From 13e73fa386cd7843d7079ec7c162ef43d15097c4 Mon Sep 17 00:00:00 2001
From: "Johan B. C. Engelen" <jbc.engelen@swissonline.ch>
Date: Thu, 30 Aug 2007 18:32:36 +0000
Subject: Update to 2Geom rev. 1113

(bzr r3622)
---
 src/2geom/d2-sbasis.cpp | 148 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 148 insertions(+)
 create mode 100644 src/2geom/d2-sbasis.cpp

(limited to 'src/2geom/d2-sbasis.cpp')

diff --git a/src/2geom/d2-sbasis.cpp b/src/2geom/d2-sbasis.cpp
new file mode 100644
index 000000000..b68e3e6c5
--- /dev/null
+++ b/src/2geom/d2-sbasis.cpp
@@ -0,0 +1,148 @@
+#include "d2.h"
+/* One would think that we would include d2-sbasis.h, however,
+ * you cannot actually include it in anything - only d2 may import it.
+ * This is due to the trickinesses of template submatching. */
+
+namespace Geom {
+
+SBasis L2(D2<SBasis> const & a, unsigned k) { return sqrt(dot(a, a), k); }
+
+D2<SBasis> multiply(Linear const & a, D2<SBasis> const & b) {
+    return D2<SBasis>(multiply(a, b[X]), multiply(a, b[Y]));
+}
+
+D2<SBasis> multiply(SBasis const & a, D2<SBasis> const & b) {
+    return D2<SBasis>(multiply(a, b[X]), multiply(a, b[Y]));
+}
+
+D2<SBasis> truncate(D2<SBasis> const & a, unsigned terms) {
+    return D2<SBasis>(truncate(a[X], terms), truncate(a[Y], terms));
+}
+
+unsigned sbasis_size(D2<SBasis> const & a) {
+    return std::max((unsigned) a[0].size(), (unsigned) a[1].size());
+}
+
+//TODO: Is this sensical? shouldn't it be like pythagorean or something?
+double tail_error(D2<SBasis> const & a, unsigned tail) {
+    return std::max(a[0].tailError(tail), a[1].tailError(tail));
+}
+
+Piecewise<D2<SBasis> > sectionize(D2<Piecewise<SBasis> > const &a) {
+    Piecewise<SBasis> x = partition(a[0], a[1].cuts), y = partition(a[1], a[0].cuts);
+    assert(x.size() == y.size());
+    Piecewise<D2<SBasis> > ret;
+    for(unsigned i = 0; i < x.size(); i++)
+        ret.push_seg(D2<SBasis>(x[i], y[i]));
+    ret.cuts.insert(ret.cuts.end(), x.cuts.begin(), x.cuts.end());
+    return ret;
+}
+
+D2<Piecewise<SBasis> > make_cuts_independant(Piecewise<D2<SBasis> > const &a) {
+    D2<Piecewise<SBasis> > ret;
+    for(unsigned d = 0; d < 2; d++) {
+        for(unsigned i = 0; i < a.size(); i++)
+            ret[d].push_seg(a[i][d]);
+        ret[d].cuts.insert(ret[d].cuts.end(), a.cuts.begin(), a.cuts.end());
+    }
+    return ret;
+}
+
+Piecewise<D2<SBasis> > rot90(Piecewise<D2<SBasis> > const &M){
+  Piecewise<D2<SBasis> > result;
+  if (M.empty()) return M;
+  result.push_cut(M.cuts[0]);
+  for (unsigned i=0; i<M.size(); i++){
+    result.push(rot90(M[i]),M.cuts[i+1]);
+  }
+  return result;
+}
+
+Piecewise<SBasis> dot(Piecewise<D2<SBasis> > const &a, 
+		      Piecewise<D2<SBasis> > const &b){
+  Piecewise<SBasis > result;
+  if (a.empty() || b.empty()) return result;
+  Piecewise<D2<SBasis> > aa = partition(a,b.cuts);
+  Piecewise<D2<SBasis> > bb = partition(b,a.cuts);
+
+  result.push_cut(aa.cuts.front());
+  for (unsigned i=0; i<aa.size(); i++){
+    result.push(dot(aa.segs[i],bb.segs[i]),aa.cuts[i+1]);
+  }
+  return result;
+}
+
+Piecewise<SBasis> cross(Piecewise<D2<SBasis> > const &a, 
+			Piecewise<D2<SBasis> > const &b){
+  Piecewise<SBasis > result;
+  if (a.empty() || b.empty()) return result;
+  Piecewise<D2<SBasis> > aa = partition(a,b.cuts);
+  Piecewise<D2<SBasis> > bb = partition(b,a.cuts);
+
+  result.push_cut(aa.cuts.front());
+  for (unsigned i=0; i<a.size(); i++){
+    result.push(cross(aa.segs[i],bb.segs[i]),aa.cuts[i+1]);
+  }
+  return result;
+}
+
+/* Replaced by remove_short_cuts in piecewise.h
+//this recursively removes the shortest cut interval until none is shorter than tol.
+//TODO: code this in a more efficient way!
+Piecewise<D2<SBasis> > remove_short_cuts(Piecewise<D2<SBasis> > const &f, double tol){
+    double min = tol;
+    unsigned idx = f.size();
+    for(unsigned i=0; i<f.size(); i++){
+        if (min > f.cuts[i+1]-f.cuts[i]){
+            min = f.cuts[i+1]-f.cuts[i];
+            idx = int(i);
+        }
+    }
+    if (idx==f.size()){
+        return f;
+    }
+    if (f.size()==1) {
+        //removing this seg would result in an empty pw<d2<sb>>...
+        return f;
+    }
+    Piecewise<D2<SBasis> > new_f=f;
+    for (int dim=0; dim<2; dim++){
+        double v = Hat(f.segs.at(idx)[dim][0]);
+        //TODO: what about closed curves?
+        if (idx>0 && f.segs.at(idx-1).at1()==f.segs.at(idx).at0()) 
+            new_f.segs.at(idx-1)[dim][0][1] = v;
+        if (idx<f.size() && f.segs.at(idx+1).at0()==f.segs.at(idx).at1()) 
+            new_f.segs.at(idx+1)[dim][0][0] = v;
+    }
+    double t = (f.cuts.at(idx)+f.cuts.at(idx+1))/2;
+    new_f.cuts.at(idx+1) = t;    
+    
+    new_f.segs.erase(new_f.segs.begin()+idx);
+    new_f.cuts.erase(new_f.cuts.begin()+idx);        
+    return remove_short_cuts(new_f, tol);
+}
+*/
+
+//if tol>0, only force continuity where the jump is smaller than tol.
+Piecewise<D2<SBasis> > force_continuity(Piecewise<D2<SBasis> > const &f, 
+                                        double tol,
+                                        bool closed){
+    if (f.size()==0) return f;
+    Piecewise<D2<SBasis> > result=f;
+    unsigned cur   = (closed)? 0:1;
+    unsigned prev  = (closed)? f.size()-1:0;
+    while(cur<f.size()){
+        Point pt0 = f.segs[prev].at1();
+        Point pt1 = f.segs[cur ].at0();
+        if (tol<=0 || L2sq(pt0-pt1)<tol*tol){
+            pt0 = (pt0+pt1)/2;
+            for (unsigned dim=0; dim<2; dim++){
+                result.segs[prev][dim][0][1]=pt0[dim];
+                result.segs[cur ][dim][0][0]=pt0[dim];
+            }
+        }
+        prev = cur++;
+    }
+    return result;
+}

+}
-- 
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