1 files changed, 72 insertions, 0 deletions
diff --git a/src/2geom/sbasis-2d.cpp b/src/2geom/sbasis-2d.cpp
new file mode 100644
index 000000000..e271fed13
--- /dev/null
+++ b/src/2geom/sbasis-2d.cpp
@@ -0,0 +1,72 @@
+#include "sbasis-2d.h"
+
+namespace Geom{
+
+SBasis extract_u(SBasis2d const &a, double u) {
+    SBasis sb;
+    double s = u*(1-u);
+    
+    for(unsigned vi = 0; vi < a.vs; vi++) {
+        double sk = 1;
+        Linear bo(0,0);
+        for(unsigned ui = 0; ui < a.us; ui++) {
+            bo += (extract_u(a.index(ui, vi), u))*sk;
+            sk *= s;
+        }
+        sb.push_back(bo);
+    }
+    
+    return sb;
+}
+
+SBasis extract_v(SBasis2d const &a, double v) {
+    SBasis sb;
+    double s = v*(1-v);
+    
+    for(unsigned ui = 0; ui < a.us; ui++) {
+        double sk = 1;
+        Linear bo(0,0);
+        for(unsigned vi = 0; vi < a.vs; vi++) {
+            bo += (extract_v(a.index(ui, vi), v))*sk;
+            sk *= s;
+        }
+        sb.push_back(bo);
+    }
+    
+    return sb;
+}
+
+SBasis compose(Linear2d const &a, D2<SBasis> const &p) {
+    D2<SBasis> omp(-p[X] + 1, -p[Y] + 1);
+    return multiply(omp[0], omp[1])*a[0] +
+           multiply(p[0], omp[1])*a[1] +
+           multiply(omp[0], p[1])*a[2] +
+           multiply(p[0], p[1])*a[3];
+}
+
+SBasis 
+compose(SBasis2d const &fg, D2<SBasis> const &p) {
+    SBasis B;
+    SBasis s[2];
+    SBasis ss[2];
+    for(unsigned dim = 0; dim < 2; dim++) 
+        s[dim] = p[dim]*(Linear(1) - p[dim]);
+    ss[1] = Linear(1);
+    for(unsigned vi = 0; vi < fg.vs; vi++) {
+        ss[0] = ss[1];
+        for(unsigned ui = 0; ui < fg.us; ui++) {
+            unsigned i = ui + vi*fg.us;
+            B += ss[0]*compose(fg[i], p);
+            ss[0] *= s[0];
+        }
+        ss[1] *= s[1];
+    }
+    return B;
+}
+
+D2<SBasis>
+compose_each(D2<SBasis2d> const &fg, D2<SBasis> const &p) {
+    return D2<SBasis>(compose(fg[X], p), compose(fg[Y], p));
+}
+
+};