(subB, subB+rot90(unitV[i]), S); + push_back(S); + + SBasis s=integral(dot(compose(dB,Linear(t0,t1)),unitV[i])); + L+=(s(1)-s(0))*(t1-t0); + lengths.push_back(L); + + t0=t1; + } +} + +void NormalBundle::draw(cairo_t *cr, unsigned NbLi, unsigned NbCol) { + D2<SBasis> B; + vector<D2<SBasis> > tB; + //Geom::Point Seg[2]; + B[1]=Linear(-100,100); + double width=*(lengths.rbegin()); + if (NbCol>0) + for(unsigned ui = 0; ui <= NbCol; ui++) { + B[0]=Linear(ui*width/NbCol); + tB = compose(*this,B); + if (tB.size()>0) cairo_d2_sb(cr, tB[0]); + } + + B[0]=SBasis(Linear(0,1)); + for(unsigned ui = 0; ui <= NbLi; ui++) { + B[1]=Linear(-100+ui*200/NbLi); + for(unsigned i = 0; i <size(); i++) { + D2<SBasis> section=composeEach((*this)[i],B); + cairo_d2_sb(cr, section); + } + } +} + + +vector<D2<SBasis> > compose(NormalBundle const &NB, + D2<SBasis> const &Binit, + Geom::Point Origin){ + vector<D2<SBasis> > result; + D2<SBasis> B=Binit; + D2<SBasis> Bcut; + vector<double> Roots; + std::map<double,unsigned> Cuts; + unsigned idx; + + B = B + (-Origin); + + //--Find intersections with fibers over segment ends. + for(unsigned i=0; i<=NB.size();i++){ + Roots=roots(B[0]); + for (vector<double>::iterator root=Roots.begin(); + root!=Roots.end();root++) + Cuts[*root]=i; + if((Cuts.count(0.)==0) and + ((B[0].valueAt(0.)<=0) or i==NB.size())) + Cuts[0.]=i; + if((Cuts.count(1.)==0) and + ((B[0].valueAt(1.)<=0) or i==NB.size())) + Cuts[1.]=i; + if (i<NB.size()) + B[0]-=(NB.lengths[i+1]-NB.lengths[i]); + } + B[0]+=*(NB.lengths.rbegin()); + + //-- Compose each piece with the relevant sbasis2d. + // TODO: use a uniform parametrization of the base. + std::map<double,unsigned>::iterator cut=Cuts.begin(); + std::map<double,unsigned>::iterator next=cut; next++; + while(next!=Cuts.end()){ + double t0=(*cut).first; + unsigned idx0=(*cut).second; + double t1=(*next).first; + unsigned idx1=(*next).second; + if (idx0 != idx1){ + idx=std::min(idx0,idx1); + } else if(B[0]((t0+t1)/2) < NB.lengths[idx0]) { // we have a left 'bump', + idx=idx0-1; + } else if(B[0]((t0+t1)/2) == NB.lengths[idx0]) { //we have a vertical segment!... + idx= (idx0==NB.size())? idx0-1:idx0; + } else //we have a right 'bump'. + idx=idx0; + + //--trim version... + if (idx>=0 and idx<NB.size()) { + for (unsigned dim=0;dim<2;dim++) + Bcut[dim]=compose(B[dim], Linear(t0,t1)); + double width=NB.lengths[idx+1]-NB.lengths[idx]; + Bcut[0]=compose(Linear(-NB.lengths[idx]/width, + (1-NB.lengths[idx])/width),Bcut[0]); + Bcut = composeEach(NB[idx], Bcut); + result.push_back(Bcut); + } + cut++; + next++; + } + return(result); +} + + + +class NormalBundleToy: public Toy { + PointSetHandle B_handle; + PointSetHandle P_handle; + PointHandle O_handle; + void draw(cairo_t *cr, std::ostringstream *notify, int width, int height, bool save, std::ostringstream *timer_stream) { + D2<SBasis> B = B_handle.asBezier(); + D2<SBasis> P = P_handle.asBezier(); + Geom::Point O = O_handle.pos; + + NormalBundle NBdle; + NBdle.setBase(B); + Geom::Point Oo(O[0]+*(NBdle.lengths.rbegin()),O[1]); + + vector<D2<SBasis> > Q=compose(NBdle,P,O); + + cairo_set_line_width (cr, 0.5); + //Base lines + cairo_set_source_rgba (cr, 0.9, 0., 0., 1); + cairo_d2_sb(cr, B); + draw_line_seg(cr, O, Oo); + cairo_stroke(cr); + + //Sections + cairo_set_source_rgba (cr, 0, 0, 0.9, 1); + cairo_d2_sb(cr, P); + for (unsigned i=0;i<Q.size();i++){ + cairo_d2_sb(cr, Q[i]); + } + cairo_stroke(cr); + + //Normal bundle + cairo_set_source_rgba (cr, 0., 0., 0., 1); + NBdle.draw(cr,3,5); + cairo_stroke(cr); + + + Toy::draw(cr, notify, width, height, save,timer_stream); + } + +public: + NormalBundleToy(){ + if(handles.empty()) { + handles.push_back(&B_handle); + handles.push_back(&P_handle); + handles.push_back(&O_handle); + for(unsigned i = 0; i < 4; i++) + B_handle.push_back(200+50*i,400); + for(unsigned i = 0; i < 4; i++) + P_handle.push_back(100+uniform()*400, + 150+uniform()*100); + O_handle.pos = Geom::Point(200,200); + } + } +}; + +int main(int argc, char **argv) { + init(argc, argv, new NormalBundleToy); + return 0; +} + +/* + Local Variables: + mode:c++ + c-file-style:"stroustrup" + c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) + indent-tabs-mode:nil + fill-column:99 + End: +*/ +// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 : + + |