// there is no elegance here. only sleep deprivation and regret.

[ipdf/code.git] / src / bezier.h

diff --git a/src/bezier.h b/src/bezier.h
index 5a773a7..52a5264 100644 (file)
--- a/src/bezier.h
+++ b/src/bezier.h
@@ -15,7 +15,7 @@ namespace IPDF
        
        extern std::vector<Real> SolveQuadratic(const Real & a, const Real & b, const Real & c, const Real & min = 0, const Real & max = 1);
 
        
        extern std::vector<Real> SolveQuadratic(const Real & a, const Real & b, const Real & c, const Real & min = 0, const Real & max = 1);
 

-       extern std::vector<Real> SolveCubic(const Real & a, const Real & b, const Real & c, const Real & d, const Real & min = 0, const Real & max = 1, const Real & delta = 1e-4);
+       extern std::vector<Real> SolveCubic(const Real & a, const Real & b, const Real & c, const Real & d, const Real & min = 0, const Real & max = 1, const Real & delta = 1e-9);

 
        /** A _cubic_ bezier. **/
        struct Bezier
 
        /** A _cubic_ bezier. **/
        struct Bezier


@@ -179,56 +179,56 @@ namespace IPDF
                }
 
                // Performs one round of De Casteljau subdivision and returns the [t,1] part.
                }
 
                // Performs one round of De Casteljau subdivision and returns the [t,1] part.

-               Bezier DeCasteljauSubdivideRight(const Real& t)
+               Bezier DeCasteljauSubdivideLeft(const Real& t)

                {
                        Real one_minus_t = Real(1) - t;
 
                        // X Coordinates
                {
                        Real one_minus_t = Real(1) - t;
 
                        // X Coordinates

-                       Real x01 = x0*t + x1*one_minus_t;
-                       Real x12 = x1*t + x2*one_minus_t;
-                       Real x23 = x2*t + x3*one_minus_t;
+                       Real x01 = x1*t + x0*one_minus_t;
+                       Real x12 = x2*t + x1*one_minus_t;
+                       Real x23 = x3*t + x2*one_minus_t;

 
 

-                       Real x012 = x01*t + x12*one_minus_t;
-                       Real x123 = x12*t + x23*one_minus_t;
+                       Real x012 = x12*t + x01*one_minus_t;
+                       Real x123 = x23*t + x12*one_minus_t;

 
 

-                       Real x0123 = x012*t + x123*one_minus_t;
+                       Real x0123 = x123*t + x012*one_minus_t;

 
                        // Y Coordinates
 
                        // Y Coordinates

-                       Real y01 = y0*t + y1*one_minus_t;
-                       Real y12 = y1*t + y2*one_minus_t;
-                       Real y23 = y2*t + y3*one_minus_t;
+                       Real y01 = y1*t + y0*one_minus_t;
+                       Real y12 = y2*t + y1*one_minus_t;
+                       Real y23 = y3*t + y2*one_minus_t;

 
 

-                       Real y012 = y01*t + y12*one_minus_t;
-                       Real y123 = y12*t + y23*one_minus_t;
+                       Real y012 = y12*t + y01*one_minus_t;
+                       Real y123 = y23*t + y12*one_minus_t;

 
 

-                       Real y0123 = y012*t + y123*one_minus_t;
+                       Real y0123 = y123*t + y012*one_minus_t;

 
                        return Bezier(x0, y0, x01, y01, x012, y012, x0123, y0123);
                }
 
                        return Bezier(x0, y0, x01, y01, x012, y012, x0123, y0123);
                }

-               // Performs one round of De Casteljau subdivision and returns the [0,t] part.
-               Bezier DeCasteljauSubdivideLeft(const Real& t)
+               // Performs one round of De Casteljau subdivision and returns the [t,1] part.
+               Bezier DeCasteljauSubdivideRight(const Real& t)

                {
                        Real one_minus_t = Real(1) - t;
 
                        // X Coordinates
                {
                        Real one_minus_t = Real(1) - t;
 
                        // X Coordinates

-                       Real x01 = x0*t + x1*one_minus_t;
-                       Real x12 = x1*t + x2*one_minus_t;
-                       Real x23 = x2*t + x3*one_minus_t;
+                       Real x01 = x1*t + x0*one_minus_t;
+                       Real x12 = x2*t + x1*one_minus_t;
+                       Real x23 = x3*t + x2*one_minus_t;

 
 

-                       Real x012 = x01*t + x12*one_minus_t;
-                       Real x123 = x12*t + x23*one_minus_t;
+                       Real x012 = x12*t + x01*one_minus_t;
+                       Real x123 = x23*t + x12*one_minus_t;

 
 

-                       Real x0123 = x012*t + x123*one_minus_t;
+                       Real x0123 = x123*t + x012*one_minus_t;

 
                        // Y Coordinates
 
                        // Y Coordinates

-                       Real y01 = y0*t + y1*one_minus_t;
-                       Real y12 = y1*t + y2*one_minus_t;
-                       Real y23 = y2*t + y3*one_minus_t;
+                       Real y01 = y1*t + y0*one_minus_t;
+                       Real y12 = y2*t + y1*one_minus_t;
+                       Real y23 = y3*t + y2*one_minus_t;

 
 

-                       Real y012 = y01*t + y12*one_minus_t;
-                       Real y123 = y12*t + y23*one_minus_t;
+                       Real y012 = y12*t + y01*one_minus_t;
+                       Real y123 = y23*t + y12*one_minus_t;

 
 

-                       Real y0123 = y012*t + y123*one_minus_t;
+                       Real y0123 = y123*t + y012*one_minus_t;

 
                        return Bezier(x0123, y0123, x123, y123, x23, y23, x3, y3);
                }
 
                        return Bezier(x0123, y0123, x123, y123, x23, y23, x3, y3);
                }


@@ -253,35 +253,19 @@ namespace IPDF
                        // Find points of intersection with the rectangle.
                        Debug("Clipping Bezier to Rect %s", r.Str().c_str());
 
                        // Find points of intersection with the rectangle.
                        Debug("Clipping Bezier to Rect %s", r.Str().c_str());
 

-                       // Convert bezier coefficients -> cubic coefficients
-                       Real xd = x0 - r.x;
-                       Real xc = Real(3)*(x1 - x0);
-                       Real xb = Real(3)*(x2 - x1) - xc;
-                       Real xa = x3 - x0 - xc - xb;

 
                        // Find its roots.
 
                        // Find its roots.

-                       std::vector<Real> x_intersection = SolveCubic(xa, xb, xc, xd);
+                       std::vector<Real> x_intersection = SolveXParam(r.x);

 
                        // And for the other side.
 
                        // And for the other side.

-                       xd = x0 - r.x - r.w;

 
 

-                       std::vector<Real> x_intersection_pt2 = SolveCubic(xa, xb, xc, xd);
+                       std::vector<Real> x_intersection_pt2 = SolveXParam(r.x + r.w);

                        x_intersection.insert(x_intersection.end(), x_intersection_pt2.begin(), x_intersection_pt2.end());
 
                        x_intersection.insert(x_intersection.end(), x_intersection_pt2.begin(), x_intersection_pt2.end());
 

-                       // Similarly for y-coordinates.
-                       // Convert bezier coefficients -> cubic coefficients
-                       Real yd = y0 - r.y;
-                       Real yc = Real(3)*(y1 - y0);
-                       Real yb = Real(3)*(y2 - y1) - yc;
-                       Real ya = y3 - y0 - yc - yb;
-

                        // Find its roots.
                        // Find its roots.

-                       std::vector<Real> y_intersection = SolveCubic(ya, yb, yc, yd);
+                       std::vector<Real> y_intersection = SolveYParam(r.y);

 
 

-                       // And for the other side.
-                       yd = y0 - r.y - r.h;
-
-                       std::vector<Real> y_intersection_pt2 = SolveCubic(ya, yb, yc, yd);
+                       std::vector<Real> y_intersection_pt2 = SolveYParam(r.y+r.h);

                        y_intersection.insert(y_intersection.end(), y_intersection_pt2.begin(), y_intersection_pt2.end());
 
                        // Merge and sort.
                        y_intersection.insert(y_intersection.end(), y_intersection_pt2.begin(), y_intersection_pt2.end());
 
                        // Merge and sort.


@@ -291,6 +275,12 @@ namespace IPDF
                        std::sort(x_intersection.begin(), x_intersection.end());
 
                        Debug("Found %d intersections.\n", x_intersection.size());
                        std::sort(x_intersection.begin(), x_intersection.end());
 
                        Debug("Found %d intersections.\n", x_intersection.size());

+                       for(auto t : x_intersection)
+                       {
+                               Real ptx, pty;
+                               Evaluate(ptx, pty, t);
+                               Debug("Root: t = %f, (%f,%f)", t, ptx, pty);
+                       }

                        
                        std::vector<Bezier> all_beziers;
                        if (x_intersection.size() <= 2)
                        
                        std::vector<Bezier> all_beziers;
                        if (x_intersection.size() <= 2)


@@ -306,7 +296,7 @@ namespace IPDF
                                Debug(" -- t0: %f to t1: %f", t0, t1);
                                Real ptx, pty;
                                Evaluate(ptx, pty, ((t1 + t0) / Real(2)));
                                Debug(" -- t0: %f to t1: %f", t0, t1);
                                Real ptx, pty;
                                Evaluate(ptx, pty, ((t1 + t0) / Real(2)));

-                               if (true || r.PointIn(ptx, pty))
+                               if (r.PointIn(ptx, pty))

                                {
                                        all_beziers.push_back(this->ReParametrise(t0, t1));
                                }
                                {
                                        all_beziers.push_back(this->ReParametrise(t0, t1));
                                }