--- /dev/null
+/* === S Y N F I G ========================================================= */
+/*! \file curve_helper.h
+** \brief Curve Helper Header
+**
+** $Id$
+**
+** \legal
+** Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
+**
+** This package is free software; you can redistribute it and/or
+** modify it under the terms of the GNU General Public License as
+** published by the Free Software Foundation; either version 2 of
+** the License, or (at your option) any later version.
+**
+** This package is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+** General Public License for more details.
+** \endlegal
+*/
+/* ========================================================================= */
+
+/* === S T A R T =========================================================== */
+
+#ifndef __SYNFIG_CURVE_HELPER_H
+#define __SYNFIG_CURVE_HELPER_H
+
+/* === H E A D E R S ======================================================= */
+#include <ETL/bezier>
+
+#include "rect.h"
+#include "real.h"
+#include "vector.h"
+
+#include <vector>
+
+/* === M A C R O S ========================================================= */
+
+/* === T Y P E D E F S ===================================================== */
+
+/* === C L A S S E S & S T R U C T S ======================================= */
+
+namespace synfig {
+
+//line helper functions
+inline Real line_point_distsq(const Point &p1, const Point &p2,
+ const Point &p, float &t)
+{
+ Vector v,vt;
+
+ v = p2 - p1;
+ vt = p - p1;
+
+ t = v.mag_squared() > 1e-12 ? (vt*v)/v.mag_squared() : 0; //get the projected time value for the current line
+
+ //get distance to line segment with the time value clamped 0-1
+ if(t >= 1) //use p+v
+ {
+ vt += v; //makes it pp - (p+v)
+ t = 1;
+ }else if(t > 0) //use vt-proj
+ {
+ vt -= v * t; // vt - proj_v(vt) //must normalize the projection vector to work
+ }else
+ {
+ t = 0;
+ }
+
+ //else use p
+ return vt.mag_squared();
+}
+
+
+//----- RAY CLASS AND FUNCTIONS --------------
+struct Ray
+{
+ Point p;
+ Vector v;
+
+ Ray() {}
+ Ray(const Point &pin, const Vector &vin):p(pin), v(vin) {}
+};
+
+/* This algorithm calculates the INTERSECTION of 2 line segments
+ (not the closest point or anything like that, just intersection)
+ //parameter values returned are [0,1]
+*/
+int intersect(const Point &p1, const Vector &v1, float &t1,
+ const Point &p2, const Vector &v2, float &t2);
+
+inline bool intersect_line_segments(const Point &a, const Point &b, float &tout,
+ const Point &c, const Point &d, float &sout)
+{
+ Vector v1(b-a), v2(d-c);
+
+ //ok so treat both lines as parametric (so we can find the time values simultaneously)
+ float t,s;
+
+ if( intersect(a,v1,t, b,v2,s) && t >= 0 && t <= 1 && s >= 0 && s <= 1 )
+ {
+ tout = t;
+ sout = s;
+ return true;
+ }
+
+ return false;
+}
+
+//Find the closest point on the curve to a point (and return its distance, and time value)
+Real find_closest(const etl::bezier<Point> &curve, const Point &point, float step, Real *closest, float *t);
+
+//----------- Rectangle helper functions ---------------
+
+template < typename T >
+inline void Bound(etl::rect<T> &r, const etl::bezier<Point> &b)
+{
+ r.set_point(b[0][0],b[0][1]);
+ r.expand(b[1][0],b[1][1]);
+ r.expand(b[2][0],b[2][1]);
+ r.expand(b[3][0],b[3][1]);
+}
+
+/*template < typename T >
+inline bool intersect(const etl::rect<T> &r1, const etl::rect<T> &r2)
+{
+ return (r1.minx < r2.maxx) &
+ (r2.minx < r1.maxx) &
+ (r1.miny < r2.maxy) &
+ (r2.miny < r1.maxy);
+}*/
+
+//----- Convex Hull of a Bezier Curve --------------
+struct BezHull
+{
+ Point p[4];
+ int size;
+
+ void Bound(const etl::bezier<Point> &b);
+};
+
+//Line Intersection
+int intersect(const Rect &r1, const Point &p, const Vector &v);
+int intersect(const Rect &r1, const Point &p); //inside or to the right
+int intersect(const BezHull &bh, const Point &p, const Vector &v);
+//int intersect(const etl::bezier<Point> &b, const Point &p, const Vector &v);
+int intersect(const etl::bezier<Point> &b, const Point &p); //for use in containment tests for regions
+
+//Curve intersection object
+class CIntersect
+{
+public:
+ struct SCurve;
+private:
+ void recurse_intersect(const SCurve &left, const SCurve &right, int depth = 0);
+
+public:
+ //size should be equal
+ typedef std::vector< std::pair<float,float > > intersect_set;
+ intersect_set times;
+
+ int max_depth;
+
+ CIntersect();
+
+ bool operator()(const etl::bezier<Point> &b1, const etl::bezier<Point> &b2);
+};
+
+}; // END of namespace studio
+
+/* === E N D =============================================================== */
+
+#endif
projects / synfig.git / blobdiff