From c2885c9d467ec359bccd7bbe7369ff4c02439414 Mon Sep 17 00:00:00 2001 From: David Gow Date: Thu, 21 Aug 2014 13:15:22 +0800 Subject: [PATCH] More broken quadtree monstrosity. --- src/bezier.h | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) diff --git a/src/bezier.h b/src/bezier.h index 6dac0d5..9a54d0c 100644 --- a/src/bezier.h +++ b/src/bezier.h @@ -1,6 +1,9 @@ #ifndef _BEZIER_H #define _BEZIER_H +#include +#include + #include "real.h" #include "rect.h" namespace IPDF @@ -32,18 +35,21 @@ namespace IPDF // discriminant < 0 => 1 real root, 2 complex conjugate roots ////HACK: We know any roots we care about will be between 0 and 1, so... + Debug("Trying to solve %fx^3 + %fx^2 + %fx + %f", a,b,c,d); Real maxi(100); Real prevRes(d); std::vector roots; - for(int i = 0; i <= 100; ++i) + for(int i = -1; i <= 100; ++i) { Real x(i); x /= maxi; Real y = a*(x*x*x) + b*(x*x) + c*x + d; - if (y == Real(0) || (y < Real(0) && prevRes > Real(0)) || (y > Real(0) && prevRes < Real(0))) + if ( ((y < Real(0)) && (prevRes > Real(0))) || ((y > Real(0)) && (prevRes < Real(0)))) { + Debug("Found root of %fx^3 + %fx^2 + %fx + %f at %f (%f)", a, b, c, d, x, y); roots.push_back(x); } + prevRes = y; } return roots; @@ -149,6 +155,7 @@ namespace IPDF { // This function is very, very ugly, but with luck my derivation is correct (even if it isn't optimal, performance wise) // (Very) rough working for the derivation is at: http://davidgow.net/stuff/cubic_bezier_reparam.pdf + Debug("Reparametrise: %f -> %f",t0,t1); Bezier new_bezier; Real tdiff = t1 - t0; Real tdiff_squared = tdiff*tdiff; @@ -180,24 +187,26 @@ namespace IPDF new_bezier.y0 = Dy0 - Dy1 + Dy2 - Dy3 + new_bezier.y1 - new_bezier.y2 + new_bezier.y3; + Debug("(%f,%f),(%f,%f),(%f,%f),(%f,%f) -> (%f,%f),(%f,%f),(%f,%f),(%f,%f)", x0, y0, x1, y1, x2, y2, x3, y3, new_bezier.x0, new_bezier.y0, new_bezier.x1, new_bezier.y1, new_bezier.x2, new_bezier.y2, new_bezier.x3, new_bezier.y3); return new_bezier; } std::vector ClipToRectangle(const Rect& r) { // Find points of intersection with the rectangle. + Debug("Clipping Bezier to Rect %s", r.Str().c_str()); // Convert bezier coefficients -> cubic coefficients Real xa = x0-x1+x2-x3; Real xb = x1 - Real(2)*x2 + Real(3)*x3; Real xc = x2 - Real(3)*x3; - Real xd = x3 + r.x; + Real xd = x3 - r.x; // Find its roots. std::vector x_intersection = SolveCubic(xa, xb, xc, xd); // And for the other side. - xd = x3 + r.x + r.w; + xd = x3 - r.x - r.w; std::vector x_intersection_pt2 = SolveCubic(xa, xb, xc, xd); x_intersection.insert(x_intersection.end(), x_intersection_pt2.begin(), x_intersection_pt2.end()); @@ -207,19 +216,20 @@ namespace IPDF Real ya = y0-y1+y2-y3; Real yb = y1 - Real(2)*y2 + Real(3)*y3; Real yc = y2 - Real(3)*y3; - Real yd = y3 + r.y; + Real yd = y3 - r.y; // Find its roots. std::vector y_intersection = SolveCubic(ya, yb, yc, yd); // And for the other side. - yd = y3 + r.y + r.h; + yd = y3 - r.y - r.h; std::vector y_intersection_pt2 = SolveCubic(ya, yb, yc, yd); y_intersection.insert(y_intersection.end(), y_intersection_pt2.begin(), y_intersection_pt2.end()); // Merge and sort. x_intersection.insert(x_intersection.end(), y_intersection.begin(), y_intersection.end()); + std::sort(x_intersection.begin(), x_intersection.end()); Debug("Found %d intersections.\n", x_intersection.size()); @@ -233,6 +243,7 @@ namespace IPDF for (auto it = x_intersection.begin()+1; it != x_intersection.end(); ++it) { Real t1 = *it; + Debug(" -- t0: %f to t1: %f", t0, t1); all_beziers.push_back(this->ReParametrise(t0, t1)); t0 = t1; } -- 2.20.1